Summary of NIST/GSA Coop Research-Use of Elevators during Fire Emergencies

NIST Special Publication 1620

Summary of NIST/GSA
Cooperative Research on the Use of
Elevators During Fire Emergencies

NIST Special Publication 1620

Summary of NIST/GSA
Cooperative Research on the Use of
Elevators During Fire Emergencies
Richard D. Peacock, Editor
Building and Fire Research Laboratory

January 2009

U.S. Department of Commerce
Carlos M. Gutierrez, Secretary
National Institute of Standards and Technology
Patrick D. Gallagher, Deputy Director

Certain commercial entities, equipment, or materials may be identified in this
document in order to describe an experimental procedure or concept adequately. Such
identification is not intended to imply recommendation or endorsement by the
National Institute of Standards and Technology, nor is it intended to imply that the
entities, materials, or equipment are necessarily the best available for the purpose.

National Institute of Standards and Technology Special Publication 1620
Natl. Inst. Stand. Technol. Spec. Publ. 1620, 349 pages (January 2009)
CODEN: NSPUE2

Table of Contents
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v

Introduction
Historically, building egress systems have evolved in response to specific large loss
incidents. Currently, systems are designed around an antiquated concept of providing
stair capacity for the largest occupant load floor in the building with little or no
consideration of occupant behavior, needs of emergency responders, or evolving
technologies. Aggressive building designs, changing occupant demographics, and
consumer demand for more efficient systems have forced egress designs beyond the
traditional stairwell-based approaches, with little technical foundation for performance
and economic trade-offs.
Underlying any building system designed to provide occupant protection in the event of a
fire emergency is the need to provide a sufficiently safe environment for a period of time
long enough to allow the occupants to take appropriate protective action. Passive and
active fire protection systems in buildings such as compartmentation, structural integrity
design, sprinklers, or construction and furnishing materials controls limit the extent of
fire growth and spread to provide greater times for occupant actions (typically referred to
as the available safe egress time or ASET). Conversely, egress system capacity, the use
of protected areas of refuge, occupant training, emergency planning efforts, and
understand occupant behavior in the event of an emergency can all aid to a reduction in
the time necessary for occupants to reach a point of safety (typically referred to as the
required safe egress time or RSET). The NIST/GSA program focuses on optimizing
RSET.
This report addresses one aspect that has the potential to significantly impact the RSET,
the use of elevators during fire emergencies. Summaries are included of NIST research
conducted as part of a cooperative effort funded in part by the U.S. General Services
Administration (GSA). This research has formed the technical basis for significant
revisions to building code provisions that consider the impact of all aspects building
design including the use of elevators by occupants and first responders, appropriate
design of stairwells, the use of refuge areas, and other active and passive fire protection
measures that may be included in a building design.
The papers included in this report describe the history and scientific underpinnings of
current egress requirements in model codes1,2. Provisions for egress stairways are traced
from the early 20th century where a minimum stair width of 510 mm was first
recommended to the now more typically used 1.12 m width. While based largely on
common practice in the 1930s, this width was also seen as appropriate to allow the entire
population of a building to fit on a single flight of stairs and remain in the relative safety
1

Bukowski, R.W., Emergency Egress from Buildings, Part 1: History and Current Regulations
for Egress Systems Design, 7th International Conference on Performance-based Codes and Fire
Safety Design Methods, Auckland, NZ, SFPE, 2008.
2
Bukowski, R.W. and Kuligowski, E.D., The Basis for Egress Provisions in U.S. Building Codes,
InterFlam 2004, Edinburgh, UK, July 2004.

of the stairwell during a fire event1. Details of current prescriptive requirements are also
described and related to estimates of building egress times for a range of specific building
occupancies2.
Like stairwell provisions, the use of elevators during fire emergencies was considered as
well. As early as 1914, properly protected elevators were seen as essential in taller
buildings, but automatic elevators were deemed unsuitable in a 1935 report1.
More recently, there has been considerable attention to the use of elevators to speed up
building evacuation. This included studies of the feasibility of elevator evacuation,
human behavior, and the use of elevator lobbies as areas of refuge3. Protection from heat,
flame, smoke, water, overheating of machinery, and loss of electrical power were seen as
important to elevator design3. Using model calculations for example buildings, elevator
evacuation was estimated to speed evacuation by 16 % to 25 % compared to evacuation
by stairs alone; the taller the building the greater the impact.
Detailed studies of smoke protection for elevator hoistways4,5, the need for enclosed
elevator lobbies6, use of elevators for evacuation of disabled occupants7, structural,
sprinkler, and elevator control designs5, and egress procedures8 have provided the
technical basis for new requirements for elevator use. Working with the American
Society of Mechanical Engineers (see, for example, reference 5), the International Code
Council (ICC), and the National Fire Protection Association (NFPA), and others, NIST
and GSA, through this research, led a revolution in code provisions for the use of
elevators by occupants and first responders during fire emergencies. The 2009 edition of
the Life Safety Code9 and Building Construction and Safety Code10 includes adoptable
(though not required) provisions for elevators for occupant evacuation prior to Phase I
recall and for fire fighter emergency operations. The 2009 edition of the International
3

Klote, J.H., An Overview of Elevator Use for Emergency Evacuation. CIB-CTBUH
Conference on Tall Buildings. Proceedings. Task Group on Tall Buildings: CIB TG50. CIB
Publication No. 290. October 20-23, 2003, Kuala Lumpur, Malaysia, Shafii, F.; Bukowski, R.;
Klemencic, R., Editors, 187-192 pp., 2003.
4
Klote, J. H., Hazards Due To Smoke Migration Through Elevator Shafts -Volume I: Analysis
And Discussion. Final Report. National Institute of Standards and Technology, NIST GCR 04864-1, June 2004
5
Bukowski, R. W.; Fleming, R. P.; Tubbs, J.; Marrion, C.; Dirksen, J.; Duke, C.; Prince, D.;
Richardson, L. F.; Beste, D.; Stanlaske, D., Elevator Controls, NFPA Journal, Vol 100, No 2, 4257, March/April 2006.
6
Bukowski, R.W., Is There a Need to Enclose Elevator Lobbies in Tall Buildings?, Building
Safety Journal, Vol 3, No 4, 26-31, August 2005.
7
Bukowski, R.W., Protected Elevators and the Disabled, J Fire Protection Engineering, 42, 4446, 48-49, Fall 2005.
8
Bukowski, R.W., Emergency Egress Strategies for Buildings, Interflam 2007. (Interflam '07).
International Interflam Conference, 11th Proceedings. September 3-5, 2007, London, England,
159-168 pp, 2007.
9
NFPA 101, Life Safety Code, 2009 Edition, National Fire Protection Association, Quincy, MA
September 2008.
10
NFPA 5000, Building Construction and Safety Code, 2009 Edition, National Fire Protection
Association, Quincy, MA October 2008.

Building Code will also include similar requirements on elevator use for fire fighter
access and occupant egress.
The following papers were published as part of this research.
•

Bukowski, R.W., Protected Elevators for Egress and Access During Fires in Tall
Buildings, Strategies for Performance in the Aftermath of the World Trade
Center. CIB-CTBUH Conference on Tall Buildings. Proceedings. Task Group
on Tall Buildings: CIB TG50. CIB Publication No. 290. October 20-23, 2003,
Kuala Lumpur, Malaysia, Shafii, F.; Bukowski, R.; Klemencic, R., Editors, 187192 pp., 2003.

•

Klote, J.H., An Overview of Elevator Use for Emergency Evacuation. CIBCTBUH Conference on Tall Buildings. Proceedings. Task Group on Tall
Buildings: CIB TG50. CIB Publication No. 290. October 20-23, 2003, Kuala
Lumpur, Malaysia, Shafii, F.; Bukowski, R.; Klemencic, R., Editors, 187-192 pp.,
2003.

•

Kuligowski, E. D., Elevators for Occupant Evacuation and Fire Department
Access. CIB-CTBUH Conference on Tall Buildings. Proceedings. Task Group
on Tall Buildings: CIB TG50. CIB Publication No. 290. October 20-23, 2003,
Kuala Lumpur, Malaysia, Shafii, F.; Bukowski, R.; Klemencic, R., Editors, 193200 pp, 2003.

•

Kuligowski, E.D., and Bukowski, R.W., Design of Occupant Egress Systems for
Tall Buildings, Use of Elevators in Fires and Other Emergencies Workshop.
Proceedings. Co-Sponsored by American Society of Mechanical Engineers
(ASME International); National Institute of Standards and Technology (NIST);
International Code Council (ICC); National Fire Protection Association (NFPA);
U.S. Access Board and International Association of Fire Fighters (IAFF). March
2-4, 2004, Atlanta, GA, 1-12 pp, 2004.

•

Klote, J. H., Hazards Due To Smoke Migration Through Elevator Shafts -Volume
I: Analysis And Discussion. Final Report. National Institute of Standards and
Technology, NIST GCR 04-864-1, June 2004

•

Klote, J. H. Hazards Due to Smoke Migration Through Elevator Shafts. Volume
2. Results of Tenability Calculations. Final Report. National Institute of Standards
and Technology, NIST GCR 04-864-2, June 2004

•

Bukowski, R.W. and Kuligowski, E.D., The Basis for Egress Provisions in U.S.
Building Codes, InterFlam 2004, Edinburgh, UK, July 2004.

•

Bukowski, R.W., Is There a Need to Enclose Elevator Lobbies in Tall Buildings?,
Building Safety Journal, Vol 3, No 4, 26-31, August 2005.

•

Bukowski, R.W., Protected Elevators and the Disabled, J Fire Protection
Engineering, 42, 44-46, 48-49, Fall 2005.

•

Bukowski, R. W.; Fleming, R. P.; Tubbs, J.; Marrion, C.; Dirksen, J.; Duke, C.;
Prince, D.; Richardson, L. F.; Beste, D.; Stanlaske, D., Elevator Controls, NFPA
Journal, Vol 100, No 2, 42-57, March/April 2006.

•

Bukowski, R.W., Emergency Egress Strategies for Buildings, Interflam 2007.
(Interflam '07). International Interflam Conference, 11th Proceedings. September
3-5, 2007, London, England, 159-168 pp, 2007.

•

Bukowski, R.W., Emergency Egress from Buildings, Part 1: History and Current
Regulations for Egress Systems Design, 7th International Conference on
Performance-based Codes and Fire Safety Design Methods, Auckland, NZ, SFPE,
2008.

A summary of each of the NIST papers that support these outcomes is included below.
The complete text of each of the papers is included as appendices to this report.

R. W. Bukowski, Protected Elevators for Egress and
Access During Fires in Tall Buildings
Included as Appendix A
Bukowski, R.W., Protected Elevators for Egress and Access During Fires
in Tall Buildings, Strategies for Performance in the Aftermath of the
World Trade Center. CIB-CTBUH Conference on Tall Buildings.
Proceedings. Task Group on Tall Buildings: CIB TG50. CIB Publication
No. 290. October 20-23, 2003, Kuala Lumpur, Malaysia, Shafii, F.;
Bukowski, R.; Klemencic, R., Editors, 187-192 pp., 2003.
Bukowski, R.W., Protected Elevators for Egress and Access During Fires
in Tall Buildings, Workshop on Building Occupant Movement During
Fire Emergencies. Proceedings. Session 2.4. June 10-11, 2004,
Gaithersburg, MD, Peacock, R. D.; Kuligowski, E. D., Editors, 14-21 pp,
NIST SP1032, January 2005.
The events of September 11 have generated renewed interest in the use of protected
elevators for egress and access. U.S. building codes contain requirements for accessible
elevators for assisted evacuation of people with disabilities. Firefighter lifts, required in
tall buildings in some countries, are being discussed to improve both the safety and
efficiency of firefighting operations. The desire for increased egress capacity of tall
buildings to facilitate simultaneous evacuation has rekindled interest in elevators as a
secondary means of egress for all occupants. Elevators used for each of these purposes
share many of the same design characteristics and the need for an extraordinary level of
safety and reliability. This paper will review the technology, safety, and reliability issues
associated with the use of elevators during fire emergencies for all three of these purposes
and the solutions being considered to address them. Operational procedures and
arrangements that influence system design considerations will be suggested. An
innovative system for operating the elevators under the remote, manual control of the fire
service will be described. Important human factors issues including communication,
signage, and training will be identified. Initial plans for a demonstration project in a U.S.
government building, as a proof-of-concept will be presented.

J. H. Klote, An Overview of Elevator Use for Emergency
Evacuation
Included as Appendix B
Klote, J.H., An Overview of Elevator Use for Emergency Evacuation.
CIB-CTBUH Conference on Tall Buildings. Proceedings. Task Group on
Tall Buildings: CIB TG50. CIB Publication No. 290. October 20-23,
2003, Kuala Lumpur, Malaysia, Shafii, F.; Bukowski, R.; Klemencic, R.,
Editors, 187-192 pp., 2003.
Throughout most of the world, warning signs next to elevators indicate that they should
not be used in fire situations. However, the idea of using elevators for fire evacuation has
gained considerable attention. This paper is an overview of what has been learned from a
number of research projects conducted at the U.S. National Institute of Standards and
Technology (NIST) in the 1980s and 1990s concerning the use of elevators during
building fires. An elevator system intended for evacuation needs to have protection from
heat, flame, smoke, water, overheating of elevator machine room equipment, and loss of
electrical power. In addition, such an elevator system needs to have a control approach to
assure protection of people traveling in the elevator. In areas of high seismic activity,
attention needs to be paid to earthquake design. Smoke protection technology for elevator
evacuation systems has been developed. Water exposure due to sprinklers and fire hoses
is a concern because of the effect that water can have on electrical and electronic elevator
components, and tests have been conducted to determine water leakage rates and observe
water leakage patterns. Further, the development of an elevator evacuation system needs
to take into account human behavior so that building occupants will be willing and
capable to use the system in an emergency. The computer program for elevator
evacuation (ELVAC) was developed to estimate time for elevator evacuation, and
ELVAC has been used to demonstrate the extent to which elevators can speed up
emergency evacuation.

E. D. Kuligowski, Elevators for Occupant Evacuation
and Fire Department Access
Included as Appendix C
Kuligowski, E. D., Elevators for Occupant Evacuation and Fire
Department Access. CIB-CTBUH Conference on Tall Buildings.
Proceedings. Task Group on Tall Buildings: CIB TG50. CIB Publication
No. 290. October 20-23, 2003, Kuala Lumpur, Malaysia, Shafii, F.;
Bukowski, R.; Klemencic, R., Editors, 193-200 pp, 2003.
This paper will present a study of the potential for elevators to reduce occupant egress
time and fire department access time for fires in tall buildings. Potential reductions in
egress and access times will be compared for some specific cases where times for current
procedures are available. The paper will review past research in elevator usage and the
structure of existing models for elevator evacuation. From this review, the assumptions
and limitations of the current elevator and egress models will be discussed, and future
plans for improvement of the existing egress prediction techniques will be presented.

E. D. Kuligowski and R. W. Bukowski, Design of
Occupant Egress Systems for Tall Buildings
Included as Appendix D
Kuligowski, E.D., and Bukowski, R.W., Design of Occupant Egress
Systems for Tall Buildings, Use of Elevators in Fires and Other
Emergencies Workshop. Proceedings. Co-Sponsored by American Society
of Mechanical Engineers (ASME International); National Institute of
Standards and Technology (NIST); International Code Council (ICC);
National Fire Protection Association (NFPA); U.S. Access Board and
International Association of Fire Fighters (IAFF). March 2-4, 2004,
Atlanta, GA, 1-12 pp, 2004.
This paper presents a discussion of the features of protected elevator systems that can
provide safe and reliable operation both for fire service access and for occupant egress
during fires. These features include water tolerant components, fail-safe power, lobbies
on each floor designed as areas of refuge, smoke protection, occupant communications,
and real time monitoring of the elevator position and operating conditions from the fire
command center. Egress simulations are used to quantify the improvements in efficiency
that can be realized by incorporating elevators into the access and egress procedures for
tall buildings. Finally, operational procedures will be discussed for the most appropriate
use of vertically zoned elevator systems that are found in most tall buildings. These
procedures would form the basis for the elevator control software that needs to be
developed for such systems.

J. H. Klote, Hazards Due To Smoke Migration Through
Elevator Shafts -Volume I: Analysis And Discussion
Included as Appendix E
Klote, J. H., Hazards Due To Smoke Migration Through Elevator Shafts Volume I: Analysis And Discussion. Final Report. National Institute of
Standards and Technology, NIST GCR 04-864-1, June 2004
During building fires, smoke often migrates through elevator hoistways to locations
remote from the fire. One of the reasons for concern is that a closed elevator door has a
leakage area of approximately 0.056 square meters (0.6 square feet). This is a report of a
project to study the hazards due to smoke flow through elevator hoistways. Smoke flow
and the resulting hazard to life are analyzed for 27 scenarios in 5 buildings ranging from
6 to 58 stories. A fire scenario is the outline of events and conditions that are critical to
determining the outcome of alternate situations and designs. In addition to the fire
location and heat release rate, the fire scenario includes the status of the doors and other
building systems. Other factors addressed are outside temperature, wind, height of
elevator hoistway, height of building, leakage paths in the building, leakage of elevator
doors, and other shafts. Stairwells are also included. Both sprinklered and nonsprinklered fires are included. Smoke transport throughout the buildings was simulated
by a combination of zone fire modeling and network modeling. Options considered for
mitigating hazards due to smoke flow through hoistways include (1) the use of enclosed
elevator lobbies with automatic closing doors, (2) temporary barriers and (3) judicious
positioning of cars within the hoistway. The results of the calculations showed that the
use of enclosed elevator lobbies increased the time to reach hazard criteria significantly
as compared the results without such lobbies. The use of automatic roll down barriers
tended to increase the time to reach hazard criteria to some extent. The use of judicious
positioning of elevator cars had no effect on the time to reach hazard criteria.

J. W. Klote, Hazards Due to Smoke Migration Through
Elevator Shafts. Volume 2. Results of Tenability
Calculations
Included as Appendix F
Klote, J. H. Hazards Due to Smoke Migration Through Elevator Shafts.
Volume 2. Results of Tenability Calculations. Final Report. National
Institute of Standards and Technology, NIST GCR 04-864-2, June 2004
This project looks at the hazard to life due to smoke migration through elevator hoistways
and the effectiveness of methods to reduce that hazard. This report of this project is in
two volumes. The first volume presents the analysis and discusses the results of that
analysis. The second volume consists of the complete results of the tenability
calculations.

R. W. Bukowski and E. D. Kuligowski, The Basis for
Egress Provisions in U.S. Building Codes
Included as Appendix G
Bukowski, R.W. and Kuligowski, E.D., The Basis for Egress Provisions in
U.S. Building Codes, InterFlam 2004, Edinburgh, UK, July 2004
Some of the earliest public safety-from-fire regulations in the US are requirements for
egress stairs -adopted by New York City in 1860. One of the first model regulations
promulgated by the National Fire Protection Association (NFPA) was the 1927 Building
Exits Code, predecessor of the Life Safety Code. Thus the need to move occupants out of
harms' way in building fires has long been central to fire safety regulations. The need to
move occupants to a safe place was underscored in numerous historical fire disasters.
Locked exits contributed to the high number of fatalities (150) in the 1911 Triangle
Shirtwaist Factory fire and exit doors that opened inwards blocked by crowds was cited
in the 492 fatalities of the Cocoanut Grove fire (1942). Incidents like these resulted in
public outcry for stronger code provisions but even today egress problems leading to high
numbers of deaths persist. The 100 fatalities at the Station Club in Rhode Island in 2003
provide the most recent example. Since the Rhode Island fire, NFPA and other code
authorities are reviewing current requirements for level of safety, especially for assembly
spaces. These current prescriptive codes used for building design contain a list of egress
specifications depending upon certain aspects of the building, such as the type of
occupancy, the configuration of the space, the presence of sprinklers, and the type of
construction of the building. These code specifications aid the designer in providing a
certain level of life safety for their building, but little effort has been put into quantifying
this level of life safety in terms of egress times. This paper attempts to describe the
prescriptive design process for specific types of buildings. Secondly, by applying some
assumptions to the egress specifications listed in the codes, an estimate of resulting egress
times for maximum occupant loads were performed for specific occupancies. The egress
times were obtained using multiple calculation methods and include estimates of premovement time, time to exit the occupied room, and time spent to travel one flight of
stairs. Lastly, additional egress issues, such as merging flows and the use of elevators for
occupant egress, are discussed.

R. W. Bukowski, Is There a Need to Enclose Elevator
Lobbies in Tall Buildings?
Included as Appendix H
Bukowski, R.W., Is There a Need to Enclose Elevator Lobbies in Tall
Buildings?, Building Safety Journal, Vol 3, No 4, 26-31, August 2005.
Several proposals have been submitted in recent years to model building code
organizations to require enclosure of elevator lobbies in order to restrict the movement of
smoke to other parts of buildings via hoistways. A significant development in this area
occurred recently when the National Institute of Standards and Technology (NIST) which was already involved with a consortium of industry representatives, codes and
standards developers, and other interested parties in a study of the protection of elevators
for occupant evacuation and fire service access - was asked by the U.S. General Services
Administration (GSA) to research the conditions under which enclosed elevator lobbies
were called for. This article will provide an overview of the progress made to date on this
line of research.

R. W. Bukowski, Protected Elevators and the Disabled
Included as Appendix I
Bukowski, R.W., Protected Elevators and the Disabled, J Fire Protection
Engineering, 42, 44-46, 48-49, Fall 2005.
The Americans With Disabilities Act (ADA) was passed in 1990 to provide equal access
to public buildings for all Americans. An objective of the ADA regulations was to permit
people with disabilities access to the places where they live, work, and play with little
thought of how they would get out in case of emergency. Fifteen years later, the fire
protection engineering community is still addressing this important issue. The purpose of
this article is to present the issues that need to be addressed in the development of
elevators that can be used in fires to safely evacuate occupants, particularly those with
limited mobility that affects their ability to use stairs. The ADA accessibility
requirements are intended to result in public buildings that can be accessed and used by
people with a range of limitations including vision, hearing, and mobility. The guidelines
provide for signs that include Braille markings, strobe lights and other visible warnings,
and doors with powered openers that are wide enough for wheelchairs. Smaller changes
in elevation require ramps or platform lifts that eliminate barriers to wheelchair users.

R. W. Bukowski, et. al., Elevator Controls
Included as Appendix J
Bukowski, R. W.; Fleming, R. P.; Tubbs, J.; Marrion, C.; Dirksen, J.;
Duke, C.; Prince, D.; Richardson, L. F.; Beste, D.; Stanlaske, D., Elevator
Controls, NFPA Journal, Vol 100, No 2, 42-57, March/April 2006.
It is important that all parties, from rescue personnel to building designers understand the
intent of the fire service operation provisions of ASME A17.1, Safety Code for Elevators
and Escalators. The development of the passenger elevator is tied directly to the
emergence of tall buildings. While various types of freight lifts were found in warehouses
and factories before the advent of the high-rise, these were considered too dangerous to
move people. In 1854, however, Elisha Graves Otis demonstrated an automatic safety
brake that changed the landscape. Within a few years, his steam elevators had eliminated
one of the major limits to building height. But, while elevators proved to be one of the
safest forms of transportation, there were instances where people were killed while using
elevators during building fires. Heat sometimes activated call buttons bringing cars to the
fire floor where smoke prevented the doors from closing (light beams are in modern day
elevators to detect people in the doorway) and water in the shaft sometimes shorted out
electrical safety devices or may have caused failure of braking systems. Thus, the use of
elevators for occupant egress or fire department access was discouraged. In 1973, the
elevator industry developed a system that recalls elevators and takes them out of service
if smoke is detected in the lobbies, machine room, or hoistway. Mandated in the
American Society of Mechanical Engineers (ASME) A17.1, Safety Code for Elevators
and Escalators,1 for all automatic passenger elevators, this system involves two distinct
phases of emergency operation.

R. W. Bukowski, Emergency Egress Strategies for
Buildings
Included in Appendix K
Bukowski, R.W., Emergency Egress Strategies for Buildings, Interflam
2007. (Interflam '07). International Interflam Conference, 11th
Proceedings. September 3-5, 2007, London, England, 159-168 pp, 2007.
The primary strategy for the safety of building occupants in emergencies (especially
fires) is by facilitating their relocation to a safe place. In other than a few institutional
occupancies (health care and detention facilities), this generally involves the use of stairs
as part of a protected means of egress (MOE) for vertical evacuation. For tall buildings
with large populations, providing sufficient stair capacity for simultaneous egress has
been considered practical by code making organizations, so the strategy of phased
evacuation has been employed. To this point in time, little attention has been paid to the
special needs of people with disabilities and other (permanent or temporary) physical
limitations in moving on stairs. The aftermath of September 11,2001 new attention is
being paid to many issues, especially emergency egress from tall buildings. A number of
experts have called for a fundamental linking of egress strategies including all of the
possible components that might be employed. In September 2006 a workshop was
organized in Atlanta by CIB Wl4:Fire and T50:Tall Buildings, with one of the discussion
topics devoted to this issue. This paper is ended to continue that discussion.

R. W. Bukowski, Emergency Egress from Buildings, Part
1: History and Current Regulations for Egress Systems
Design
Included as Appendix L
Bukowski, R.W., Emergency Egress from Buildings, Part 1: History and
Current Regulations for Egress Systems Design, 7th International
Conference on Performance-based Codes and Fire Safety Design
Methods, Auckland, NZ, SFPE, 2008.
Bukowski, R.W., Emergency Egress from Ultra-Tall Buildings, Tall &
Green, Typology for a Sustainable Urban Future, CTBUH, Dubai UAE,
March 2008.
The increasing height of buildings coupled with changing demographics and public
concerns about the safety of tall buildings have led to a call for a fundamental rethinking
of egress systems. This paper provides a review of the approaches currently found in
building regulations internationally, and attempts to identify the origins of these
specifications including the extent to which they may be based on scientific data or
consensus opinion. The case for moving to a performance metric of time is presented and
a set of criteria for evaluating egress systems against safe egress time is suggested.
Performance criteria based on practical objectives are suggested but these and suggested
regulatory thresholds need to be vetted through the existing consensus process of model
code development and regulatory adoption followed in the adopting jurisdiction. The
result should be a design approach that addresses the needs of occupants and buildings of
all heights with criteria based on sound engineering principles.

Appendix A
Protected Elevators for Egress and Access During Fires
in Tall Buildings

Proceedings of the CIB-CTBUH Int. Conf. on Tall Buildings, 20-23 October 2003, Malaysia

PROTECTED ELEVATORS FOR EGRESS AND ACCESS
DURING FIRES IN TALL BUILDINGS
Richard W. Bukowski, P.E., FSFPE
NIST Building and Fire Research Laboratory
100 Bureau Drive MS8664
Gaithersburg, Maryland 20899 USA
+1 301 975 6853
[email protected]
The events of September 11, 2001 have generated renewed interest in the use of protected
elevators for egress and access. U.S. building codes contain requirements for accessible
elevators for assisted evacuation of people with disabilities. Firefighter lifts, required in tall
buildings in some countries, are being discussed to improve both the safety and efficiency of
firefighting operations. The desire for increased egress capacity of tall buildings to facilitate
simultaneous evacuation has rekindled interest in elevators as a secondary means of egress
for all occupants. Elevators used for each of these purposes share many of the same design
characteristics and the need for an extraordinary level of safety and reliability.
HISTORY
The development of the passenger elevator is tied directly to the
emergence of tall buildings. While various types of freight lifts were found
in warehouses and factories these were considered too dangerous to
move people. In 1854 Elisha Graves Otis demonstrated an automatic
safety brake that changed the landscape. Within a few years his steam
elevators had eliminated one of the major limits to building height. But
while elevators proved to provide one of the safest forms of transportation
there were instances where people were killed while using elevators during
building fires. Heat sometimes activated call buttons bringing cars to the
fire floor where smoke prevented the doors from closing (light beams are
used to detect people in the doorway) and water in the shaft sometimes
shorted out safety devices. Thus the use of elevators for occupant egress
or fire department access was discouraged.
In the 1973 the elevator industry developed a system that recalls the
elevators and takes them out of service if smoke is detected in the lobbies,
machine room, or hoistway. Mandated in the Safety Code for Elevators
and Escalators1 (ASME A17.1) for all (automatic) passenger elevators this
system involves two, distinct phases of emergency operation. In Phase 1,
the detection of smoke or heat in specific locations results in the elevators
being immediately recalled to the ground floor (unless this is where smoke
was detected), the doors open, and the elevators are locked out of service.
The responding fire department can then choose to use the elevators
under manual control of a firefighter in the car by use of a special firefighter
key, in what is called Phase 2 operation. While Phase 2 is sometimes
used to evacuate people with disabilities, some fire department “standard
Figure 1 - Typical
operating procedures” for high-rise firefighting depend on the stairs for
electric elevator
access, staging, and operations. ASME publishes a Guide for Emergency
2
Personnel (A17.4) that includes detailed instructions for firefighters’ service operation.
CURRENT REQUIREMENTS FOR EMERGENCY USE ELEVATORS
All U.S. building codes contain a requirement for accessible elevators as a part of the
accessible means of egress in any building with an accessible floor above the third floor.
These requirements are all identical, being extracted from the ADA Accessibility Guidelines
(ADAAG) and mandated under the Americans with Disabilities Act (ADA).
A recent survey3 by the International Organization for Standardization (ISO) TC178
Committee identified at least twelve countries that require firefighter lifts in tall buildings

Richard W. Bukowski P.E., FSFPE

(generally those exceeding 30 m in height) to provide for fire department access and to
support operations as well as to evacuate people with disabilities. England has such a
requirement supported by a British Standard (BS 5588 Part 5)4 requiring firefighter lifts in
buildings exceeding 18 m (60 ft) in height. Firefighter lifts are also provided in the Petronas
Towers, the world’s tallest buildings in Kuala Lumpur, Malaysia.
The NFPA’s Life Safety Code (NFPA 101)5 includes provisions for egress elevators to be
provided as a secondary means of egress for air traffic control towers where the small
footprint prohibits two, “remote” stairs. These are secure facilities not open to the public and
with limited numbers of occupants.
While the above requirements exist for elevators for
emergency use by firefighters and people with
disabilities, there are currently no codes or standards
in the world for egress elevators for use by building
occupants. There is, however, an example of a
structure that uses elevators as the primary means of
egress and fire service access. This is the
Stratosphere Tower in Las Vegas, Nevada (Fig 2).
Essentially an eleven-story building sited atop an 250
m (800-foot) tower, it has a single emergency stair that
is considered impractical. Thus the four, double deck
elevators are designed for emergency use. One is
reserved for use by the fire department with the
remaining three used under manual control to
evacuate all occupants from the two lower floors that
are designed as areas of refuge. Occupancy of the
tower is limited to the number of people that can be
evacuated by the elevators in one hour6.
COMMON CHARACTERISTICS

Figure 2 - Stratosphere Tower in
Las Vegas

Whether for access by the fire service or for egress,
elevators provided for use in fire emergencies share several characteristics intended to
assure safety and reliability. They are required to be installed in a smokeproof hoistway
constructed to a 2-hr fire resistance and pressurized against smoke infiltration. Enclosed
lobbies are required on every floor, which are also 2-hr (1-hr in fully sprinklered buildings) and
pressurized. In fact, the lobby is crucial to safe operation since elevator doors are particularly
susceptible to jamming under even mild pressure differences. Thus, the smoke control
system should pressurize the shaft and lobby together so that there is a minimal pressure
difference across the door.
The lobbies are provided with a 2-way communication system to the building fire command
center so that people in the lobby can be informed of the status of any impending rescue.
Emergency power to operate the elevator in the case of main power failure is also specified.
Water intrusion into the hoistway can short out safety components such as switches that
prevent the doors from opening unless there is a car present, and even the safety brake; so
water protection or waterproof components are needed.
Within the United States, any use of the elevator for fire service access or for rescue of
people with disabilities is done under manual control of a firefighter in each car under Phase
2 recall. The elevator industry cannot guarantee that its automatic controls will react
appropriately to all hazards that might occur and cannot assure safe operation. Thus, the
trained operator must be able to recognize hazardous conditions and cease operations. This
represents a resource allocation problem for most fire departments that simply cannot assign
a firefighter to every car. Further, the susceptibility of safety controls to failure from water
results in a requirement for an automatic shutdown of elevator power before activation of fire
sprinklers in the machine room or hoistway. This would result in any operating elevator cars
to suddenly come to a halt.

Proceedings of the CIB-CTBUH Int. Conf. on Tall Buildings, 20-23 October 2003, Malaysia

SOLUTIONS FOR RELIABLE EMERGENCY ELEVATORS
The first solution is to eliminate the susceptibility to water by using waterproof components
and eliminating the requirement to shut down power. Next is to eliminate the need for
firefighters to operate each car.
Here we propose operating the elevators
under remote manual control. The
elevator industry would identify every
parameter critical to the safe operation of
the elevator and these would be monitored
and displayed in real time on the standard
fire service interface7 recently
implemented in the National Fire Alarm
Code8 (NFPA 72). This interface was
developed as a tool for incident
management that can collect information
from its own sensors and other building
systems (through a common communication
protocol such as BACnet) and display the
information in a format common to all
manufacturers’ systems. The interface
further supports specific control functions so that the operator could manually initiate recall if
any monitored parameters exceed the allowable operating envelope (Fig 3).
Figure 3 - NIST prototype fire service
interface

Because continuous monitoring of the system is crucial to safe and reliable operation, we
propose incorporating a triple redundant communication pathway. The fire alarm system is
currently required to incorporate two redundant communication trunks usually run up the two
stairways. Either trunk is sufficient for the full system operation and two-way communication
to the entire building. While these trunks are “remote” it is possible that a single event could
sever both trunks, rendering the portion of the system above the breaks inoperable. We
propose providing a wireless link between the bottom (generally the fire command center)
and the top of the system as a third, independent pathway. This would maintain full operation
of the system should both trunks fail. This would add little cost, ensure high reliability, and
can be done with current technology.
One outstanding reliability question involves the provision of emergency power to the
elevators. Most tall buildings have triple redundant power systems with generators on site.
The problem is that the power is generated at the base of the building and the hoisting and
controllers are at the top. How do we provide a reliable transmission path between the two?
It may be possible to use a battery/inverter system in the machine room with sufficient
capacity to move the cars safely to the bottom. Similar systems powered from small batteries
are used in seismic areas to move cars a single floor.
DEVELOPMENT OF OPERATING PROCEDURES
Prior research and recent advances can address all of the technology issues identified as
critical to the safe and reliable operation of elevators during fires. The remaining piece is the
development of operating procedures for access, egress, and rescue of the disabled that are
sensitive to the human factors issues and to the need for these activities to occur
simultaneously in tall buildings. Thus the systems must be designed and used such that they
do not interfere with all these uses.

Firefighter Lifts
Many US fire departments have adopted operating procedures for fires in tall buildings that
incorporate elevator access that are similar to those described in a draft CEN/ISO standard9
for firefighter lifts. The primary differences relate to the fact that most firefighter lifts are

Richard W. Bukowski P.E., FSFPE

dedicated to this use and
thus are immediately
available to the fire
service on their arrival. In
the US firefighters use the
passenger elevators that
are either still operating or
are waiting at the ground
floor in Phase 1 recall.
The procedure is for the
firefighters to use the lift
to transport people and
equipment to the
protected lobby 2-3 floors
below the fire floor where
they stage for their
suppression operations.
The firefighters then move
up the stairway to the fire
floor with a standard
length of hose (30 m is
common in the US and 60
m in Europe), which is
connected to the standpipe
Figure 4 - firefighter lifts carry people and equipment to
located in the stairs. This is
the floor below the fire with attack staged from the stairs9
important because once
charged with water the hose becomes very stiff. The hose is usually looped down the stairs
and back up so that it can be advanced onto the fire floor more easily. Working from the
stairway also provides a protected area to which the firefighters can retreat in case the fire
threatens them. The common hose lengths dictate the distribution of firefighter lifts within a
building in the same way as the distribution of standpipes. For example, the New York City
building regulations require standpipes located so that one is within 40 m (125 feet) – 30 m
(100 feet) of hose plus 10 m (25 feet) of water throw from the nozzle of any point on a floor.
Figure 4 is an illustration of firefighting procedures utilizing a firefighter lift, taken from the
CEN/ISO draft.
This operating procedure highlights the importance and interrelationship of the firefighter lift,
protected lobbies, associated stairway and standpipe. These components form a system
described in BS5588 as a firefighting shaft. The need for an associated stairway impacts on
the arrangement of the components and on the designation of multiple cars of an elevator
group as firefighter lifts. It also raises issues of the firefighting lift and stair used for occupant
egress.
Egress Assistance for People with Disabilities
Standards for firefighter lifts all include their use by firefighters to provide evacuation
assistance for people with disabilities. Even in the US where there are no firefighter lift
standards the building codes require accessible elevators (part of an accessible means of
egress) that are used by the fire service to evacuate people with disabilities. The procedures
generally are that such occupants proceed to the protected lobby (sometimes called an area
of refuge) and request evacuation assistance through a two-way communication system (to
the fire command center) provided.
Not covered is any procedure for coordinating the use of the lift for evacuation assistance
with that of firefighting. First priority will be given to moving firefighters and equipment to the
staging floor to allow the start of suppression operations. Then a firefighter would
presumably be assigned to begin to collect waiting occupants in the lift under manual control.
Command staff in the fire command center could inform the operator on which floors there
are occupants waiting and these could be gathered in some logical order and taken to the

Proceedings of the CIB-CTBUH Int. Conf. on Tall Buildings, 20-23 October 2003, Malaysia

ground floor. If there are more occupants than can be
assisted in a single trip there is a question about the order in
which they are removed. Presumably, this would be done for
the floors nearest the fire first, then above the fire and finally
below the fire. Because these people are required to wait it is
especially important to provide this two-way communication
system to the lobby (Fig 5) so that they can be reassured that
assistance is coming. The real-time monitoring system
described earlier would assure that conditions in the occupied
lobbies remain tenable.
Occupant Egress Elevators
As mentioned earlier, with only rare exceptions for special
cases, elevators are taken out of service in fires and people
are advised never to use elevators during fires. This policy
does not represent a severe hardship for most buildings and
occupants, but poses problems for people with (mobility)
disabilities and for tall buildings where stairway egress times
can be measured in hours.

Figure 5 - Maintaining
communication with
waiting occupants is crucial

Operational procedures for occupant egress elevators raise some interesting issues. First,
how can overcrowding be avoided? Elevators have weight switches that disable an elevator
that is overcrowded. Without a floor warden or firefighter controlling the loading it is likely that
occupants may attempt to overcrowd an elevator during emergency evacuation. Similarly,
the elevators are unlikely to be capable of handling a large fraction of the floor load – the
system specified for air traffic control towers is designed for elevator evacuation of not more
than half the occupants. How will at least half the occupants be encouraged to take the
stairs? One possibility is to limit the capacity of the lobbies so the excess is forced into the
stairways. Another is the phased direction of the elevators to evacuate floors near the fire
first. If occupants have the choice of waiting in the lobby or beginning to move to safety down
stairs, what choice will they make?
Egress elevators are most likely to be utilized in tall buildings and here the elevator systems
are vertically zoned in 30- to 40-floor sections. How would elevator evacuation be operated
with vertically zoned elevators? One example where this is being done is for an 88-story
building currently under construction in Melbourne, Australia. In the Eureka Place Tower,
elevators in the third of the building containing the fire are taken out of service and occupants
all use the stairways to the next (lower) transfer floor where they board express elevators to
grade. People with disabilities are assisted by firefighters in their dedicated lifts within the
zone of origin. This strategy is similar to the Petronas Towers where occupants above the
sky bridge level use stairs to that level, move across to the other tower, and use the elevators
to grade.
Coordination of emergency elevator uses
Finally, the complete integration of the elevators
into the emergency operational plans in tall
buildings presents some coordination issues
that will need to be addressed. One example is
whether firefighter lifts and egress elevators can
share common lobbies (Fig 6). Occupants
awaiting egress may interfere with staging of
suppression operations. Another is access to
stairs and the use of the stairs for mounting the
fire attack as discussed previously. A third is
the sequence of egress operations. First priority
would be given to egress of occupants from a
few floors around the fire floor. Next a group of

Figure 6 - Will shared lobbies lead to
interference between operations and
egress?

Richard W. Bukowski P.E., FSFPE

floors above the first group should be evacuated but if a disabled person enters a lobby on
another floor at what point should that person be extracted? These sequencing delays would
likely cause people on other floors to use the stairs rather than awaiting the elevators.
Should people above the fire take the stairs to a point and then transfer to the elevators while
people below the fire should take the stairs all the way? NIST plans to incorporate elevators
into evacuation models so that a series of simulations can be conducted to identify the most
effective operational procedures. NIST is also working with the US elevator industry to
develop control software that can adapt to changing conditions and maintain safe and reliable
operation of the elevator system.
Concluding remarks
Operational procedures and sequencing will have an effect on the design and arrangement of
the entire egress system and need careful thought. The operational procedures selected
must take into account complex human behavioral issues to be successful and also have
significant impacts on the design and arrangement of the systems. Thus these issues should
be discussed and resolved as a system so that appropriate requirements can be developed
for standardization. Finally, there are significant advantages in developing common
approaches globally. With the degree to which people travel internationally it is highly
advantageous to have consistent emergency procedures so that people know how to react
and do not depend on instructions that may not be understood clearly due to language
difficulties.
REFERENCES
1

Safety Code for Elevators and Escalators, ASME A17.1-2000, American Society of Mechanical
Engineers, NY, 2000
2
Guide for Emergency Personnel, ASME A17.4-1999, ibid
3
Comparison of worldwide lift (elevator) safety standards – Firefighters lifts (elevators), ISO/TR
16765:2002(E), International Organization for Standardization, Geneva, Switzerland, 2002
4
Fire Precautions in the Design, Construction, and Use of Buildings, BS 5588 Part 5 1991, Code of
Practice for Firefighting Lifts and Stairs, British Standards Institution, London
5
Life Safety Code (NFPA 101 2000, National Fire Protection Association, Quincy, MA 02269
6
Quiter, J. R. Application of Performance Based Concepts at the Stratosphere Tower, Las Vegas,
Nevada. Rolf Jensen and Associates, Inc., Deerfield, IL. Fire Risk and Hazard Assessment
Symposium. Research and Practice: Bridging the Gap. Proceedings. National Fire Protection Research
Foundation. June 26-28, 1996, San Francisco,CA, 118-126 pp, 1996.
7
Bukowski, R. W. Development of a Standardized Fire Service Interface for Fire Alarm Systems.
National Institute of Standards and Technology, Gaithersburg, MD Fire Protection Engineering, 4,6-8,
SFPE Bethesda, MD, Spring 2000.
8
National Fire Alarm Code NFPA 72 (2002 ed.) Nat Fire Prot. Assn., Quincy, MA 02269, 2002.
9
Safety rules for the construction and installation of lifts – Part 72:Firefighter lifts, CEN TC10,
Committee for European Standardization, Brussels, BE.

Appendix B

An Overview of Elevator Use for Emergency Evacuation

Proceedings of the CIB-CTBUH International Conference on Tall Buildings, 8-10 May 2003, Malaysia

AN OVERVIEW OF ELEVATOR USE FOR EMERGENCY EVACUATION

John H. Klote
John H. Klote, Inc. – Fire and Smoke Consulting
Leesburg, VA, USA
Abstract
Throughout most of the world, warning signs next to elevators indicate that they should not be used in fire situations. However,
the idea of using elevators for fire evacuation has gained considerable attention. This paper is an overview of what has been
learned from a number of research projects conducted at the U.S. National Institute of Standards and Technology (NIST) in the
1980s and 1990s concerning the use of elevators during building fires. An elevator system intended for evacuation needs to have
protection from heat, flame, smoke, water, overheating of elevator machine room equipment, and loss of electrical power. In
addition, such an elevator system needs to have a control approach to assure protection of people traveling in the elevator. In
areas of high seismic activity, attention needs to be paid to earthquake design. Smoke protection technology for elevator
evacuation systems has been developed. Water exposure due to sprinklers and fire hoses is a concern because of the effect that
water can have on electrical and electronic elevator components, and tests have been conducted to determine water leakage
rates and observe water leakage patterns. Further, the development of an elevator evacuation system needs to take into account
human behavior so that building occupants will be willing and capable to use the system in an emergency. The computer
program for elevator evacuation (ELVAC) was developed to estimate time for elevator evacuation, and ELVAC has been used to
demonstrate the extent to which elevators can speed up emergency evacuation.
Keywords: Elevators, Evacuation, Fire, Human behavior, Piston effect, Smoke Control, Smoke.

1. Introduction
Throughout most of the world, warning signs next to elevators indicate they should not be used in fire
situations. These elevators are not intended as means of fire egress, and they should not be used for fire
evacuation (Sumka 1987). Frequently, the fire service uses elevators during fires for mobilization and rescue.
The idea of using elevators to speed up emergency evacuation has gained considerable attention. Elevator
evacuation has also gained interest as a means of emergency egress for people with mobility limitations.
Bazjanac (1974, 1977) examined the effect of using elevators to speed up building evacuation. In the 1980s
and 1990s, the U.S. National Institute of Standards and Technology (NIST) conducted a number of research
projects that examined the use of elevators during building fires. This paper is an overview of what has
been learned from this research. For NIST work concerning elevator smoke control, readers are referred to
Klote (1980, 1983, 1984, 1988, 1995). A joint U.S. and Canadian project also studied elevator smoke
control (Klote and Tamura 1986a, 1986b, 1987, 1991a, 1991b; Tamura and Klote 1988, 1989a, 1989b,
1990).
NIST projects examined the feasibility of using elevators for emergency evacuation (Klote 1993a, Klote et al.
1992a, 1993, Klote and Braun 1996, Klote, Levin and Groner 1994, 1995). NIST sponsored studies of
human considerations regarding elevator evacuation (Groner and Levin 1992, 1995; Levin and Groner 1992,
1994a, 1994b, 1995). Because elevator lobbies can be used for staging areas or areas of refuge, NIST
research concerning these areas is also of interest (Klote 1993b, Klote et al. 1992b).

Klote

2. Concern With Elevator Evacuation
The 1976 edition of the Life Safety Code (NFPA 101 1976) listed the following "problems" involved with the
use of elevators as fire exits1:
!"

Persons seeking to escape from a fire by means of an elevator may have to wait at the elevator
door for some time, during which they may be exposed to fire, smoke or developing panic.

!"

Automatic elevators respond to the pressing of buttons in such a way that it would be quite
possible for an elevator descending from floors above a fire to stop automatically at the floor
involved in the fire and open automatically, exposing occupants to fire and smoke.

!"

Modern elevators cannot start until doors are fully closed. A large number of people seeking to
crowd into an elevator in case of emergency might make it impossible to start.

!"

Any power failure, such as the burning out of electric supply cables during a fire, may render the
elevators inoperative or might result in trapping persons in elevators stopped between floors.
Under fire conditions there might not be time to permit rescue of trapped occupants through
emergency escape hatches or doors.

In addition, there are other concerns. Fire or smoke might damage elevator equipment. Water from
sprinklers or fire hoses could short out or cause other problems with electrical power and control wiring for
the elevator. Overheating of elevator equipment could result in malfunction of elevators. Pressurization for
smoke control could result in elevator doors jamming open, limiting movement of the car. Piston effect due
to elevator car motion could pull smoke into the elevator lobby or the hoistway (elevator shaft). However, it
is possible to design an emergency elevator evacuation systems (EEES) with a high level of protection
relative to these concerns.

Fig. 1 Elevator system including elevator equipment,
machine room, hoistway and elevator lobby
3. EEES Concept
An EEES includes the elevator equipment, hoistway, machine room, and other equipment and controls needed
for safe operation of the elevator during the evacuation process. Because people must be protected from fire
and smoke while they wait for an elevator, the system must include protected elevator lobbies (Figure 1).
Such protected elevator lobbies also help to prevent the fire from activating elevator buttons so that elevator
cars are prevented from being called by the fire to the fire floor2.

1
2

This edition of the Life Safety Code was the last edition to list these "problems".

Even buttons that are not heat sensitive can short out when subjected to the elevated temperatures of a fire.

Klote

An EEES must have protection from heat, flame, smoke, water, overheating of elevator machine room
equipment, and loss of electrical power. In addition, an EEES must have a control approach that assures
protection of the people traveling in the elevator. In areas of high seismic activity, attention must be paid to
earthquake design. Further, the development of an EEES needs to take into account human behavior so that
building occupants will be willing and capable to operate the system in an emergency. The following sections
address these issues.
The concern about people crowding into an elevator and doors not closing is significant only when there are
enough people to form a crowd. Some EEESs might only be intended for use by a small number of people.
Examples of such low use EEESs are (1) a system intended only for use by a few persons with mobility
limitations, and (2) a system at an air traffic control tower (ATCT). For the purposes of this paper, a small
number of people is taken to be a number that will not result in crowding that could force elevator doors to
remain open and prevent motion of the car. For other applications, the conventional methods of people
movement (Pauls 2002, Nelson and Mowrer 2002, Klote and Milke 2002) can be used to evaluate the potential
for crowding.
4. EEES Protection

4.1 Heat and Flame
Compartmentation is one of the oldest methods of fire protection and has been extensively used to limit the
spread of fire. Compartmentation is also one approach to smoke protection, and this is addressed in the next
section. As a convenience to the reader the concepts of compartmentation are briefly described here, and for
further information readers are referred to Barnett (1992), Boring, Spence and Wells (1981), Bushev et al.
(1978) and Campbell (1991).
Buildings are divided into compartments formed by fire barriers. These barriers are walls, partitions and floorceiling assemblies that have a level of fire resistance. The traditional approach to evaluate fire resistance is to
subject a section of a barrier to a standard fire in a standard furnace. Each building fire is unique in duration
and temperature, and it is not surprising that the performance of barriers in building fires differs to some
extent from the performance in standard tests. Historically, the goal of fire resistant construction was property
protection, but the goals of current codes include life safety. The building codes require specific levels of fire
resistance for specific applications with the goal of protecting life.

4.2 Smoke
The mechanisms that can be used to provide smoke protection are air flow, buoyancy, compartmentation,
dilution and pressurization. Detailed information about these mechanisms is presented by Klote and Milke
(1992, 2002). Because of the concern about supplying oxygen to the fire as discussed by Klote and Milke, air
flow is not recommended for smoke protection of EEESs. Buoyancy is primarily used to manage smoke in
large spaces such as atria and shopping malls. Systems that rely on buoyancy are inappropriate for smoke
protection of EEESs.
Pressurization Systems: Systems relying on compartmentation with pressurization are designed on the
basis of no smoke leakage into protected spaces. Accordingly, analysis of such pressurization systems is less
complex than that of systems using compartmentation alone or compartmentation with dilution. Acceptance
testing and routine testing of pressurization systems is done by measurement of the pressure difference
produced when the system is operating. Such testing provides a level of assurance about system performance
during a fire. For systems that have windows breaking, windows opening, or doors opening to the outside;
smoke control systems by pressurization as discussed later can maintain pressurization during such pressure
fluctuations. Considering the potential for windows to break during unsprinklered fires, pressurization systems
are recommended for smoke protection of EEESs in unsprinklered buildings.
Piston Effect: Elevator car motion results in increased air pressure in the direction of motion. There is a
concern that this piston effect could reduce the effectiveness of an elevator smoke control system. An
analysis of elevator piston effect was developed and experimentally verified (Klote 1988; Klote and Tamura

Klote

1986a). Based on this analysis, Klote and Milke (1992, 2002) provide a simple method for design evaluation
of elevator piston effect.
Elevator Doors Jamming: Elevator doors jam open when the force of the door mechanism is insufficient to
overcome the force of friction. The friction force increases with the pressure difference from the hoistway to
the lobby. In tall buildings, elevator doors frequently jam open during extremely cold weather. This is caused
by stack effect induced pressure differences. Elevator mechanics commonly adjust the door closing forces to
prevent door jamming. During elevator smoke control operation, the possibility of door jamming may
decrease or increase. If the leakage area of the elevator lobby doors is less than that of the elevator doors,
the pressure difference across the elevator doors can be less than that normally occurring. In field tests
conducted by Klote (1984), no door jamming was encountered at pressure differences as high as 75 Pa (0.3 in
H2O). When door jamming was encountered in an elevator without smoke control, it was found that only a
small additional force applied by the palms of the hands was sufficient to overcome jamming. Fire fighters
can be taught to overcome door jamming this way, and elevator doors could be fitted with grips or handles to
aid in this effort.

4.3 Water
During a building fire water from sprinklers and fire hoses can damage electronic, electrical, and mechanical
components of an EEES. The water exposure of some suppression and firefighting devices are listed in Table
1. For fires in the hoistway, elevator lobbies or machine room, the most appropriate action seems to be to take
the elevators out of service. Fires in the hoistway or elevator lobbies can easily result in untenable conditions
within the EEES. Further, an elevator cannot be expected to operate when there is a fire in the machine room,
because of elevator equipment exposure to elevated temperatures. If there is a fire in the hoistway, elevator
lobbies or machine room; the EEES should be shut down. Because of the limited fuel load, relatively small
compartment size and the fire resistive construction, fires in the hoistway, elevator lobbies or machine room
are not believed to have as high a potential for hazard as fires in many other building spaces. If evacuation is
needed, other vertical paths (other elevators and stairs) can be used.

Table 1.Water flows of some suppression and firefighting devices
Device
12.7 mm (0.50 in) Sprinkler Head
29 mm (1.125 in) Solid-Stream Hose Nozzle
Manually Held Hose with Spray Nozzle
Master Flow Devices

L/min
67-200
950
40-1150
1900-7500

gpm
17.7-53
250
11-300
500-2000

Water Leakage of Elevator Doors: Klote and Braun (1996) conduced experiments of the water flow
around elevator doors and into the hoistway in a specially built facility at NIST (Figure 2). The elevator doors
were supplied by an elevator manufacturer. The tests consisted of a water exposure in the elevator lobby, and
water leakage of the elevator doors was determined by collecting water in the tank shown in Figure 2. The
water exposure was a ceiling sprinkler, sidewall sprinkler, standing water set up, or a fire hose. The positions of
the sprinklers is shown in Figure 2. Figure 3 shows the set up for the standing water test. The set up for the
fire hose test is shown in Figure 4. The results of their study are summarized in Table 2.

Klote

Fig. 2 Laboratory facility for testing water leakage of elevator doors

Klote

Fig. 3 Set up standing water tests

Fig. 4 Set up for fire hose tests

Klote

Table 2. Results of elevator door1 water leakage tests (Klote and Braun 1996)
Type of Water Exposure
Ceiling Mounted Sprinkler2
Sidewall Sprinkler2
Standing Water
Fire Hose

Water Exposure
29 L/s
46 gpm
2.8 L/s
44 gpm
12 mm
0.5 in.
28 L/s
440 gpm

Measured Water Leakage
L/s
gpm
0.22
3.3
0.13
2.1
0.84
13
13.5
210

1

The results above are for standard gibs and brackets around elevator doors.

2

Test conducted with open floor drain in elevator lobby. The depth of water (standing water) at

the bottom of the elevator doors was not measured, but it appeared to be on the order of 2.5
mm (0.1 in.).

Approaches to Minimize Water Damage: For fires outside the EEES, the two major locations of concern
about water damage are the machine room and the hoistway. Two potential approaches to minimize water
damage are:
1.

use of elevator components that can function in a wet environment, and

2.

prevention of water from entering the hoistway or machine room.

Some methods that might be used to minimize or prevent water from entering the hoistway (elevator shaft)
are use of sloping floors, floor drains and doors with seals. Other methods might include exterior elevators or
elevators located in their own towers and are separated from the building by a section of exterior walkway or
an exterior elevator lobby.
Currently no elevators have been developed with water resistant components for operation during fire
evacuations. However, many elevators operate outdoors on exterior walls of buildings with many of the
system components exposed to rain, wind and extremes of temperature. These outdoor conditions are
believed to be much more severe than those associated with water flow inside a hoistway due to a building
fire. Without routine testing for water resistance, components that degraded from years of use or were
accidentally damaged would go undetected and unrepaired.
Further research and development are needed to find reliable methods of protection the EEES from water
damage.

4.4 Overheating Of Elevator Machine Room Equipment
Loss of cooling can result in loss of elevator service due to overheating of elevator equipment, and precautions
need to be taken to minimize the likelihood of such overheating. The maximum operating temperatures of
most elevator equipment are in the range of 30 to 35 C (86 to 95 F). There are several approaches to
providing the necessary machine room cooling, but dedicated air conditioning equipment has significant
advantages. Dedicated equipment located in the machine room or outside the building eliminates the
possibility of damage to this equipment from fire outside the machine room to the extent that the fire resistive
construction withstands the fire. Further, dedicated equipment uses less electrical power than non-dedicated
equipment with resulting advantages concerning reliability of electrical power.

4.5 Electrical Power
Reliability of electric power consists of assuring a source of power and assuring continued distribution of power
to where it is used. Some components that can be used to ensure reliability of power are fire protected
distribution, redundant feeds, power from multiple substations outside the building, and emergency generator
sets. Because elevator evacuation can tolerate short duration power loss, uninterruptable power supplies are
not necessary. Any consideration of reliability of electric power should consider potential causes of power
failure and the consequences of that failure.

Klote

4.6 Earthquakes
The concern with earthquakes is that the counterweight could become dislodged from its rails resulting in a
collision between the elevator car and the counterweight. Such a collision could result in injury or fatality to
elevator passengers. In areas of high seismic activity, some elevators have strengthened rails and a seismic
switch to sense significant acceleration. The strengthened rails allow safe elevator operation up to a specific
level of earthquake induced acceleration. If the seismic switch senses acceleration greater than this specific
level, the elevators are put into an emergency mode to prevent collision with the counterweight and then
taken out of service. Such an approach can be applied to EEESs that are in areas of high seismic activity.
5. Availability
When an elevator in an EEES is out of service for scheduled or unscheduled maintenance, it cannot be used
for evacuation. If there are many elevators in a building, the number of elevators used for evacuation can be
selected to allow for a percentage that may be out of service.
In buildings with only one elevator, the above redundancy approach to assuring availability is not possible.
Two other approaches to maximize availability are off hours maintenance and short turn around repairs.
Scheduled maintenance can be done during off hours when the building is shut down or in a low state of
activity. Maintenance contracts can put a premium on fast repair for unscheduled maintenance. When an
elevator is out of service, a sign should clearly indicate this so that valuable evacuation time is not wasted
waiting for an elevator that can not come.

6. Elevator Control
Readers are familiar with automatic elevator controls that are common in passenger elevators in most of the
world. There are two other modes of operation: elevator recall and firefighters operation. Upon alarm of a
smoke detector in an elevator lobby, the elevator goes into a recall mode in which the car is moved to the exit
landing and removed from service. In the event of a fire on the exit floor, the elevator goes to an alternate
floor and is taken out of service. This recall is referred to as Phase I. The landing to which the car is moved is
the exit floor or an alternate floor if smoke was detected on the exit floor. After recall, firefighters can operate
the elevator, and such operation is under the control of the firefighter inside the elevator. This firefighter’s
operation is referred to as Phase II.
Some approaches that might be used to control elevators during an elevator emergency evacuation are:
!"

normal use (with less sensitive detectors),

!"

Phase II, and

!"

other mode of elevator operation.

In an EEES, the elevator (including the elevator lobbies, hoistway and machine room) is protected from the
fire effects as discussed above. Thus the elevator is operating in an environment without fire. There is no
physical reason why an elevator so protected cannot continue to operate normally provided that the smoke
detector in the elevator lobby does not go into alarm. As stated earlier, an alarm from this smoke detector will
result in Phase I elevator recall. Typical smoke detectors are very sensitive, and they can be put into alarm by
a quantity of smoke so small that a person might not notice. Such small amounts of smoke may enter the
lobby when lobby doors are opened for evacuation. Such low levels of smoke are not a tenability concern. To
avoid unwanted elevator recall, the smoke detectors in the elevator lobbies that initiate Phase I operation can
be replaced with less sensitive detectors such as heat detectors.
Using normal operation during evacuation is not appropriate for evacuation of large numbers of people, where
a full elevator car might stop at every floor on its way to the exit floor. However, normal mode would be
appropriate for evacuation of small numbers of people, such as a few persons with disabilities in an office
building or the small number of workers in an ATCT. The computer program for elevator evacuation (ELVAC)
by Klote, Alvord, Levin, and Groner (1992) can be used to estimate time for elevator evacuation.

Klote

The fire service, using Phase II operation, could also use elevators for evacuation of small numbers of people.
Further, it is possible that building personnel could operate the elevators under Phase II for evacuation before
the fire service arrives. Use of Phase II by non-fire service people would require that the elevator operators
be trained and that the general approach not adversely affect fire service operations. Phase II service must
only be provided by people who are aware of the location and extent of the fire and of its potential for
endangering people using elevators.
Approach 3 listed above is a mode of elevator operation that could be developed specifically for emergency
evacuation. Features that could be considered for this emergency evacuation mode might include the ability
to prioritize evacuation and the ability to cancel calls from a floor with untenable conditions in the elevator
lobby. Such capabilities may be needed for evacuation of large numbers of people.
If EEESs are to be developed for evacuation of large numbers of people from buildings, further research and
development are needed to find appropriate methods of elevator control.
7. Human Considerations
Designing and building elevators that can be safely used during a fire emergency is only half the job. The
building occupants must be willing to use the EEES and be able to use it. The NIST feasibility study of
elevator evacuation at ATCTs (Klote, Levin and Groner 1994; Levin and Groner 1994a) included visits to 13
control towers where interviews were conducted with air traffic controllers and other personnel.
The interviews consisted of informal discussions that lasted about 15 minutes. Considering the twenty year
campaign to teach people not to use elevators during fires, it was expected that occupants would have a
strong preference for using stairs during fires. It was not surprising that nearly all those interviewed
expressed a strong preference for using stairs as the first choice escape route. There were considerable
differences among the interviewees on how willingly they would use elevators if there was smoke in the stairs.
A few would use it without hesitation, and a few indicated they would try other alternatives (wait for
helicopters, escape to catwalk, or use ladders). The majority indicated that they would use elevators if it were
necessary with little delay but with considerable concern.
At some ATCTs there were complaints about elevator service. It is well known in the elevator industry that
buildings with only one elevator have more complaints about out-of-service elevators than buildings with
multiple elevators. When there is only one elevator, occupants have to walk when elevators are not operating.
In addition to complaints about out-of-service elevators, there were complaints about rough rides, and at one
ATCT a cable for the counterweight had broken. While none of these occurrences were life threatening, the
occupants at these towers were emphatic in expressing reluctance about elevators for fire evacuation. At
ATCTs with few complaints about elevator service, occupants were more willing to accept the idea of EEES.
Good maintenance of the elevator will encourage people to trust the EEES.
Communication is important to inform people waiting for elevators of the status of elevator evacuation and to
inform people outside the building about the status of those waiting. The communication devices can be
intercoms or telephones, but they must be capable of two way conversation. One device is needed in each
elevator lobby, and another is needed at a location accessible to the emergency personnel.
In order to develop confidence in EEESs, education is needed to describe the safety features. Such education
should also address general aspects of fire evacuation. This education can be by a combination of formal
training classes, viewing videos, performing fire drills, reading an emergency plan and group discussions.
Levin and Groner (1994) provide more information about such education.
8. Speeding Up Evacuation
The extent that elevators could be used to speed up evacuation in General Services Administration (GSA)
office buildings was calculated by Klote et al. (1992a). For horizontal movement and movement on stairs,
conventional methods of people movement were used. For movement on elevators, the computer program
ELVAC (Klote 1993a) was used. ELVAC uses the generally accepted methods to calculate people movement by
elevators (Strakosch 1983).

Klote
Constant
Deceler ati on
Tr ansit ional
Decel eration

Constant
Acceleration Tr ansit ional
Acceleration
Constant Velocity

Leveling

Time
Figure 5. Velocity of elevator that reaches normal operating velocity

For many trips, elevator motion is depicted in Figure 5. Motion starts with constant acceleration, followed by
transitional acceleration, and constant velocity motion. Constant acceleration ends when the elevator
reaches a predetermined velocity which is typically about 60% of the normal operating velocity. For office
buildings, normal operating velocity generally is from 1 to 9 m/s (200 to 1800 fpm), and acceleration is
from 0.6 to 2.4 m/s2 (2 to 8 ft/s2). Deceleration has the same magnitude as the acceleration, and total
acceleration time equals the total deceleration time. Usually elevators do not stop exactly at the desired
floor at the end of deceleration, so the elevator must be moved slowly up or down to get it nearly level with
the floor. For cars not reaching normal velocity, the elevator car velocity is simpler.
In addition to elevator motion, ELVAC includes the (1) the start up time before elevator evacuation for the
car to go to the discharge floor, (2) time for passengers to enter and leave the elevator on each trip, (3)
the time for elevator doors to open and close on each trip. ELVAC also incorporates the following
inefficiencies: (1) trip inefficiency (2) basic transfer inefficiency, (2) door inefficiency and (3) other
inefficiency. Klote (1993a) discusses these inefficiencies and provides some values.
Table 3. Summary of Elevator Evacuation Calculations of the GSA Study (Klote, et al. 1992a)

Building
General Services Building
Hoffman Building II
White Flint North Building
Jackson Federal Building

Location
Washington, DC
Alexandria, VA
Bethesda, MD
Seattle, WA

Number
Of Stories

Optimum
By Elevator1

Speed Up
Evacuation By2

7
13
18
36

NA
33%
17%
65%

NA
25%
16%
22%

1

The optimum by elevators is the percent of occupants using elevators that results in the fastest building evacuation. In
these calculations, the upper floors were evacuated by elevator, and the other floors were evacuated using stairs.
2
This is the decrease in evacuation time using the optimum combination of elevators and stairs over evacuation by stairs
only.

Table 3 is a summary of the elevator evacuation calculations of the GSA study. In these calculations, some
of the elevators were considered out of service and not used for the evacuation calculations. Calculations
were based on a number of upper floors being evacuated by elevators, and the rest of the occupants used
stairs. For the General Services Building, there was no combination of elevators and stairs that was as fast
as evacuation by stairs alone. The General Services Building is a large monumental building that takes up a
city block in down town Washington, DC. One of the reason that elevators could not speed up evacuation of
this building is that it has high stair capacity.
The calculations show that the elevator use has the potential to speed up evacuation significantly for the
other three buildings studied. The extent to which elevators have the potential to speed up evacuation
depend on many factors including the number of floors in the building, the capacity of the elevators, the
capacity of the stairs, and the number of elevators in service during evacuation. However, it appears that in
general to he potential benefit of using elevators is greater for taller buildings.

Klote

Conclusions
The use of elevators to speed up emergency evacuation is feasible. An EEES must have protection from heat,
flame, smoke, water, overheating of elevator machine room equipment, and loss of electrical power. In areas
of high seismic activity, attention must be paid to earthquake design. Further research is needed to (1)
develop reliable methods of protection the EEES from water damage, (2) develop appropriate methods of
elevator control, (3) develop appropriate approaches to getting people to accept and use EEES in emergencies.
Acknowledgements
So many people have made valuable contributions to elevator research during the 1980s and 1990s that it is not possible
the thank them all, but the following come to mind. Bernard Levin and Norm Groner provided valuable input concerning
human behavior. Daniel Alvord helped with the development of ELVAC. Emile Braun contributed to the elevator water
tests. Development of this overview paper is part of a research project sponsored by NIST, and Richard Bukowski is
NIST’s technical representative for that research project.
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Bazjanac, V. (1974) Another Way Out? Progressive Architecture, April, pp. 88-89.
Bazjanac, V. (1977) Simulation of Elevator Performance in High-Rise Buildings Under Conditions of Emergency. Human

Response to Tall Buildings, Ed by D. J. Conway. Dowden, Hutchinson & Ross, Stroudsburg, PA, pp. 316-328.

Groner, N. E., Levin, B. M. (1995) Will Building Occupants Use Elevators for Evacuation? Factors Affecting Compliance
With the Emergency Plan. Proceedings of Elevators, Fire and Accessibility, 2nd Symposium.. April 19-21, 1995, ASME,
New York, NY, pp. 194-196.
Groner, N. E., Levin, B. M. (1992) Human Factors Considering in the Potential for Using Elevators in Building Emergency
Evacuation Plans, NIST-GCR-92-615, NIST, Gaithersburg, MD.
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Bureau of Standards, Gaithersburg, MD.
Klote, J. H. (1993a) A Method for Calculation of Elevator Evacuation Time. Journal of Fire Protection Engineering, Vol. 5,
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Klote, J. H. (1993b) Design of Smoke Control Systems for Areas of Refuge. ASHRAE Transactions, Vol. 99, No. 2, pp.
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Klote, J. H. (1995) Design of Smoke Control Systems for Elevator Fire Evacuation Including Wind Effects. Proceedings of
Elevators, Fire and Accessibility, 2nd Symposium. April 19-21, 1995, ASME, New York, NY, pp. 59-77.
Klote, J. H. et al. (1992a) Feasibility and Design Considerations of Emergency Evacuation by Elevators. NISTIR 4870,
NIST, Gaithersburg, MD.
Klote, J. H. et al. (1992b) Staging Areas for Persons With Mobility Limitations. NISTIR 4770, NIST, Gaithersburg, MD.
Klote, J. H. et al. (1993) Workshop on Elevator Use During Fires. NISTIR 4993, NIST, Gaithersburg, MD.
Klote, J. H., Braun, E. (1996) Water Leakage of Elevator Doors With Application to Building Fire Suppression. NISTIR
5925, NIST, Gaithersburg, MD.
Klote, J. H., Levin, B. M., Groner, N. E. (1994) Feasibility of Fire Evacuation by Elevators at FAA Control Towers. NISTIR
5445, NIST, Gaithersburg, MD.
Klote, J. H., Levin, B. M., Groner, N. E. (1995) Emergency Elevator Evacuation Systems. Proceedings of Elevators, Fire
and Accessibility, 2nd Symposium, April 19-21, 1995, ASME, New York, NY, pp. 131-150.
Klote, J. H., Milke, J. A. (1992) Design of Smoke Management Systems, ASHRAE, Atlanta, GA.
Klote, J. H., Milke, J. A. (2002) Principles of Smoke Management, ASHRAE, Atlanta, GA.
Klote, J. H., Tamura, G. T. (1986a) Elevator Piston Effect and the Smoke Problem, Fire Safety Journal, Vol. 11 No. 3, pp.
227-233.
Klote, J. H., Tamura, G. T. (1986b) Smoke Control and Fire Evacuation by Elevators, ASHRAE Transactions, Vol. 92, Part
1A, pp. 231-245.

Klote
Klote, J. H., Tamura, G. T. (1987) Experiments of Piston Effect on Elevator Smoke Control, ASHRAE Transactions, Vol. 93,
Part 2, pp. 2217-2228.
Klote, J. H., Tamura, G. T. (1991a) Design of Elevator Smoke Control Systems for Fire Evacuation, ASHRAE Transactions,
Vol. 97, Part 2, pp. 634-642.
Klote, J. H., Tamura, G. T. (1991b) Smoke Control Systems for Elevator Fire Evacuation. Elevators and Fire. Council of
American Building Officials and National Fire Protection Association. February 19-20, 1991, Baltimore, MD, pp. 83-94.
Levin, B. M., Groner, N. E. (1992) Human Behavior Aspects of Staging Areas for Fire Safety in GSA Buildings. NIST GCR
92-606, NIST, Gaithersburg, MD.
Levin, B. M., Groner, N. E. (1994a) Human Factors Considerations for the Potential Use of Elevat ors for Fire Evacuation of
FAA Air Traffic Control Towers. NIST GCR 94-656, NIST, Gaithersburg, MD.
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Emergency Evacuation Plans, NIST-GCR-92-615, NIST, Gaithersburg, MD.
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Evacuation System. Proceedings of Elevators, Fire and Accessibility, 2nd Symposium, April 19-21, 1995, 190-193 pp,
1995, ASME, New York, NY, 2002.
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Fire Protection Engineers, Boston, MA.
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MA.
Strakosch, G. R. (1983) "Vertical Transportation: Elevators and Escalators", Wiley & Sons, NY, 2nd Edition., pp. 122-127.
Sumka, E. H. (1988) Presently, Elevators Are Not Safe in Fire Emergencies, Elevator World, Vol. 36, No. 11, pp. 34-40.
Tamura, G. T., Klote, J. H. (1988) Experimental Fire Tower Studies on Adverse Pressures Caused by Stack and Wind
Action: Studies on Smoke Movement and Control, ASTM International Symposium on Characterization and Toxicity of
Smoke, December 5, 1988, Phoenix, AZ.
Tamura, G. T., Klote, J. H. (1989a) Experimental Fire Tower Studies of Elevator Pressurization Systems for Smoke Control.

ASHRAE Transactions, Vol. 93, No. 2, 2235-2256.

Tamura, G. T., Klote, J. H. (1989b) Experimental Fire Tower Studies on Mechanical Pressurization to Control Smoke
Movement Caused by Fire Pressures. Proceedings of International Association for Fire Safety Science. Fire Safety Science.
2nd International Symposium. June 13-17, 1988, Tokyo, Japan, Hemisphere Publishing Corp., New York, pp. 761-769.
Tamura, G. T., Klote, J. H. (1990) Experimental Fire Tower Studies on Controlling Smoke Movement Caused by Stack and
Wind Action. Proceedings of International Association for Fire Safety Science. Fire Safety Science. 2nd International
Symposium. June 13-17, 1988, Tokyo, Japan, Hemisphere Publishing Corp., New York, pp. 165-177.

Appendix C
Elevators for Occupant Evacuation and Fire Department
Access

Proceedings of the CIB-CTBUH International Conference on Tall Buildings, 8-10 May 2003, Malaysia

ELEVATORS FOR OCCUPANT EVACUATION AND FIRE DEPARTMENT
ACCESS
E. KULIGOWSKI
National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
Abstract
This paper will present a study of the potential for elevators to reduce occupant egress time and fire department access time
for fires in tall buildings. Potential reductions in egress and access times will be compared for some specific cases where
times for current procedures are available. The paper will review past research in elevator usage and the structure of
existing models for elevator evacuation. From this review, the assumptions and limitations of the current elevator and
egress models will be discussed, and future plans for improvement of the existing egress prediction techniques will be
presented.
Keywords: Elevators, evacuation, firefighter lifts, elevator evacuation, evacuation models

1.

Introduction

The recent events have caused fire safety experts to question the adequacy of phased evacuation plans
for high-rise buildings. Also, the issue of lengthy travel times and physical exertion of firefighters
ascending stairs of a high-rise building to reach the fire floor is a concern. Inquiries of fire departments
following the incident indicates that most have adopted access by elevator policies for buildings
exceeding 6 stories, but there are currently no provisions for firefighter lifts in the U.S. elevator codes.
During total evacuation of a tall building, it is likely that there would be significant congestion in the
stairways with a larger number of occupants, when compared with occupant numbers during phased
evacuation, at the same time as firefighters traveling against the flow. Increasing the number or width
of the stairwells in a building represents an extremely expensive option, especially for existing buildings.
A viable option is to design elevators capable of providing a safe exit route out of the building for
occupants and safe access to the fire area for firefighters. Several issues concerning elevator use in
emergencies, such as human behavior, control, training, equipment reliability, and communication,
should be addressed before this mode of vertical transportation can be implemented.
1.1 Current Requirements for Firefighter Lifts
Firefighter lifts are protected elevators provided in tall buildings for use by the fire department for
moving people and equipment to the fire area and which also may be used by the fire department to
provide evacuation assistance to people with disabilities. The provision of lifts dedicated to fire
department use in an emergency is required in at least 12 countries around the world. As a recent
survey by the ISO TC178 committee shows1 operating procedures for fire department use of elevators
are similar. For example they are generally required in buildings taller than 30 m, are provided with
enclosed lobbies on each floor, and are housed in a two hour smoke protected shaft. Emergency
power to the controllers and motor is required and the cars are operated under manual control by a
firefighter.
British Standard 5588, Part 5 entitled Code of Practice for Firefighting Stairs and Lifts2 describes what is
referred to as a firefighting shaft. This is a dedicated, protected elevator with lobbies on every floor
and an associated stairway fitted with a standpipe. The procedure is to move people and equipment to
the lobby three floors below the fire. The hose team then advances up the stairs from the elevator
drop-off position, connects to the standpipe, and proceeds with the attack. Enough firefighting shafts
are required so that any point on a floor can be reached with 60 m of hose. The commentary describes
several advantages to fire department dedicated lifts, such as reduction of travel time to the access
floor, preservation of the building for a longer period of time, and increased safety to the occupants of
the building. The standard also recognizes that firefighters who climb several flights of stairs outfitted
with heavy gear and equipment may lose needed energy to fight the fire by the time they reach the fire
floor.

Kuligowski

In the US, ASME A17.1-2000, the Safety Code for Elevators and Escalators3, does not provide for the
use of elevators in emergencies either by firefighters or by occupants (except as noted below). Since
1973, A17.1 has contained emergency procedures that take the elevators out of service if smoke is
detected in any lobby or in the machine room or hoistway. Under this condition the elevators are
directed immediately to the ground floor where the doors open and the elevators are locked out (called
Phase I recall). Subsequently, the responding fire department can reactivate individual cars under
manual control using a special key (Called Phase II operation). U.S. building regulations require that
buildings taller than three floors and likely to be used by people with disabilities be provided with an
accessible elevator protected in a manner similar to that described for firefighter lifts. A means of
summoning assistance from the fire department is required and they would use that elevator under
Phase II operation to evacuate the disabled person.
The use of elevators for fire department access would enable the firefighters to ride to a specific floor,
depending upon what is specified by the department’s Standard Operating Procedures (SOPs)4.
Examples of U.S. City Fire Department’s SOPs5 state that the elevators would take firefighters from the
lobby to the floor two floors below the fire floor while others, e.g. the Chicago Fire Department6, state
that the elevator would stop three floors below the fire. In either case, the firefighters from an engine
company, for instance, would exit the elevator on the designated floor, travel via stairs to establish a
hose line one to two floors below the fire floor, and continue stair travel with the hose line to the fire
floor.
1.2 Research on Egress Elevators
In a fire emergency, elevators are not only the focus for fire department access, but for evacuation
purposes as well. Work was done in the early 1990s at the National Institute of Standards and
Technology (NIST)7,8,9,10,11 on the use of elevators for evacuation in which pros and cons were
established that still exist today. The advantages noted for elevator evacuation are the following:
!
Occupants usually exit buildings the same way that they enter
!
Elevator evacuation takes less physical effort
!
Stair congestion is an unpleasant experience
!
Overall evacuation time is decreased
!
Elderly or disabled occupants may rely on elevators as their only option
On the other hand, with an elevator evacuation plan, there are many issues to consider and prepare for
in an emergency. First, the 30 year campaign cautioning the public against using elevators in the event
of a fire could severely lessen the occupants’ confidence in the elevator system. Also, occupants could
become impatient and overcrowd the elevator, which causes the car to stop functioning and remain at
the floor indefinitely10. One way for these issues to be addressed is through a training program and
extensive evacuation plan for the building. The evacuation plan of a single rise elevator system could
involve, for example, the use of elevators by the higher floors of the buildings, stairs used by the lower
floors, and fire wardens on each floor directing his/her occupants to the correct evacuation route8.
Since training may not be as helpful for visitors of the high rise building, the use of fire wardens
becomes even more important in elevator evacuation.
For an 88-floor residential building in Melbourne, Australia, an evacuation strategy has been used in the
building design to allow for elevator use during evacuation. The Eureka Place Tower12 is separated,
according to the elevator arrangement, into vertical evacuation zones. The plan states that occupants
within the vertical zone that includes the fire floor would evacuate via the stairs until they reach the
next transfer floor. At the transfer floors, which are located on levels 24 and 52 of the Eureka Place
Tower, the occupants would then take the express elevators to the ground floor. The express elevators
will be located in separate shafts in order to avoid water and smoke damage, and will be accompanied
by other lifts provided for firefighter access.
Along with an evacuation plan, a reliable voice communication system can provide information on the
progress of the fire and evacuation system8. Also, a decision made on the appropriate control of the
elevator system (manual or automatic) in an emergency lends itself to certain advantages and
disadvantages presented in the literature13,14,15.

Kuligowski

1.3 Elevator Evacuation Models
In order to capture the differences in evacuation by stairs only, elevators only, or both, evacuation
modeling and calculations can be done. ELVAC7 is the only commonly available model dedicated to the
calculation of evacuation time by elevators. Other elevator models, typically used for elevator design
within a building, can also be used to calculate the transit time of the last person to reach the lobby,
which is ultimately the evacuation time of the building. These models have limitations when using
them to simulate total evacuation of a building, as well as make assumptions, which will be addressed
later in this report.
The three topics covered in this report focus on a firefighter lift case study, the U.S. General Services
Administration (GSA) building evacuation case study, and a review of current elevator evacuation
models. The case studies will be used to estimate the ultimate reduction in travel time by incorporating
elevators into the evacuation plan for occupant evacuation and fire department access. For the
firefighter lift study, firefighter travel via stairs will be compared to travel by elevator to a designated
floor accompanied by continual travel via stairs to the fire floor. In the GSA evacuation study8, several
ELVAC and stair evacuation calculations were made to show the reduction in travel time when both
elevators and stairs are used simultaneously for evacuation, instead of stairs only. Finally, the
limitations and assumptions of current elevators models will be discussed as well as future needs in the
area of elevator evacuation modeling.

2. Firefighter Lift Case Study
For this case study, the commercial building used was designed by a Dallas architectural firm and
stretches 40 stories above ground and 4 parking levels below. A typical floor of the building contains
approximately 3000 m2 of floor space, with 500 m2 occupied by the core space. The core contains
elevators, 2 stairwells, bathrooms, mechanical closets, etc.
The stairs are located diagonally across the core area from each other, each measuring 1.2 m (3.9 ft)
wide with 26 7/11 steps per flight. The 7/11 terminology refers the height of the riser followed by the
depth of the tread in inches, meaning that for each step, the riser height is 17.8 cm (7 in) and the tread
width is 27.9 cm (11 in). The height of each floor is 4.5 m (15 ft), creating a travel distance of 11 m
(36 ft) per flight of stairs, including the landing distance.
The elevators for a commercial building are assumed to have a speed of 5.08 m/s (1000 fpm), per
Table 10.7 of the Vertical Transportation Handbook16, and average acceleration of 1.5 m/s2 (5 ft/s2).
For this case study, it is also assumed that a crew of 5 firefighters and their equipment will be traveling
in the elevator and stairs together at one time. There are other characteristics that were assumed for
the elevators that only affect the outcome of this case study in a trivial manner, such as the full car
load, type of door, the door inefficiency, and door closing time.
For this case study, the fire is placed on the 35th floor. Two groups of five firefighters are analyzed in
their attempts to reach floor 35. Group 1 traverses 34 flights of stairs from the lobby to floor 35.
Group 2 takes the elevators to the 33rd floor and travels the stairs an additional 2 flights. Hand
calculations were made for firefighter travel up the stairs, while hand calculations and the ELVAC model
were used to calculate the one-way elevator travel time from the lobby to the 33rd floor. ELVAC is
primarily a model used to calculate gross elevator evacuation time from buildings, and the hand
calculated one-way elevator travel time was used to check ELVAC results.
To obtain firefighter travel speeds on stairs and horizontal building components, adjustments were
made to data already recorded from people movement studies17,18,19. Frantzich’s data show a range of
velocities for upstairs movement from (0.5 to 0.75) m/s, Fruin gives values of (0.5 to 0.65) m/s and
Predtechenskii and Milinskii state a range of (0.33 to 0.92) m/s for low density situations. On one
hand, these values may be low if studied during nonemergency situations, but alternatively, firefighters
are typically equipped with heavy gear and equipment, on the order of 25 to 45 kg per firefighter,
which should be accounted for. The primary walking speed used in this case study for firefighter travel
up stairs is 0.35 m/s (adjusted from 0.5 m/s for heavy gear). Another velocity used came from the

Kuligowski

New York Fire Department’s rule of thumb that states firefighters average 60 seconds per floor
(unobstructed flow), which is not sustainable throughout the ascent of high-rise buildings. 60 seconds
per floor will be used as the conservative ascent time and 0.35 m/s will be used as the other extreme.
For horizontal building component speed, again the standard value of 1.2 m/s20 was adjusted to a
conservative value of 0.8 m/s for gear and heavy equipment.
The breakdown of the elevator calculations are as follows (multiple values indicate a range of travel
speeds for that calculation):
Group 1:
o The time to traverse 34 flights of stairs = 17 min at 0.35 m/s; 34 min at 60 seconds per flight
(more conservative)
Group 2:
o The one way travel time of the elevator from the lobby to the 33rd floor = 45 s with 5.08 m/s
elevator speed
o The horizontal travel time from the elevator to the stairs on the 33rd floor = 30 s at 1.2 m/s;
45 s at 0.8 m/s (more conservative)
o The time to traverse two flights of stairs = 60 s at 0.35 m/s; 120 s at 60 seconds per flight
(more conservative)
The travel times calculated for both Groups in this case study neglect firefighter response time to the
building, travel to the elevator or stairs from the building entrance, and time spent on the floor locating
the point of attack, since both need to perform these activities in a fire situation.
After performing an additional calculation of adding the elevator travel, horizontal travel, and stair
travel times together for Group 2, the results are as follows:
!
Group 1: 17 to 34 min
!
Group 2: 2.5 to 3.5 min
It may seem obvious that an elevator would give some advantage in speed over stair use. But, when
other factors, such as heavy gear and equipment and increased elevator technology play a role,
elevators substantially become a more viable and constructive option. The difference between use of
stairs (Group 1) and elevators (Group 2) for firefighter ascent is approximately (15 to 30) minutes. This
is a large difference in time lost due to stair use, especially when a fire can grow significantly in a
matter of minutes. By using elevators as the primary means of ascent, Group 2 was able to reach the
fire at least 15 min earlier in this case study. In fifteen minutes, the environment can be less toxic for
the occupants, the fire smaller, and the property less damaged. Also, Group 2 would have more energy
to exert on fire fighting activities on the floor, when compared to Group 1. The limitation associated
with the calculation was the estimation made in the firefighter movement speed, as shown by the range
of results in both Groups.

3. Elevator Evacuation Study
In the early 90s, four GSA buildings were analyzed as potential applications to incorporate elevator
evacuation8. The four selected were the Hoffman Building II (Virginia), White Flint North Building
(Maryland), Jackson Federal Building (Seattle), and General Services Building (Washington, DC), and
were chosen to gather different building heights, elevator capabilities, and architectural characteristics.
For each building, evacuation times were calculated for the following conditions: 1) Total evacuation of
the building by stairs only; 2) Total evacuation of the building by elevators only; and 3) Total
evacuation of the building by various distributions of occupants to stairs and elevators (the optimal time
value is shown in Table 1). For the stair calculations, Klote et al.8 used the people movement
methodology laid out by Nelson and MacLennan21. For these calculations, people on each floor were
assumed to be waiting at the door to the stairs as soon as evacuation begins. For the elevator
calculations, the ELVAC model7 was used which simulates 2-stop elevator trips until the entire building
has been evacuated. Again, for these calculations, people were assumed to be waiting at the closest
elevator lobbies as soon as evacuation began. Table 1 shows the characteristics of each building,

Kuligowski

including the number of floors, the number of stairs and elevators used, and the total population of
each building. Also, the table shows the total evacuation time of the building (minutes) if only stairs
were used, the total evacuation time if only the elevators were used, and the last column shows the
optimal (fastest) gross evacuation time when a combination of stairs and elevators are used.
Additionally, the Hoffman building and the White Flint North Building’s analysis did not use the full
capacity of elevators available to the building. The Hoffman building used 5 out of the 6 elevators in
each group and the White Flint building used 4 out of the 6. This was due to the fact that the existing
elevator lobbies were incapable of holding as many people as would be discharged from all elevators
simultaneously, and in that case, the evacuation capacity of the elevators was restricted by the size of
the lobby.
Building

Floors

Stairs/
Elevators

Total
Population

Hoffman
White Flint
Jackson
GSA

13
18
36
7

2/ 2 groups of 5
2/ 1 group of 4
2/ 3 rises of 6
6/ 6 groups of 2

3506
1425
3021
3621

Evac.
Time by
Stairs
14.9 min
14.3
23.1
7

Evac.
Time by
Elevators
24.3 min
28.6
16.5
17

Optimal
Time by
Both
11.2 min
12.0
12.8
6.3

Table 1: Summary of GSA buildings and modeling results
In each of the four buildings analyzed, the optimal time was reached by designing for a combination of
floors or percentage of the floor dedicated to elevator usage while the other portion of the building
evacuated by stairs. The use of elevators for evacuation made the largest contribution for the tallest
building, which was the Jackson Federal building equipped with low, mid, and high rise elevators. The
elevator designation that provided the optimal result for this building was the following: 65 % of
occupants from the mid and high rise floors, all occupants from floors 11 through 14, and only 3 % on
floors 1 through 13. All others in the Jackson building used the stairs. For the single rise elevator
systems in the Hoffman, White Flint, and GSA buildings, the elevator designation that provided the
optimal result was for total elevator evacuation from the upper floors of the building and stairs from the
lower floors. Overall, it was shown that by using a combination of evacuation systems, stairs and
elevators, the total evacuation time of the building can be reduced by a substantial amount, especially
with taller buildings. This study is limited by the averaged movement calculations used, and the
assumption that all occupants were waiting at the stair or elevator lobbies as soon as the evacuation
began. Also, another limitation is that occupants were not studied using both stairs and elevators
during a single evacuation route, as performed in the evacuation plan for the Eureka Place Tower.

4. Elevator Evacuation Modeling
While the GSA calculations were made using the ELVAC model, there are certainly limitations associated
with this and other current elevator evacuation models. Due to the fact that elevators are rarely used
for occupant evacuation, other than by the fire department in Phase II, few evacuation models are
available that incorporate evacuation via elevators. The commercial models presently being used to
simulate building evacuation in a fire situation typically model movement by stairs only, with or without
the incorporation of behavior simulation. There has yet to be a commercially-available, complete
simulation package to describe the entire fire scenario, including premovement and action decision
making, environmental conditions inside the building, occupant behavior, and movement throughout
the building via stairs, escalators, and elevators. The limitations of the current models extend beyond
the obvious lack of elevator simulation. There is also a lack of data on occupant behavior during
elevator use in evacuation. The uncertainties on whether or not occupants will feel comfort in using
elevators arise from the lack of data on occupant overcrowding of cars on a floor, impatience due to
long waits in the elevator lobby, and behavior around their particular social unit (for example, will
groups remain together and let an elevator pass if there is not enough room in the car for the entire
group?). Another modeling uncertainty is how the model will simulate the evacuation plan that will
take place in the building. The model may need to incorporate fire wardens, manual and automatic
control of the elevators, and multi-use of stairs and elevators by the same group of occupants.

Kuligowski

As mentioned earlier, ELVAC8 is a model dedicated to the simulation of building evacuation by elevator
only. ELVAC, as will be explained, only gives the gross evacuation time of the building, and along with
its assumptions, may cause the model to lose accuracy in calculation, especially when compared to a
complete simulation model. The model uses the 2-stop evacuation approach, meaning that the car
travels from the lobby to a specific floor and then back down to the lobby, independent of the number
of tenants occupying the car.
ELVAC also assumes that all occupants using the elevators for
evacuation are waiting at the elevator lobbies as soon as evacuation begins. Changes could be made
to ELVAC to move towards more of a simulation model, such as equipping the elevators with load
sensors, which most have, that would recognize when a car has additional space and enable the car to
pick up more occupants on the way down to the lobby. Also, in an actual evacuation, it is certain that
people would be arriving at the elevator lobby at different times, and the load sensor device would aid
in evacuation of stragglers to the lobby area after most of the occupants have been evacuated. ELVAC,
by giving only the gross evacuation time, does not simulate the car movement from floor to floor and
the times associated with these movements. In an actual fire evacuation, it is most likely that the cars
will move to the fire floor (and floors above and below) to evacuate these occupants first. By
incorporating car simulation into ELVAC, evacuation times by elevators may be more accurate,
especially for worst case scenarios when the fire is on a high floor of the building. Lastly, ELVAC does
not account for the actual design of the control of the elevators. This difference in control may cause
delays in start-time if operated by a human, instead of computer.
ELEVATE and the Building Traffic Simulator (BTS) are both models used to design the elevators for
buildings, including the number and size of the cars, for normal daily operation. ELEVATE, a
commercial model, can be used to indirectly calculate total evacuation time by identifying the time that
the final person has arrived at the ground floor from the elevators22,23. The user must specify a
destination to the ground floor as 100 % and the arrival rate (persons per 5 minutes) of the building’s
occupants to the elevator lobbies. As of now, evacuation modeling procedures are not specified in the
users manual. BTS24,25, on the other hand, is a currently noncommercial model capable of simulating
evacuation via the building’s transportation devices, which includes elevators (with different control
methods), escalators, and stairs. The model uses input of the building’s floor shape, position of the
transportation devices, passenger traffic (e.g. arrival rates to the lobbies), passenger selection of
transports, and passenger walking speeds (to simulate tenants who may need to walk from one
transportation device to the other during movement and/or movement on stairs) to model an
evacuation. According to its developers24,25, evacuation can be modeled defining the occupant’s
walking speed, space requirement, and decision on which transportation mode(s) to use throughout the
evacuation. Both ELEVATE and BTS provide a step toward simulation evacuation models, since these
models are continually aware of occupant loads and positions (in elevator cars or stairs, depending on
the model) in time throughout the evacuation. On the other hand, like ELVAC, there is no introduction
of fire conditions and human behavior, as a complete simulation evacuation package could include.
Also, for each of the three models, occupants are either automatically waiting at the elevator lobbies
(ELVAC) or given an arrival rate (people/time period – ELEVATE, BTS) for appearing at the designated
transport device, which neglects specific behavior and movement time delays occurring from their
original position to the location of the transport device.
The three elevator models discussed in this report, ELVAC, ELEVATE, and BTS, all have advantages and
disadvantages for using each for evacuation simulation purposes. ELVAC gives the gross evacuation
time of the building by elevators only and assumes that all occupants are waiting at the elevator lobbies
as soon as the evacuation begins. ELEVATE will simulate down-peak (evening rush hour for the
building, for example) elevator movement with 100 % probability of movement to the ground floor, and
BTS will also simulate down-peak movement of the occupants using elevators, escalators, and stairs
during their exit journey. The simulation models, ELEVATE and BTS, have the extra advantage of
continual data on the current position of the cars and occupants, as well as an attempt to model
premovement behavior through the use of occupant arrival rates to the elevator lobbies. However,
none of these models incorporate specific behavior and movement time delays that occur before
reaching the transport device, human behavior in relation to elevator and stair use during a fire, and
the condition of the fire in the building during the evacuation. These are main reasons why a complete
evacuation simulation package would be a valuable asset for evacuation design. It should be noted
that relevant literature in human behavior is sparse26,27,28,29; because elevators are not commonly used
for design of the evacuation system of a building, data on humans and elevator use is lacking for this
simulation package.

Kuligowski

5. Conclusions
Elevator use in emergency situations can make a significant time saving contribution to travel towards
the fire for the fire service and the evacuation of the occupants in the building. The calculations done
for the firefighter case study showed that firefighters traveled to the fire floor (15 to 30) min faster via
elevators when compared to stair access. The stair travel calculation, using two different estimates for
the firefighter walking speeds, resulted in a range of travel time values differing by a factor of two.
Research is needed in the area of firefighter movement to assess which travel times within the
calculated range (17 to 34 min) are more accurate.
Also, the evacuation time of occupants using a combination of stair calculations and ELVAC calculations
for the elevators shows improvement over stair or elevator movement alone for the GSA examples
studied. This is especially true for the taller building with multi-rise elevators. With these calculations,
assumptions were made that the occupants were waiting at the elevator lobbies and staircases as soon
as evacuation began. Also, the occupants were assumed to use only the stairs or the elevators during
their descent, unlike the evacuation plan of the Eureka Place Tower, in which a resident could use a
combination of the two during egress.
Lastly, there is a need for a complete simulation package that includes movement of the occupants on
stairs, elevator movement of the cars and occupants, environmental conditions in the building due to
the fire, the contribution of the building to fire and egress, and human behavior and movement during
the entire evacuation. Currently, there are evacuation models that focus on all of these aspects except
elevator usage, and elevator models that neglect these aspects of building evacuation except for
elevator usage. Unfortunately, much data is lacking about the behavior of occupants using elevators
during an emergency, which needs to be addressed.
Overall, elevators lessen the travel time of firefighters and occupants to their prospective destinations,
if used properly and with an appropriate emergency plan. There are many obstacles which need to be
met in order for these plans to work properly. Recently, there has been an awakening to the
importance of research in these areas for eventual use in buildings all over the world.

Acknowledgements
The author recognizes the help of Mr. Richard Bukowski, of the National Institute of Standards and Technology, as an
advisor of this project. The assistance in research on elevators modeling from Roger Howkins and Dr. Richard Peters
(ELVATE), Dr. John Klote (ELVAC), and Dr. Marja-Liisa Siikonen (BTS) is also appreciated. Mr. Mike Scianna, Commander –
Bureau of Operations, Chicago Fire Department, and Mr. John O’Donoghue, Fire Officer, Massachusetts Firefighting Academy
provided information about FD operations in high-rise buildings. Finally, Mr. Jason Averill provided the building used for FD
access calculations30.
References
1
Comparison of worldwide lift (elevator) safety standards – Firefighters lifts (elevators), ISO/TR 16765:2002(E),
International Organization for Standardization, Geneva, Switzerland, 2002.
2

Fire Precautions in the Design, Construction, and Use of Buildings, BS 5588 Park 5 1991, Code of Practice for Firefighting
Lifts and Stairs, BSI, London.

3

Safety Code for Elevators and Escalators, ASME A17.1-2000, Amer Soc Mech Eng, NY, 2000.

4

Klaene, B. and Sanders, R. (2001), Firefighters’ Use of Elevators, Using elevators during a fire requires establishing specific
SOPs, NFPA Journal, Vol. 95, No. 4, July/August 2001.

5

Phoenix Fire Department Standard Operating Procedures, http://phoenix.gov/FIRE/20205.html.

6

Verbal/Email Communication: Michael Scianna, Chicago Fire Department. October 2002.

7
Klote, J.H. (1993), A Method of Calculation of Elevator Evacuation Time, National Institute of Standards and Technology,
Gaithersburg, MD, Journal of Fire Protection Engineering, 5(3), 1993, pp. 83-95.
8

Klote, J.H., Alvord, D.M., Levin, B.M., and Groner, N.E. (1992), Feasibility and Design Considerations of Emergency
Evacuation by Elevators, National Institute of Standards and Technology, Gaithersburg, MD, NISTIR 4870.

Kuligowski

9

Klote, J.H. and Alvord, D.M. (1992), Routine for Analysis of the People Movement Time for Elevator Evacuation, National
Institute of Standards and Technology, Gaithersburg, MD, NISTIR 4730.

10
Klote, J.H., Deal, S.P., Donoghue, E.A., Levin, B.M., and Groner, N.E. (1993), Fire Evacuation By Elevators, Elevator World,
June 1993.
11

Klote, J.H., Levin, B.M., and Groner, N.E. (1995), Emergency Elevator Evacuation Systems, Proceedings of the 2nd

Symposium on Elevators, Fire, and Accessibility, Baltimore, MD, April, 1995.
12

Aloi, S. and Rogers, J. (2002), Reach for the Sky, Fire Prevention & Fire Engineers Journal, Vol. 62, No. 219, FPA London,
April 2002.

13

Levin, B.M, and Groner, N.E. (1995), Some Control and Communication Considerations in Designing an Emergency
Elevator Evacuation System, Proceedings of the 2nd Symposium on Elevators, Fire, and Accessibility, Baltimore, MD, April,
1995.
Groner, N.E. (1995), Selecting Strategies for Elevator Evacuations, Proceedings of the 2nd Symposium on Elevators, Fire,

14

and Accessibility, Baltimore, MD, April, 1995.

15
Groner, N.E. and Levin, B.M. (1992), Human Factors Considerations in the Potential for Using Elevators in Building
Emergency Evacuation Plans, George Mason University, Washington, DC, July 1992.
16

Strakosch, G.R. (1998), The Vertical Transportation Handbook Third Edition, John Wiley & Sons, Inc., New York, USA.

17

Frantzich, H. (1996), Study of Movement on Stairs During Evacuation Using Video Analysis Techniques, Department of Fire
Safety Engineering, Lund Institute of Technology, Lund University, March 1996.
18

Fruin, J.J. (1987), Pedestrian Planning and Design, Revised Edition, Elevator World, Inc. Mobile, Alabama.

19
Predtechenskii, V.M. and Milinskii, A.I. (1978), Planning for Foot Traffic Flow in Buildings, Amerind Publishing Co. Pvt. Ltd.,
New Delhi, 1978.
20
Nelson, H.E. and Mowrer, F.W. (2002), Section 3, Chapter 14 Emergency Movement, The SFPE Handbook of Fire
Protection Engineering, Third Edition, National Fire Protection Association, Quincy, MA.
21
Nelson, H.E. and MacLennan, H.A. (1995), Section 3, Chapter 14 Emergency Movement, The SFPE Handbook of Fire
Protection Engineering, Second Edition, National Fire Protection Association, Quincy, MA.
22

Caporale, R.S., Elevate Traffic Analysis Software (Eliminating the Guesswork), ELEVATE website:
research.com/elevators/Elevate/Papers/EW%20review/engin.pdf
23

http://www.peters-

Verbal/Email communication: Roger Howkins, ELEVATE; Richard Peters, Peters Research, UK. August 2002.

24
Siikonen, M.-L., Susi, T., and Hakonen, H. (2001) Passenger Traffic Flow Simulation in Tall Buildings, Elevator World, Inc.,
August 2001.
25

Email communication: Marja-Liisa Siikonen, Kone Elevators, Finland. August, November 2002.

26

Bryan, J.L. (1977), Smoke as a Determinant of Human Behavior in Fire Situations (Project People). Final Report, University
of Maryland, College Park, MD, National Bureau of Standards, Gaithersburg, MD, NBS GCR 77-94; 304 p. June 30, 1977.
27
Wood, P.G. (1980), Chapter 6 A Survey of Behaviour in Fires, Fires and Human Behaviour, Canter (ed.), John Wiley &
Sons, Ltd., New York.
28

Quarantelli, E.L. (1975), Panic Behavior in Fire Situations: Findings and a Model From the English Language Research
Literature, Proceedings from the UJNR Panel on Fire Research and Safety, 4th Joint Panel Meeting, February 5-9, 1979,
Tokyo, Japan, 405-428 pp.

29
Jin, T. (1997), Studies on Human Behavior and Tenability in Fire Smoke, Fire Safety Science – Proceedings of the Fifth
International Symposium, International Association for Fire Safety Science, 3-21 pp.
30
Averill, J.D. (1998), Performance-Based Codes: Economics, Documentation, and Design, National Institute of Standards
and Technology, Gaithersburg, MD, NIST-GCR-98-752.

Appendix D
Design of Occupant Egress Systems for Tall Buildings

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Design of Occupant Egress Systems for Tall Buildings
CIB2004 Session Number: HTB T1 Occupant Issues
Authors:
Erica D. Kuligowski
Richard W. Bukowski, P.E., FSFPE
Abstract:
This paper presents a discussion of the features of protected elevator
systems that can provide safe and reliable operation both for fire service access
and for occupant egress during fires. These features include water tolerant
components, fail-safe power, lobbies on each floor designed as areas of refuge,
smoke protection, occupant communications, and real time monitoring of the
elevator position and operating conditions from the fire command center. Egress
simulations are used to quantify the improvements in efficiency that can be
realized by incorporating elevators into the access and egress procedures for tall
buildings. Finally, operational procedures will be discussed for the most
appropriate use of vertically zoned elevator systems that are found in most tall
buildings. These procedures would form the basis for the elevator control
software that needs to be developed for such systems.

1

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5/14/2004

Design of Occupant Egress Systems for Tall Buildings
Erica D. Kuligowski & Richard W. Bukowski, P.E., FSFPE*
National Institute of Standards and Technology
ABSTRACT
This paper presents a discussion of the features of protected elevator systems that can
provide safe and reliable operation both for fire service access and for occupant egress during
fires. These features include water tolerant components, fail-safe power, lobbies on each floor
designed as areas of refuge, smoke protection, occupant communications, and real time
monitoring of the elevator position and operating conditions from the fire command center.
Egress simulations are used to quantify the improvements in efficiency that can be realized by
incorporating elevators into the access and egress procedures for tall buildings. Finally,
operational procedures will be discussed for the most appropriate use of vertically zoned elevator
systems that are found in most tall buildings. These procedures would form the basis for the
elevator control software that needs to be developed for such systems.

INTRODUCTION
The unexpected collapse of the World Trade Center buildings has prompted a reexamination of the way egress systems are designed for tall buildings. Current designs specify a
certain number, width, and spacing of stairs that depend upon the assumed occupant load and
building use. The egress system at each floor is sized for the number of occupants on that floor,
reflecting the assumption that tall buildings will be evacuated by partial or phased evacuation
procedures. In the discussion of the need to design for simultaneous evacuation of tall buildings,
concerns have been raised about the adequacy of relying solely on stairs to move large numbers
of people from significant heights.
These discussions naturally turn to whether the elevators that normally provide vertical
transportation can be designed to supplement the stairways and provide a safe exit route during
fires. It is speculated that if future buildings were required to be designed for simultaneous
evacuation under current egress design practices, there will be a building height beyond which
the stairs would occupy such a large portion of the floor area that such buildings would be
impractical. Despite a 30-year policy in the U.S. codes against the use of elevators in fires, many
experts now feel that elevators can be made safe for occupant egress. Some of the relevant
research was done in the 1980s by NIST in support of egress elevators in air traffic control
towers1,2 where the small footprint prohibits the provision of two, remote stairs. NIST is once
again working with the U.S. codes and standards organizations and the affected industries to
address any remaining technical issues and to develop performance requirements for elevator
egress systems. This paper presents a discussion of the features of protected elevator systems
that can provide safe and reliable operation both for fire service access and for occupant egress
during fires.
CURRENT REQUIREMENTS FOR EMERGENCY USE OF ELEVATORS
All U.S. building codes contain a requirement for accessible elevators as a part of the
means of egress in any building with an accessible floor above the third floor. These

*

E.D. Kuligowski is a fire protection engineer and R.W. Bukowski is a senior research engineer, Building
and Fire Research Laboratory, National Institute of Standards and Technology, Gaithersburg, MD.

2

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5/14/2004

requirements are all identical, being extracted from the ADA Accessibility Guidelines (ADAAG)
and mandated under the Americans with Disabilities Act (ADA).
A recent survey3 by the International Organization for Standardization (ISO) TC178
Committee identified at least twelve countries that require firefighter lifts in tall buildings (generally
those exceeding 30 m (98 ft) in height) to provide for fire department access and to support
operations as well as to evacuate people with disabilities. England has such a requirement
supported by a British Standard (BS 5588 Part 5)4 requiring firefighter lifts in buildings exceeding
18 m (60 ft) in height. Firefighter lifts are also provided in the Petronas Towers, the world’s tallest
buildings in Kuala Lumpur, Malaysia.
The NFPA’s Life Safety Code (NFPA 101)5 includes provisions for egress elevators to be
provided as a secondary means of egress for air traffic control towers where the small footprint
prohibits two, “remote” stairs. However, these are secure facilities not open to the public and with
limited numbers of occupants.
While the above requirements exist for elevators for emergency use by firefighters and
people with disabilities, there are currently no codes or standards in the world for egress
elevators for use by general building occupants. Since 1973, ASME A17.1, the Safety Code for
Elevators and Escalators6, has contained emergency procedures that take the elevators out of
service if smoke is detected in any lobby, in the elevator machine room, or hoistway. Under this
condition the elevators are directed immediately to the ground floor where the doors open and the
elevators are locked out (called Phase I recall). Subsequently, the responding fire department
can reactivate individual cars under manual control using a special key (called Phase II
operation).
Several issues concerning elevator use in emergencies, such as equipment reliability,
communication, control, human behavior, and operational procedures, need to be addressed
before this mode of vertical transportation can be implemented.
FEATURES OF PROTECTED ELEVATORS
Safe and Reliable Equipment7,8
If used in an emergency, an elevator needs to be able to withstand the problems
associated with heat, smoke, and water from a fire. It is important to address issues of water
tolerant elevator parts, fail-safe power, enclosed lobbies on all floors, and smoke protection of the
equipment, hoistway, and lobby.
Because water can come from many different sources, such as sprinkler systems and fire
fighting operations, the elevator must be equipped with water tolerant components. Water can
possibly enter in an elevator shaft and short out safety components such as switches that prevent
the doors from opening unless there is a car present, and even compromise the safety brake.
Elevators can be designed to operate on the outside of buildings, so it is clear that water-tolerant
technology is available and used today.
Another reliability issue is emergency power for the elevators if the main power fails.
Current codes require at least one elevator that serves every floor to be provided with emergency
power. If the power and control wiring is installed within the hoistway the elevator would continue
to operate as long as the hoistway was intact.
To protect occupants from the fire while awaiting the elevator and provide an area of
refuge for people with disabilities, enclosed lobbies should be provided on each floor of the
building. The lobby also protects the hoistway from direct exposure to the fire and smoke that

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might threaten the elevator car moving past the floor of the fire. These lobbies would require at
least 1 hour fire rated, smoke tight enclosures (assuming a fully-sprinklered building).
Elevators would be installed in a smokeproof shaft constructed to a 1 hour fire resistance
and pressurized against smoke infiltration. This would prevent smoke and heat from moving
through the building via the shafts. The elevator lobby would be pressurized to protect it from
smoke and to minimize pressure differences across the hoistway door that can jam the door
mechanism.
Emergency communication7,8
Occupants and firefighters can communicate with the Fire Command Station via two
systems, the emergency phone in the elevator car and a two-way voice communication system
provided in the lobby. This allows the occupants in the lobby to remain informed of the status of
any impending rescue. Further it allows the fire command personnel to understand the number
and situation of the occupants on each floor waiting for the elevators.
Control
The firefighter manually operating the elevator (Phase II operation) knows little about the
fire conditions in other parts of the building, especially the conditions in the elevator machine
room to which the controller is exposed. Using the newly developed fire service interface9,10 it is
possible to provide real-time monitoring of elevator system status and any conditions that may
threaten its continued safe operation. This interface was developed as a tool for incident
management that can collect information from its own sensors and other building systems
(through a common communication protocol such as BACnet) and display the information in a
format common to all manufacturers’ systems. The interface further supports specific control
functions so that the operator could manually initiate recall if any monitored parameters exceed
the allowable operating envelope.
Because continuous monitoring of the system is crucial to safe and reliable operation it
would employ a triple redundant communication pathway. The fire alarm system is currently
required to incorporate two, redundant communication trunks usually run up the two stairways.
Either trunk is sufficient for the full system operation and two-way communication to the entire
building. While these trunks are “remote” it is possible that a single event could sever both
trunks, rendering the portion of the system above the breaks inoperable. By providing a third
wireless link between the bottom (generally the fire command center) and the top of the system,
this should maintain full operation of the system if both trunks fail. This would add little cost, high
reliability, and can be done with current technology. Emergency power could be supplied by
conductors run up the hoistway, so that power is available as long as the hoistway is intact.
EGRESS SIMULATIONS
In order to quantify the increase in efficiency of fire department access and egress via
elevators, two studies were performed. The first involves fire department access to a fire floor in
a high-rise building. The fire department access times using elevators were compared with
access times using stairs. The second case study reviews work done at NIST in the early 90s to
show the benefit of elevators for egress in four GSA buildings11.
Firefighter Lift Case Study
For this case study, the commercial building used was designed by a Dallas architectural
firm and stretches 40 stories above ground with 4 parking levels below. A typical floor of the
building contains approximately 3000 m2 (32,292 ft2) of floor space, with 500 m2 (5382 ft2)

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occupied by the core space. The core contains elevators, 2 stairwells, bathrooms, and
mechanical closets.
The stairs are located diagonally across the core area from each other, each measuring
1.2 m (44 in) wide with 26 7/11 steps per flight. The 7/11 terminology refers the height of the riser
followed by the depth of the tread in inches, meaning that for each step, the riser height is 0.18 m
(7 in) and the tread width is 0.28 m (11 in). The height of each floor is 4.5 m (15 ft), creating a
travel distance of 11 m (36 ft) per flight of stairs, including the landing distance.
The elevators for a commercial building are assumed to have a speed of 5.08 m/s (1000
ft/min), per Table 10.7 of the Vertical Transportation Handbook12, and average acceleration of 1.5
m/s2 (5 ft/s2). For this case study, it is also assumed that a crew of 5 firefighters and their
equipment will be traveling in the elevator and stairs together at one time. There are other
characteristics that were assumed for the elevators that only affect the outcome of this case study
in a trivial manner, such as the full car load, type of door, the door inefficiency, and door closing
time.
For this case study, the fire originates on the 35th floor. Two groups of five firefighters
are analyzed in their attempts to reach floor 35. Group 1 traverses 34 flights of stairs from street
level to floor 35. Group 2 takes the elevators to the 33rd floor and travels the stairs an additional
2 flights. Hand calculations were made for firefighter travel up the stairs, while hand calculations
and the ELVAC model were used to calculate the one-way elevator travel time from the lobby to
the 33rd floor. ELVAC is a model used to calculate gross elevator evacuation time from
buildings, and the hand calculated one-way elevator travel time was used to compare to ELVAC
results.
The travel times calculated for both Groups in this case study neglect firefighter response
time to the building, travel to the elevator or stairs from the building entrance, and time spent on
the floor locating the point of attack, since both need to perform these activities in a fire situation.
To obtain firefighter travel speeds on stairs and horizontal building components,
adjustments were made to data already recorded from people movement studies13,14,15.
Frantzich’s data show a range of velocities for upstairs movement from (0.5 to 0.75) m/s, Fruin
gives values of (0.5 to 0.65) m/s and Predtechenskii and Milinskii state a range of (0.33 to 0.92)
m/s for low density situations. On one hand, these values may be low if studied during
nonemergency situations, but alternatively, firefighters are typically equipped with heavy gear and
equipment, on the order of 25 to 45 kg per firefighter, which should be accounted for.
The primary walking speed used in this case study for firefighter travel up stairs is 0.35
m/s (adjusted from 0.5 m/s13,14,15 for heavy gear). Another velocity used came from the New York
Fire Department’s rule of thumb that states firefighters average 60 seconds per floor
(unobstructed flow), which is not sustainable throughout the ascent of high-rise buildings. 60
seconds per floor will be used as the conservative ascent time and 0.35 m/s will be used as the
other extreme. For horizontal building component speed, again the standard value of 1.2 m/s16
was adjusted to a conservative value of 0.8 m/s for gear and heavy equipment.
The breakdown of the elevator calculations are as follows (multiple values indicate a
range of travel speeds for that calculation):
Group 1:
o The time to traverse 34 flights of stairs = 17 min at 0.35 m/s; 34 min at 60 seconds per
flight (more conservative)
Group 2:
o The one way travel time of the elevator from the lobby to the 33rd floor = 45 s with 5.08
m/s elevator speed

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o

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The horizontal travel time from the elevator to the stairs on the 33rd floor = 30 s at 1.2
m/s; 45 s at 0.8 m/s (more conservative)
The time to traverse two flights of stairs = 60 s at 0.35 m/s; 120 s at 60 seconds per flight
(more conservative)

After performing an additional calculation of adding the elevator travel, horizontal travel,
and stair travel times together for Group 2, the results are as follows:
!" Group 1: 17 to 34 min
!" Group 2: 2.5 to 3.5 min
It may seem obvious that an elevator would give some advantage in speed over stair
use. But, when other factors, such as heavy gear and equipment and increased elevator
technology play a role, elevators substantially become a more viable and constructive option.
The difference between use of stairs (Group 1) and elevators (Group 2) for firefighter ascent
ranged between (15 and 30) min. This is a large difference in time lost to travel by stair,
especially when a fire can grow significantly in a matter of minutes. By using elevators as the
primary means of ascent, Group 2 was able to reach the fire at least 15 min earlier in this case
study. In 15 min, the environment can be less toxic for the occupants, the fire smaller, and the
property less damaged. Also, Group 2 would have more energy to exert on fire fighting activities
on the floor, when compared to Group 1. The limitation associated with the calculations was the
estimation made in the firefighter movement speed, as shown by the range of results in both
Groups.
Elevator Evacuation Study
In the early 90s, four General Services Administration (GSA) buildings were analyzed as
potential applications to incorporate elevator evacuation11. The four selected were chosen to
gather different building heights, elevator capabilities, and architectural characteristics.
For each building, evacuation times were calculated for the following conditions: 1) Total
evacuation of the building by stairs only; 2) Total evacuation of the building by elevators only; and
3) Total evacuation of the building by various distributions of occupants to stairs and elevators
(the optimal time value is shown in Table 1).
For the stair calculations, Klote et al.11 used the people movement methodology laid out
by Nelson and MacLennan17. For these calculations, people on each floor were assumed to be
waiting at the door to the stairs as soon as evacuation begins. For the elevator calculations, the
ELVAC model18 was used which simulates 2-stop elevator trips (movement occurs only between
the specific floor and the ground floor) until the entire building has been evacuated. Again, for
these calculations, people were assumed to be waiting at the closest elevator lobbies as soon as
evacuation began.
Table 1 shows the characteristics of each building, including the number of floors, the
number of stairs and elevators used, and the total population of each building. Also, the table
shows the total evacuation time of the building (minutes) if only stairs were used, the total
evacuation time if only the elevators were used, and the last column shows the optimal (fastest)
gross evacuation time when a combination of stairs and elevators are used. Additionally, the
Hoffman building and the White Flint North Building’s analysis did not use the full capacity of
elevators available to the building. The Hoffman building used 5 out of the 6 elevators in each
group and the White Flint building used 4 out of the 6. This was due to the fact that the existing
elevator lobbies were incapable of holding as many people as would be discharged from all
elevators simultaneously, and in that case, the evacuation capacity of the elevators is restricted
by the size of the lobby.

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Table 1 Summary of GSA buildings and modeling results
Building

Floors

Stairs/
Elevators

Total
Population

Hoffman
White Flint
Jackson
GSA

13
18
36
7

2/ 2 groups of 5
2/ 1 group of 4
2/ 3 rises of 6
6/ 6 groups of 2

3506
1425
3021
3621

Evac.
Time by
Stairs
14.9 min
14.3
23.1
7

Evac.
Time by
Elevators
24.3 min
28.6
16.5
17

Optimal
Time by
Both
11.2 min
12.0
12.8
6.3

In each of the four buildings analyzed, the optimal time was reached by designing for a
combination of floors or percentage of the floor dedicated to elevator usage while the other
portion of the building evacuated by stairs. The use of elevators for evacuation made the largest
contribution for the tallest building, which was the Jackson Federal building equipped with low,
mid, and high rise elevators. The elevator designation that provided the optimal result for this
building was the following: 65 % of occupants from the mid and high rise floors, all occupants
from floors 11 through 14, and only 3 % on floors 1 through 13. All others in the Jackson building
used the stairs. Even though the percentage distributions of occupants to stairs or elevators are
quite detailed and complicated in this example, they are presented in order to show the generality
that more occupants from the higher floors would use the elevator and more occupants from the
lower floors would be distributed to the stairs. In an actual evacuation plan, the distribution of
occupants to certain building components (stairs or elevators) should be more straightforward
and easy to follow.
For the single rise elevator systems in the Hoffman, White Flint, and GSA buildings, the
elevator designation that provided the optimal result was for total elevator evacuation from the
upper floors of the building and stairs from the lower floors. Overall, it was shown that by using a
combination of evacuation systems, stairs and elevators, the total evacuation time of the building
can be reduced by a substantial amount with taller buildings. This study is limited by the
averaged movement calculations used, and the assumption that all occupants were waiting at the
stair or elevator lobbies as soon as the evacuation began. Also, another limitation is that
occupants were not studied using both stairs and elevators during a single evacuation route.
OPERATIONAL PROCEDURES
Prior research and recent advances can address all of the technology issues identified as
critical to the safe and reliable operation of elevators during fires. The remaining piece is the
development of operating procedures for firefighter access, occupant egress, and rescue of the
disabled that are sensitive to human factors issues and the need for these activities to occur
simultaneously in tall buildings. Thus, the systems must be designed and used such that they do
not interfere with all three uses.
Firefighter Lifts
Many US fire departments, Phoenix Fire Department for example19, have adopted
operating procedures for fires in tall buildings that incorporate elevator access that are similar to
those described in a draft CEN/ISO20 standard for firefighter lifts. The primary differences relate
to the fact that most firefighter lifts are dedicated to this use and thus are immediately available to
the fire service on their arrival. In the US, firefighters use passenger elevators that are either still
operating or are waiting at the ground floor in Phase 1 recall.
The procedure is for the firefighters to use the lift to transport people and equipment to
the protected lobby 2-3 floors below the fire floor where they stage for their suppression
operations, as discussed earlier in the firefighter lift case study. The firefighters then move up the
stairway to the fire floor with a standard length of hose (30 m (98 ft) is common in the US and 60

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m (197 ft) in Europe), which is connected to the standpipe located in the stairs. This is important
because once charged with water the hose becomes very stiff. The hose is usually looped down
the stairs and back up so that it can be advanced onto the fire floor more easily. Working from
the stairway also provides a protected area to which the firefighters can retreat in case the fire
threatens them. The common hose lengths dictate the distribution of firefighter lifts within a
building in the same way as the distribution of standpipes. For example, the New York City
building regulations require standpipes located so that one is within 38 m (125 ft) (30.5 m (100 ft)
of hose plus 7.6 m (25 ft) of water throw from the nozzle) of any point on a floor.
This operating procedure highlights the importance and interrelationship of the firefighter
lift, protected lobbies, associated stairway and standpipe. These components form a system
described in BS55882 as a firefighting shaft. The need for an associated stairway impacts on the
arrangement of the components and on the designation of multiple cars of an elevator group as
firefighter lifts.
Occupant Egress Elevators
As mentioned earlier, with only rare exceptions for special cases, elevators are taken out
of service in fires and people are advised not to use elevators during fires. This policy does not
represent a severe hardship for most buildings and occupants, but poses problems for people
with (mobility) disabilities and for tall buildings where stairway egress times can be measured in
hours. Coupled with the recent loss of public confidence in the structural stability of tall buildings
caused by the collapse of the World Trade Center, there are increasing pressures to find ways in
which elevator assisted egress can be provided safely.
Operational procedures for occupant egress elevators raise some interesting issues.
First, the 30-year campaign cautioning the public against the use of elevators in the event of fire
could severely lessen the occupants’ confidence in the elevator system. Also, occupants could
become impatient and overcrowd the elevator, which can cause the car to stop functioning and
remain at the floor indefinitely21. Due to a fundamental lack of understanding of human use of
elevators in emergencies, the time for which occupants will wait at an elevator is also unknown.
Without proper preparation and training, occupants may become fearful of the dangerous
conditions and decide to use the stairs. If the building is designed for a certain distribution of
occupants between stairs and elevators, this could cause congestion in the stairway. It seems
natural to suggest that fire wardens, who understand the capabilities of elevators in such
emergencies, will lead the occupants to safety by following the planned evacuation procedure for
their floor. The evacuation plan of a single rise elevator system could involve, for example, the
use of elevator by the higher floors of the building, stairs by the lower floors, and the fire wardens
on each floor directing his/her occupants to the correct evacuation route11. However, this implies
that the fire wardens are present at the time of the emergency, have the appropriate training, and
that the other occupants will follow their directions. Another concern for the evacuation
procedures is whether or not the elevators attend to the disabled population first before
evacuating other building occupants. This is crucial to understand because if a disabled
occupant resides on a floor designated to take the stairs, the building should be aware of the
occupant’s needs and plan accordingly. Overall, it will be essential to understand the human
behavior of the occupants during their interaction with the elevators. Work has been done in the
human factors engineering and psychology fields about such a concern22,23,24, but much more
work still needs to be completed to update current elevator use and concerns in light of
September 11, 2001. For instance, will social groups within the building stay together throughout
the duration of the evacuation, or will they allow group break-up during elevator descent? This is
crucial because of the possibility of sending elevators without full capacity to the ground floor.
Egress elevators are most likely to be utilized in tall buildings, some with systems that are
vertically zoned in 30- to 40-floor sections. A concern for these tall buildings is how elevator
evacuation would be operated with vertically zoned elevators. One example where this is being
done is for an 88-story building currently under construction in Melbourne, Australia25. In the

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Eureka Place Tower, elevators in the vertical third of the building containing the fire are taken out
of service and occupants all use the stairways to the next (lower) transfer floor where they board
express elevators to grade. People with disabilities are assisted by firefighters in their dedicated
lifts within the zone of origin in order to evacuate the building. This strategy is similar to the
Petronas Towers where occupants above the sky bridge level use stairs to that level, move
across to the other tower, and use the elevators to grade.
Egress Assistance for People with Disabilities26
Standards for firefighter lifts all include their use by firefighters to provide evacuation
assistance for people with disabilities. Even in the US where there are no firefighter lift standards
the building codes require accessible elevators (part of an accessible means of egress) that may
be used by the fire service to evacuate people with disabilities. These elevators are normally
used for travel in nonemergency situations, but may be used by the fire service for disabled
occupant egress if an emergency occurs. The procedures generally are that such occupants
proceed to the protected lobby (sometimes called an area of refuge) and request evacuation
assistance through a two-way communication system (to the fire command center) provided.
Exceptions are provided for fully sprinklered buildings.
Not covered is any procedure for coordinating the use of the lift for evacuation assistance
with that of firefighting. First priority will be given to moving firefighters and equipment to the
staging floor to allow the start of suppression operations. Then a firefighter would presumably be
assigned to begin to collect waiting occupants in the lift under manual control. Command staff in
the fire command center could inform the operator on which floors there are occupants waiting
and these could be gathered in some logical order and taken to the ground floor. If there are
more occupants than can be assisted in a single trip, there is a question about the order in which
they are removed. Presumably, this would be done for the floors nearest the fire first, then above
the fire and finally below the fire. Because these people are required to wait, it is especially
important to provide this two-way communication system to the lobby so that they can be
reassured that assistance is coming. The real-time monitoring system described earlier would
assure that conditions in the occupied lobbies remain tenable.
CONCLUSION
Elevator use in emergency situations can provide safe and reliable operation both for fire
service access and for occupant egress. A combination of reliable features, appropriate
equipment, and effective operational procedures allows for successful evacuation of buildings via
elevators and stairwells.
During a fire situation, the elevator needs to be able to withstand the effects of smoke,
heat, and water. The current elevator technology can successfully perform this duty with the
inclusion of water tolerant elevator parts, fail-safe power, lobbies of all floors, and smoke
protection of the equipment, shaft, and lobby. Also, to aid in the use of elevators for fire
department access and occupant egress, the use of emergency communication and remote
manual control accompanied by continuous monitoring of the fire situation add another level of
safety to elevator use. The Fire Command Station is continuously made aware of the increasing
danger to occupants and the firefighters, and can change their evacuation, rescue, and
firefighting strategies accordingly.
Elevators can make a significant time saving contribution to travel towards the fire for the
fire service and the evacuation of the occupants in the building. The calculations done for the
firefighter case study showed that firefighters traveled to the fire floor 15 min to 30 min faster via
elevators when compared to stair access. The stair travel calculation, using two different
estimates for the firefighter walking speeds, resulted in a range of travel time values differing by a
factor of two. Research is needed in the area of firefighter movement to assess which travel

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times within the calculated range 17 min to 34 min are more accurate. Also, the evacuation time
of occupants using a combination of stair calculations and ELVAC calculations for the elevators
shows improvement over stair or elevator movement alone for the GSA examples studied. This
is especially true for the taller building with multi-rise elevators.
Lastly, operational procedures are crucial in ensuring quick movement to safety for all
occupants and emergency responders in the building. It is key for the occupants to recognize
their main mode of travel (elevator or stairs) and understand the wait times associated. As part of
this, other occupants may have priority, such as the disabled.
With all elements in place, safe and reliable features, operational procedures, and
comfort in using elevators by occupants and firefighters, the use of elevators can provide a faster
and safer route for evacuating a high-rise building.

REFERENCES
1

Klote, J.H, Levin, B.M., and Groner, N.E., “Feasibility of Fire Evacuation by Elevators at FAA
Control Towers,” NISTIR 5445; 110 p. May 1994.
2

Levin, B. M.; Groner, N. E., “Human Factors Considerations for the Potential Use of Elevators for
Fire Evacuation of FAA Air Traffic Control Towers,” NIST GCR 94-656; 23 p. August 1994.
3

Comparison of worldwide lift (elevator) safety standards – Firefighters lifts (elevators), ISO/TR
16765:2002(E), International Organization for Standardization, Geneva, Switzerland, 2002
4

Fire Precautions in the Design, Construction, and Use of Buildings, BS 5588 Part 5 1991, Code
of Practice for Firefighting Lifts and Stairs, BSI, London

5

Life Safety Code (NFPA 101) 2000, Nat Fire Prot Assn, Quincy, MA 02269

6

Safety Code for Elevators and Escalators, ASME A17.1-2000, Amer Soc Mech Eng, NY, 2000

7

Klote, J.H., Levin, B.M., and Groner, N.E., “Emergency Elevator Evacuation Systems,” Fire and
Accessibility, 2nd Symposium, Proceedings, April 19,21, 1995, American Society of Mechanical
Engineers, New York, NY, 131-150 pp., 1995.
8

Chapman, E.F., “Elevator Design for the 21st Century: Design Criteria for Elevators When Used
as the Primary Means of Evacuation During Fire Emergencies. American Society of Mechanical
Engineers (ASME); Elevators, Fire and Accessibility, 2nd Symposium, Proceedings, April 19-21,
1995, New York, NY, 157-162 pp., 1995.

9

Bukowski, R. W. Development of a Standardized Fire Service Interface for Fire Alarm Systems.
National Institute of Standards and Technology, Gaithersburg, MD Fire Protection Engineering,
4,6-8, SFPE Bethesda, MD, Spring 2000.
10

National Fire Alarm Code (NFPA 72) 2002, Nat Fire Prot Assn, Quincy, MA 02269, “Section
7.10 “Standard Fire Service Interface.”
11

Klote, J.H., Alvord, D.M., Levin, B.M., and Groner, N.E. (1992), Feasibility and Design
Considerations of Emergency Evacuation by Elevators, National Institute of Standards and
Technology, Gaithersburg, MD, NISTIR 4870.

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12

Strakosch, G.R. (1998), The Vertical Transportation Handbook Third Edition, John Wiley &
Sons, Inc., New York, USA.

13

Frantzich, H. (1996), Study of Movement on Stairs During Evacuation Using Video Analysis
Techniques, Department of Fire Safety Engineering, Lund Institute of Technology, Lund
University, March 1996.
14

Fruin, J.J. (1987), Pedestrian Planning and Design, Revised Edition, Elevator World, Inc.
Mobile, Alabama.
15

Predtechenskii, V.M. and Milinskii, A.I. (1978), Planning for Foot Traffic Flow in Buildings,
Amerind Publishing Co. Pvt. Ltd., New Delhi, 1978.
16

Nelson, H.E. and Mowrer, F.W. (2002), Section 3, Chapter 14 Emergency Movement, The
SFPE Handbook of Fire Protection Engineering, Third Edition, National Fire Protection
Association, Quincy, MA.
17

Nelson, H.E. and MacLennan, H.A. (1995), Section 3, Chapter 14 Emergency Movement, The
SFPE Handbook of Fire Protection Engineering, Second Edition, National Fire Protection
Association, Quincy, MA.
18

Klote, J.H. (1993), A Method of Calculation of Elevator Evacuation Time, National Institute of
Standards and Technology, Gaithersburg, MD, Journal of Fire Protection Engineering, 5(3), 1993,
pp. 83-95.
19

Phoenix Fire Department Standard Operating Procedures, http://phoenix.gov/FIRE/20205.html.

20

Safety rules for the construction and installation of lifts – Part 72:Firefighter lifts, CEN TC10,
Committee for European Standardization, Brussels, BE.
21

Klote, J.H., Deal, S.P., Donoghue, E.A., Levin, B.M., and Groner, N.E. (1993), Fire Evacuation
By Elevators, Elevator World, June 1993.
22

Levin, B.M, and Groner, N.E. (1995), Some Control and Communication Considerations in
Designing an Emergency Elevator Evacuation System, Proceedings of the 2nd Symposium on
Elevators, Fire, and Accessibility, Baltimore, MD, April, 1995.
23

Groner, N.E. (1995), Selecting Strategies for Elevator Evacuations, Proceedings of the 2nd
Symposium on Elevators, Fire, and Accessibility, Baltimore, MD, April, 1995.
24

Groner, N.E. and Levin, B.M. (1992), Human Factors Considerations in the Potential for Using
Elevators in Building Emergency Evacuation Plans, George Mason University, Washington, DC,
July 1992.
25

Aloi, S. and Rogers, J. (2002), Reach for the Sky, Fire Prevention & Fire Engineers Journal,
Vol. 62, No. 219, FPA London, April 2002.
26

FEMA & USFA, “Emergency Procedures for Employees with Disabilities in Office Occupancies,”
United States Fire Administration, Emmitsburg, Maryland, National Institute of Standards and
Technology, Gaithersburg, MD, National Task Force on
Life Safety and People with Disabilities, YR.

11

Appendix E
Hazards Due To Smoke Migration Through Elevator
Shafts -Volume I: Analysis And Discussion

NIST GCR 04-864-I

Hazards Due to Smoke Migration
Through Elevator Shafts – Volume I:
Analysis and Discussion. Final Report
John H. Klote
John H. Klote, Inc.
43262 Meadowood Court
Leesburg, VA 20176

NIST GCR 04-864-I

Hazards Due to Smoke Migration
Through Elevator Shafts – Volume I:
Analysis and Discussion. Final Report
Prepared for
U.S. Department of Commerce
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899-8664
By
John H. Klote
John H. Klote, Inc.
43262 Meadowood Court
Leesburg, VA 20176

June 2004

U.S. Department of Commerce
Donald L. Evans, Secretary
Technology Administration
Phillip J. Bond, Under Secretary for Technology
National Institute of Standards and Technology
Arden L. Bement, Jr., Director

Notice
This report was prepared for the Building and Fire Research Laboratory
of the National Institute of Standards and Technology under Contract number
SB134-03-W-0477. The statement and conclusions contained in this report
are those of the authors and do not necessarily reflect the views of the
National Institute of Standards and Technology or the Building and Fire
Research Laboratory.

ii

Table of Contents
Abstract ........................................................................................................................................... 1
1. Introduction................................................................................................................................. 1
2. Scenarios ..................................................................................................................................... 2
3. Buildings ..................................................................................................................................... 2
3.1 Fire Type............................................................................................................................... 2
3.2 Fire Floors............................................................................................................................. 3
3.3 Building Flow Paths.............................................................................................................. 3
3.4 Weather ................................................................................................................................. 3
3.5 Building Temperature ........................................................................................................... 3
3.6 Methods for Reduction of Hoistway Smoke Flow ............................................................... 4
3.6.1 Enclosed Elevator Lobbies ............................................................................................ 4
3.6.2 Temporary Barriers........................................................................................................ 4
3.6.3 Positioning Of Elevator Cars ......................................................................................... 4
3.7 Arrangement of Doors .......................................................................................................... 4
3.8 Windows ............................................................................................................................... 4
4. Analysis of Scenarios.................................................................................................................. 4
4.1 Smoke Transport................................................................................................................... 5
4.3 People Movement ................................................................................................................. 5
4.4 Tenability .............................................................................................................................. 5
4.4.1 Visibility ........................................................................................................................ 5
4.4.2 Exposure to Toxic Gases ............................................................................................... 6
4.4.3 Exposure to Heat............................................................................................................ 7
5. Discussion of Results.................................................................................................................. 7
5.1 Fire Types ............................................................................................................................. 7
5.2 Temperature .......................................................................................................................... 7
5.3 Methods of Reducing Smoke Flow through Hoistways ....................................................... 7
5.3.1 Enclosed Elevator Lobbies ............................................................................................ 7
5.3.2 Automatic Roll Down Barriers ...................................................................................... 8
5.3.3 Positioning Of Elevator Cars ......................................................................................... 8
5.4 Outside Temperature............................................................................................................. 8
6. Future Research .......................................................................................................................... 8
7. Summary & Conclusions ............................................................................................................ 9
8. References................................................................................................................................... 9
Appendix A – Fires....................................................................................................................... 22
Appendix B – Fuel Properties....................................................................................................... 28
Appendix C – Wind ...................................................................................................................... 30

ii

List of Figures
Figure 1. Typical Floor Plan of Building A.................................................................................. 15
Figure 2. Typical Floor Plan of Buildings B and C ...................................................................... 15
Figure 3. Elevator Layout for Building D..................................................................................... 16
Figure 4. Ground Floor Plan of Building D.................................................................................. 17
Figure 5. Elevator Layout for Building E ..................................................................................... 18
Figure 6. Ground Floor Plan of Building E .................................................................................. 19
Figure 7. HRR Curves of Fires Used in This Project ................................................................... 20
Figure 8. Thermal Tolerance of Naked Humans at Rest With Low Air Movement..................... 21

List of Tables
Table 1.
Table 2.
Table 3.
Table 4.

List of Scenarios ............................................................................................................ 12
List of Buildings ............................................................................................................ 12
Building Flow Areas...................................................................................................... 13
Calculated Time (minutes) to Reach Tenability Specific Limits .................................. 14

iii

Hazards Due To Smoke Migration Through Elevator
Shafts – Volume I: Analysis

Abstract
During building fires, smoke often migrates through elevator hoistways to locations remote from the fire.
One of the reasons for concern is that a closed elevator door has a leakage area of approximately 0.056
square meters (0.6 square feet). This is a report of a project to study the hazards due to smoke flow
through elevator hoistways. Smoke flow and the resulting hazard to life are analyzed for 27 scenarios in 5
buildings ranging from 6 to 58 stories. A fire scenario is the outline of events and conditions that are
critical to determining the outcome of alternate situations and designs. In addition to the fire location and
heat release rate, the fire scenario includes the status of the doors and other building systems. Other
factors addressed are outside temperature, wind, height of elevator hoistway, height of building, leakage
paths in the building, leakage of elevator doors, and other shafts. Stairwells are also included. Both
sprinklered and non-sprinklered fires are included. Smoke transport throughout the buildings was
simulated by a combination of zone fire modeling and network modeling. Options considered for
mitigating hazards due to smoke flow through hoistways include (1) the use of enclosed elevator lobbies
with automatic closing doors, (2) temporary barriers and (3) judicious positioning of cars within the
hoistway. The results of the calculations showed that the use of enclosed elevator lobbies increased the
time to reach hazard criteria significantly as compared the results without such lobbies. The use of
automatic roll down barriers tended to increase the time to reach hazard criteria to some extent. The use
of judicious positioning of elevator cars had no effect on the time to reach hazard criteria.

1. Introduction
During a building fire, smoke can travel through building shafts to threaten life at locations remote from
the fire. The focus of this project is smoke movement through elevator shafts, and methods that might be
used to reduce the resulting hazard to life.
After September 11, 2001, many people have indicated a need to reexamine basic concepts and consider
major failure modes. While less extreme fires are also considered in this project, the focus is on the
effects of a unsprinklered fire that involves an entire floor of a building. These large unsprinklered fires
can have durations measured in hours. Because almost all modern buildings are sprinklered, this
unsprinklered fire is a failure mode that could be due to a variety of causes (inadequate or no water
supply, failure of a sprinkler system component, fire overpowering the sprinklers, arson, and terrorism).
In the absence of comprehensive sprinkler performance data for the United States, a sprinkler failure rate
between 1% and 4% may be considered1.
This project looks at the hazard to life due to smoke migration through elevator hoistways and the
effectiveness of methods to reduce that hazard. These methods are: (1) enclosed elevator lobbies, (2)
temporary barriers directly in front of elevator doors and (3) judicious positioning of elevator cars. Some
of the parameters considered for this project are fire size, fire location, outside temperature and wind.
1

Hasemi (1985) indicates sprinkler success rates in Japan of 98% for well maintained systems and 96% for poorly maintained
systems. For Australia and New Zealand, Marryatt (1988) indicates a sprinkler success rate of 99% or greater for most
occupancies.

1

The time scale for large building fires often consists of a number of hours (Routley, Jennings and Chubb,
1991; Nelson, 1987, 1989; Best and Demers, 1982). Accordingly, the duration of the simulations for this
project are two hours.
This report of this project is in two volumes. The first volume presents the analysis and discusses the
results of that analysis. The second volume (Klote, 2003) consists of the complete results of the tenability
calculations. The calculations of this project are for office buildings, but they may have application to
other occupancies.

2. Scenarios
It is not possible to analyze all the scenarios of the relevant parameters, and a rational analysis is used for
selection of scenarios. This rational approach is based on an understanding of how stack effect, buoyancy
and wind effect force smoke flow in buildings.
1. When it is cold outside, stack effect (also called normal stack effect) results in upward airflow in
building shafts. When a fire is below the neutral plane, normal stack effect can also drive smoke
upward through shafts to floors above the neutral plane.
2. When it is hot outside, reverse stack effect results in downward airflow in shafts. For a fire above the
neutral plane, reverse stack effect might result in downward smoke flow in shafts.
3. When hot smoke enters a shaft, the elevated temperature of the smoke increases the intensity of
normal stack effect.
4. When hot smoke enters a shaft, the elevated temperature of the smoke decreases the intensity of
reverse stack effect.
5. When all the building windows are closed, wind forces have a minimum effect on building smoke
flow.
6. When the one or more fire room windows are open and the wind direction is toward the open
windows, wind forces have a significant effect on building smoke flow.
The points above were kept in mind in development of the scenario list of Table 1.

3. Buildings
The buildings have a number of things in common. All of the buildings are office buildings. The floor to
floor height is 4.0 m (13.1 ft) except for the ground floor which is 6 m (19.7 ft). The buildings have
basements that house mechanical equipment. See Table 2 for a list of the buildings with information
about the elevators. Figures 1 to 6 are schematics of the buildings.

3.1 Fire Type
This project used the following fires: (1) sprinklered fire, (2) room fire, and (3) floor fire. Details of these
fires are provided in Appendix A, and the heat release rates (HRR) of these fires are shown in Figure 7.
The sprinklered fire is representative of what might be expected of an office workstation fire that was
successfully suppressed by a sprinkler system. The room fire can be thought of as a conference room with
furniture and some storage materials in cardboard boxes. After ignition, the room fire grows until the
room is fully involved in fire.
The floor fire can be thought of as starting in an open floor plan office space. Early in the fire
development, windows start breaking. After this, the fire is considered to be controlled by the amount of
ventilation air through the broken windows. On an occupied floor, it might be expected that the occupants

2

would take action to prevent the fire from becoming so big. For any number of reasons, a floor might not
be occupied during a fire, and development of such a fire becomes more likely.

3.2 Fire Floors
The fire locations for this project are on the second floor and the top occupied floor of the building. These
fire locations were chosen to be above the neutral plane and below the neutral plane to allow for the
effects of normal and reverse stack effect.

3.3 Building Flow Paths
Building leakage consists of: (1) construction gaps and cracks in walls, partitions and floors, (2) gaps
around closed doors, and (3) large openings such as open doors and windows. The values of flow paths
used for this project are listed in Table 3.
The leakage values of walls and floors are representative of values that can be expected for tight building
construction as discussed by Klote and Milke (2002) and NFPA 92A (2000). It is generally recognized
that the vent at the top of elevator shafts has an impact on airflow and smoke flow in buildings.
Traditionally, these elevator vents have been required by codes, and the value of the vents used in this
project are listed in Table 3.
The effects of door deflection due to exposure to high temperature gases are not included in the leakage
values. While some data on warping of fire doors during furnace tests is provided by VanGeyn (1994), it
is believed that there is insufficient information for estimation of the leakage of warped doors in this
project.
Failure of compartmentation would require complex and time consuming analysis that is beyond the
scope of this project. Such failure would be expected at some locations in buildings subjected to a fully
developed fire that involved a large space such as one or more floors. It is anticipated that such
compartmentation failure would result in increases in hazard to life. Even without compartmentation
failure, the analysis of this project provides limited information about the hazard at locations remote from
the fire and provides information about the relative effectiveness of various methods to reduce hazards
due to smoke flow through hoistways.

3.4 Weather
The temperatures and wind velocities for many locations in the United States and other countries are
listed in the ASHRAE Handbook of Fundamentals (ASHRAE 2001). The values of design temperature
and wind speed vary over a wide range for these locations. The values of weather data chosen for this
project were chosen such that they could occur at many locations in the United States. These values are:
Winter Outdoor Temperature

–16!C (3!F)

Summer Outdoor Temperature

35!C (95!F)

Wind Speed

11 m/s (25 mph)

3.5 Building Temperature
Generally, an HVAC system maintains the interior of a building in the range of about 21!C to 24!C (70!F
to 76!F). For airflow and smoke flow in buildings, an important factor is the difference between the
building temperature and that of the outdoors. For this project, the building temperature is the same as
that of the shafts, and this building temperature is arbitrarily selected as 23!C (73!F ).

3

3.6 Methods for Reduction of Hoistway Smoke Flow
The following potential methods to reduce the smoke flow through hoistways are considered.
3.6.1 Enclosed Elevator Lobbies
Enclosed elevator lobbies consist of walls, doors, floors and ceilings that form a continuous barrier on all
sides of an elevator lobby. It is the intent that the doors would automatically close in the event of a fire.
3.6.2 Temporary Barriers
Two types of temporary barriers can be considered: (1) automatic accordion barriers that form an
enclosed elevator lobby and (2) automatic roll down barriers located directly in front of the elevator
doors. For this project, it is considered that the accordion barriers have a fire resistance such that they
would be expected to remain in place for some time when exposed to a fully developed fire. For this
reason, the results of the simulations with conventional enclosed lobbies can be thought of as indicative of
what would happen with enclosed lobbies formed with automatic accordion barriers.
The automatic roll down barriers would be installed above each elevator door such that they would roll
down in the event of a fire. It is anticipated that such doors would be activated along with elevator recall.
For this project, it is considered that the roll down barriers have a fire resistance such that they would be
expected to remain in place when exposed to a fully developed fire.
The roll down doors of this project should be thought of as products that could possibly be developed and
not as commercially available products. The flow area around the roll down doors (Table 3) used for this
project was based on engineering judgment of what the leakage could be for such a door in an existing
building.
3.6.3 Positioning Of Elevator Cars
The idea of judicious positioning of elevator cars is to locate the elevator cars in the hoistway at a floor
above the fire floor to provide added resistance to smoke flow to floors above the elevator cars. This
approach has the drawback that cars fixed in this position cannot be used mobilization or rescue by the
fire service. However, this project addresses only the smoke restricting potential of the judicious
positioning approach. When the judicious positioning approach is used, it is considered that all elevator
cars will be at the floor above the fire floor. The leakage areas for judicious positioning of elevator cars
(Table 3, Shafts with Cars in Place) are based on hoistway and other dimensions from NEII (1983).

3.7 Arrangement of Doors
For this project, it is considered that the stairwell doors and exterior building doors are closed.

3.8 Windows
For this project, the windows are considered closed except for fully developed floor fire where the fire
breaks widows as discussed in Appendix A.

4. Analysis of Scenarios
The method of analysis can be considered a hazard analysis that evaluates the hazard to life for each
scenario. Generally hazard analysis consists of (1) smoke transport calculations, (2) people movement
(fire evacuation) calculations and (3) tenability calculations. For reasons discussed below, the analyses of
this project do not include people movement calculations.

4

4.1 Smoke Transport
The method of analysis of this project has been used for a number of applications. Ferreira (1998, 2002)
describes use of this method for design applications, and Hadjisophocleous, Fu and Lougheed (2002) use
this method as part of a study of smoke flow in a stair shaft. Klote (2002a) used the method to evaluate
the hazard due to various combinations of open stairwell doors. Klote (2002b) and Klote and Milke
(2002) also provide information about use of this method.
The smoke transport calculations were done by a combination of CONTAMW (Walton 1997; Dols,
Denton and Walton 2000) and CFAST (Peacock, et al. 1993). The approach is to use CFAST to simulate
the fire and flow of combustion products to adjacent spaces, and to use CONTAMW for unsteady flow of
combustion products throughout the building. Numeric realities limit CFAST simulations to a relatively
small number of rooms. However, CONTAMW can be used to simulate flows in buildings of hundreds
and possibly thousands of rooms and other spaces.
CONTAMW is a network airflow program that can simulate contaminant flow. The model was developed
for indoor air quality, but it has been extensively used for smoke management applications. CONTAMW
solves the continuity of mass equation for a network that represents a building, and it can solve the
concentration equations to calculate the concentration of one or more contaminants that flow through the
network. For fire applications, the major shortcoming of CONTAMW is that it has no energy equation so
it is unable to calculate the temperature of the spaces in the building. The temperature used in
CONTAMW simulations are based on the results of CFAST simulations for spaces near the fire.
CONTAMW Version 2 was used to allow the use of unsteady temperatures.
CFAST is a two zone fire model. In such a model, the gases in a room are represented two zones: (1) an
upper layer of hot smoke and (2) a lower layer of relatively uncontaminated air. In the fire room, a smoke
plume rises above the fire and flows into the upper layer. Also, smoke can flow from one room to another.

4.3 People Movement
The hazard of exposure to toxic gases depends on the exposure time. Fire evacuation calculations or
simulations of people movement can be used to predict exposure times. A more conservative alternative
is to consider the safety of people with mobility limitations who would need to stay in one place for the
duration of the fire. For this project, this alternative is used with a 30 minute fire duration.

4.4 Tenability
The proprietary computer program, SMOKE4, was used for this project to make the fractional effective
dose (FED) and visibility calculations described in this section. The FED is a used to predict the toxic
effect of exposure to combustion gases. Tenability calculations consist of evaluating visibility and the
effects of exposure to toxic gases and heat. While lack of visibility does not in itself result in fatality, it
disorients people, and this interferes with evacuation and prolongs exposure time. Exposure to heat can
either be direct exposure to hot gases or exposure to radiant flux, but exposure to hot gases is the primary
form of heat exposure for the scenarios of this project.
4.4.1 Visibility
For any instant, the visibility can be calculated from

Si "

K
2.303! mCi

where
Si = visibility at the end of interval i, m (ft);
K = proportionality constant (8 for illuminated signs, and 2 for non-illuminated signs);

5

!m
Ci

= mass optical density, m2/g (ft2/lb);
= concentration of material burned in interval i, g/m3 (lb/ft3).

The mass optical density depends on the material burned and combustion conditions (flaming or
pyrolysis). Mulholland (2002) provides optical densities of a number of materials, and these values range
from 0.12 m2/g (590 ft2/lb) to 1.4 m2/g (6800 ft2/lb). It is well known that flaming combustion of
polyurethane produces a dense black smoke, and this smoke has a mass optical density of 0.33 m2/g (1600
ft2/lb). For this project, the mass optical density was chosen as 0.33 m2/g (1600 ft2/lb).
For this project, the following visibility limits were considered: (1) 8 m (25 ft), (2) 15 m (49 ft), and (3)
30 m (98 ft). A visibility of 15m (49 ft) or of 30 m (98 ft) would not be expected to interfere with people
movement in the buildings of this project, but people would probably be aware that there is some smoke.
However, it is expected that a visibility of 8 m (25 ft) or less would hinder evacuation. For this paper,
smoke with a visibility of 8 m (25 ft) or less is referred to as obscuring smoke or smoke that obscures
vision.
4.4.2 Exposure to Toxic Gases
The methods that can be used to evaluate the effect of exposure to toxic gases are (1) the fractional
incapacitating dose, (2) the N-gas model, and (3) the fractional effective dose (FED). Klote and Milke
(2002) provide a detailed discussion of these methods. These methods are typically based on data from
exposure times of 20 minutes, and they can be used be used to predict the toxic effects of exposures for
somewhat different times. The exposure times of this project are 2 hours. The mathematical formulation
of the first two methods is such that the predictions with this exposure time are of questionable value.
However, the FED has a simple form that leads the author to believe that predictions using the FED for
this exposure time can be applied for this project.
The mass concentration of material burned, Ci, was obtained from CONTAMW. The FED can be used to
obtain an approximation of the effects of exposure to toxic gases.
n

FED =
where
FED
Ci
#t
LCt50

$ C #t
i "1

i

LCt 50

= fractional effective dose at the end of interval i (dimensionless);
= concentration of material burned at interval i, g/m3 (lb/ft3);
= time interval, min (min);
= lethal exposure dose from test data, g m-3 min (lb ft-3 min).

This equation is written here for uniform time intervals as were produced by CONTAMW, and it
evaluates the FED for the exposure time at the end of interval i (exposure time is n#t). An FED greater
than or equal to one indicates fatality. The concentration is in mass of the material burned per unit
volume. A FED of 0.5 can be considered a rough indication of incapacitation. For this project, the
following terms are used as follows:
Tenable:
Incapacitating:
Untenable:

FED < 0.5
0.5 < FED < 1
FED > 1

FED less than 0.5.
FED equal to or greater than 0.5 and less than 1.
FED equal to or greater than 1.

The LC50 is the concentration of airborne combustion products that is lethal to 50% of the subjects
exposed for a specified time. The lethal exposure dose, LCt50, is the product of the LC50 and the exposure
time. See Appendix B for the values of lethal exposure dose used in this project.

6

4.4.3 Exposure to Heat
Generally contact with dry air of temperatures greater than 121!C (250!F) can be expected to result in skin
burns. Also, contact with dry air at a temperature less than approximately 121!C (250!F) leads to
hyperthermia. Figure 8 shows the data of Blockley (1973) for the thermal tolerance of naked humans at rest
with low air movement. The thermal tolerance depends on moisture. For humid conditions, it can be seen
that for a 15 minute exposure the tolerance is about 88!C (190!F), and for a 30 minute exposure the
tolerance is about 60!C (140!F).

5. Discussion of Results
The results of the tenability calculations are listed in Volume II of this report, and these results are
summarized in Table 4.

5.1 Fire Types
As expected, the sprinklered fire (scenario 1) did not result in any significant threat away from region of
the fire. The fully developed room fires (scenarios 2, 18–21) were not a very significant threat at locations
remote from the fire room.
The fully developed floor fires (scenarios 3–17, 22–27) resulted in significant threats at floors remote
from the fire floor. For these fires, the time to reach smoke obscuration on floors remote from the fire
ranged from 24 minutes to 100 minutes. While these times are long, they are representative of the times
involved with some major multiple death fires.

5.2 Temperature
The temperatures calculated by CFAST are shown in Appendix A. At some distance from the fire, the
smoke temperature drops to such an extent that it is not a concern. Because this project focuses on smoke
flow through the hoistways, temperature exposure is only a minor issue. Further, the temperatures
resulting from the sprinklered fire are not a concern. For the room fire, the fire room rapidly becomes
untenable (Figure A1), and the open plan office space on the fire floor remains tenable for some time
(Figure A2). For the floor fire, the temperature rises rapidly so that the floor quickly becomes untenable
(Figure A3). However, the temperature in the enclosed elevator lobby remains tenable throughout the fire
(Figure A5).

5.3 Methods of Reducing Smoke Flow through Hoistways
5.3.1 Enclosed Elevator Lobbies
Many of the scenarios included enclosed elevator lobbies (EEL on Table 1). The use of such lobbies,
extends the time to obscuring smoke and untenable conditions on floors away from the fire. This can be
shown in a number of scenarios. For example, scenarios 9 and 10 are the same except that scenario 9 has
enclosed elevator lobbies, and scenario 10 does not (Table 4). It can be seen that with enclosed elevator
lobbies, the time to obscuring smoke on the top floor increases from 31 to 66 minutes. Further, without
enclosed elevator lobbies, the top floor becomes untenable in 56 minutes, and with elevator lobbies it
does not become untenable during the 120 minute simulation.
For the scenarios with floor fires, the pairs of scenarios listed below are with and without enclosed
elevator lobbies. It can be seen that with enclosed elevator lobbies the time to smoke obscuration
increases significantly.
Scenarios

Increase in Time to Smoke Obscuration on Top
Floor Due to Enclosed Elevator Lobbies

7

3, 4
5, 6
9, 10
14, 15
24, 25

158%
193%
113%
48%
52%

5.3.2 Automatic Roll Down Barriers
A number of scenarios included automatic roll down barriers (TB on Table 1). For the scenarios with
floor fires, the pairs of scenarios listed below are with and without automatic roll down barriers.
Scenarios
6, 7
10, 12
15, 16
25, 26

Increase in Time to Smoke Obscuration on Top
Floor Due to Automatic Roll Down Barriers
0%
13%
20%
19%

It can be seen that with automatic roll down barriers, the time to smoke obscuration increases only
slightly. The predicted performance of these roll down barriers is highly dependant on the leakage of such
barriers, and roll down barriers with less leakage than used in this project would be expected to perform
better.
5.3.3 Positioning Of Elevator Cars
A number of scenarios included positioning of elevator cars (JPC on Table 1). For the scenarios with floor
fires, the pairs of scenarios listed below are with and without positioning of elevator cars.
Scenarios
6, 8
10, 13
15, 17
25, 27

Increase in Time to Smoke Obscuration on Top
Floor Due to Automatic Roll Down Barriers
0%
0%
0%
0%

It can be seen that with positioning of elevator cars, the time to smoke obscuration remains unchanged
from that without enclosed elevator lobbies.

5.4 Outside Temperature
All the scenarios discussed so far have been with the winter outside temperature. Scenarios 22 and 23 are
with the summer outside temperature. As expected for these scenarios, the fire was on the top occupied
floor, and there was little smoke flow to floors below.

6. Future Research
As already stated, this study did not include compartmentation failure. Future research is needed to
evaluate the extent to which compartmentation failure would impact smoke flow through elevator
hoistways.
The method of analysis used for this project used two computer models (CFAST and CONTAMW) as
described earlier. This approach is cumbersome, time consuming, and yields questionable results for
scenarios involving reverse stack effect. Research is needed to develop a fire model capable of simulating
smoke flow and temperatures throughout high rise buildings.

8

7. Summary & Conclusions
The intent of this project is to study the hazard to life due to smoke migration through elevator hoistways
and the effectiveness of various methods to reduce that hazard.
While compartmentation failure is beyond the scope of this project, such failure would be expected at
some locations in buildings subjected to a fully developed fire that involved a large space such as one or
more floors. It is anticipated that such compartmentation failure would result in increases in hazard to life.
Even without compartmentation failure, the analysis of this project provides limited information about the
hazard at locations remote from the fire and provides information about of the relative effectiveness of
various methods to reduce hazards due to smoke flow through hoistways.
For the buildings and conditions analyzed, the following conclusions are made.
(1)

The fully developed floor fires resulted in significant threats at floors remote from the fire
floor. For these fires, the time to reach smoke obscuration on floors remote from the fire
ranged from 24 minutes to 100 minutes. While these times are long, they are representative of
the times involved with some major multiple death fires.

(2)

Smoke from successfully sprinklered fires did not result in hazard conditions at floors away
from the fire floor.

(3)

The use of enclosed elevator lobbies increased the time to reach hazard criteria significantly
(from 52% to 193%) in comparison with analysis without such lobbies.

(4)

The use of automatic roll down barriers tended to increase the time to reach hazard criteria
(from 0% to 20%) in comparison with analysis without such barriers. If tighter roll down
barriers had been used for the analysis of this project, it is expected that they would have
performed better.

(5)

The use of judicious positioning of elevator cars had no effect on the time to reach hazard
criteria.

8. References
ASHRAE 2001. Handbook of Fundamentals, American Society of Heating, Refrigerating and AirConditioning Engineers, Atlanta, GA.
Aynsley, R. M. 1989. The Estimation of Wind Pressures at Ventilation Inlets and Outlets on Buildings,
ASHRAE Transactions, Vol. 95, Part 2, pp. 707-721.
Best, R. and Demers, D. P. 1982. Investigation Report on the MGM Grand Hotel Fire - Las Vegas,
Nevada, November 21, 1980, National Fire Protection Association, Quincy, MA.
Blockley, W. V. 1973. Biology Data Book, Federation of American Societies for Experimental Biology,
Bethesda, MD.
Dols, W. S., Denton, K. R. and Walton, G. N. 2000. CONTAMW User Manual, National Institute of
Standards and Technology, Gaithersburg, MD.
Dyrbye, C. and Hansen, S. O. 1997. Wind Loads on Structures, Wiley, New York, NY.
Evans, D. D. and Stroup, D. W. 1986. Methods to Calculate the Response Time of Heat and Smoke
Detectors Installed Below Large Unobstructed Ceilings, Fire Technology, Vol. 22, No. 1, pp. 54-65.
Evans, D. D., Stroup, D. W. and Martin, P. 1986. Evaluating Thermal Fire Detection Systems (SI Units),
NBSSP 713, National Bureau of Standards, Gaithersburg, MD.

9

Ferreira, M.J. 1998. Analysis of Smoke Control System Design Using a Computer-based Airflow
Analysis, Pacific Rim Conference, Society of Fire Protection Engineers, Bethesda, MD.
Ferreira, M.J. 2002. Use of Multi-Zone Modeling for High-Rise Smoke Control Design, ASHRAE
Transactions, Vol. 108, Part 2.
Hadjisophocleous, G. V., Fu, Z. and Lougheed, G. D. 2002. Computational and Experimental Study of
Smoke Flow in the Stair Shaft of a 10-Story Tower, ASHRAE Transactions, Vol. 108, Part 1.
Hasemi, Y. 1985. Analysis of Failures of Automatic Sprinklers in Actual Fires, UJNR Panel on Fire
Research and Safety, 8th Joint Meeting May 13-21, 1985. Tsukuba, Japan, pp 794-807.
Heskestad, G. 1984. Engineering Relations for Fire Plumes, Fire Safety Journal, Vol. 7, No. 1, pp. 25-32.
Kandola, B. S. 1986a. Comparison of Wind Tunnel Pressure Measurements and Smoke Movement
Computer Predictions Inside a Five-Story Model building, Fire Safety Journal, Vol. 10, No. 3, pp. 229238.
Kandola, B. S. 1986b. The Effects of Simulated Pressure and Outside Wind on the Internal Pressure
Distribution in a Five-Story Building, Fire Safety Journal, Vol. 10, No. 3, pp. 211-227.
Kandola, B. S. 1986c. A Wind Tunnel Building Model for the Investigation of Smoke Movement
Problems, Fire Safety Journal, Vol. 10, No. 3, pp. 203-209.
Klote, J. H. 1995. Design of Smoke Control Systems for Elevator Fire Evacuation Including Wind
Effects, 2nd Symposium on Elevators, Fire, and Accessibility, Baltimore, MD April 19-21, 1995, ASME,
New York.
Klote, J. H. 2002a. Tenability and Open Doors in Pressurized Stairwells – Final Report, ASHRAE 1203TRP, ASHRAE, Atlanta, GA.
Klote, J. H. 2002b. Smoke Management Applications of CONTAM. ASHRAE Transactions, Vol. 108,
Part 2.
Klote, J. H. 2003. Hazards Due to Smoke Migration through Elevator Shafts – Vol. II: Results of
Tenability Calculations, John H. Klote, Inc., Leesburg, VA.
Klote, J. H. and Milke, J. A. 2002. Principles of Smoke Management, ASHRAE, Atlanta, GA.
Liu, H. 1991. Wind Engineering – A Handbook for Structural Engineers, Prentice Hall, Englewood, NJ.
MacDonald, A. J. 1975. Wind Loading on Buildings, Wiley, New York, NY.
Madrzykowski, D. 1996. Office Work Station Heat Release Rate Study: Full Scale vs. Bench Scale, 7th
International Interflam Conference, March 26-28, 1996, Cambridge, England. Proceedings. pp 47-55.
Madrzykowski, D. and Vittori, R. L. 1992. A Sprinkler Fire Suppression Algorithm, Journal of Fire
Protection Engineering, Vol. 4, No. 4, pp. 151-164.
Marryatt, H. W. 1988. Fire – A Century of Automatic Sprinkler Protection in Australia and New Zealand
1986 – 1986, Australian Fire Protection Association, North Melbourne, Australia.
Mulholland, G. 2002. Smoke Production and Properties, SFPE Handbook of Fire Protection Engineering,
National Fire Protection Association, Quincy, MA.
Nelson, H. E. 1987. An Engineering Analysis of the Early Stages of Fire Development - The Fire at the
Dupont Plaza Hotel and Casino - December 31, 1986, National Institute of Standards and Technology,
NISTIR 87-3560.
Nelson, H. E. 1989. An Engineering View of the Fire May 4, 1988 in the First Interstate Bank Building,
Los Angeles, California, National Institute of Standards and Technology, NISTIR 89-4061.

10

NEII, 1983. Vertical Transportation Standards: Standards for Elevators, Escalators and Dumbwaiters,
National Elevator Industry, Inc., New York, NY.
NFPA 2000. Recommended Practice for Smoke Control Systems, NFPA 92A, National Fire Protection
Association, Quincy, MA.
Peacock, R. D., et al., 1993. CFAST, the Consolidated Model of Fire Growth and Smoke Transport,
National Institute of Standards and Technology, NIST Technical Note 1299.
Purser, D. A. 2002. Toxicity Assessment of Combustion Products, SFPE Handbook of Fire Protection
Engineering, National Fire Protection Association, Quincy, MA.
Routley, G., Jennings, C. and Chubb, M. 1991. High-rise Office Building Fire - One Meridian Plaza,
Technical Report, United States Fire Administration.
Shaw, C. T. and Tamura, G. T. 1977. The Calculation of Air Infiltration Rates Caused by Wind and Stack
Action for Tall Buildings, ASHRAE Transactions, Vol. 83, Part 2, pp. 145-158.
Simiu, E. and Scanlan, R. H. 1996. Wind Effects on Structures: Fundamentals and Application to Design,
3rd Ed., Wiley, New York, NY.
Tamanini, F. 1976. The Application of Water Sprays to the Extinguishment of Crib Fires, Combustion
Science and Technology, Vol. 14, pp. 17-23.
VanGeyn, M. 1994. National Fire Door Fire Test Project. Positive Pressure Furnace Fire Tests.
Technical Report. National Fire Protection Research Foundation, Quincy, MA, Report 6285, 201 p.
Walton, G. N. 1997. CONTAM96 User Manual, NISTIR 6056, National Institute of Standards and
Technology, Gaithersburg, MD.

11

Table 1. List of Scenarios
Scenario
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27

Building1
A
A
A
A
B
B
B
B
C
C
C
C
C
D
D
D
D
D
D
D
D
D
D
E
E
E
E

Fire
Type2
SP
FDR
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDR
FDR
FDR
FDR
FDF
FDF
FDF
FDF
FDF
FDF

Fire
Floor3
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
36
36
2
2
2
2

Enclosed
Elev. Lobby
Y
Y
Y
N
Y
N
N
N
Y
N
N
N
N
Y
N
N
N
Y
N
N
N
Y
N
Y
N
N
N

Weather4
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-W
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
S-NW
S-NW
W-NW
W-NW
W-NW
W-NW

1

Alternative
Methods5
None
None
None
None
None
None
TB
JPC
None
None
None
TB
JPC
None
None
TB
JPC
None
None
TB
JPC
None
None
None
None
TB
JPC

See Table 2.
SP is a sprinklered fire. FDR is a fully developed room fire. FDF for fully developed floor fire.
3
FDR fires are located in a conference room on the floor indicated, and FDF fires are located in the open floor plan
space on that floor.
4
W-NW for winter with no wind. S-NW for summer with no wind. W-NW winter with no wind. W-W winter with
wind.
5
TB for temporary barriers over elevator car doors. JPC for judicious positioning of cars within hoistways.
2

Table 2. List of Buildings
Building
A
B
C
D

Number of
Stories*
6
13
16
35

Passenger Elevators
1 Bank of 3 Elevators
1 Bank of 6 Elevators
1 Bank of 6 Elevators
3 Banks of 6 Elevators: Low,
Medium & High Rise
E
58
3 Banks of 8 Elevators: Low,
Medium & High Rise
*
Does not include mechanical penthouse.

12

Service
Elevator
None
None
None
2
2

Table 3. Building Flow Areas
Component
Exterior Wall
Exterior Wall Below Grade5
Interior Wall
Elevator Wall
Floor
Roof5
Closed Doors:
Single Door
Double Door
Elevator Doors6
Large Elevator Doors7
Open Doors:
Single Door
Double Door
Shaft Equivalent Area8:
Stairwell
3 Car Passenger Elevator
4 Car Passenger Elevator
2 Car Service Elevator
Open Elevator Vent9:
3 Car Passenger Elevator
4 Car Passenger Elevator
2 Car Service Elevator
Roll Down Barriers
Shafts with Cars in Place:
3 Car Passenger Elevator
4 Car Passenger Elevator

Path
Type1
O
O
O
O
O
O

Path
Identifier2
W-EXT
W-UG
W-INT
W-EL
FLOOR
ROOF

Area4
m /m2 (ft2/ft2)
0.00017
0.000085
0.00011
0.00084
0.000052
0.000026

Flow
Coefficient3
0.65
0.65
0.65
0.65
0.65
0.65

2

T
T
T
T

DR-SI
DR-DO
DR-EL42
DR-EL48

0.65
0.65
0.65
0.65

m2
0.016
0.027
0.047
0.049

T
T

DR-SI-O
DR-DO-O

0.35
0.35

1.95
3.90

21
42

O
O
O
O

STAIR
EL-P3
EL-P4
EL-S2

0.60
0.60
0.06
0.60

2.3
230
360
160

25
2500
3900
1700

O
O
O
T

EL-P3V
EL-P4V
EL-S2V
ROLL

0.32
0.32
0.32
0.65

0.70
1.05
0.52
0.011

7.5
11.3
5.6
0.12

O
O

EL-P3C
EL-P4C

0.65
0.65

6.5
9.1

70
98

1

ft2
0.17
0.29
0.50
0.53

O indicates an orifice path for which flow is in one direction. T indicates a two-directional flow path. The two-directional flow is
used for doors, and the leakage is uniformly distributed over the height of the door.
2
The path identifiers are used with CONTAMW for data input.
3
The flow coefficient is defined as m A-1/2 (2 ! "p)-1/2 where m is the mass flow through the path, ! is the density of gas flowing
in the path, and "p is the pressure difference across the path.
4
Areas for walls and floors are listed as area of flow path per unit of area of wall or of floor as appropriate.
5
Due to lack of experimental data, the flow areas of the exterior wall below grade and the roof were estimated at half that of the
exterior wall and the floor respectively.
6
This elevator door is 1.07 m (3.5 ft) wide. It is used for all passenger elevators of this study except for Building E.
7
This elevator door is 1.22 m (4.0 ft) wide. It is used for the passenger elevators of Building E and the service elevators.
8
Shaft equivalent areas are used to calculate the pressure losses due to friction in shafts. For more information, see chapter 6 of
Klote and Milke(2002).
9
Vent area was calculated at 3.5% of the shaft area but not less than 0.28 m2 (3 ft2).

13

Table 4. Calculated Time (minutes) to Reach Tenability Specific Limits

Scenario1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27

Building
A
A
A
A
B
B
B
B
C
C
C
C
C
D
D
D
D
D
D
D
D
D
D
E
E
E
E

Fire Floor2
Visibility FED
5
–
–
–
1
6
1
6
1
6
1
6
1
6
1
6
1
6
1
6
1
6
1
6
1
6
1
6
1
6
1
6
1
6
–
–
–
–
–
–
–
–
1
6
1
6
1
6
1
6
1
6
1
6

Top Floor of
Low Rise2,3
Visibility
FED
–
–
–
–
62
–
24
49
88
–
30
56
30
55
30
56
66
–
31
56
40
79
35
63
31
56
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
89
–
–
–
–
–
–
–
–
–
–
–

1

Top Floor of
Mid Rise2,4
Visibility
FED
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
52
86
48
82
49
80
48
82
–
–
–
–
–
–
–
–
–
–
–
–
55
92
48
85
51
85
48
85

Top Floor of
High Rise2,5
Visibility
FED
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
74
–
50
89
60
100
50
89
–
–
20
40
28
54
20
40
1
6
1
6
73
–
48
85
57
98
48
85

For descriptions of the scenarios and locations of the fire floor, see Table 1.
The tenability limits used for this project are visibility of 8 m (25 ft) and an FED of 1 in the open plan office space of the floor
indicated.
3
Buildings A, B and C have only one elevator rise, and data listed for these buildings is for the top occupied floor. For Building D,
the top occupied floor of the low rise is for floor 13. For Building E, the top occupied floor of the low rise is for floor 23.
4
For Building D, the top occupied floor of the mid rise is for floor 25. For Building E, the top occupied floor of the mid rise is for
floor 42.
5
For Building D, the top occupied floor of the high rise is for floor 35. For Building E, the top occupied floor of the high rise is for
floor 58.
2

14

Figure 1. Typical Floor Plan of Building A

Figure 2. Typical Floor Plan of Buildings B and C

15

Figure 3. Elevator Layout for Building D

16

Figure 4. Ground Floor Plan of Building D

17

Figure 5. Elevator Layout for Building E

18

Figure 6. Ground Floor Plan of Building E

19

Figure 7. HRR Curves of Fires Used in This Project

20

Figure 8. Thermal Tolerance of Naked Humans at Rest With Low Air Movement

21

Appendix A – Fires
The fires considered for this analysis are: (1) sprinklered fire, (2) fully developed room fire, and (3) fully
developed floor fire. These fires are discussed below.

Sprinklered Fire
Sprinklered fires generally proceed through an incubation period of slow and uneven growth followed by
a period of established growth. Established growth is often represented by an idealized parabolic equation
(Heskestad 1984).

Q! = ! t 2

(A.1)

where

Q!

t

= heat release rate of fire, kW (Btu/s);
= fire growth coefficient, kW/s2 (Btu/s3);
= time after ignition, s.

Fires following this equation are called t-squared fires. It is generally recognized that consideration of the
incubation period is not necessary for design of smoke management systems, and where t is considered the
time from effective ignition. In the CFAST zone fire model, the following SI version of the above equation
is used to aid data input2

"t
Q! $ 1000 %
% tg
'

#
&&
(

2

(A.2)

where

Q!

t
tg

= heat release rate of fire, kW;
= time after effective ignition, s;
= growth time, s.

When t = tg, the above equation gives a value of Q! = 1000 kW. The growth times used in CFAST are:
Growth Type
Slow
Medium
Fast
Ultra Fast

tg (s)
600
300
150
75

Madrzykowski (1996) conducted a series of fire tests of office workstations. The growth type that is
closest to that of these workstation fires is medium growth with a growth time, tg, of 300s. For this study,
the sprinklered fire will have a growth stage of a medium t-squared fire.
For this study, the HRR is considered to decrease after sprinkler activation. This HRR decay after sprinkler
actuation can be expressed as

Q! $ Q! act e * (t *tact ) /)
2

(A.3)

! $ 1000(t / t ) 2 which
NFPA 92B (2000) and some other sources have a similar equation in English units: Q
g

! = 1000 Btu/s when t = tg.
gives Q
22

where

Q!
Q! act

t
tact

!

= post sprinkler actuation HRR, kW (Btu/s);
= HRR at sprinkler actuation, kW (Btu/s);
= time from ignition, s (s);
= time of sprinkler actuation, s (s);
= time constant of fire suppression, s (s).

For a number of fuel packages likely to be found in offices, Madrzykowski and Vettori (1992) conducted
sprinklered fire experiments with a spray density of 0.10 gpm/ft2 (0.07 mm/s) of water. They determined
that a fire decay curve with a time constant of 435 s had a higher HRR than most of the sprinklered fires.
Evans (1993) used this data and data for wood crib fires with sprinkler spray densities of 0.06 gpm/ft2
(0.041 mm/s) and 0.097 gpm/ft2 (0.066 mm/s) from Tamanini (1976) to develop the following correlation

!"

C!
w1.85

(A.4)

where
w
= spray density, gpm/ft2 (mm/s);
= 6.15 (3.0).
C!
While equation (A.4) has not been experimentally verified, it does allow us to adjust the decay time for
sprinkler densities other than those of Madrzykowski and Vettori.
Sprinkler actuation depends on gas temperature and velocity near the sprinkler. In a fire a jet of hot gases
flows radially from where the smoke plume intersects the ceiling. The response time index (RTI) was
developed as a measure of sprinkler responsiveness that is independent of velocity. The RTI of standard
sprinklers range from about 77 to 155 m1/2 s1/2 (140 to 280 ft1/2 s1/2), and the RTI of quick-response
sprinklers (QRS) range from about 28 to 55 m1/2 s1/2 (50 to 100 ft1/2 s1/2).
Several computer programs have been developed that use correlations for such a ceiling jet and the RTI to
predict actuation time. The program DETACT-QS (Evans and Stroup 1986) assumes that the thermal
device is located in a relatively large area, that only the ceiling jet heats the device and there is no heating
from the accumulated hot gases in the room. The required program inputs are the height of the ceiling
above the fuel, the distance of the thermal device from the axis of the fire, the actuation temperature of
the thermal device, the response time index (RTI) for the device, and the rate of heat release of the fire.
The program outputs are the ceiling gas temperature and the device temperature both as a function of time
and the time required for device actuation. DETACT-T2 (Evans, Stroup and Martin 1986) is similar to
DETACT-QS except it is specifically for t-squared fires. Several zone fire models are capable of
calculating ceiling jet temperatures and predicting actuation, and the CFAST model was used to calculate
activation time for this project.
For estimation of activation time in this study, a sprinkler with an RTI of 155 m1/2 s1/2 (280 ft1/2 s1/2) was in
a 10 m (33 ft) square room with a ceiling height of 2.8 m (9.2 ft). The fire growth was the medium tsquared curve mentioned above. The sprinkler was located under the ceiling and 2.1 m (7 ft) horizontally
from the center line of the smoke plume. CFAST predicted an activation time of about 252 s at 706 kW
(670 Btu/s). For calculation of decay after sprinkler activation, a time constant of 435 s was used.

Conference Room Fire
This is an unsprinklered fire that is limited to a conference room that was used for storage. The conference
room includes materials in corrugated cardboard boxes and a number of pieces of upholstered furniture.
Because some upholstered furniture burns like an ultra fast fire, the ultra fast growth type was used for the
early stage of this fire until the room flashed over. Flashover is a transition from a locally isolated fire to a
room totally involved in fire. This transition only takes a few seconds.

23

After flashover the airflow through this window controls the HRR, and this HRR can be expressed as a
function of the door opening to the room

Q! ! Cvc Aw H w1/ 2

(A.5)

where

Q!

= heat release rate of fire, kW (Btu/s);
= area of ventilation opening, m2 (ft2);
= height of ventilation opening, m (ft);
= 1260 (61.2).

Aw
Hw
Cvc

The door opening is 0.914 m (3 ft) wide by 2.13 m (7 ft) high. From equation (A.5), the heat release rate
of the fully developed fire is 3590 kW (3400 Btu/s).
To get temperatures to use in CONTAMW, a CFAST simulation was made of the fire in the conference
room and open office space on the fire floor. The conference room is 3.2 m (10.5 ft) by 4.3 m (14.1 ft).
This indicated that flashover occurred at 133 s. The temperatures are shown in Figures A1 and A2.

Temperature (C)

1500

1000

Upper Layer

500

Lower Layer
Average
0
0

600

1200

1800

2400

3000

3600

Time (s)

Figure A1. CFAST simulated temperatures of the conference room

24

4200

150

HRR (kW)

125
100
Upper Layer
75

Lower Layer
Average

50
25
0
0

600

1200

1800

2400

3000

3600

4200

Time (s)

Figure A2. CFAST simulated temperatures of the open office area on the fire floor

The average temperatures shown in Figures A1 and A2 are weighted averages, and they were
calculated from
Tav #
where
Tav
Tu
Tl
H
Z

Tu ( H ! Z ) " Tl Z
H

(A.6)

= weighted average temperature,
= upper layer temperature,
= lower layer temperature,
= floor to ceiling height,
= smoke layer interface.

Open Office Plan Fire
For the buildings of this study, the gross floor area is in the range of 1900 m2 (20,400 ft2) to 2040 m2
(22,000 ft2). For these calculations, the net floor area of open office space is taken as 1670 m2 (18,000
ft2), and the area of the windows is taken as 364 m2 (3920 ft2). One fully developed floor fire was used for
these buildings.
The HHR calculations are based on the assumption that as the fire breaks the windows open, the fire is
ventilation controlled as described by equation (A.5). At 600 s after ignition, the fire starts breaking
windows, and this continues until all the windows are broken at 1550 s. At 600 s, the area of broken
window is 2.26 m2 (24.3 ft2), and at 1550 s all of the windows are broken with a HRR of 680,000 kW
(645,000 Btu/s). On an area basis, the maximum HRR is 407 kW/m2 (35.8 Btu/s ft2). Based on
Madrzykowski’s work (1996), workstation fires can support this level of fire.
The growth stage of the fire was approximated by a t-square fire that grows to 680,000 kW (645,000
Btu/s) in 1550 s. From equation A1, the fire growth coefficient is 0.283 kW/s2 (0.268 Btu/s3).
After the windows are broken, the fire continues to burn at this rate for 1 hour. The workstations burned
by Madrzykowski do not have sufficient fuel to support this fire for such a time. However, such a fire

25

could be supported by other fuel in the office space such as bookcases with books, boxes filled with
paper, file cabinets filled with records and rolls of drawings. The decay phase of the fire is from 3600 s to
7200 s, and a time constant of 435 s was used for decay.
Because of restrictions on data input, CFAST version 3.1.7 could not be used to simulate a fire with such
a large HRR. For this reason, a scaled down version of the fire had to be simulated by CFAST to obtain
the temperatures for use in the CONTAMW simulations. CFAST simulations were made of the floor fire
with (1) an elevator shaft and no enclosed elevator lobby and (2) an enclosed elevator lobby. The
temperatures from these CFAST simulations are listed in Figures A.3 to A.5. The average temperatures
were calculated as before.

Temperature (C)

2000

1500

1000

Upper Layer
Lower Layer
Average

500

0
0

600

1200

1800

2400

3000

3600

Time (s)

Figure A3. CFAST simulated temperatures of open office area

26

4200

Temperature (C)

200

150

100

50

0
0

600

1200

1800

2400

3000

3600

4200

Time (s)

Figure A4. CFAST simulated temperature of the elevator shaft without an enclosed lobby

140
Temperature (C)

120
100

Upper Layer

80

Lower Layer

60

Average

40
20
0
0

600 1200 1800 2400 3000 3600 4200
Time (s)

Figure A5. CFAST simulated temperatures of the enclosed elevator lobby

27

Appendix B – Fuel Properties
The chemical heat of combustion of the mixture of two fuels can be calculated as

!H ch " f1!H ch1 # f 2 !H ch 2 ,

(B.1)

and the mass optical density the mixture of two fuels can be calculated as

$ m " f1$ m1 # f 2$ m 2

(B.2)

where
!Hch

= chemical heat of combustion of the mixture (kJ/kg),

!Hch1

= chemical heat of combustion of component 1 (kJ/kg),

!Hch2

= chemical heat of combustion of component 2 (kJ/kg),

$m,

= mass optical density of the mixture (m2/g),

$m1

= mass optical density of component 1 (m2/g),

$m2

= mass optical density of component 2 (m2/g),

f1

= mass fraction of component 1 (dimensionless),

f2

= mass fraction of component 2 (dimensionless).

The lethal exposure dose, LCt50, of the mixture can be expressed as

LCt50 " f1LCt50,1 # f 2 LCt50,2

(B.3)

where LCt 50is the lethal exposure dose from test data (Table A1).
Table A1. Approximate Lethal Exposure Dose, LCt50, for Common Materials (adapted from
Purser 2002)
Nonflaming Fire
Material
lb ft-3 min g m-3 min
Cellulosics
0.046
730
C, H, O plastics
0.031
500
PVC
0.031
500
Wool/Nylon (low N2)
0.031
500
Flexible Polyurethane
0.042
680
Rigid Polyurethane
0.0039
63
1
Modacrylic/PAN
0.010
160
1
PAN is polyacrylonitrile.

Fuel Controlled Fire
lb ft-3 min g m-3 min
0.19
3120
0.075
1200
0.019
300
0.057
920
0.087
1390
0.0062
100
0.0087
140

Fully Developed Fire
lb ft-3 min g m-3 min
0.047
750
0.033
530
0.012
200
0.0044
70
0.012
200
0.0034
54
0.0028
45

Cellulosic materials (wood, paper, cardboard, etc.) are very common fuels in building fires. They often
burn in combination with some amount of polymers. For these calculations the mixture used is 75%
cellulosic material and 25% polyurethane foam. The properties are listed below.

28

Chemical Heat of

Mass Optical

Component

Mass Fraction

Combustion (kJ/kg)

Density (m2/g)

Cellulosic Material

0.75

13,000

0.28

Polyurethane Foam

0.25

17,600

0.33

Properties of the mixture are

!H ch " f1!H ch1 # f 2 !H ch 2 " (.75)(13, 000) # (.25)(17, 600) " 14,150 kJ/kg

$ m " f1$ m1 # f 2$ m 2 " (.75)(0.28) # (.25)(0.33) " 0.29 m2/g
For a fuel controlled fire, the lethal exposure dose of the fuel mixture is

LCt50 " f1LCt50,1 # f 2 LCt50,2 " (.75)(3120) # (.25)(1390) " 2690 g m-3 min .
For a fully developed fire, the lethal exposure dose of the fuel mixture is

LCt50 " f1LCt50,1 # f 2 LCt50,2 " (.75)(750) # (.25)(200) " 612 g m-3 min .
Mass Consumption
The mass of fuel consumed in a fire is

m! "

Q!
!H ch

(B.4)

where

m!
Q!

= mass of fuel consumed (kg/s),
= heat release rate (kW).

The peak values of HRR and mass consumption are listed below for the fires of this project.
Peak HRR (kW)
Sprinklered Fire
Conference Room Fire

Open Office Plan Fire

Peak Mass Consumption (kg/s)

706

0.050

3,590

0.254

680,000

48.1

29

Appendix C – Wind
For information about wind and smoke management, readers are referred to Kandola (1986a, 1986b) and
Klote (1995). For additional information about wind pressures on buildings see Aynsley (1989), Shaw
and Tamura (1977) and Kandola (1986c). Several civil engineering texts provide useful information about
wind engineering, for example Dyrbye and Hansen (1997); Liu (1991), MacDonald (1975) and Simiu and
Scanlan (1996).
The wind velocity at the top of a building wall is

"! #
U H $ U met % met &
' H met (
where
UH
Umet
Hmet
H

! met
!

amet
a

amet

"H#
% &
'! (

a

(C.1)

= wind velocity at the top of the wall, m/s (fpm);
= measured wind velocity, m/s (fpm);
= height of wind measurement, m (ft);
= upwind height of the wall, m (ft);
= boundary layer height in the vicinity of the wind anemometer, m (ft);
= boundary layer height in the vicinity of the building, m (ft);
= wind exponent in the vicinity of the wind anemometer, dimensionless;
= wind exponent in the vicinity of the building, dimensionless.

General values of boundary layer height, ! , are listed the ASHRAE Handbook of Fundamentals. The
weather service measures wind data at airports and other locations typically at 10 m (33 ft) above the
ground. For this project, the wind values are calculated as if the building was located in urban or suburban
terrain with wooded areas or other similar obstructions.
The pressure that the wind exerts on a wall can be expressed as

pw $

1
2
K wChCw ) oU met
2

(C.2)

where

"! #
Ch $ % met &
' H met (
Cw
)o
Kw

2 amet

2a

"H#
% & (dimensionless);
'! (

(C.3)

= wind coefficient (dimensionless);
= density of outside air, kg/m3 (lb/ft3);
= 1.00 (0.0129).

For this project, the values of the above parameters are:

! met
!
amet
a
Hmet
H
Umet

)o

270 m (900 ft)
370 m (1200 ft)
0.14
0.22
10 m (33 ft)
67 m (220 ft) Building C
11 m/s (25 mph)
1.37 kg/m3 (0.0855 lb/ft3) at –16 *C (3 *F)

30

From equations (C.1) and (C.3), values of UH and Ch are listed below.
Umet
m/s
11

Building
C

Umet
mph
25

UH
m/s
12

UH
mph
27

Ch
1.19

Average values of Cw can be obtained from Klote and Milke (2002) depending on values of h/w and l/w,
where h = height to parapit, l = length, and w = width. h/w is 1.9 and l/w is 1.5 for Building C.
Average Values of Cw for Building C:
Wind Angle, !
0
90

A
0.8
-.0.8

B
-0.25
-0.8

C
-0.8
0.8

D
-0.8
-0.25

The wind angle is used in Klote and Milke and is illustrated in Figure C.1.

Figure C.1 Wind Angle.
For a wind angle of zero, the wind pressure is:
A
Pa
79

B
in. H2O
0.31

Pa
-25

C
in. H2O
-0.10

Pa
-79

31

D
in. H2O
-0.31

Pa
-79

in. H2O
-0.31

Appendix F
Hazards Due to Smoke Migration Through Elevator
Shafts. Volume 2. Results of Tenability Calculations

NIST GCR 04-864-II

Hazards Due to Smoke Migration
Through Elevator Shafts – Volume II:
Results of Tenability Calculations.
Final Report
John H. Klote
John H. Klote, Inc.
43262 Meadowood Court
Leesburg, VA 20176

NIST GCR 04-864-II

Hazards Due to Smoke Migration
Through Elevator Shafts – Volume II:
Results of Tenability Calculations.
Final Report
Prepared for
U.S. Department of Commerce
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899-8664
By
John H. Klote
John H. Klote, Inc.
43262 Meadowood Court
Leesburg, VA 20176

June 2004

U.S. Department of Commerce
Donald L. Evans, Secretary
Technology Administration
Phillip J. Bond, Under Secretary for Technology
National Institute of Standards and Technology
Arden L. Bement, Jr., Director

Notice
This report was prepared for the Building and Fire Research Laboratory
of the National Institute of Standards and Technology under Contract number
SB134-03-W-0477. The statements and conclusions contained in this report
are those of the authors and do not necessarily reflect the views of the
National Institute of Standards and Technology or the Building and Fire
Research Laboratory.

ii

i

Table of Contents
1. Introduction................................................................................................................................. 1
2. Key to Tables .............................................................................................................................. 1
3. References................................................................................................................................... 1

List of Tables
Table 01.
Table 02.
Table 03.
Table 04.
Table 05.
Table 06.
Table 07.
Table 08.
Table 09.
Table 10.
Table 11.
Table 12.
Table 13.
Table 14.
Table 15.
Table 16.
Table 17.
Table 18.
Table 19.
Table 20.
Table 21.
Table 22.
Table 23.
Table 24.
Table 25.
Table 26.
Table 27.

Results of Tenability Analysis for Scenario 01. ............................................................ 2
Results of Tenability Analysis for Scenario 02. ............................................................ 3
Results of Tenability Analysis for Scenario 03. ............................................................ 4
Results of Tenability Analysis for Scenario 04. ............................................................ 5
Results of Tenability Analysis for Scenario 05. ............................................................ 6
Results of Tenability Analysis for Scenario 06. ............................................................ 8
Results of Tenability Analysis for Scenario 07. .......................................................... 10
Results of Tenability Analysis for Scenario 08. .......................................................... 12
Results of Tenability Analysis for Scenario 09. .......................................................... 14
Results of Tenability Analysis for Scenario 10. .......................................................... 16
Results of Tenability Analysis for Scenario 11. .......................................................... 18
Results of Tenability Analysis for Scenario 12. .......................................................... 20
Results of Tenability Analysis for Scenario 13. .......................................................... 23
Results of Tenability Analysis for Scenario 14. .......................................................... 25
Results of Tenability Analysis for Scenario 15. .......................................................... 35
Results of Tenability Analysis for Scenario 16. .......................................................... 45
Results of Tenability Analysis for Scenario 17. .......................................................... 55
Results of Tenability Analysis for Scenario 18. .......................................................... 65
Results of Tenability Analysis for Scenario 19. .......................................................... 68
Results of Tenability Analysis for Scenario 20. .......................................................... 73
Results of Tenability Analysis for Scenario 21. .......................................................... 79
Results of Tenability Analysis for Scenario 22. .......................................................... 84
Results of Tenability Analysis for Scenario 23. .......................................................... 92
Results of Tenability Analysis for Scenario 24. .......................................................... 93
Results of Tenability Analysis for Scenario 25. ........................................................ 108
Results of Tenability Analysis for Scenario 26. ........................................................ 123
Results of Tenability Analysis for Scenario 27. ........................................................ 138

ii

Hazards Due To Smoke Migration Through Elevator
Shafts – Volume II: Results of Tenability Calculations
1. Introduction
This project looks at the hazard to life due to smoke migration through elevator hoistways and the
effectiveness of methods to reduce that hazard. This report of this project is in two volumes. The first
volume presents the analysis and discusses the results of that analysis (Klote, 2003). The second volume
consists of the complete results of the tenability calculations. The results of the tenability calculations are
listed in Tables 1 through 27.

2. Key to Tables
CONTAMW limits the length of names of zones (or rooms) to 4 characters. The following symbols are
used in the zone names of this project.
EL
ELME
EL-S
LOBY
L-SR
MECH
OPEN
SW
T

Elevator
Elevator Mechanical Room
Service Elevator
Passenger Elevator Lobby
Service Elevator Lobby
Mechanical Space
Open Plan Office Space
Stairwell
Toilet

3. Reference
Klote, J. H. 2003. Hazards Due to Smoke Migration through Elevator Shafts – Vol. I: Analysis and
Discussion, John H. Klote, Inc., Leesburg, VA.

1

Table 01.

Level

Results of Tenability Analysis for Scenario 01.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

2
2
2
2
2

OPEN
LOBY
EL01
SW2
SW1

2.9
11.3
22.6
30.9
11.7

3.9
17.0
52.1
****
18.8

5.6
28.6
****
****
43.9

****
****
****
****
****

****
****
****
****
****

2
3
3
3
4

TO-2
EL01
SW2
SW1
EL01

45.0
32.5
46.8
25.7
41.6

86.6
87.1
****
41.8
****

****
****
****
****
****

****
****
****
****
****

****
****
****
****
****

4
4
5
5
5

SW2
SW1
EL01
SW2
SW1

64.6
41.5
49.7
88.9
56.0

****
70.4
****
****
93.0

****
****
****
****
****

****
****
****
****
****

****
****
****
****
****

6
6
R
R

EL01
SW1
SW1
EL1

56.5
71.8
98.5
56.6

****
****
****
****

****
****
****
****

****
****
****
****

****
****
****
****

2

Table 02.

Level

Results of Tenability Analysis for Scenario 02.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

2
2
2
2
2

LOBY
EL01
TO-1
SW2
C-Rm

6.3
17.8
1.0
5.4
1.0

8.6
24.0
1.0
7.5
1.0

12.0
33.0
1.0
10.7
1.0

47.1
97.5
3.6
48.0
0.0

61.4
****
4.9
65.6
0.0

3
3
3
3
4

LOBY
EL01
TO-1
SW2
LOBY

69.0
23.3
8.5
10.5
98.4

99.9
30.6
11.7
13.6
****

****
41.2
16.3
18.0
****

****
****
54.8
58.1
****

****
****
69.9
76.6
****

4
4
4
5
5

EL01
TO-1
SW2
LOBY
EL01

28.0
87.6
16.9
111.8
32.1

36.2
****
21.1
****
40.9

48.1
****
26.6
****
54.0

****
****
69.5
****
****

****
****
89.1
****
****

5
6
6
R

SW2
EL01
SW2
EL1

25.6
35.5
39.2
35.6

30.9
44.8
46.3
44.9

37.8
58.7
55.3
58.9

84.2
****
****
****

****
****
****
****

3

Table 03.

Level

Results of Tenability Analysis for Scenario 03.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

G
G
2
2
2

LOBY
EL01
OPEN
LOBY
EL01

15.8
24.9
1.0
1.0
1.8

18.3
27.9
1.0
1.0
2.2

21.0
31.4
1.0
1.6
2.9

41.0
58.6
4.9
8.1
11.3

47.0
67.8
6.2
9.8
13.3

2
2
3
3
3

SW1
TO-2
LOBY
EL01
SW1

2.2
5.1
14.3
2.8
6.0

2.9
6.6
16.7
3.6
7.3

3.8
8.2
19.3
4.4
8.9

14.4
22.0
37.8
13.6
21.5

16.7
24.9
43.1
15.7
24.0

4
4
5
5
6

EL01
SW1
EL01
SW1
OPEN

4.0
10.8
5.2
15.9
51.4

4.8
12.6
6.1
17.9
56.4

5.8
14.6
7.2
19.9
62.2

15.7
27.7
17.6
33.4
****

17.9
30.3
19.9
36.2
****

6
6
6
6
R

LOBY
EL01
SW1
TO-2
SW1

75.6
6.4
21.0
47.7
27.2

84.5
7.4
23.0
52.0
29.2

96.3
8.6
25.0
57.1
31.4

****
19.4
39.1
92.7
47.1

****
21.6
42.3
****
50.8

R

EL1

6.5

7.5

8.7

19.4

21.7

4

Table 04.

Level

Results of Tenability Analysis for Scenario 04.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

2
2
2
2
3

OPEN
EL01
SW1
TO-2
OPEN

1.0
1.0
2.5
6.0
12.3

1.0
1.1
3.2
7.7
14.7

1.0
1.7
4.2
9.6
17.4

4.9
9.0
15.2
23.9
36.5

6.2
11.0
17.5
26.9
42.1

3
3
3
4
4

EL01
SW1
TO-2
OPEN
EL01

1.6
6.5
35.6
76.0
2.1

1.9
7.9
40.9
98.3
2.8

2.6
9.5
47.6
****
3.5

10.9
22.3
90.4
****
12.5

13.0
24.8
****
****
14.6

4
5
5
5
5

SW1
OPEN
EL01
SW1
TO-2

11.9
61.5
2.9
17.7
55.4

13.7
69.1
3.6
19.7
61.6

15.7
80.3
4.4
21.7
69.2

29.0
****
13.8
35.4
****

31.6
****
16.0
38.4
****

6
6
6
6
R

OPEN
EL01
SW1
TO-2
SW1

18.7
3.6
23.6
21.9
29.9

21.1
4.4
25.6
24.5
32.1

23.7
5.2
27.7
27.3
34.5

42.8
14.9
42.6
50.5
51.1

48.5
17.0
46.1
58.2
55.1

R

EL1

3.7

4.4

5.3

15.0

17.1

5

Table 05.

Level

Results of Tenability Analysis for Scenario 05.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

G
G
G
2
2

EL01
LOBY
EL02
OPEN
EL01

26.5
15.9
28.4
1.0
1.7

29.8
18.4
32.0
1.0
2.0

33.8
21.2
36.5
1.0
2.7

65.3
42.2
72.8
4.9
10.8

77.1
49.0
88.8
6.2
12.7

2
2
2
2
3

LOBY
EL02
SW1
TO-2
EL01

1.0
1.7
1.9
4.4
2.8

1.0
2.0
2.5
5.7
3.5

1.3
2.8
3.3
7.2
4.3

7.4
11.0
13.1
20.4
13.5

9.0
13.0
15.4
23.2
15.6

3
3
3
4
4

LOBY
EL02
SW1
EL01
EL02

14.4
2.8
5.0
4.1
3.9

16.7
3.4
6.2
5.0
4.8

19.3
4.2
7.6
6.0
5.8

38.0
13.4
19.7
16.0
15.7

43.5
15.5
22.1
18.2
17.9

4
5
5
5
6

SW1
EL01
EL02
SW1
EL01

8.9
5.6
5.2
13.0
7.0

10.6
6.6
6.2
14.9
8.0

12.3
7.7
7.3
16.8
9.3

25.2
18.3
17.8
29.9
20.4

27.7
20.6
20.1
32.5
22.8

6
6
7
7
7

EL02
SW1
EL01
EL02
SW1

6.6
16.9
8.4
7.8
20.4

7.6
18.8
9.6
8.9
22.3

8.8
20.8
10.9
10.2
24.2

19.7
34.1
22.4
21.5
38.0

22.1
36.9
24.8
23.9
41.0

8
8
8
9
9

EL01
EL02
SW1
EL01
EL02

9.8
9.0
23.6
11.0
10.2

11.0
10.2
25.4
12.5
11.5

12.5
11.6
27.4
13.9
12.9

24.3
23.2
41.6
26.0
24.8

26.7
25.6
44.8
28.5
27.3

9
10
10
10
11

SW1
EL01
EL02
SW1
OPEN

26.4
12.4
11.4
29.1
68.1

28.3
13.8
12.7
31.0
75.6

30.3
15.4
14.2
33.1
86.8

45.0
27.7
26.3
48.3
****

48.5
30.2
28.8
51.9
****

11
11
11
11
11

EL01
LOBY
EL02
SW1
TO-2

13.6
89.0
12.5
31.8
62.5

15.1
****
13.9
33.8
68.1

16.7
****
15.5
35.9
75.6

29.3
****
27.7
51.5
****

31.8
****
30.3
55.2
****

6

Table 05.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

12
12
12
12
12

OPEN
EL01
LOBY
EL02
SW1

67.2
14.8
24.6
13.6
34.8

73.6
16.4
26.8
15.0
36.8

82.3
18.0
29.1
16.7
39.0

****
30.7
45.5
29.1
55.2

****
33.4
49.3
31.7
59.0

12
13
13
13
13

TO-2
OPEN
EL01
LOBY
EL02

62.8
71.3
16.0
23.7
14.7

67.9
78.2
17.6
25.8
16.2

74.5
87.8
19.3
27.9
17.8

****
****
32.2
43.4
30.4

****
****
34.8
46.8
33.1

13
13
R
R
R

SW1
TO-2
SW1
EL01
EL02

38.5
66.7
43.8
16.0
14.8

40.7
72.1
46.2
17.6
16.3

43.0
79.3
48.8
19.3
17.9

59.9
****
67.1
32.2
30.5

63.9
****
72.0
34.9
33.1

7

Table 06.

Level

Results of Tenability Analysis for Scenario 06.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

2
2
2
2
2

OPEN
EL01
EL02
SW1
TO-2

1.0
1.0
1.0
2.7
6.7

1.0
1.2
1.3
3.5
8.4

1.0
1.8
1.8
4.5
10.4

4.9
9.3
9.4
15.7
25.1

6.2
11.3
11.4
18.1
28.3

3
3
3
3
3

OPEN
EL01
EL02
SW1
TO-2

14.2
1.8
1.8
7.0
41.4

16.8
2.1
2.1
8.6
48.3

19.6
2.8
2.8
10.3
57.2

41.1
11.5
11.5
23.4
****

48.1
13.6
13.7
25.9
****

4
4
4
5
5

EL01
EL02
SW1
EL01
EL02

2.6
2.6
12.9
3.4
3.4

3.1
3.1
14.8
4.1
4.1

3.9
3.9
16.8
5.0
5.0

13.4
13.4
30.4
15.1
15.0

15.6
15.6
33.2
17.3
17.3

5
6
6
6
7

SW1
EL01
EL02
SW1
EL01

18.9
4.2
4.2
24.5
5.0

20.9
5.0
5.0
26.6
5.9

23.0
6.0
6.0
28.7
7.0

37.3
16.5
16.5
44.2
17.8

40.5
18.8
18.8
47.9
20.2

7
7
8
8
8

EL02
SW1
EL01
EL02
SW1

5.0
29.7
5.9
5.8
34.9

5.9
31.9
6.8
6.8
37.3

7.0
34.2
7.9
7.9
39.8

17.8
51.1
19.1
19.0
58.0

20.2
55.1
21.4
21.4
62.3

9
9
9
10
10

EL01
EL02
SW1
EL01
EL02

6.7
6.6
40.2
7.4
7.3

7.7
7.6
42.7
8.5
8.4

8.9
8.8
45.6
9.7
9.6

20.2
20.1
64.8
21.2
21.1

22.6
22.5
69.8
23.7
23.6

10
11
11
11
12

SW1
EL01
EL02
SW1
OPEN

45.5
8.0
8.0
51.0
27.3

48.3
9.2
9.1
54.0
30.2

51.3
10.5
10.4
57.3
33.3

72.3
22.1
22.1
81.1
56.9

78.4
24.6
24.5
89.0
64.3

12
12
12
12
13

EL01
EL02
SW1
TO-2
OPEN

8.8
8.7
56.9
33.7
24.9

9.9
9.8
60.1
37.3
27.5

11.2
11.1
63.7
41.5
30.3

23.0
22.9
92.7
74.8
50.6

25.5
25.4
****
87.5
56.3

8

Table 06.

Level
13
13
13
13
13
R
R
R

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)
EL01
EL02
TO-1
SW1
TO-2
SW1
EL01
EL02

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

9.5
9.4
45.7
63.4
30.9

10.7
10.6
52.0
67.2
34.1

71.7
9.5
9.4

77.0
10.7
10.6

9

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

12.0
11.9
60.6
72.0
37.6

23.9
23.7
****
****
65.0

26.4
26.3
****
****
74.3

84.0
12.0
11.9

****
23.9
23.8

****
26.4
26.3

Table 07.

Level

Results of Tenability Analysis for Scenario 07.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

2
2
2
2
2

OPEN
EL01
EL02
SW1
TO-2

1.0
1.0
1.0
3.5
8.9

1.0
1.3
1.3
4.5
10.9

1.0
1.8
1.8
5.8
13.2

4.9
9.4
9.4
18.1
29.2

6.2
11.5
11.5
20.7
33.0

3
3
3
3
3

OPEN
EL01
EL02
SW1
TO-2

18.1
1.8
1.8
9.5
63.7

21.1
2.1
2.1
11.3
78.2

24.3
2.8
2.8
13.3
****

52.0
11.5
11.5
27.2
****

62.0
13.7
13.7
30.0
****

4
4
4
5
5

EL01
EL02
SW1
EL01
EL02

2.5
2.5
16.9
3.3
3.3

3.0
3.0
19.0
4.0
4.0

3.9
3.9
21.2
4.9
4.9

13.4
13.4
36.1
15.0
15.0

15.6
15.6
39.5
17.2
17.2

5
6
6
6
7

SW1
EL01
EL02
SW1
EL01

24.0
4.1
4.1
30.8
4.9

26.2
4.9
4.9
33.2
5.8

28.5
5.9
5.9
35.8
6.9

45.3
16.4
16.3
54.7
17.6

49.4
18.7
18.7
59.4
20.0

7
7
8
8
8

EL02
SW1
EL01
EL02
SW1

4.9
37.6
5.7
5.7
44.6

5.8
40.3
6.7
6.7
47.7

6.9
43.4
7.8
7.8
51.2

17.6
64.2
18.8
18.8
74.8

20.0
69.8
21.2
21.2
82.3

9
9
9
10
10

EL01
EL02
SW1
EL01
EL02

6.5
6.5
51.8
7.1
7.1

7.5
7.5
55.3
8.2
8.2

8.7
8.6
59.0
9.5
9.5

19.9
19.9
87.9
20.9
20.9

22.4
22.3
98.3
23.4
23.3

10
11
11
11
12

SW1
EL01
EL02
SW1
OPEN

59.1
7.8
7.8
37.7
26.3

62.9
8.9
8.9
42.5
29.1

67.6
10.2
10.2
49.0
32.2

****
21.8
21.8
****
54.9

****
24.3
24.3
****
61.9

12
12
12
12
13

EL01
EL02
SW1
TO-2
OPEN

8.5
8.5
33.8
37.7
24.2

9.7
9.6
37.4
42.0
26.8

10.9
10.9
41.7
47.6
29.6

22.7
22.6
80.2
89.9
49.5

25.2
25.1
****
****
55.1

10

Table 07.

Level
13
13
13
13
13
R
R
R

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)
EL01
EL02
TO-1
SW1
TO-2
SW1
EL01
EL02

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

9.2
9.1
51.4
32.4
33.8

10.4
10.3
60.0
35.7
37.3

39.8
9.2
9.2

43.6
10.4
10.4

11

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

11.7
11.7
72.5
39.4
41.5

23.5
23.5
****
70.6
73.9

26.1
26.0
****
85.0
86.0

48.1
11.8
11.7

85.7
23.6
23.5

****
26.1
26.1

Table 08.

Level

Results of Tenability Analysis for Scenario 08.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

2
2
2
2
2

OPEN
EL01
EL02
SW1
TO-2

1.0
1.0
1.0
2.7
6.7

1.0
1.3
1.3
3.5
8.4

1.0
1.8
1.8
4.5
10.4

4.9
9.3
9.4
15.7
25.1

6.2
11.3
11.4
18.1
28.3

3
3
3
3
3

OPEN
EL01
EL02
SW1
TO-2

14.1
1.8
1.8
7.0
41.3

16.7
2.1
2.1
8.6
48.2

19.6
2.8
2.8
10.3
57.0

41.0
11.5
11.5
23.3
****

47.9
13.6
13.7
25.9
****

4
4
4
5
5

EL01
EL02
SW1
EL01
EL02

2.6
2.6
12.9
3.4
3.4

3.1
3.1
14.8
4.1
4.1

3.9
3.9
16.8
5.0
5.0

13.4
13.4
30.4
15.1
15.0

15.6
15.6
33.2
17.3
17.3

5
6
6
6
7

SW1
EL01
EL02
SW1
EL01

18.9
4.2
4.2
24.5
5.0

20.9
5.0
5.0
26.5
5.9

23.0
6.0
6.0
28.6
7.0

37.3
16.5
16.5
44.1
17.8

40.5
18.8
18.8
47.8
20.2

7
7
8
8
8

EL02
SW1
EL01
EL02
SW1

5.0
29.7
5.9
5.8
34.9

5.9
31.8
6.8
6.8
37.2

7.0
34.2
7.9
7.9
39.8

17.8
51.0
19.1
19.0
57.9

20.2
55.0
21.4
21.4
62.2

9
9
9
10
10

EL01
EL02
SW1
EL01
EL02

6.7
6.6
40.1
7.4
7.3

7.7
7.6
42.7
8.5
8.4

8.9
8.8
45.5
9.7
9.6

20.2
20.1
64.7
21.2
21.1

22.6
22.5
69.7
23.7
23.6

10
11
11
11
12

SW1
EL01
EL02
SW1
OPEN

45.5
8.0
8.0
50.9
27.3

48.2
9.2
9.1
53.9
30.2

51.3
10.5
10.4
57.2
33.3

72.2
22.1
22.1
81.0
56.9

78.3
24.6
24.5
88.8
64.3

12
12
12
12
13

EL01
EL02
SW1
TO-2
OPEN

8.8
8.7
56.8
33.7
24.9

9.9
9.8
60.0
37.3
27.5

11.2
11.1
63.6
41.5
30.4

23.0
22.9
92.5
74.8
50.6

25.5
25.4
****
87.5
56.3

12

Table 08.

Level
13
13
13
13
13
R
R
R

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)
EL01
EL02
TO-1
SW1
TO-2
SW1
EL01
EL02

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

9.5
9.4
45.7
63.3
30.9

10.7
10.6
52.0
67.1
34.1

71.6
9.5
9.4

76.9
10.7
10.6

13

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

12.0
11.9
60.7
71.8
37.6

23.9
23.8
****
****
65.0

26.4
26.3
****
****
74.3

83.8
12.0
11.9

****
23.9
23.8

****
26.4
26.3

Table 09.

Level

Results of Tenability Analysis for Scenario 09.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

G
G
G
2
2

EL01
LOBY
EL02
OPEN
EL01

25.7
15.4
27.4
1.0
1.6

28.9
17.9
30.9
1.0
1.9

32.7
20.7
35.2
1.0
2.6

63.5
41.3
70.6
4.9
10.5

75.1
48.0
86.0
6.2
12.4

2
2
2
2
3

LOBY
EL02
SW1
TO-2
EL01

1.0
1.6
1.8
4.3
2.7

1.0
2.0
2.4
5.5
3.3

1.2
2.7
3.0
6.9
4.0

7.2
10.7
12.8
20.1
13.1

8.9
12.6
15.0
22.8
15.1

3
3
3
4
4

LOBY
EL02
SW1
EL01
EL02

13.9
2.6
4.7
3.9
3.7

16.2
3.2
5.8
4.7
4.5

18.8
3.9
7.1
5.7
5.4

37.2
13.0
19.0
15.4
15.1

42.7
15.1
21.4
17.5
17.3

4
5
5
5
6

SW1
EL01
EL02
SW1
EL01

8.3
5.2
4.9
12.0
6.5

9.8
6.1
5.8
13.8
7.6

11.5
7.2
6.8
15.7
8.7

24.2
17.5
17.1
28.6
19.5

26.7
19.8
19.3
31.2
21.8

6
6
7
7
7

EL02
SW1
EL01
EL02
SW1

6.0
15.6
7.8
7.2
18.8

7.0
17.4
8.9
8.3
20.7

8.2
19.4
10.2
9.5
22.6

18.9
32.5
21.4
20.6
36.0

21.2
35.2
23.8
22.9
38.9

8
8
8
9
9

EL01
EL02
SW1
EL01
EL02

9.0
8.3
21.8
10.2
9.4

10.2
9.5
23.6
11.5
10.6

11.6
10.8
25.5
12.9
11.9

23.1
22.1
39.2
24.8
23.6

25.5
24.5
42.3
27.2
26.0

9
10
10
10
11

SW1
EL01
EL02
SW1
EL01

24.4
11.4
10.4
26.8
12.6

26.2
12.8
11.7
28.6
13.9

28.1
14.2
13.1
30.6
15.5

42.3
26.3
25.0
45.2
27.8

45.5
28.8
27.4
48.6
30.3

11
11
12
12
12

EL02
SW1
EL01
EL02
SW1

11.5
29.0
13.7
12.4
31.2

12.8
30.9
15.1
13.8
33.1

14.2
32.9
16.7
15.3
35.2

26.3
47.9
29.1
27.5
50.6

28.8
51.4
31.7
30.1
54.2

14

Table 09.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

13
13
13
13
13

OPEN
EL01
LOBY
EL02
SW1

71.2
14.7
92.5
13.4
33.4

79.8
16.2
****
14.8
35.3

93.3
17.8
****
16.4
37.5

****
30.5
****
28.7
53.1

****
33.1
****
31.3
56.7

13
14
14
14
14

TO-2
OPEN
EL01
LOBY
EL02

64.6
68.1
15.7
26.7
14.3

70.6
74.7
17.3
29.0
15.8

78.8
84.0
18.9
31.5
17.4

****
****
31.7
48.8
29.9

****
****
34.4
53.0
32.4

14
14
15
15
15

SW1
TO-2
OPEN
EL01
LOBY

35.7
63.6
70.0
16.7
24.8

37.7
68.8
76.6
18.3
26.9

39.9
75.6
85.8
20.0
29.2

55.8
****
****
32.9
45.0

59.6
****
****
35.6
48.6

15
15
15
16
16

EL02
SW1
TO-2
OPEN
EL01

15.2
38.5
65.6
54.1
17.7

16.7
40.5
70.8
59.5
19.3

18.4
42.8
77.7
65.9
21.0

31.0
59.1
****
****
34.1

33.6
63.0
****
****
36.8

16
16
16
16
R

LOBY
EL02
SW1
TO-2
SW1

24.2
16.1
41.9
43.4
46.9

26.2
17.7
44.1
47.2
49.3

28.3
19.3
46.5
51.6
51.9

43.4
32.1
63.5
82.6
70.6

46.7
34.7
67.7
93.3
75.8

R
R

EL01
EL02

17.8
16.2

19.4
17.7

21.1
19.4

34.1
32.1

36.8
34.7

15

Table 10.

Level

Results of Tenability Analysis for Scenario 10.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

2
2
2
2
2

OPEN
EL01
EL02
SW1
TO-2

1.0
1.0
1.0
2.6
6.5

1.0
1.2
1.2
3.3
8.1

1.0
1.8
1.8
4.3
10.1

4.9
9.2
9.2
15.3
24.7

6.2
11.2
11.2
17.7
27.9

3
3
3
3
3

OPEN
EL01
EL02
SW1
TO-2

14.0
1.7
1.7
6.8
40.2

16.6
2.0
2.0
8.2
46.9

19.5
2.8
2.8
9.9
55.4

40.8
11.3
11.3
22.9
****

47.7
13.4
13.4
25.4
****

4
4
4
5
5

EL01
EL02
SW1
EL01
EL02

2.4
2.4
12.4
3.2
3.1

3.0
3.0
14.3
3.9
3.9

3.8
3.8
16.2
4.8
4.8

13.1
13.1
29.7
14.7
14.6

15.3
15.3
32.4
16.9
16.9

5
6
6
6
7

SW1
EL01
EL02
SW1
EL01

18.1
3.9
3.9
23.6
4.8

20.2
4.8
4.8
25.6
5.7

22.2
5.8
5.7
27.6
6.7

36.3
16.1
16.0
42.7
17.3

39.4
18.4
18.3
46.2
19.7

7
7
8
8
8

EL02
SW1
EL01
EL02
SW1

4.7
28.5
5.5
5.5
33.3

5.6
30.6
6.5
6.4
35.6

6.7
32.8
7.6
7.5
38.0

17.3
49.2
18.4
18.4
55.5

19.6
53.0
20.9
20.8
59.6

9
9
9
10
10

EL01
EL02
SW1
EL01
EL02

6.2
6.1
38.1
6.9
6.8

7.2
7.1
40.6
7.9
7.8

8.4
8.3
43.2
9.1
9.0

19.5
19.4
61.7
20.5
20.4

22.0
21.9
66.2
23.0
22.9

10
11
11
11
12

SW1
EL01
EL02
SW1
EL01

42.9
7.5
7.5
47.7
8.1

45.5
8.6
8.5
50.6
9.3

48.4
9.8
9.8
53.6
10.6

68.0
21.4
21.3
75.0
22.2

73.3
23.9
23.8
81.5
24.8

12
12
13
13
13

EL02
SW1
EL01
EL02
SW1

8.0
52.6
8.7
8.7
57.5

9.2
55.6
9.9
9.8
60.7

10.5
58.8
11.2
11.1
64.1

22.1
83.0
23.0
22.9
92.7

24.7
91.1
25.5
25.4
****

16

Table 10.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

14
14
14
14
14

OPEN
EL01
EL02
SW1
TO-2

28.2
9.3
9.2
62.7
34.7

31.1
10.5
10.4
66.3
38.4

34.3
11.8
11.7
70.7
42.8

58.7
23.7
23.6
****
77.6

66.5
26.3
26.2
****
91.4

15
15
15
15
15

OPEN
EL01
EL02
TO-1
SW1

26.0
9.9
9.8
48.6
68.9

28.8
11.0
11.0
55.9
73.5

31.7
12.5
12.4
66.4
79.2

52.9
24.4
24.3
****
****

59.1
27.0
26.9
****
****

15
16
16
16
16

TO-2
OPEN
EL01
EL02
TO-1

32.4
25.2
10.5
10.4
45.2

35.7
27.8
11.7
11.6
51.1

39.4
30.6
13.1
13.0
59.1

68.9
50.4
25.2
25.1
****

79.4
55.9
27.7
27.6
****

16
16
R
R
R

SW1
TO-2
SW1
EL01
EL02

77.0
31.1
88.7
10.5
10.4

83.1
34.2
96.0
11.8
11.7

91.3
37.7
****
13.1
13.0

****
64.2
****
25.2
25.1

****
73.1
****
27.8
27.6

17

Table 11.

Level

Results of Tenability Analysis for Scenario 11.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

2
2
2
2
2

OPEN
EL01
EL02
SW1
TO-2

1.0
1.0
1.0
2.8
6.6

1.0
1.2
1.2
3.6
8.3

1.0
1.8
1.8
4.7
10.3

4.9
9.3
9.3
16.1
25.0

6.2
11.3
11.4
18.5
28.2

3
3
3
3
3

OPEN
EL01
EL02
SW1
TO-2

13.7
1.7
1.7
7.5
40.0

16.3
2.0
2.0
9.0
46.7

19.1
2.7
2.7
10.8
55.1

40.0
11.3
11.3
24.1
****

46.7
13.4
13.4
26.7
****

4
4
4
5
5

EL01
EL02
SW1
EL01
EL02

2.3
2.3
13.8
3.0
3.0

2.9
2.9
15.8
3.8
3.8

3.7
3.7
17.9
4.7
4.6

13.0
13.0
31.7
14.5
14.4

15.2
15.2
34.6
16.7
16.7

5
6
6
6
6

SW1
OPEN
EL01
EL02
SW1

20.5
90.1
3.8
3.8
26.8

22.6
****
4.7
4.6
28.9

24.7
****
5.6
5.5
31.2

39.6
****
15.8
15.7
47.9

43.0
****
18.1
18.0
51.9

6
7
7
7
7

TO-2
OPEN
EL01
EL02
SW1

76.5
100.9
4.6
4.5
33.7

88.3
****
5.4
5.4
36.1

****
****
6.5
6.4
38.7

****
****
17.0
16.9
57.4

****
****
19.3
19.2
62.0

7
8
8
8
8

TO-2
EL01
EL02
SW1
TO-2

87.7
5.3
5.2
41.9
110.2

****
6.2
6.1
44.8
****

****
7.3
7.1
47.9
****

****
18.1
18.0
69.3
****

****
20.4
20.3
75.5
****

9
9
9
10
10

EL01
EL02
SW1
EL01
EL02

5.9
5.9
52.7
6.7
6.6

6.9
6.8
56.1
7.7
7.6

8.0
7.9
59.9
8.8
8.7

19.1
19.0
89.7
20.0
19.9

21.5
21.4
****
22.5
22.3

10
11
11
12
12

SW1
EL01
EL02
EL01
EL02

70.1
7.3
7.1
7.9
7.8

76.6
8.4
8.2
9.0
8.9

86.1
9.6
9.5
10.3
10.1

****
21.0
20.8
21.8
21.6

****
23.4
23.2
24.3
24.1

18

Table 11.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

13
13
14
14
14

EL01
EL02
OPEN
EL01
EL02

8.6
8.4
45.1
9.2
9.0

9.7
9.6
51.5
10.4
10.2

11.0
10.8
60.4
11.7
11.5

22.6
22.4
****
23.4
23.2

25.1
25.0
****
26.0
25.7

15
15
15
15
16

OPEN
EL01
EL02
TO-2
OPEN

33.0
9.8
9.6
39.2
32.8

36.4
11.0
10.8
43.7
36.1

40.3
12.4
12.1
49.3
39.8

70.9
24.2
24.0
92.8
68.9

82.1
26.7
26.5
****
79.2

16
16
16
R
R

EL01
EL02
TO-2
EL01
EL02

10.4
10.2
47.2
10.5
10.3

11.7
11.5
53.8
11.7
11.5

13.0
12.8
63.0
13.0
12.8

25.0
24.7
****
25.0
24.7

27.5
27.2
****
27.5
27.3

19

Table 12.

Level

Results of Tenability Analysis for Scenario 12.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

2
2
2
2
2

OPEN
EL01
EL02
TO-1
SW2

1.0
1.0
1.0
11.7
2.2

1.0
1.3
1.3
14.0
2.9

1.0
1.8
1.8
16.6
3.8

4.9
9.3
9.4
34.5
15.0

6.2
11.2
11.4
39.6
17.4

2
2
3
3
3

SW1
TO-2
OPEN
EL01
EL02

1.8
4.2
10.2
1.8
1.8

2.2
5.4
12.5
2.3
2.3

2.9
6.9
14.9
2.9
2.9

12.3
19.9
32.4
11.7
11.8

14.5
22.6
37.2
13.8
13.9

3
3
3
3
4

TO-1
SW2
SW1
TO-2
OPEN

43.3
3.9
4.3
26.4
58.6

50.9
4.9
5.4
29.8
71.2

60.6
6.1
6.6
33.9
91.2

****
18.0
18.0
64.3
****

****
20.4
20.4
74.2
****

4
4
4
4
4

EL01
EL02
SW2
SW1
TO-2

2.8
2.7
5.9
7.8
111.5

3.4
3.4
7.1
9.2
****

4.2
4.1
8.6
10.8
****

13.8
13.8
20.8
23.1
****

16.0
16.0
23.3
25.5
****

5
5
5
5
5

OPEN
EL01
EL02
TO-1
SW2

38.2
3.7
3.7
34.7
8.0

43.2
4.5
4.4
38.8
9.5

49.9
5.4
5.4
43.8
11.0

****
15.6
15.5
84.8
23.5

****
17.9
17.8
****
25.9

5
5
6
6
6

SW1
TO-2
OPEN
EL01
EL02

11.6
93.1
38.2
4.7
4.6

13.3
****
42.5
5.6
5.4

15.0
****
48.0
6.6
6.5

27.6
****
92.1
17.2
17.1

30.1
****
****
19.5
19.4

6
6
6
6
7

TO-1
SW2
SW1
TO-2
OPEN

35.1
10.5
15.4
85.5
39.7

38.7
11.9
17.2
****
43.8

43.1
13.7
19.0
****
48.9

78.5
26.1
31.7
****
89.6

93.7
28.5
34.3
****
****

7
7
7
7
7

EL01
EL02
TO-1
SW2
SW1

5.6
5.4
36.6
12.9
19.0

6.6
6.4
40.1
14.6
20.8

7.7
7.5
44.3
16.3
22.7

18.7
18.5
77.5
28.7
35.5

21.1
20.9
91.1
31.1
38.3

20

Table 12.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

7
8
8
8
8

TO-2
OPEN
EL01
EL02
TO-1

84.9
41.7
6.5
6.2
38.7

****
45.7
7.5
7.3
42.1

****
50.7
8.7
8.5
46.3

****
89.7
20.0
19.8
78.4

****
****
22.4
22.2
91.2

8
8
8
9
9

SW2
SW1
TO-2
OPEN
EL01

15.6
22.4
86.8
44.1
7.3

17.3
24.1
****
48.1
8.4

19.0
26.0
****
53.0
9.6

31.3
39.2
****
91.3
21.2

33.8
42.1
****
****
23.7

9
9
9
9
9

EL02
TO-1
SW2
SW1
TO-2

7.0
41.0
18.3
25.4
90.2

8.1
44.5
20.0
27.2
****

9.4
48.7
21.8
29.0
****

20.9
80.3
34.1
42.8
****

23.4
92.8
36.6
45.8
****

10
10
10
10
10

OPEN
EL01
EL02
TO-1
SW2

46.8
8.0
7.8
43.8
21.1

50.9
9.2
8.9
47.3
22.8

55.8
10.6
10.2
51.5
24.6

94.0
22.3
22.0
83.1
37.0

****
24.8
24.5
95.6
39.7

10
10
11
11
11

SW1
TO-2
OPEN
EL01
EL02

28.3
95.3
49.9
8.8
8.6

30.1
****
54.1
10.0
9.7

32.0
****
59.0
11.4
11.0

46.2
****
97.9
23.4
23.0

49.4
****
****
25.9
25.6

11
11
11
11
12

TO-1
SW2
SW1
TO-2
OPEN

46.8
24.0
31.1
102.8
53.4

50.5
25.7
33.0
****
57.6

54.7
27.4
35.0
****
62.6

86.8
40.2
49.6
****
****

99.5
43.0
52.9
****
****

12
12
12
12
12

EL01
EL02
TO-1
SW2
SW1

9.6
9.2
50.4
27.0
33.9

10.8
10.5
54.1
28.7
35.8

12.2
11.8
58.5
30.5
37.9

24.3
24.0
91.7
43.8
52.9

26.9
26.5
****
46.7
56.3

12
13
13
13
13

TO-2
OPEN
EL01
EL02
TO-1

69.6
57.3
10.3
9.9
54.4

76.2
61.6
11.6
11.1
58.3

85.4
66.7
13.0
12.6
62.8

****
****
25.3
24.8
98.0

****
****
27.9
27.4
****

21

Table 12.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

13
13
13
14
14

SW2
SW1
TO-2
OPEN
EL01

30.3
36.8
69.2
34.6
10.9

32.1
38.8
75.1
38.1
12.3

34.0
40.9
82.9
42.2
13.7

47.9
56.4
****
73.2
26.1

51.0
59.9
****
83.9
28.7

14
14
14
14
14

EL02
TO-1
SW2
SW1
TO-2

10.6
59.3
34.2
40.0
33.4

11.8
63.4
36.1
42.1
36.8

13.3
68.3
38.1
44.4
40.6

25.6
****
52.8
60.3
70.1

28.2
****
56.1
63.9
80.3

15
15
15
15
15

OPEN
EL01
EL02
TO-1
SW2

30.4
11.6
11.1
48.9
39.0

33.3
12.9
12.5
55.0
41.0

36.6
14.4
13.9
62.5
43.3

60.7
26.9
26.3
****
59.1

68.2
29.5
29.0
****
62.7

15
15
16
16
16

SW1
TO-2
OPEN
EL01
EL02

43.6
30.5
29.0
12.2
11.8

45.8
33.5
31.8
13.6
13.1

48.2
36.7
34.8
15.1
14.7

64.8
61.2
56.6
27.6
27.1

68.8
68.9
63.0
30.3
29.8

16
16
16
16
R

TO-1
SW2
SW1
TO-2
SW1

43.4
45.8
47.9
29.7
53.2

48.2
48.2
50.2
32.5
55.8

54.2
50.7
52.8
35.6
58.5

97.1
68.8
70.5
58.4
78.9

****
73.6
75.2
65.2
85.0

R
R

EL01
EL02

12.3
11.8

13.7
13.2

15.2
14.7

27.7
27.2

30.3
29.8

22

Table 13.

Level

Results of Tenability Analysis for Scenario 13.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

2
2
2
2
2

OPEN
EL01
EL02
SW1
TO-2

1.0
1.0
1.0
2.6
6.5

1.0
1.2
1.2
3.3
8.1

1.0
1.8
1.8
4.3
10.1

4.9
9.2
9.2
15.3
24.7

6.2
11.2
11.2
17.7
27.9

3
3
3
3
3

OPEN
EL01
EL02
SW1
TO-2

13.9
1.7
1.7
6.8
40.1

16.6
2.0
2.0
8.2
46.7

19.4
2.8
2.8
9.9
55.2

40.7
11.3
11.3
22.9
****

47.6
13.4
13.4
25.4
****

4
4
4
5
5

EL01
EL02
SW1
EL01
EL02

2.4
2.4
12.3
3.2
3.1

3.0
3.0
14.2
3.9
3.9

3.8
3.8
16.2
4.8
4.8

13.1
13.1
29.7
14.7
14.6

15.3
15.3
32.4
16.9
16.9

5
6
6
6
7

SW1
EL01
EL02
SW1
EL01

18.1
3.9
3.9
23.5
4.8

20.1
4.8
4.8
25.5
5.7

22.2
5.8
5.7
27.6
6.7

36.2
16.1
16.0
42.7
17.3

39.3
18.4
18.3
46.2
19.7

7
7
8
8
8

EL02
SW1
EL01
EL02
SW1

4.7
28.5
5.5
5.5
33.3

5.6
30.5
6.5
6.4
35.5

6.7
32.8
7.6
7.5
37.9

17.3
49.1
18.4
18.4
55.4

19.6
52.9
20.9
20.8
59.5

9
9
9
10
10

EL01
EL02
SW1
EL01
EL02

6.2
6.1
38.0
6.9
6.8

7.2
7.1
40.5
7.9
7.8

8.4
8.3
43.1
9.1
9.0

19.5
19.4
61.6
20.5
20.4

22.0
21.9
66.1
23.0
22.9

10
11
11
11
12

SW1
EL01
EL02
SW1
EL01

42.8
7.5
7.5
47.7
8.1

45.5
8.6
8.5
50.5
9.3

48.3
9.8
9.8
53.5
10.6

67.9
21.4
21.3
74.8
22.2

73.2
23.9
23.8
81.3
24.8

12
12
13
13
13

EL02
SW1
EL01
EL02
SW1

8.0
52.5
8.7
8.7
57.4

9.2
55.5
9.9
9.8
60.6

10.5
58.7
11.2
11.1
64.0

22.1
82.8
23.0
22.9
92.4

24.7
90.9
25.6
25.4
****

23

Table 13.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

14
14
14
14
14

OPEN
EL01
EL02
SW1
TO-2

28.2
9.3
9.2
62.6
34.7

31.1
10.5
10.4
66.2
38.4

34.3
11.8
11.7
70.6
42.8

58.7
23.7
23.6
****
77.6

66.5
26.3
26.2
****
91.4

15
15
15
15
15

OPEN
EL01
EL02
TO-1
SW1

26.1
9.9
9.8
48.6
68.8

28.8
11.0
11.0
55.9
73.3

31.7
12.5
12.4
66.4
79.0

52.9
24.4
24.3
****
****

59.1
27.0
26.9
****
****

15
16
16
16
16

TO-2
OPEN
EL01
EL02
TO-1

32.4
25.2
10.5
10.4
45.2

35.7
27.8
11.7
11.6
51.1

39.4
30.6
13.1
13.0
59.1

68.9
50.4
25.2
25.1
****

79.4
55.9
27.7
27.6
****

16
16
R
R
R

SW1
TO-2
SW1
EL01
EL02

76.8
31.1
88.4
10.5
10.4

82.9
34.2
95.8
11.8
11.7

91.1
37.7
****
13.1
13.0

****
64.3
****
25.2
25.1

****
73.1
****
27.8
27.6

24

Table 14.

Level

Results of Tenability Analysis for Scenario 14.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

B
B
B
B
B

MECH
L-SR
L-MR
L-HR
EL-S

40.6
65.5
64.9
59.6
91.7

47.8
77.0
76.0
69.4
****

57.1
92.6
90.7
82.2
****

****
****
****
****
****

****
****
****
****
****

B
B
B
B
B

EL01
EL02
EL03
EL04
SW2

59.2
70.4
63.6
54.5
72.2

69.0
82.7
74.1
63.3
85.3

81.8
99.3
87.9
74.7
****

****
****
****
****
****

****
****
****
****
****

G
G
G
G
G

OPEN
SW1
L-SR
L-MR
L-HR

10.3
18.5
17.7
16.6
15.5

12.6
21.3
20.4
19.1
17.9

15.0
24.4
23.3
21.9
20.6

32.7
48.9
44.8
41.9
39.7

37.6
57.3
51.2
47.6
45.0

G
G
G
G
G

EL-S
EL01
EL02
EL03
EL04

26.5
17.6
20.2
19.8
19.7

29.7
20.3
23.0
22.6
22.5

33.4
23.2
26.0
25.6
25.5

60.5
44.9
48.9
48.5
48.5

68.9
51.5
55.7
55.5
55.5

G
G
G
2
2

T01
T02
SW2
OPEN
SW1

17.2
19.9
18.9
1.0
1.0

19.8
22.7
21.7
1.0
1.7

22.6
25.7
24.7
1.0
2.0

42.9
48.7
47.4
4.8
10.6

48.7
55.7
54.3
6.1
12.7

2
2
2
2
2

L-SR
CR01
CR02
EL-S
EL01

1.0
1.6
1.4
3.8
1.2

1.7
1.9
1.8
4.7
1.8

2.0
2.6
2.4
5.8
2.2

9.8
11.2
10.7
17.0
10.6

11.7
13.3
12.7
19.4
12.7

2
2
2
2
2

EL02
EL03
EL04
T01
T02

1.9
1.8
1.8
1.8
2.2

2.6
2.4
2.4
2.2
2.9

3.3
3.0
3.0
2.9
3.8

13.2
13.0
13.0
12.2
14.1

15.5
15.2
15.2
14.3
16.4

2
3
3
3
3

SW2
SW1
L-SR
EL-S
EL01

1.0
2.0
22.1
5.9
2.8

1.5
2.7
25.1
7.1
3.5

1.9
3.5
28.4
8.5
4.4

9.5
13.0
61.0
20.6
14.5

11.4
15.1
76.7
23.2
16.7

25

Table 14.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

3
3
3
3
4

EL02
EL03
EL04
SW2
SW1

4.5
3.4
3.2
2.8
3.1

5.5
4.2
4.0
3.5
3.9

6.7
5.3
5.1
4.3
4.9

18.7
16.4
16.1
14.0
15.1

21.2
18.8
18.5
16.2
17.3

4
4
4
4
4

L-SR
EL-S
EL01
EL02
EL03

24.4
8.0
4.5
7.7
5.0

27.3
9.4
5.5
9.0
6.1

30.8
10.9
6.6
10.7
7.4

65.5
23.7
17.7
24.0
19.3

83.9
26.4
20.1
26.8
21.9

4
4
5
5
5

EL04
SW2
SW1
L-SR
EL-S

4.8
4.7
4.3
26.3
9.9

5.8
5.7
5.2
29.3
11.5

7.0
6.8
6.3
33.0
13.1

18.7
17.6
17.0
69.6
26.3

21.3
19.9
19.2
91.3
29.1

5
5
5
5
5

EL01
EL02
EL03
EL04
SW2

6.2
11.3
6.8
6.2
6.7

7.4
13.0
7.9
7.4
7.8

8.7
14.9
9.4
8.8
9.1

20.5
29.2
21.9
21.0
20.6

23.1
32.3
24.6
23.6
22.8

6
6
6
6
6

SW1
L-SR
EL-S
EL01
EL02

5.5
28.0
11.7
7.9
15.0

6.5
31.2
13.3
9.1
17.0

7.7
35.0
15.1
10.6
19.1

18.7
73.5
28.7
23.0
34.3

21.0
99.4
31.5
25.6
37.7

6
6
6
7
7

EL03
EL04
SW2
SW1
L-SR

8.4
7.7
8.6
6.6
29.7

9.7
8.9
9.9
7.7
32.9

11.3
10.4
11.3
9.0
37.0

24.2
23.0
23.0
20.2
77.5

27.0
25.7
25.2
22.5
****

7
7
7
7
7

EL-S
EL01
EL02
EL03
EL04

13.4
9.5
18.8
9.9
8.9

15.0
10.8
20.9
11.4
10.3

16.9
12.4
23.3
13.0
11.9

30.7
25.2
39.4
26.3
24.8

33.6
28.0
43.0
29.1
27.5

7
8
8
8
8

SW2
SW1
L-SR
EL-S
EL01

10.3
7.7
31.2
14.9
10.9

11.7
8.9
34.6
16.6
12.5

13.3
10.3
38.9
18.6
14.1

25.1
21.7
81.6
32.6
27.3

27.3
24.0
****
35.5
30.1

26

Table 14.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

8
8
8
8
9

EL02
EL03
EL04
SW2
SW1

22.6
11.3
10.1
11.9
8.8

24.9
12.9
11.6
13.5
10.0

27.4
14.6
13.3
15.1
11.5

44.3
28.2
26.4
26.8
23.0

48.3
31.1
29.1
29.1
25.2

9
9
9
9
9

L-SR
EL-S
EL01
EL02
EL03

32.7
16.3
12.4
26.3
12.7

36.2
18.1
13.9
28.8
14.3

40.7
20.1
15.7
31.4
16.1

86.2
34.3
29.1
49.2
30.0

****
37.3
32.0
53.5
32.9

9
9
10
10
10

EL04
SW2
SW1
L-SR
EL-S

11.3
13.5
9.9
34.2
17.6

12.8
15.0
11.2
37.9
19.5

14.5
16.7
12.7
42.7
21.5

27.8
28.4
24.2
91.6
35.9

30.6
30.7
26.4
****
39.0

10
10
10
10
10

EL01
EL02
EL03
EL04
SW2

13.7
30.0
13.9
12.4
14.9

15.3
32.6
15.6
13.9
16.5

17.1
35.4
17.5
15.7
18.1

30.8
54.1
31.6
29.1
29.8

33.7
58.6
34.6
31.9
32.1

11
11
11
11
11

SW1
L-SR
EL-S
EL01
EL02

10.9
36.1
18.8
14.9
33.7

12.3
40.0
20.7
16.6
36.4

13.8
45.1
22.8
18.5
39.3

25.4
98.5
37.3
32.4
58.8

27.7
****
40.5
35.3
63.6

11
11
11
12
12

EL03
EL04
SW2
SW1
L-SR

15.1
13.4
16.2
11.9
38.1

16.8
15.0
17.8
13.3
42.3

18.8
16.8
19.6
14.9
47.9

33.1
30.3
31.4
26.7
****

36.2
33.2
33.8
29.0
****

12
12
12
12
12

EL-S
EL01
EL02
EL03
EL04

20.0
16.1
37.3
16.2
14.4

21.9
17.9
40.1
18.0
16.0

24.0
19.8
43.1
20.0
17.8

38.7
33.9
63.5
34.5
31.5

41.9
36.9
68.5
37.6
34.4

12
13
13
13
13

SW2
SW1
L-SR
EL-S
EL01

17.5
12.9
40.3
21.1
17.3

19.1
14.3
44.8
23.1
19.0

20.9
15.9
51.1
25.2
21.0

32.9
27.9
****
40.0
35.3

35.3
30.2
****
43.3
38.3

27

Table 14.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

13
13
13
13
14

EL02
EL03
EL04
SW2
SW1

40.8
17.3
15.3
18.7
13.8

43.8
19.1
16.9
20.4
15.3

47.0
21.1
18.8
22.1
16.9

68.1
35.8
32.6
34.3
29.0

73.4
39.0
35.5
36.8
31.3

14
14
14
14
14

L-SR
L-MR
EL-S
EL01
EL02

42.3
28.1
22.1
18.3
36.2

47.1
30.6
24.1
20.1
39.1

53.9
33.2
26.3
22.1
42.3

****
51.4
41.2
36.5
63.7

****
55.8
44.5
39.6
69.3

14
14
14
15
15

EL03
EL04
SW2
SW1
L-SR

18.3
16.1
19.9
14.7
42.1

20.2
17.8
21.6
16.2
46.5

22.2
19.7
23.3
17.9
52.4

37.1
33.6
35.7
30.0
****

40.3
36.5
38.2
32.4
****

15
15
15
15
15

L-MR
EL-S
EL01
EL02
EL03

28.4
23.1
19.3
35.5
19.3

30.8
25.1
21.1
38.3
21.2

33.4
27.3
23.2
41.3
23.3

51.2
42.3
37.7
62.0
38.2

55.5
45.6
40.9
67.4
41.5

15
15
15
16
16

EL04
T01
SW2
SW1
L-SR

16.9
37.1
20.9
15.6
44.5

18.7
40.4
22.6
17.1
49.3

20.6
44.4
24.4
18.8
55.8

34.6
78.6
36.9
31.1
****

37.5
94.1
39.5
33.5
****

16
16
16
16
16

L-MR
EL-S
EL01
EL02
EL03

29.3
24.0
20.3
35.8
20.2

31.7
26.0
22.2
38.5
22.1

34.3
28.2
24.2
41.5
24.3

52.1
43.4
38.9
61.7
39.3

56.4
46.7
42.1
67.0
42.7

16
16
17
17
17

EL04
SW2
SW1
L-SR
L-MR

17.8
21.9
16.5
49.8
30.3

19.5
23.7
18.0
56.1
32.7

21.5
25.5
19.7
65.2
35.3

35.5
38.1
32.1
****
53.2

38.5
40.7
34.5
****
57.5

17
17
17
17
17

EL-S
EL01
EL02
EL03
EL04

24.9
21.4
36.3
21.1
18.5

27.0
23.2
39.0
23.0
20.3

29.2
25.3
42.0
25.2
22.2

44.4
40.1
62.1
40.4
36.3

47.8
43.3
67.2
43.8
39.4

28

Table 14.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

17
18
18
18
18

SW2
SW1
L-MR
EL-S
EL01

22.9
17.3
31.3
25.8
22.4

24.7
18.9
33.8
27.9
24.3

26.5
20.7
36.4
30.1
26.4

39.2
33.1
54.4
45.4
41.3

41.9
35.5
58.7
48.8
44.5

18
18
18
18
19

EL02
EL03
EL04
SW2
SW1

37.0
21.9
19.2
23.9
18.2

39.8
23.9
21.0
25.7
19.8

42.7
26.1
23.0
27.5
21.6

62.6
41.4
37.2
40.3
34.0

67.7
44.8
40.2
43.0
36.5

19
19
19
19
19

L-MR
EL-S
EL01
EL02
EL03

32.3
26.7
23.4
37.8
22.8

34.8
28.7
25.3
40.5
24.8

37.4
31.0
27.5
43.5
26.9

55.5
46.3
42.5
63.4
42.4

59.9
49.8
45.8
68.4
45.9

19
19
20
20
20

EL04
SW2
OPEN
SW1
L-SR

19.9
24.9
65.0
19.0
41.4

21.8
26.7
72.0
20.7
44.3

23.8
28.5
81.6
22.5
47.4

38.0
41.4
****
35.0
69.0

41.1
44.1
****
37.5
74.7

20
20
20
20
20

L-MR
CR01
EL-S
EL01
EL02

33.4
83.2
27.5
24.4
38.7

35.9
93.4
29.6
26.4
41.4

38.5
****
31.8
28.6
44.3

56.7
****
47.3
43.7
64.2

61.1
****
50.7
47.0
69.2

20
20
20
20
20

EL03
EL04
T01
T02
SW2

23.6
20.6
87.1
49.1
25.8

25.6
22.5
98.4
52.8
27.6

27.8
24.5
****
56.9
29.5

43.4
38.8
****
85.4
42.5

46.8
41.9
****
94.4
45.2

21
21
21
21
21

OPEN
SW1
L-SR
L-MR
CR01

47.9
19.9
40.0
34.4
61.3

51.9
21.6
42.7
36.9
67.0

56.9
23.3
45.6
39.6
74.1

93.5
36.0
65.6
57.9
****

****
38.5
70.8
62.3
****

21
21
21
21
21

EL-S
EL01
EL02
EL03
EL04

28.4
25.4
39.5
24.3
21.3

30.5
27.5
42.2
26.4
23.1

32.7
29.6
45.1
28.6
25.2

48.2
44.9
65.0
44.3
39.5

51.7
48.2
70.0
47.8
42.7

29

Table 14.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

21
21
21
22
22

T01
T02
SW2
OPEN
SW1

48.6
44.5
26.8
45.8
20.8

53.1
47.8
28.6
49.4
22.5

58.8
51.5
30.5
53.7
24.3

****
77.0
43.5
85.2
37.0

****
84.5
46.3
96.7
39.5

22
22
22
22
22

L-SR
L-MR
CR01
EL-S
EL01

39.4
35.4
58.3
29.2
26.5

42.0
37.9
63.3
31.4
28.5

44.8
40.6
69.2
33.6
30.7

64.0
58.9
****
49.2
46.1

68.8
63.3
****
52.7
49.5

22
22
22
22
22

EL02
EL03
EL04
T01
T02

40.3
25.0
21.9
46.3
43.2

43.0
27.1
23.8
50.2
46.3

46.0
29.4
25.8
54.9
49.7

65.8
45.2
40.3
91.0
73.6

70.8
48.7
43.4
****
80.3

22
23
23
23
23

SW2
OPEN
SW1
L-SR
L-MR

27.7
45.2
21.7
39.3
36.3

29.5
48.6
23.4
41.9
38.8

31.4
52.5
25.2
44.6
41.5

44.6
81.6
38.0
63.3
59.8

47.4
91.5
40.6
67.9
64.2

23
23
23
23
23

CR01
EL-S
EL01
EL02
EL03

57.3
30.1
27.5
41.1
25.8

61.9
32.2
29.6
43.8
27.9

67.4
34.5
31.8
46.8
30.1

****
50.2
47.3
66.6
46.0

****
53.7
50.7
71.6
49.6

23
23
23
23
24

EL04
T01
T02
SW2
OPEN

22.6
45.6
42.8
28.7
45.1

24.5
49.2
45.8
30.5
48.3

26.5
53.5
49.0
32.4
52.0

41.0
86.3
71.9
45.7
79.6

44.2
98.7
78.2
48.5
88.6

24
24
24
24
24

SW1
L-SR
L-MR
CR01
EL-S

22.6
39.5
37.0
57.0
31.0

24.4
42.0
39.6
61.5
33.1

26.2
44.7
42.3
66.7
35.5

39.0
63.1
60.6
****
51.2

41.6
67.5
65.0
****
54.7

24
24
24
24
24

EL01
EL02
EL03
EL04
T01

28.6
41.9
26.5
23.1
45.5

30.7
44.6
28.6
25.0
48.9

32.9
47.6
30.9
27.1
52.9

48.5
67.4
46.8
41.7
83.6

52.0
72.3
50.4
44.9
94.7

30

Table 14.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

24
24
25
25
25

T02
SW2
OPEN
SW1
L-SR

42.8
29.7
45.2
23.6
39.7

45.7
31.5
48.3
25.4
42.2

48.8
33.4
51.8
27.2
44.9

71.0
46.8
78.1
40.1
63.0

77.0
49.7
86.4
42.8
67.3

25
25
25
25
25

L-MR
CR01
EL-S
EL01
EL02

37.5
57.3
31.9
29.6
42.6

40.0
61.6
34.1
31.7
45.4

42.7
66.6
36.4
34.0
48.3

60.6
99.7
52.2
49.7
68.1

64.9
****
55.8
53.2
73.0

25
25
25
25
25

EL03
EL04
T01
T02
SW2

27.1
23.7
45.6
43.0
30.7

29.3
25.7
48.8
45.8
32.6

31.6
27.7
52.6
48.9
34.5

47.6
42.3
81.7
70.4
48.0

51.2
45.5
91.8
76.2
50.9

26
26
26
26
26

OPEN
SW1
L-SR
L-MR
L-HR

45.7
24.7
40.3
38.0
56.6

48.7
26.4
42.8
40.5
60.6

52.2
28.3
45.5
43.1
65.3

77.5
41.3
63.5
60.9
96.1

85.2
44.0
67.7
65.1
****

26
26
26
26
26

EL-S
EL01
EL02
EL03
EL04

32.9
30.7
43.4
27.8
24.3

35.1
32.8
46.1
29.9
26.2

37.4
35.1
49.1
32.3
28.3

53.3
50.9
68.8
48.4
43.0

56.9
54.4
73.6
52.1
46.2

26
26
26
27
27

T01
T02
SW2
OPEN
SW1

46.2
43.6
31.8
46.5
25.8

49.4
46.4
33.6
49.5
27.6

53.1
49.4
35.6
53.0
29.4

81.5
70.7
49.2
78.1
42.6

91.0
76.3
52.1
85.8
45.3

27
27
27
27
27

L-SR
L-HR
EL-S
EL03
EL04

40.8
58.3
33.9
28.4
24.8

43.3
62.5
36.1
30.6
26.8

45.9
67.2
38.5
32.9
28.9

63.8
98.7
54.4
49.2
43.6

68.0
****
58.0
52.8
46.8

27
27
27
28
28

T01
T02
SW2
OPEN
SW1

46.7
44.1
32.9
47.5
27.0

49.8
46.8
34.8
50.6
28.8

53.5
49.8
36.7
54.0
30.7

80.9
70.7
50.5
78.9
43.9

90.0
76.1
53.4
86.4
46.7

31

Table 14.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

28
28
28
28
28

L-SR
L-HR
EL-S
EL03
EL04

41.7
60.1
35.0
29.0
25.4

44.1
64.3
37.2
31.2
27.3

46.8
69.2
39.6
33.6
29.4

64.6
****
55.7
49.9
44.2

68.8
****
59.3
53.6
47.4

28
28
28
29
29

T01
T02
SW2
OPEN
SW1

47.8
45.0
34.0
48.8
28.3

50.9
47.8
35.9
51.9
30.1

54.5
50.8
37.9
55.4
32.0

81.7
71.5
51.8
80.2
45.5

90.6
76.9
54.8
87.6
48.3

29
29
29
29
29

L-SR
L-HR
EL-S
EL03
EL04

42.7
62.4
36.2
29.6
25.9

45.2
66.7
38.4
31.8
27.8

47.8
71.7
40.8
34.2
29.9

65.7
****
57.0
50.5
44.8

69.9
****
60.6
54.3
48.0

29
29
29
30
30

T01
T02
SW2
OPEN
SW1

49.1
46.2
35.3
50.4
29.8

52.3
48.9
37.2
53.5
31.7

55.9
51.9
39.3
57.0
33.6

82.9
72.6
53.3
81.8
47.2

91.7
78.0
56.3
89.1
50.1

30
30
30
30
30

L-SR
L-HR
EL-S
EL03
EL04

43.8
44.3
37.4
30.2
26.4

46.4
47.5
39.7
32.4
28.4

49.0
51.0
42.1
34.8
30.5

67.0
76.6
58.4
51.2
45.3

71.2
84.4
62.1
55.0
48.6

30
30
30
31
31

T01
T02
SW2
OPEN
SW1

50.7
47.6
36.7
52.2
31.5

53.9
50.3
38.7
55.4
33.4

57.6
53.3
40.7
58.9
35.4

84.6
74.0
54.9
83.7
49.2

93.4
79.3
58.0
91.1
52.1

31
31
31
31
31

L-SR
L-HR
EL-S
EL03
EL04

45.2
41.3
38.8
30.8
26.9

47.7
44.1
41.0
33.0
28.8

50.4
47.2
43.5
35.4
31.0

68.4
69.3
59.9
51.8
45.9

72.7
75.6
63.6
55.6
49.2

31
31
31
32
32

T01
T02
SW2
OPEN
SW1

52.6
49.1
38.2
54.5
33.6

55.9
51.9
40.2
57.7
35.5

59.6
54.9
42.3
61.3
37.5

86.8
75.7
56.7
86.3
51.6

95.5
81.0
59.8
93.6
54.6

32

Table 14.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

32
32
32
32
32

L-SR
L-HR
EL-S
EL03
EL04

46.7
40.2
40.3
31.3
27.4

49.2
42.9
42.6
33.5
29.4

51.9
45.8
45.0
35.9
31.5

70.1
66.6
61.6
52.4
46.4

74.3
72.2
65.4
56.2
49.7

32
32
32
33
33

T01
T02
SW2
OPEN
SW1

54.9
50.9
39.9
57.3
36.0

58.3
53.7
41.9
60.6
38.0

62.1
56.8
44.0
64.2
40.1

89.6
77.6
58.7
89.5
54.5

98.4
82.9
61.9
96.9
57.6

33
33
33
33
33

L-SR
L-HR
EL-S
EL03
EL04

48.4
39.7
42.0
31.8
27.8

50.9
42.3
44.3
34.0
29.8

53.7
45.1
46.8
36.5
32.0

72.0
65.1
63.6
53.1
47.0

76.3
70.4
67.4
56.9
50.3

33
33
33
34
34

T01
T02
SW2
OPEN
SW1

58.0
53.0
41.9
60.8
39.3

61.5
55.9
43.9
64.2
41.4

65.5
59.0
46.1
68.0
43.5

93.4
80.0
61.0
93.8
58.5

****
85.3
64.2
****
61.8

34
34
34
34
34

L-SR
L-HR
EL-S
EL03
EL04

50.3
39.4
43.9
32.3
28.3

52.9
42.0
46.3
34.6
30.3

55.7
44.8
48.8
37.0
32.5

74.3
64.3
65.8
53.6
47.5

78.7
69.3
69.7
57.4
50.8

34
34
34
35
35

T01
T02
SW2
OPEN
SW1

52.7
55.5
44.1
66.0
44.2

56.5
58.5
46.2
69.7
46.4

60.8
61.7
48.5
73.7
48.8

89.3
82.8
63.7
****
64.9

97.9
88.2
67.0
****
68.5

35
35
35
35
35

L-SR
L-HR
EL-S
EL03
EL04

52.6
40.1
46.2
32.8
28.8

55.3
42.7
48.6
35.1
30.8

58.1
45.5
51.2
37.5
33.0

77.0
65.2
68.5
54.2
48.0

81.4
70.3
72.4
58.0
51.4

35
35
35
36
36

T01
T02
SW2
MECH
ELME

62.0
58.5
46.8
67.4
70.8

66.7
61.6
49.0
71.0
74.7

72.0
64.8
51.3
74.9
79.1

****
86.4
67.0
****
****

****
91.9
70.5
****
****

33

Table 14.

Level
36
36
36
36
R

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)
EL-S
EL03
EL04
SW2
SW2

48.9
32.9
28.8
50.3
54.9

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

51.4
35.1
30.9
52.6
57.3

54.0
37.6
33.0
54.9
59.8

34

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

71.7
54.2
48.1
71.2
77.1

75.7
58.1
51.4
74.9
81.0

Table 15.

Level

Results of Tenability Analysis for Scenario 15.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

B
B
B
B
B

MECH
L-SR
L-MR
L-HR
EL01

53.4
83.2
47.9
40.2
83.2

65.1
****
57.6
47.5
****

83.5
****
71.1
57.4
****

****
****
****
****
****

****
****
****
****
****

B
B
B
B
G

EL02
EL03
EL04
SW2
OPEN

81.6
61.9
65.1
91.2
7.7

99.5
73.1
77.6
****
9.7

****
88.9
96.5
****
11.9

****
****
****
****
27.9

****
****
****
****
31.7

G
G
G
G
G

SW1
L-SR
EL-S
EL01
EL02

22.4
16.7
29.8
11.1
11.1

25.6
19.3
33.3
13.3
13.2

29.2
22.1
37.5
15.6
15.6

60.3
42.3
67.5
32.4
32.3

72.3
48.1
77.1
36.6
36.5

G
G
G
G
G

EL03
EL04
T01
T02
SW2

9.8
9.8
16.3
19.0
20.9

11.8
11.9
18.8
21.7
23.9

14.1
14.2
21.5
24.6
27.1

30.4
30.6
40.9
46.3
52.0

34.5
34.7
46.3
52.6
59.9

2
2
2
2
2

OPEN
SW1
L-SR
CR01
CR02

1.0
1.0
1.0
1.7
1.5

1.0
1.6
1.7
2.0
1.9

1.0
2.0
2.0
2.8
2.6

4.8
10.3
9.9
11.7
11.1

6.1
12.4
11.8
13.7
13.1

2
2
2
2
2

EL-S
EL01
EL02
EL03
EL04

3.8
1.5
2.0
2.1
2.1

4.7
1.9
2.8
2.9
2.9

5.8
2.6
3.8
3.9
3.9

16.8
11.9
14.7
15.6
15.5

19.1
14.1
17.2
18.3
18.1

2
2
2
3
3

T01
T02
SW2
SW1
L-SR

1.8
2.2
1.0
2.2
21.0

2.4
2.9
1.5
2.9
23.8

3.0
3.8
1.9
3.7
26.8

12.5
14.2
9.4
13.2
54.1

14.7
16.4
11.3
15.3
65.1

3
3
3
3
3

CR02
EL-S
EL01
EL02
EL03

33.3
6.4
2.6
3.7
3.0

38.7
7.6
3.2
4.7
3.9

46.0
9.0
4.0
5.8
5.0

****
21.2
14.4
17.7
17.1

****
23.8
16.7
20.3
19.8

35

Table 15.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

3
3
4
4
4

EL04
SW2
SW1
L-SR
EL-S

3.0
3.0
3.6
23.6
8.8

3.9
3.8
4.4
26.4
10.3

4.9
4.8
5.3
29.6
11.9

16.9
14.8
15.7
58.8
24.9

19.6
17.0
17.9
71.2
27.5

4
4
4
4
4

EL01
EL02
EL03
EL04
SW2

3.8
5.6
3.9
3.9
5.4

4.6
6.7
4.9
4.8
6.5

5.7
8.1
6.1
6.0
7.7

16.7
20.7
18.5
18.3
18.9

19.1
23.4
21.2
21.0
21.2

5
5
5
5
5

SW1
L-SR
EL-S
EL01
EL02

4.9
25.9
11.1
5.0
7.5

5.9
28.8
12.7
6.0
8.9

7.0
32.1
14.5
7.2
10.5

17.9
63.2
28.0
18.8
23.6

20.2
77.2
30.7
21.3
26.4

5
5
5
6
6

EL03
EL04
SW2
SW1
L-SR

4.8
4.7
7.7
6.3
27.9

5.9
5.8
9.0
7.4
30.9

7.1
7.0
10.5
8.7
34.4

19.8
19.5
22.2
19.9
67.3

22.5
22.3
24.5
22.1
83.6

6
6
6
6
6

EL-S
EL01
EL02
EL03
EL04

13.2
6.3
9.6
5.7
5.6

14.9
7.4
11.1
6.8
6.7

16.8
8.7
12.8
8.2
8.0

30.6
20.7
26.5
21.1
20.8

33.5
23.3
29.4
23.8
23.5

6
7
7
7
7

SW2
SW1
L-SR
EL-S
EL01

9.9
7.6
29.8
15.1
7.5

11.3
8.8
32.8
16.9
8.7

12.9
10.2
36.6
18.9
10.1

24.9
21.6
71.5
33.0
22.4

27.1
23.9
90.6
36.0
25.1

7
7
7
7
8

EL02
EL03
EL04
SW2
SW1

11.7
6.5
6.4
11.9
8.9

13.4
7.7
7.6
13.4
10.2

15.2
9.2
9.0
15.1
11.6

29.3
22.2
21.9
27.1
23.2

32.4
25.1
24.7
29.3
25.4

8
8
8
8
8

L-SR
EL-S
EL01
EL02
EL03

31.5
16.8
8.7
13.9
7.3

34.7
18.7
9.9
15.7
8.6

38.6
20.7
11.5
17.6
10.1

75.7
35.1
24.1
32.2
23.4

98.8
38.2
26.8
35.3
26.2

36

Table 15.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

8
8
9
9
9

EL04
SW2
SW1
L-SR
EL-S

7.1
13.7
10.1
33.2
18.4

8.4
15.3
11.5
36.5
20.4

9.9
17.0
13.0
40.6
22.4

23.0
29.0
24.6
80.2
37.1

25.8
31.3
26.8
****
40.2

9
9
9
9
9

EL01
EL02
EL03
EL04
SW2

9.8
16.0
8.1
7.9
15.3

11.2
17.9
9.5
9.3
16.9

12.8
20.0
11.0
10.8
18.7

25.7
34.9
24.5
24.0
30.6

28.4
38.2
27.3
26.9
33.0

10
10
10
10
10

SW1
L-SR
EL-S
EL01
EL02

11.3
34.8
19.9
10.9
18.2

12.7
38.3
21.9
12.4
20.2

14.3
42.6
24.0
13.9
22.3

25.9
85.2
38.8
27.1
37.6

28.1
****
42.0
29.9
41.0

10
10
10
11
11

EL03
EL04
SW2
SW1
L-SR

8.9
8.7
16.8
12.5
36.7

10.3
10.0
18.5
13.9
40.4

11.9
11.7
20.2
15.5
45.1

25.5
25.0
32.1
27.3
91.6

28.4
27.9
34.6
29.5
****

11
11
11
11
11

EL-S
EL01
EL02
EL03
EL04

21.3
11.9
20.4
9.7
9.4

23.3
13.5
22.4
11.1
10.8

25.5
15.1
24.7
12.8
12.5

40.4
28.5
40.3
26.5
26.0

43.7
31.3
43.9
29.4
28.8

11
12
12
12
12

SW2
SW1
L-SR
EL-S
EL01

18.2
13.6
38.7
22.6
12.9

19.9
15.0
42.7
24.6
14.5

21.7
16.7
47.8
26.8
16.3

33.9
28.6
99.6
42.0
29.8

36.3
30.9
****
45.3
32.7

12
12
12
12
13

EL02
EL03
EL04
SW2
SW1

22.5
10.4
10.1
19.6
14.6

24.6
11.9
11.6
21.3
16.1

26.9
13.6
13.2
23.0
17.8

43.0
27.4
26.9
35.4
29.8

46.6
30.4
29.7
38.0
32.2

13
13
13
13
13

L-SR
EL-S
EL01
EL02
EL03

40.8
23.8
13.9
24.6
11.1

45.0
25.9
15.6
26.8
12.7

50.7
28.1
17.3
29.2
14.4

****
43.4
31.0
45.6
28.4

****
46.8
34.0
49.4
31.3

37

Table 15.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

13
13
14
14
14

EL04
SW2
SW1
L-SR
EL-S

10.8
20.8
15.6
40.7
24.9

12.3
22.6
17.1
44.6
27.0

14.0
24.4
18.8
49.6
29.2

27.7
36.9
31.0
96.0
44.7

30.6
39.6
33.3
****
48.1

14
14
14
14
14

EL01
EL02
EL03
EL04
SW2

15.5
28.2
11.8
11.5
21.9

17.2
30.6
13.4
12.9
23.7

19.1
33.2
15.2
14.7
25.5

33.4
51.2
29.2
28.5
38.3

36.4
55.5
32.2
31.5
41.0

15
15
15
15
15

MECH
SW1
L-SR
CR01
EL-S

40.4
16.4
36.4
54.2
25.8

43.8
18.0
39.1
59.5
27.9

48.0
19.7
42.0
65.9
30.2

80.1
31.9
63.0
****
45.7

92.5
34.3
68.4
****
49.2

15
15
15
15
15

EL01
EL02
EL03
EL04
T01

16.2
29.6
12.5
12.0
38.1

17.9
32.1
14.1
13.6
41.3

19.9
34.8
15.9
15.4
45.0

34.3
53.1
30.1
29.3
75.7

37.4
57.6
33.1
32.2
87.5

15
15
16
16
16

T02
SW2
OPEN
SW1
L-SR

39.1
22.9
41.3
17.3
37.1

42.3
24.7
44.8
18.9
39.8

45.9
26.6
48.9
20.7
42.7

71.9
39.4
80.7
32.9
63.2

79.7
42.1
92.7
35.4
68.5

16
16
16
16
16

CR01
EL-S
EL01
EL02
EL03

55.1
26.8
16.9
30.9
13.1

60.4
28.9
18.7
33.4
14.8

66.7
31.2
20.6
36.1
16.6

****
46.8
35.1
54.7
30.8

****
50.3
38.3
59.4
33.9

16
16
16
16
17

EL04
T01
T02
SW2
OPEN

12.7
41.6
40.0
23.9
42.5

14.3
45.2
43.1
25.7
46.0

16.0
49.6
46.7
27.6
50.2

30.0
84.7
72.3
40.5
82.1

33.0
99.3
79.8
43.3
94.2

17
17
17
17
17

SW1
L-SR
CR01
EL-S
EL01

18.2
38.1
56.5
27.8
17.5

19.9
40.8
61.7
29.9
19.3

21.6
43.8
68.1
32.2
21.3

34.0
64.2
****
47.9
35.9

36.4
69.4
****
51.4
39.1

38

Table 15.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

17
17
17
17
17

EL02
EL03
EL04
T01
T02

32.0
13.8
13.3
42.8
41.1

34.6
15.4
14.9
46.4
44.2

37.4
17.3
16.7
50.9
47.8

56.2
31.6
30.7
86.2
73.3

61.0
34.7
33.7
****
80.8

17
18
18
18
18

SW2
OPEN
SW1
L-SR
CR01

25.0
43.7
19.2
39.1
57.8

26.8
47.3
20.8
41.9
63.1

28.6
51.5
22.6
44.8
69.5

41.7
83.6
35.0
65.3
****

44.5
95.7
37.5
70.5
****

18
18
18
18
18

EL-S
EL01
EL02
EL03
EL04

28.8
18.1
33.1
14.4
13.8

30.9
19.9
35.7
16.0
15.5

33.2
21.9
38.5
17.9
17.3

49.0
36.6
57.6
32.4
31.4

52.5
39.8
62.5
35.5
34.5

18
18
18
19
19

T01
T02
SW2
OPEN
SW1

44.0
42.2
26.0
45.0
20.1

47.7
45.4
27.8
48.6
21.8

52.2
49.0
29.7
52.9
23.6

87.8
74.5
42.9
85.1
36.1

****
81.9
45.7
97.3
38.7

19
19
19
19
19

L-SR
CR01
EL-S
EL01
EL02

40.2
59.2
29.8
18.7
34.1

42.9
64.5
31.9
20.5
36.7

45.9
71.0
34.2
22.5
39.6

66.3
****
50.1
37.3
58.9

71.5
****
53.6
40.5
63.9

19
19
19
19
19

EL03
EL04
T01
T02
SW2

15.0
14.4
45.3
43.4
27.1

16.7
16.1
49.0
46.6
28.9

18.6
17.9
53.6
50.2
30.8

33.1
32.1
89.4
75.7
44.1

36.2
35.2
****
83.1
47.0

20
20
20
20
20

OPEN
SW1
L-SR
CR01
EL-S

46.3
21.1
41.4
60.6
30.8

49.9
22.8
44.1
66.0
32.9

54.3
24.7
47.1
72.6
35.3

86.7
37.3
67.5
****
51.2

99.0
39.8
72.7
****
54.8

20
20
20
20
20

EL01
EL02
EL03
EL04
T01

19.2
35.1
15.6
15.0
46.6

21.0
37.7
17.3
16.7
50.4

23.1
40.6
19.3
18.6
55.1

37.9
60.1
33.8
32.8
91.1

41.2
65.2
37.0
35.9
****

39

Table 15.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

20
20
21
21
21

T02
SW2
OPEN
SW1
L-SR

44.6
28.2
47.6
22.2
42.5

47.8
30.0
51.4
23.9
45.3

51.5
31.9
55.8
25.7
48.3

76.9
45.4
88.5
38.4
68.7

84.3
48.2
****
41.0
73.9

21
21
21
21
21

CR01
EL-S
EL01
EL02
EL03

62.1
31.8
19.7
36.0
16.2

67.6
34.0
21.6
38.6
17.9

74.2
36.4
23.6
41.5
19.9

****
52.4
38.5
61.3
34.5

****
56.0
41.8
66.4
37.7

21
21
21
21
22

EL04
T01
T02
SW2
OPEN

15.6
47.9
45.8
29.3
44.5

17.2
51.9
49.1
31.1
48.0

19.1
56.6
52.8
33.1
52.2

33.5
92.9
78.3
46.6
82.2

36.5
****
85.6
49.5
92.4

22
22
22
22
22

SW1
L-SR
CR01
EL-S
EL01

23.3
43.7
58.4
32.9
20.2

25.0
46.5
63.5
35.1
22.1

26.8
49.5
69.4
37.4
24.2

39.6
70.0
****
53.5
39.1

42.3
75.2
****
57.2
42.3

22
22
22
22
22

EL02
EL03
EL04
T01
T02

36.8
16.8
16.0
48.9
47.1

39.5
18.5
17.8
52.8
50.4

42.4
20.5
19.7
57.5
54.1

62.4
35.2
34.1
92.6
79.7

67.6
38.4
37.2
****
87.0

22
23
23
23
23

SW2
OPEN
SW1
L-SR
CR01

30.5
42.4
24.4
44.8
55.8

32.3
45.8
26.1
47.6
60.6

34.3
49.7
27.9
50.7
66.0

48.0
77.6
40.9
71.1
****

50.9
86.6
43.5
76.2
****

23
23
23
23
23

EL-S
EL01
EL02
EL03
EL04

33.9
20.8
37.6
17.3
16.6

36.2
22.7
40.3
19.1
18.4

38.6
24.7
43.2
21.1
20.3

54.7
39.6
63.3
35.9
34.7

58.4
42.9
68.6
39.1
37.8

23
23
23
24
24

T01
T02
SW2
OPEN
SW1

49.6
48.2
31.6
40.8
25.5

53.5
51.6
33.5
44.0
27.3

58.0
55.3
35.5
47.7
29.1

91.6
80.7
49.3
73.6
42.2

****
88.0
52.2
81.7
44.9

40

Table 15.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

24
24
24
24
24

L-SR
CR01
EL-S
EL01
EL02

45.8
53.7
35.0
21.3
38.2

48.6
58.1
37.3
23.2
40.9

51.6
63.2
39.7
25.3
43.9

71.8
96.3
56.0
40.2
64.1

76.9
****
59.7
43.5
69.4

24
24
24
24
24

EL03
EL04
T01
T02
SW2

17.9
17.1
49.8
49.1
32.8

19.7
18.9
53.6
52.4
34.7

21.7
20.8
58.0
56.1
36.7

36.5
35.3
89.8
81.2
50.6

39.8
38.5
****
88.3
53.6

25
25
25
25
25

OPEN
SW1
L-SR
CR01
EL-S

41.1
26.7
47.0
54.0
36.1

44.3
28.5
49.8
58.3
38.4

47.9
30.4
52.8
63.3
40.8

73.7
43.5
73.1
96.0
57.2

81.6
46.3
78.2
****
60.9

25
25
25
25
25

EL01
EL02
EL03
EL04
T01

21.8
38.8
18.4
17.7
50.8

23.8
41.6
20.2
19.4
54.6

25.8
44.5
22.3
21.4
59.0

40.9
64.8
37.2
36.0
90.4

44.2
70.1
40.4
39.1
****

25
25
26
26
26

T02
SW2
OPEN
SW1
L-SR

50.4
33.9
36.6
27.9
45.3

53.7
35.9
39.4
29.7
47.9

57.3
37.9
42.5
31.6
50.7

82.4
52.0
63.9
44.9
69.6

89.5
55.1
69.7
47.7
74.2

26
26
26
26
26

EL-S
EL01
EL02
EL03
EL04

37.3
22.5
39.5
19.3
18.5

39.6
24.4
42.2
21.1
20.3

42.0
26.5
45.2
23.2
22.3

58.5
41.5
65.5
38.4
37.1

62.2
44.8
70.8
41.8
40.3

26
26
26
27
27

T01
T02
SW2
OPEN
SW1

48.0
48.3
35.2
50.4
29.2

51.3
51.2
37.1
53.6
31.0

55.0
54.5
39.1
57.2
33.0

81.6
77.0
53.4
82.9
46.4

89.9
83.0
56.5
90.6
49.2

27
27
27
27
27

L-SR
EL-S
EL03
EL04
T01

45.5
38.5
19.7
18.9
50.7

48.1
40.8
21.6
20.7
53.9

50.8
43.2
23.7
22.8
57.7

69.4
59.9
39.0
37.6
85.5

73.8
63.6
42.4
40.9
94.8

41

Table 15.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

27
27
28
28
28

T02
SW2
OPEN
SW1
L-SR

48.5
36.5
52.2
30.7
46.8

51.4
38.4
55.4
32.5
49.4

54.5
40.5
59.1
34.5
52.2

76.2
54.9
85.0
48.1
70.9

81.9
58.0
92.8
50.9
75.3

28
28
28
28
28

EL-S
EL03
EL04
T01
T02

39.8
20.2
19.3
52.4
50.0

42.1
22.0
21.1
55.7
52.9

44.6
24.2
23.2
59.6
56.1

61.3
39.5
38.1
87.6
77.9

65.1
42.9
41.3
96.9
83.6

28
29
29
29
29

SW2
OPEN
SW1
L-SR
EL-S

37.8
48.0
32.3
48.3
41.1

39.8
52.0
34.2
50.9
43.5

41.9
56.4
36.1
53.7
46.0

56.4
83.8
49.9
72.5
62.9

59.6
91.8
52.8
77.0
66.7

29
29
29
29
29

EL03
EL04
T01
T02
SW2

20.6
19.7
44.3
51.7
39.3

22.5
21.6
48.1
54.6
41.3

24.6
23.6
52.5
57.8
43.5

40.0
38.5
81.3
79.7
58.2

43.4
41.8
90.1
85.4
61.4

30
30
30
30
30

OPEN
SW1
L-SR
EL-S
EL03

46.8
34.1
49.8
42.6
21.0

50.9
36.0
52.5
45.0
22.9

55.5
38.0
55.3
47.5
25.0

84.0
52.0
74.3
64.5
40.4

92.2
55.0
78.8
68.4
43.9

30
30
30
30
31

EL04
T01
T02
SW2
OPEN

20.0
42.7
53.5
40.9
45.8

21.9
46.4
56.5
43.0
49.8

24.0
50.6
59.8
45.1
54.5

39.0
79.4
81.8
60.1
84.0

42.2
88.2
87.5
63.4
92.5

31
31
31
31
31

SW1
L-SR
EL-S
EL03
EL04

36.2
51.5
44.2
21.4
20.5

38.1
54.2
46.7
23.3
22.4

40.2
57.1
49.2
25.5
24.4

54.5
76.2
66.4
40.8
39.4

57.6
80.8
70.3
44.3
42.7

31
31
31
32
32

T01
T02
SW2
OPEN
SW1

42.7
55.6
42.7
44.5
38.6

46.4
58.6
44.8
48.4
40.6

50.6
61.9
47.0
52.9
42.8

79.7
84.1
62.2
83.1
57.4

88.7
89.8
65.5
91.9
60.6

42

Table 15.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

32
32
32
32
32

L-SR
EL-S
EL03
EL04
T01

53.4
46.0
21.8
20.9
42.3

56.1
48.5
23.7
22.8
45.9

59.0
51.0
25.8
24.8
50.0

78.3
68.4
41.3
39.8
79.2

82.9
72.4
44.7
43.1
88.2

32
32
33
33
33

T02
SW2
OPEN
SW1
L-SR

57.9
44.7
43.8
41.6
55.4

61.0
46.8
47.5
43.7
58.2

64.4
49.0
51.8
45.9
61.2

86.6
64.5
82.1
61.1
80.7

92.4
68.0
91.3
64.4
85.4

33
33
33
33
33

EL-S
EL03
EL04
T01
T02

48.0
22.2
21.3
41.9
60.5

50.5
24.1
23.2
45.5
63.7

53.1
26.3
25.2
49.5
67.1

70.7
41.7
40.3
78.3
89.6

74.8
45.2
43.6
87.4
95.4

33
34
34
34
34

SW2
OPEN
SW1
L-SR
EL-S

46.9
43.3
45.5
57.8
50.2

49.1
46.9
47.7
60.6
52.8

51.4
51.1
50.0
63.6
55.5

67.2
81.2
66.0
83.4
73.3

70.7
90.6
69.5
88.1
77.4

34
34
34
34
34

EL03
EL04
T01
T02
SW2

22.6
21.7
41.7
63.5
49.5

24.6
23.6
45.1
66.8
51.7

26.7
25.7
49.0
70.3
54.1

42.2
40.7
77.4
93.0
70.2

45.6
44.1
86.5
98.9
73.9

35
35
35
35
35

OPEN
SW1
L-SR
EL-S
EL03

42.6
51.3
60.4
52.8
23.0

46.1
53.7
63.3
55.4
24.9

50.0
56.2
66.4
58.1
27.1

79.1
73.6
86.5
76.3
42.6

88.5
77.6
91.3
80.5
46.1

35
35
35
35
36

EL04
T01
T02
SW2
MECH

22.1
41.2
66.9
52.5
75.2

24.0
44.5
70.3
54.8
79.1

26.1
48.2
73.9
57.2
83.5

41.2
75.6
97.0
73.9
****

44.5
84.4
****
77.6
****

36
36
36
36
36

ELME
EL-S
EL03
EL04
SW2

79.3
55.8
23.0
22.1
56.1

83.6
58.4
25.0
24.0
58.5

88.3
61.3
27.1
26.1
61.0

****
79.9
42.6
41.2
78.4

****
84.2
46.1
44.5
82.3

43

Table 15.

Level
R

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)
SW2

60.8

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

63.4

66.1

44

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

84.4

88.6

Table 16.

Level

Results of Tenability Analysis for Scenario 16.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

B
B
B
B
B

MECH
L-SR
L-MR
L-HR
EL-S

38.5
61.7
41.3
37.1
83.7

45.0
72.2
48.6
43.3
****

53.7
86.2
58.3
51.3
****

****
****
****
****
****

****
****
****
****
****

B
B
B
B
B

EL01
EL02
EL03
EL04
SW2

61.3
57.6
52.2
50.4
66.6

71.5
67.1
60.5
58.4
78.2

84.9
79.4
70.9
68.5
93.8

****
****
****
****
****

****
****
****
****
****

G
G
G
G
G

OPEN
SW1
L-SR
EL-S
EL01

7.6
17.2
15.2
25.4
12.1

9.5
19.9
17.6
28.5
14.4

11.8
22.9
20.3
31.9
16.8

27.6
45.5
39.2
57.3
34.0

31.4
52.8
44.4
65.0
38.3

G
G
G
G
G

EL02
EL03
EL04
T01
T02

12.3
11.4
11.5
15.5
17.8

14.5
13.5
13.7
17.9
20.4

16.9
15.9
16.0
20.5
23.2

34.2
32.8
33.1
39.4
43.9

38.7
37.1
37.5
44.5
49.8

G
2
2
2
2

SW2
OPEN
SW1
L-SR
CR01

17.6
1.0
1.0
1.0
1.6

20.3
1.0
1.6
1.6
1.9

23.2
1.0
2.0
2.0
2.7

44.4
4.8
10.2
9.6
11.2

50.6
6.1
12.2
11.5
13.3

2
2
2
2
2

CR02
EL-S
EL01
EL02
EL03

1.4
3.6
1.3
1.9
1.9

1.9
4.4
1.8
2.6
2.5

2.4
5.5
2.3
3.4
3.3

10.7
16.3
11.0
13.6
13.8

12.7
18.6
13.1
16.0
16.2

2
2
2
2
3

EL04
T01
T02
SW2
SW1

1.9
1.8
2.0
1.0
2.0

2.5
2.2
2.8
1.4
2.7

3.3
2.9
3.7
1.9
3.4

13.7
12.2
13.8
9.2
12.7

16.1
14.3
16.1
11.1
14.9

3
3
3
3
3

L-SR
EL-S
EL01
EL02
EL03

21.0
5.8
2.7
3.8
3.0

23.8
6.9
3.3
4.8
3.9

26.9
8.3
4.1
5.9
4.9

56.2
20.2
14.2
17.5
16.2

68.9
22.7
16.5
20.1
18.6

45

Table 16.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

3
3
4
4
4

EL04
SW2
SW1
L-SR
EL-S

3.0
2.8
3.2
23.5
7.9

3.8
3.5
3.9
26.3
9.3

4.8
4.4
4.9
29.5
10.8

16.0
14.1
15.0
61.0
23.5

18.4
16.2
17.2
75.8
26.1

4
4
4
4
4

EL01
EL02
EL03
EL04
SW2

4.0
6.0
4.3
4.2
4.8

4.9
7.3
5.3
5.1
5.8

6.0
8.8
6.5
6.3
6.9

17.0
21.4
18.3
18.0
17.8

19.4
24.1
20.9
20.6
20.1

5
5
5
5
5

SW1
L-SR
EL-S
EL01
EL02

4.4
25.6
9.9
5.6
8.6

5.3
28.5
11.4
6.6
10.0

6.4
31.9
13.1
7.8
11.7

17.0
65.5
26.2
19.5
25.1

19.3
82.9
29.0
22.0
27.9

5
5
5
6
6

EL03
EL04
SW2
SW1
L-SR

5.6
5.4
6.8
5.6
27.5

6.7
6.5
8.0
6.7
30.4

8.0
7.7
9.4
7.8
34.0

20.3
19.8
20.8
18.8
69.8

23.0
22.4
23.1
21.1
91.0

6
6
6
6
6

EL-S
EL01
EL02
EL03
EL04

11.8
7.0
11.2
6.8
6.5

13.4
8.2
12.8
8.0
7.7

15.1
9.6
14.7
9.5
9.0

28.6
21.7
28.7
22.1
21.5

31.4
24.3
31.7
24.8
24.2

6
7
7
7
7

SW2
SW1
L-SR
EL-S
EL01

8.7
6.8
29.2
13.4
8.4

10.0
7.9
32.3
15.1
9.7

11.6
9.2
36.1
16.9
11.2

23.3
20.4
74.3
30.7
23.7

25.5
22.7
****
33.6
26.4

7
7
7
7
8

EL02
EL03
EL04
SW2
SW1

13.8
8.0
7.6
10.5
7.9

15.6
9.3
8.8
11.9
9.1

17.6
10.8
10.3
13.5
10.5

32.2
23.8
23.0
25.3
21.9

35.3
26.5
25.7
27.5
24.1

8
8
8
8
8

L-SR
EL-S
EL01
EL02
EL03

30.8
14.9
9.8
16.4
9.1

34.0
16.7
11.1
18.4
10.5

38.1
18.6
12.7
20.5
12.1

79.1
32.6
25.6
35.6
25.3

****
35.5
28.3
38.9
28.1

46

Table 16.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

8
8
9
9
9

EL04
SW2
SW1
L-SR
EL-S

8.6
12.0
9.0
32.4
16.4

9.9
13.6
10.3
35.8
18.2

11.5
15.2
11.7
40.1
20.1

24.4
27.1
23.2
84.6
34.3

27.1
29.3
25.4
****
37.3

9
9
9
9
9

EL01
EL02
EL03
EL04
SW2

11.0
19.0
10.2
9.6
13.6

12.5
21.0
11.7
11.0
15.1

14.1
23.3
13.3
12.6
16.8

27.3
38.9
26.7
25.7
28.6

30.1
42.4
29.6
28.4
30.9

10
10
10
10
10

SW1
L-SR
EL-S
EL01
EL02

10.0
33.9
17.7
12.2
21.6

11.4
37.5
19.5
13.8
23.7

12.8
42.2
21.6
15.5
26.0

24.4
91.4
35.9
28.9
42.1

26.6
****
39.0
31.7
45.8

10
10
10
11
11

EL03
EL04
SW2
SW1
L-SR

11.2
10.6
14.9
11.0
35.9

12.8
12.0
16.5
12.4
39.8

14.5
13.6
18.2
13.9
44.9

28.1
26.9
30.0
25.6
****

31.0
29.7
32.3
27.9
****

11
11
11
11
11

EL-S
EL01
EL02
EL03
EL04

18.9
13.4
24.0
12.2
11.4

20.8
15.0
26.3
13.8
12.9

22.8
16.7
28.7
15.6
14.6

37.3
30.3
45.3
29.4
28.0

40.5
33.2
49.1
32.3
30.8

11
12
12
12
12

SW2
SW1
L-SR
EL-S
EL01

16.2
12.0
38.0
20.0
14.5

17.8
13.4
42.2
21.9
16.1

19.5
15.0
47.9
24.0
17.9

31.5
26.8
****
38.7
31.7

33.9
29.1
****
41.9
34.7

12
12
12
12
13

EL02
EL03
EL04
SW2
SW1

26.5
13.1
12.3
17.4
12.9

28.8
14.8
13.8
19.0
14.4

31.3
16.6
15.6
20.8
16.0

48.4
30.6
29.1
32.9
28.0

52.3
33.5
31.9
35.4
30.3

13
13
13
13
13

L-SR
EL-S
EL01
EL02
EL03

40.4
21.1
15.5
28.9
14.0

45.0
23.0
17.2
31.3
15.7

51.6
25.2
19.0
33.9
17.6

****
40.0
33.0
51.4
31.7

****
43.2
36.0
55.5
34.7

47

Table 16.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

13
13
14
14
14

EL04
SW2
SW1
L-SR
EL-S

13.0
18.5
13.8
39.6
22.1

14.7
20.2
15.3
43.6
24.0

16.4
21.9
16.9
49.0
26.2

30.1
34.2
29.0
****
41.1

33.0
36.8
31.3
****
44.4

14
14
14
14
14

EL01
EL02
EL03
EL04
SW2

16.7
31.8
14.9
13.8
19.6

18.4
34.4
16.6
15.5
21.2

20.3
37.0
18.5
17.3
23.0

34.6
55.5
32.8
31.0
35.4

37.6
59.9
35.8
33.9
38.0

15
15
15
15
15

MECH
SW1
L-SR
CR01
EL-S

54.4
14.6
38.9
76.8
22.9

63.5
16.0
42.6
92.6
24.9

79.3
17.7
47.1
****
27.1

****
29.9
85.9
****
42.1

****
32.2
****
****
45.4

15
15
15
15
15

EL01
EL02
EL03
EL04
T01

17.6
33.9
15.7
14.6
35.9

19.4
36.5
17.5
16.2
39.0

21.3
39.3
19.4
18.0
42.7

35.7
58.3
33.7
31.9
74.2

38.8
62.9
36.9
34.8
87.3

15
15
16
16
16

T02
SW2
OPEN
SW1
L-SR

45.7
20.5
41.6
15.4
39.8

51.2
22.2
45.4
16.9
43.3

58.8
23.9
50.1
18.6
47.6

****
36.5
87.4
30.7
79.8

****
39.1
****
33.2
91.2

16
16
16
16
16

CR01
EL-S
EL01
EL02
EL03

55.2
23.8
18.4
35.8
16.5

61.0
25.8
20.2
38.4
18.3

68.2
27.9
22.2
41.3
20.2

****
43.0
36.7
60.7
34.7

****
46.3
39.9
65.5
37.8

16
16
16
16
17

EL04
T01
T02
SW2
OPEN

15.3
40.7
41.1
21.4
41.7

16.9
44.5
44.8
23.0
45.4

18.8
49.3
49.4
24.9
49.9

32.7
88.7
84.1
37.5
84.9

35.7
****
97.8
40.1
99.3

17
17
17
17
17

SW1
L-SR
CR01
EL-S
EL01

16.1
36.5
55.0
24.6
19.2

17.7
39.3
60.5
26.7
21.0

19.4
42.2
67.2
28.8
23.0

31.6
63.2
****
44.0
37.7

34.1
68.7
****
47.3
40.9

48

Table 16.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

17
17
17
17
17

EL02
EL03
EL04
T01
T02

37.4
17.3
15.9
41.2
40.0

40.1
19.0
17.7
45.0
43.2

43.0
21.0
19.5
49.7
46.9

62.8
35.6
33.5
87.6
73.6

67.8
38.8
36.5
****
81.7

17
18
18
18
18

SW2
OPEN
SW1
L-SR
CR01

22.3
42.0
17.0
36.6
55.1

24.0
45.6
18.6
39.2
60.3

25.8
49.9
20.3
42.1
66.8

38.5
83.3
32.6
62.0
****

41.1
96.4
35.0
67.2
****

18
18
18
18
18

EL-S
EL01
EL02
EL03
EL04

25.5
20.0
38.8
18.0
16.6

27.5
21.8
41.6
19.8
18.3

29.7
23.9
44.6
21.8
20.2

44.9
38.6
64.8
36.5
34.3

48.2
41.8
69.9
39.7
37.3

18
18
18
19
19

T01
T02
SW2
OPEN
SW1

41.8
40.0
23.2
42.4
17.8

45.5
43.1
24.9
45.9
19.4

50.0
46.7
26.8
50.1
21.1

86.7
71.9
39.5
82.3
33.5

****
79.4
42.2
94.5
36.0

19
19
19
19
19

L-SR
CR01
EL-S
EL01
EL02

37.0
55.3
26.3
20.7
40.1

39.6
60.4
28.4
22.6
42.9

42.4
66.6
30.6
24.7
46.0

61.9
****
45.8
39.5
66.6

66.8
****
49.2
42.7
71.9

19
19
19
19
19

EL03
EL04
T01
T02
SW2

18.8
17.3
42.4
40.4
24.1

20.6
19.0
46.0
43.4
25.9

22.6
20.9
50.5
46.8
27.7

37.4
35.1
86.0
71.3
40.6

40.6
38.1
****
78.3
43.3

20
20
20
20
20

OPEN
SW1
L-SR
CR01
EL-S

43.0
18.7
37.7
55.8
27.2

46.4
20.3
40.3
60.8
29.3

50.5
22.0
43.0
66.8
31.5

81.8
34.5
62.2
****
46.8

93.3
37.0
67.0
****
50.2

20
20
20
20
20

EL01
EL02
EL03
EL04
T01

21.4
41.4
19.5
17.9
43.0

23.3
44.2
21.3
19.7
46.6

25.4
47.3
23.4
21.6
51.0

40.3
68.2
38.2
35.8
85.7

43.5
73.6
41.5
38.8
99.8

49

Table 16.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

20
20
21
21
21

T02
SW2
OPEN
SW1
L-SR

40.8
25.0
43.7
19.6
38.2

43.8
26.8
47.1
21.2
40.8

47.2
28.7
51.1
22.9
43.6

71.1
41.6
81.8
35.5
62.5

78.0
44.4
92.9
38.0
67.2

21
21
21
21
21

CR01
EL-S
EL01
EL02
EL03

56.4
28.1
22.1
42.5
20.1

61.3
30.2
24.0
45.4
22.0

67.2
32.4
26.1
48.5
24.0

****
47.8
41.1
69.8
39.1

****
51.2
44.3
75.3
42.3

21
21
21
21
22

EL04
T01
T02
SW2
OPEN

18.5
43.8
41.5
26.0
44.3

20.3
47.4
44.5
27.8
47.8

22.2
51.7
47.8
29.7
51.7

36.5
85.8
71.4
42.7
81.7

39.5
99.3
78.0
45.5
92.3

22
22
22
22
22

SW1
L-SR
CR01
EL-S
EL01

20.5
38.9
57.0
29.0
22.7

22.1
41.5
61.9
31.1
24.7

23.9
44.3
67.6
33.3
26.7

36.5
63.2
****
48.8
41.8

39.1
67.9
****
52.2
45.1

22
22
22
22
22

EL02
EL03
EL04
T01
T02

43.6
20.8
19.1
44.7
42.3

46.5
22.7
20.9
48.3
45.3

49.7
24.8
22.9
52.6
48.6

71.2
39.8
37.2
86.3
72.0

76.8
43.2
40.3
99.5
78.6

22
23
23
23
23

SW2
OPEN
SW1
L-SR
CR01

27.0
43.5
21.5
39.5
55.7

28.8
46.7
23.1
42.1
60.1

30.7
50.4
24.9
44.8
65.2

43.9
77.6
37.6
63.6
99.4

46.6
86.4
40.2
68.3
****

23
23
23
23
23

EL-S
EL01
EL02
EL03
EL04

29.9
23.4
44.5
21.4
19.7

32.0
25.3
47.4
23.4
21.5

34.3
27.4
50.7
25.5
23.5

49.8
42.5
72.5
40.6
37.9

53.3
45.8
78.2
44.0
41.0

23
23
23
24
24

T01
T02
SW2
OPEN
SW1

45.3
42.9
28.0
42.6
22.4

48.8
45.9
29.8
45.7
24.1

53.0
49.2
31.7
49.1
25.9

85.2
72.3
45.0
74.2
38.7

97.0
78.7
47.8
81.8
41.3

50

Table 16.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

24
24
24
24
24

L-SR
CR01
EL-S
EL01
EL02

39.7
54.5
30.8
24.0
45.3

42.2
58.6
33.0
25.9
48.3

44.9
63.4
35.2
28.0
51.5

63.4
94.9
50.9
43.2
73.5

67.9
****
54.3
46.5
79.3

24
24
24
24
24

EL03
EL04
T01
T02
SW2

22.0
20.3
45.4
43.0
29.0

24.0
22.1
48.7
45.9
30.9

26.1
24.1
52.7
49.1
32.8

41.3
38.5
82.8
71.6
46.2

44.7
41.6
93.2
77.7
49.0

25
25
25
25
25

OPEN
SW1
L-SR
CR01
EL-S

42.6
23.5
40.2
54.6
31.8

45.7
25.2
42.7
58.6
33.9

49.0
27.0
45.4
63.1
36.2

73.2
39.9
63.7
93.7
52.0

80.4
42.5
68.1
****
55.4

25
25
25
25
25

EL01
EL02
EL03
EL04
T01

24.7
46.1
22.7
20.8
45.8

26.6
49.1
24.6
22.7
49.2

28.8
52.4
26.8
24.7
53.0

43.9
74.5
42.1
39.2
82.0

47.3
80.3
45.5
42.3
91.8

25
25
26
26
26

T02
SW2
OPEN
SW1
L-SR

43.5
30.1
41.9
24.5
40.2

46.4
31.9
44.9
26.3
42.7

49.5
33.9
48.0
28.1
45.3

71.5
47.3
70.8
41.1
63.2

77.5
50.2
77.3
43.7
67.4

26
26
26
26
26

EL-S
EL01
EL02
EL03
EL04

32.8
25.4
47.0
23.4
21.5

34.9
27.4
50.1
25.4
23.3

37.3
29.5
53.4
27.5
25.4

53.1
44.7
75.5
43.0
40.0

56.6
48.1
81.4
46.4
43.1

26
26
26
27
27

T01
T02
SW2
OPEN
SW1

45.6
43.4
31.2
45.9
25.7

48.8
46.1
33.0
48.8
27.5

52.4
49.1
35.0
52.2
29.3

79.6
70.3
48.6
76.7
42.4

88.4
75.8
51.5
84.1
45.1

27
27
27
27
27

L-SR
EL-S
EL03
EL04
T01

40.5
33.8
23.9
22.0
46.1

42.9
36.0
26.0
23.9
49.2

45.5
38.4
28.2
25.9
52.7

63.2
54.2
43.7
40.6
79.4

67.3
57.8
47.2
43.8
88.2

51

Table 16.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

27
27
28
28
28

T02
SW2
OPEN
SW1
L-SR

43.6
32.3
47.1
26.9
41.5

46.3
34.2
50.1
28.7
43.9

49.3
36.1
53.5
30.6
46.6

69.8
49.9
78.0
43.8
64.2

75.1
52.8
85.3
46.6
68.4

28
28
28
28
28

EL-S
EL03
EL04
T01
T02

35.0
24.5
22.5
47.4
44.8

37.2
26.5
24.4
50.5
47.5

39.5
28.7
26.5
54.1
50.4

55.5
44.3
41.2
80.7
70.9

59.1
47.8
44.4
89.5
76.2

28
29
29
29
29

SW2
OPEN
SW1
L-SR
EL-S

33.6
48.7
28.4
42.7
36.2

35.4
51.8
30.2
45.2
38.4

37.4
55.2
32.1
47.8
40.8

51.3
79.8
45.4
65.6
56.9

54.3
87.1
48.2
69.7
60.5

29
29
29
29
29

EL03
EL04
T01
T02
SW2

25.0
22.9
49.0
46.1
34.9

27.0
24.9
52.2
48.9
36.8

29.3
26.9
55.8
51.8
38.8

44.9
41.7
82.6
72.4
52.8

48.5
44.9
91.4
77.7
55.9

30
30
30
30
30

OPEN
SW1
L-SR
EL-S
EL03

50.5
29.9
44.0
37.5
25.5

53.6
31.8
46.5
39.7
27.6

57.1
33.7
49.2
42.1
29.8

81.9
47.3
67.1
58.3
45.5

89.2
50.1
71.3
62.0
49.0

30
30
30
30
31

EL04
T01
T02
SW2
OPEN

23.4
50.9
47.7
36.3
50.2

25.3
54.1
50.5
38.3
53.5

27.4
57.8
53.5
40.3
57.2

42.2
84.9
74.1
54.5
82.5

45.4
93.8
79.4
57.6
89.9

31
31
31
31
31

SW1
L-SR
EL-S
EL03
EL04

31.8
45.5
38.9
26.0
23.8

33.7
48.0
41.2
28.0
25.8

35.7
50.7
43.6
30.3
27.9

49.4
68.7
60.0
46.1
42.7

52.3
73.0
63.7
49.6
45.9

31
31
31
32
32

T01
T02
SW2
OPEN
SW1

43.4
49.5
37.9
50.3
33.9

46.6
52.3
39.9
53.9
35.9

50.2
55.3
41.9
57.9
37.9

75.2
76.1
56.4
83.9
52.0

82.7
81.4
59.5
91.4
55.0

52

Table 16.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

32
32
32
32
32

L-SR
EL-S
EL03
EL04
T01

47.1
40.5
26.5
24.3
41.9

49.7
42.8
28.6
26.2
45.0

52.4
45.3
30.8
28.3
48.4

70.6
61.8
46.6
43.2
72.6

74.9
65.5
50.2
46.4
79.6

32
32
33
33
33

T02
SW2
OPEN
SW1
L-SR

51.5
39.7
50.8
36.6
48.9

54.3
41.7
54.7
38.6
51.5

57.4
43.8
58.9
40.7
54.3

78.3
58.5
86.0
55.2
72.7

83.6
61.7
93.7
58.3
77.0

33
33
33
33
33

EL-S
EL03
EL04
T01
T02

42.3
26.9
24.7
41.7
53.7

44.6
29.0
26.7
44.8
56.6

47.1
31.3
28.8
48.1
59.8

63.8
47.1
43.7
72.0
80.9

67.6
50.7
46.9
78.9
86.2

33
34
34
34
34

SW2
OPEN
SW1
L-SR
EL-S

41.7
50.8
40.0
51.0
44.3

43.8
54.8
42.1
53.6
46.7

45.9
59.3
44.3
56.5
49.2

60.9
87.8
59.4
75.1
66.2

64.2
95.9
62.8
79.5
70.0

34
34
34
34
34

EL03
EL04
T01
T02
SW2

27.4
25.1
42.0
56.4
44.1

29.5
27.1
45.0
59.3
46.2

31.7
29.2
48.4
62.6
48.4

47.6
44.2
72.3
83.9
63.7

51.2
47.4
79.3
89.3
67.1

35
35
35
35
35

OPEN
SW1
L-SR
EL-S
EL03

51.5
45.2
53.4
46.6
27.8

55.6
47.5
56.1
49.0
29.9

60.4
49.8
58.9
51.6
32.2

91.0
66.2
77.8
68.9
48.1

99.9
69.9
82.3
72.8
51.7

35
35
35
35
36

EL04
T01
T02
SW2
MECH

25.6
42.5
59.4
46.9
67.9

27.6
45.5
62.5
49.0
71.5

29.7
48.9
65.8
51.3
75.4

44.7
73.0
87.5
67.1
****

47.9
80.2
93.1
70.6
****

36
36
36
36
36

ELME
EL-S
EL03
EL04
SW2

71.4
49.4
27.9
25.7
50.3

75.3
51.9
29.9
27.6
52.6

79.7
54.5
32.2
29.7
55.0

****
72.2
48.1
44.7
71.4

****
76.2
51.7
48.0
75.1

53

Table 16.

Level
R

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)
SW2

54.9

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

57.3

59.9

54

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

77.2

81.2

Table 17.

Level

Results of Tenability Analysis for Scenario 17.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

B
B
B
B
B

MECH
L-SR
L-MR
L-HR
EL01

53.5
83.2
48.0
40.2
83.2

65.2
****
57.6
47.5
****

83.6
****
71.1
57.4
****

****
****
****
****
****

****
****
****
****
****

B
B
B
B
G

EL02
EL03
EL04
SW2
OPEN

81.7
61.9
65.1
91.3
7.7

99.5
73.1
77.7
****
9.7

****
88.9
96.6
****
11.9

****
****
****
****
27.9

****
****
****
****
31.7

G
G
G
G
G

SW1
L-SR
EL-S
EL01
EL02

22.5
16.7
29.8
11.1
11.1

25.6
19.3
33.4
13.3
13.2

29.2
22.1
37.5
15.6
15.6

60.4
42.3
67.5
32.4
32.3

72.3
48.1
77.1
36.6
36.6

G
G
G
G
G

EL03
EL04
T01
T02
SW2

9.8
9.8
16.3
19.0
21.0

11.8
11.9
18.8
21.7
23.9

14.1
14.2
21.5
24.6
27.1

30.4
30.6
40.9
46.3
52.1

34.5
34.7
46.3
52.6
59.9

2
2
2
2
2

OPEN
SW1
L-SR
CR01
CR02

1.0
1.0
1.0
1.7
1.5

1.0
1.6
1.7
2.0
1.9

1.0
2.0
2.0
2.8
2.6

4.8
10.3
9.9
11.7
11.1

6.1
12.4
11.8
13.7
13.1

2
2
2
2
2

EL-S
EL01
EL02
EL03
EL04

3.8
1.5
2.0
2.1
2.1

4.7
1.9
2.8
2.9
2.9

5.8
2.6
3.8
3.9
3.9

16.8
11.9
14.7
15.6
15.5

19.2
14.1
17.2
18.3
18.1

2
2
2
3
3

T01
T02
SW2
SW1
L-SR

1.8
2.2
1.0
2.2
21.0

2.4
2.9
1.5
2.9
23.8

3.0
3.8
1.9
3.7
26.8

12.5
14.2
9.4
13.2
54.1

14.7
16.4
11.3
15.3
65.1

3
3
3
3
3

EL-S
EL01
EL02
EL03
EL04

6.4
2.6
3.7
3.0
3.0

7.6
3.2
4.7
3.9
3.9

9.0
4.0
5.8
5.0
4.9

21.2
14.4
17.7
17.1
16.9

23.8
16.7
20.3
19.8
19.6

55

Table 17.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

3
4
4
4
4

SW2
SW1
L-SR
EL-S
EL01

3.0
3.6
23.7
8.8
3.8

3.8
4.4
26.4
10.3
4.6

4.8
5.3
29.6
11.9
5.7

14.8
15.7
58.8
24.9
16.7

17.0
17.9
71.2
27.5
19.1

4
4
4
4
5

EL02
EL03
EL04
SW2
SW1

5.6
3.9
3.9
5.4
4.9

6.7
4.9
4.8
6.5
5.9

8.1
6.1
6.0
7.7
7.0

20.7
18.5
18.3
18.9
17.9

23.4
21.2
21.0
21.2
20.2

5
5
5
5
5

L-SR
EL-S
EL01
EL02
EL03

25.9
11.1
5.0
7.5
4.8

28.8
12.7
6.0
8.9
5.9

32.1
14.5
7.2
10.5
7.1

63.2
28.0
18.8
23.6
19.8

77.2
30.7
21.3
26.4
22.5

5
5
6
6
6

EL04
SW2
SW1
L-SR
EL-S

4.7
7.7
6.3
27.9
13.2

5.8
9.0
7.4
30.9
14.9

7.0
10.5
8.7
34.4
16.8

19.5
22.2
19.9
67.3
30.6

22.3
24.5
22.1
83.6
33.5

6
6
6
6
6

EL01
EL02
EL03
EL04
SW2

6.3
9.6
5.7
5.6
9.9

7.4
11.1
6.8
6.7
11.3

8.7
12.8
8.2
8.0
12.9

20.7
26.5
21.1
20.8
24.9

23.3
29.4
23.8
23.5
27.1

7
7
7
7
7

SW1
L-SR
EL-S
EL01
EL02

7.6
29.8
15.1
7.5
11.7

8.8
32.9
16.9
8.7
13.4

10.2
36.6
18.9
10.1
15.2

21.6
71.5
33.0
22.5
29.4

23.9
90.6
36.0
25.1
32.4

7
7
7
8
8

EL03
EL04
SW2
SW1
L-SR

6.5
6.4
11.9
8.9
31.5

7.7
7.6
13.4
10.2
34.7

9.2
9.0
15.1
11.6
38.6

22.2
21.9
27.1
23.2
75.7

25.1
24.7
29.3
25.4
98.8

8
8
8
8
8

EL-S
EL01
EL02
EL03
EL04

16.8
8.7
13.9
7.3
7.1

18.7
9.9
15.7
8.6
8.4

20.7
11.5
17.6
10.1
9.9

35.1
24.1
32.2
23.4
23.0

38.2
26.8
35.3
26.2
25.8

56

Table 17.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

8
9
9
9
9

SW2
SW1
L-SR
EL-S
EL01

13.7
10.1
33.2
18.4
9.8

15.3
11.5
36.5
20.4
11.2

17.0
13.0
40.6
22.5
12.8

29.0
24.6
80.2
37.1
25.7

31.3
26.8
****
40.2
28.4

9
9
9
9
10

EL02
EL03
EL04
SW2
SW1

16.0
8.1
7.9
15.4
11.3

17.9
9.5
9.3
16.9
12.7

20.0
11.0
10.8
18.7
14.3

34.9
24.5
24.0
30.6
25.9

38.2
27.3
26.9
33.0
28.1

10
10
10
10
10

L-SR
EL-S
EL01
EL02
EL03

34.8
19.9
10.9
18.2
8.9

38.3
21.9
12.4
20.2
10.3

42.6
24.0
13.9
22.3
11.9

85.3
38.8
27.1
37.6
25.5

****
42.0
29.9
41.0
28.4

10
10
11
11
11

EL04
SW2
SW1
L-SR
EL-S

8.7
16.8
12.5
36.7
21.3

10.0
18.5
13.9
40.4
23.3

11.7
20.2
15.5
45.1
25.5

25.0
32.2
27.3
91.7
40.4

27.9
34.6
29.5
****
43.7

11
11
11
11
11

EL01
EL02
EL03
EL04
SW2

11.9
20.4
9.7
9.4
18.2

13.5
22.4
11.1
10.8
19.9

15.1
24.7
12.8
12.5
21.7

28.5
40.3
26.5
26.0
33.9

31.3
43.9
29.4
28.8
36.3

12
12
12
12
12

SW1
L-SR
EL-S
EL01
EL02

13.6
38.7
22.6
13.0
22.5

15.0
42.7
24.6
14.5
24.6

16.7
47.8
26.8
16.3
26.9

28.6
99.7
42.0
29.8
43.0

30.9
****
45.3
32.7
46.6

12
12
12
13
13

EL03
EL04
SW2
SW1
L-SR

10.4
10.1
19.6
14.6
40.8

11.9
11.6
21.3
16.1
45.0

13.6
13.2
23.0
17.8
50.7

27.4
26.9
35.4
29.8
****

30.4
29.7
38.0
32.2
****

13
13
13
13
13

EL-S
EL01
EL02
EL03
EL04

23.8
13.9
24.6
11.1
10.8

25.9
15.6
26.8
12.7
12.3

28.1
17.3
29.2
14.4
14.0

43.4
31.0
45.6
28.4
27.7

46.8
34.0
49.4
31.3
30.6

57

Table 17.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

13
14
14
14
14

SW2
SW1
L-SR
EL-S
EL01

20.8
15.6
40.7
24.9
15.5

22.6
17.1
44.6
27.0
17.2

24.4
18.8
49.6
29.2
19.1

36.9
31.0
96.0
44.7
33.4

39.6
33.3
****
48.1
36.4

14
14
14
14
15

EL02
EL03
EL04
SW2
MECH

28.2
11.8
11.5
21.9
40.4

30.6
13.4
12.9
23.7
43.8

33.2
15.2
14.7
25.5
48.0

51.2
29.2
28.5
38.3
80.1

55.5
32.2
31.5
41.0
92.5

15
15
15
15
15

SW1
L-SR
CR01
EL-S
EL01

16.4
36.4
54.2
25.8
16.2

18.0
39.1
59.5
27.9
17.9

19.7
42.1
65.9
30.2
19.9

31.9
63.0
****
45.7
34.3

34.3
68.4
****
49.2
37.4

15
15
15
15
15

EL02
EL03
EL04
T01
T02

29.7
12.5
12.0
38.1
39.2

32.1
14.1
13.6
41.3
42.3

34.8
15.9
15.4
45.0
45.9

53.1
30.1
29.3
75.7
71.9

57.6
33.1
32.2
87.5
79.7

15
16
16
16
16

SW2
OPEN
SW1
L-SR
CR01

22.9
41.3
17.3
37.1
55.1

24.7
44.8
18.9
39.8
60.4

26.6
48.9
20.7
42.7
66.7

39.4
80.7
32.9
63.2
****

42.1
92.7
35.4
68.5
****

16
16
16
16
16

EL-S
EL01
EL02
EL03
EL04

26.8
16.9
30.9
13.1
12.7

28.9
18.7
33.4
14.8
14.3

31.2
20.6
36.1
16.6
16.0

46.8
35.1
54.7
30.8
30.0

50.3
38.3
59.4
33.9
33.0

16
16
16
17
17

T01
T02
SW2
OPEN
SW1

41.6
40.0
23.9
42.5
18.2

45.2
43.1
25.7
46.0
19.9

49.6
46.7
27.6
50.2
21.6

84.7
72.3
40.5
82.1
34.0

99.3
79.8
43.3
94.2
36.4

17
17
17
17
17

L-SR
CR01
EL-S
EL01
EL02

38.1
56.5
27.8
17.5
32.0

40.8
61.7
29.9
19.3
34.6

43.8
68.1
32.2
21.3
37.4

64.2
****
47.9
35.9
56.2

69.4
****
51.4
39.1
61.0

58

Table 17.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

17
17
17
17
17

EL03
EL04
T01
T02
SW2

13.8
13.3
42.8
41.1
25.0

15.4
14.9
46.4
44.2
26.8

17.3
16.7
50.9
47.8
28.6

31.6
30.7
86.2
73.3
41.7

34.7
33.7
****
80.8
44.5

18
18
18
18
18

OPEN
SW1
L-SR
CR01
EL-S

43.7
19.2
39.1
57.8
28.8

47.3
20.8
41.9
63.1
30.9

51.5
22.6
44.8
69.6
33.2

83.6
35.0
65.3
****
49.0

95.7
37.5
70.5
****
52.5

18
18
18
18
18

EL01
EL02
EL03
EL04
T01

18.1
33.1
14.4
13.8
44.0

19.9
35.7
16.0
15.5
47.7

21.9
38.5
17.9
17.3
52.2

36.6
57.6
32.4
31.4
87.8

39.8
62.5
35.5
34.5
****

18
18
19
19
19

T02
SW2
OPEN
SW1
L-SR

42.2
26.0
45.0
20.1
40.2

45.4
27.8
48.6
21.8
43.0

49.0
29.7
52.9
23.6
45.9

74.5
42.9
85.1
36.1
66.4

81.9
45.7
97.3
38.7
71.5

19
19
19
19
19

CR01
EL-S
EL01
EL02
EL03

59.2
29.8
18.7
34.1
15.0

64.5
31.9
20.5
36.8
16.7

71.0
34.2
22.5
39.6
18.6

****
50.1
37.3
58.9
33.1

****
53.6
40.5
63.9
36.2

19
19
19
19
20

EL04
T01
T02
SW2
OPEN

14.4
45.3
43.4
27.1
46.3

16.1
49.0
46.6
28.9
49.9

17.9
53.6
50.2
30.8
54.3

32.1
89.4
75.7
44.1
86.7

35.2
****
83.1
47.0
99.0

20
20
20
20
20

SW1
L-SR
CR01
EL-S
EL01

21.2
41.4
60.6
30.8
19.2

22.8
44.1
66.0
32.9
21.0

24.7
47.1
72.6
35.3
23.1

37.3
67.5
****
51.2
37.9

39.8
72.7
****
54.8
41.2

20
20
20
20
20

EL02
EL03
EL04
T01
T02

35.1
15.6
15.0
46.6
44.6

37.7
17.3
16.7
50.4
47.8

40.6
19.3
18.6
55.1
51.5

60.2
33.8
32.8
91.1
76.9

65.2
37.0
35.9
****
84.3

59

Table 17.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

20
21
21
21
21

SW2
OPEN
SW1
L-SR
CR01

28.2
47.7
22.2
42.5
62.1

30.0
51.4
23.9
45.3
67.6

31.9
55.8
25.7
48.3
74.2

45.4
88.5
38.4
68.7
****

48.2
****
41.0
73.9
****

21
21
21
21
21

EL-S
EL01
EL02
EL03
EL04

31.8
19.7
36.0
16.2
15.6

34.0
21.6
38.6
17.9
17.2

36.4
23.7
41.5
19.9
19.1

52.4
38.5
61.3
34.5
33.5

56.0
41.8
66.4
37.7
36.5

21
21
21
22
22

T01
T02
SW2
OPEN
SW1

48.0
45.8
29.3
44.5
23.3

51.9
49.1
31.2
48.1
25.0

56.6
52.8
33.1
52.2
26.8

92.9
78.3
46.6
82.2
39.6

****
85.7
49.6
92.4
42.3

22
22
22
22
22

L-SR
CR01
EL-S
EL01
EL02

43.7
58.4
32.9
20.3
36.8

46.5
63.5
35.1
22.1
39.5

49.5
69.5
37.5
24.2
42.4

70.0
****
53.5
39.1
62.4

75.2
****
57.2
42.3
67.6

22
22
22
22
22

EL03
EL04
T01
T02
SW2

16.8
16.0
48.9
47.1
30.5

18.5
17.8
52.8
50.4
32.3

20.5
19.7
57.5
54.1
34.3

35.2
34.1
92.6
79.7
48.0

38.4
37.2
****
87.0
50.9

23
23
23
23
23

OPEN
SW1
L-SR
CR01
EL-S

42.4
24.4
44.8
55.8
33.9

45.9
26.1
47.6
60.6
36.2

49.7
27.9
50.7
66.1
38.6

77.6
40.9
71.1
****
54.8

86.6
43.5
76.3
****
58.4

23
23
23
23
23

EL01
EL02
EL03
EL04
T01

20.8
37.6
17.3
16.6
49.6

22.7
40.3
19.1
18.4
53.5

24.7
43.2
21.1
20.3
58.0

39.6
63.3
35.9
34.7
91.6

42.9
68.6
39.1
37.9
****

23
23
24
24
24

T02
SW2
OPEN
SW1
L-SR

48.3
31.6
40.8
25.5
45.8

51.6
33.5
44.0
27.3
48.6

55.3
35.5
47.7
29.1
51.6

80.7
49.3
73.6
42.2
71.8

88.0
52.2
81.7
44.9
76.9

60

Table 17.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

24
24
24
24
24

CR01
EL-S
EL01
EL02
EL03

53.7
35.0
21.3
38.2
17.9

58.1
37.3
23.2
40.9
19.7

63.2
39.7
25.3
43.9
21.7

96.3
56.0
40.2
64.1
36.5

****
59.7
43.5
69.4
39.8

24
24
24
24
25

EL04
T01
T02
SW2
OPEN

17.1
49.9
49.1
32.8
41.1

18.9
53.6
52.4
34.7
44.3

20.8
58.0
56.1
36.7
47.9

35.3
89.8
81.2
50.6
73.7

38.5
****
88.3
53.6
81.6

25
25
25
25
25

SW1
L-SR
CR01
EL-S
EL01

26.7
47.0
54.0
36.1
21.9

28.5
49.8
58.3
38.4
23.8

30.4
52.8
63.3
40.8
25.8

43.5
73.1
96.0
57.2
40.9

46.3
78.2
****
60.9
44.2

25
25
25
25
25

EL02
EL03
EL04
T01
T02

38.8
18.4
17.7
50.8
50.4

41.6
20.2
19.4
54.6
53.7

44.5
22.3
21.4
59.0
57.4

64.8
37.2
36.0
90.4
82.4

70.1
40.5
39.1
****
89.5

25
26
26
26
26

SW2
OPEN
SW1
L-SR
EL-S

33.9
36.6
27.9
45.3
37.3

35.9
39.4
29.7
47.9
39.6

37.9
42.5
31.6
50.7
42.0

52.0
63.9
44.9
69.6
58.5

55.1
69.7
47.7
74.2
62.2

26
26
26
26
26

EL01
EL02
EL03
EL04
T01

22.5
39.5
19.3
18.5
48.0

24.4
42.2
21.1
20.3
51.3

26.5
45.2
23.2
22.3
55.0

41.5
65.5
38.4
37.1
81.6

44.8
70.8
41.8
40.4
89.9

26
26
27
27
27

T02
SW2
OPEN
SW1
L-SR

48.3
35.2
50.4
29.2
45.5

51.3
37.1
53.6
31.0
48.1

54.5
39.1
57.2
33.0
50.8

77.0
53.4
82.9
46.4
69.4

83.0
56.5
90.7
49.2
73.8

27
27
27
27
27

EL-S
EL03
EL04
T01
T02

38.5
19.7
18.9
50.7
48.5

40.8
21.6
20.7
54.0
51.4

43.2
23.7
22.8
57.7
54.5

59.9
39.0
37.6
85.5
76.2

63.6
42.4
40.9
94.8
81.9

61

Table 17.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

27
28
28
28
28

SW2
OPEN
SW1
L-SR
EL-S

36.5
52.2
30.7
46.8
39.8

38.4
55.4
32.5
49.4
42.1

40.5
59.1
34.5
52.2
44.6

54.9
85.0
48.1
70.9
61.3

58.0
92.8
50.9
75.4
65.1

28
28
28
28
28

EL03
EL04
T01
T02
SW2

20.2
19.3
52.4
50.0
37.8

22.0
21.1
55.8
52.9
39.8

24.2
23.2
59.6
56.1
41.9

39.5
38.1
87.6
77.9
56.4

42.9
41.3
96.9
83.6
59.6

29
29
29
29
29

OPEN
SW1
L-SR
EL-S
EL03

48.0
32.3
48.3
41.1
20.6

52.0
34.2
50.9
43.5
22.5

56.4
36.1
53.7
46.0
24.6

83.8
49.9
72.5
62.9
40.0

91.8
52.9
77.0
66.7
43.4

29
29
29
29
30

EL04
T01
T02
SW2
OPEN

19.7
44.3
51.7
39.3
46.8

21.6
48.1
54.6
41.3
50.9

23.6
52.5
57.8
43.5
55.5

38.5
81.3
79.7
58.2
84.0

41.8
90.1
85.4
61.4
92.2

30
30
30
30
30

SW1
L-SR
EL-S
EL03
EL04

34.1
49.8
42.6
21.0
20.0

36.0
52.5
45.0
22.9
21.9

38.0
55.3
47.5
25.0
24.0

52.1
74.3
64.5
40.4
39.0

55.0
78.8
68.4
43.9
42.2

30
30
30
31
31

T01
T02
SW2
OPEN
SW1

42.7
53.5
40.9
45.8
36.2

46.4
56.5
43.0
49.8
38.1

50.6
59.8
45.1
54.5
40.2

79.4
81.8
60.1
84.0
54.5

88.2
87.5
63.4
92.5
57.6

31
31
31
31
31

L-SR
EL-S
EL03
EL04
T01

51.5
44.2
21.4
20.5
42.7

54.2
46.7
23.3
22.4
46.4

57.1
49.2
25.5
24.4
50.6

76.2
66.4
40.8
39.4
79.7

80.8
70.3
44.3
42.7
88.7

31
31
32
32
32

T02
SW2
OPEN
SW1
L-SR

55.6
42.7
44.5
38.6
53.4

58.6
44.8
48.4
40.6
56.1

61.9
47.0
52.9
42.8
59.0

84.1
62.2
83.1
57.4
78.3

89.8
65.5
91.9
60.6
83.0

62

Table 17.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

32
32
32
32
32

EL-S
EL03
EL04
T01
T02

46.0
21.8
20.9
42.3
57.9

48.5
23.7
22.8
45.9
61.0

51.0
25.9
24.8
50.0
64.4

68.4
41.3
39.8
79.2
86.6

72.4
44.7
43.1
88.2
92.4

32
33
33
33
33

SW2
OPEN
SW1
L-SR
EL-S

44.7
43.8
41.6
55.4
48.0

46.8
47.5
43.7
58.2
50.5

49.0
51.8
45.9
61.2
53.1

64.5
82.1
61.1
80.7
70.7

68.0
91.3
64.4
85.4
74.8

33
33
33
33
33

EL03
EL04
T01
T02
SW2

22.2
21.3
41.9
60.5
46.9

24.1
23.2
45.5
63.7
49.1

26.3
25.2
49.5
67.1
51.4

41.7
40.3
78.3
89.6
67.2

45.2
43.6
87.4
95.4
70.7

34
34
34
34
34

OPEN
SW1
L-SR
EL-S
EL03

43.3
45.5
57.8
50.2
22.6

46.9
47.7
60.6
52.8
24.6

51.1
50.0
63.6
55.5
26.7

81.2
66.0
83.4
73.3
42.2

90.6
69.5
88.2
77.4
45.6

34
34
34
34
35

EL04
T01
T02
SW2
OPEN

21.7
41.7
63.5
49.5
42.6

23.6
45.1
66.8
51.7
46.1

25.7
49.0
70.3
54.1
50.0

40.7
77.4
93.0
70.2
79.1

44.1
86.5
98.9
73.9
88.5

35
35
35
35
35

SW1
L-SR
EL-S
EL03
EL04

51.3
60.4
52.8
23.0
22.1

53.7
63.3
55.4
24.9
24.0

56.2
66.4
58.1
27.1
26.1

73.6
86.5
76.3
42.6
41.2

77.6
91.3
80.5
46.1
44.5

35
35
35
36
36

T01
T02
SW2
MECH
ELME

41.2
66.9
52.5
75.2
79.3

44.5
70.3
54.8
79.2
83.6

48.2
73.9
57.2
83.5
88.3

75.6
97.0
73.9
****
****

84.4
****
77.6
****
****

36
36
36
36
R

EL-S
EL03
EL04
SW2
SW2

55.8
23.0
22.1
56.1
60.8

58.4
25.0
24.0
58.5
63.4

61.3
27.1
26.1
61.1
66.1

79.9
42.6
41.2
78.4
84.4

84.2
46.1
44.5
82.3
88.6

63

Table 17.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

64

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

Table 18.

Level

Results of Tenability Analysis for Scenario 18.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

G
G
G
2
2

L-HR
EL03
EL04
F-RM
CR02

4.0
16.0
18.3
1.0
10.2

5.6
23.6
28.3
1.0
16.7

8.2
39.3
****
1.0
30.1

58.3
****
****
1.6
****

****
****
****
2.1
****

2
2
3
3
4

EL03
EL04
EL03
EL04
EL03

1.0
1.0
1.2
1.1
2.0

1.0
1.0
1.7
1.6
2.5

1.0
1.0
1.9
1.9
2.9

5.3
5.4
8.3
8.2
11.1

7.0
7.1
10.5
10.4
13.8

4
5
5
6
6

EL04
EL03
EL04
EL03
EL04

1.9
2.9
2.8
3.9
3.7

2.4
3.5
3.3
4.6
4.3

2.9
4.1
3.9
5.4
5.0

10.9
13.8
13.3
16.2
15.6

13.6
16.9
16.4
19.7
19.1

7
7
8
8
9

EL03
EL04
EL03
EL04
EL03

4.9
4.6
5.9
5.5
6.9

5.7
5.3
6.9
6.3
7.9

6.7
6.2
7.9
7.3
9.1

18.5
17.7
20.6
19.7
22.6

22.3
21.5
24.7
23.7
26.9

9
10
10
11
11

EL04
EL03
EL04
EL03
EL04

6.4
7.9
7.2
8.9
8.1

7.3
9.0
8.3
10.0
9.2

8.4
10.3
9.5
11.5
10.5

21.5
24.5
23.2
26.2
24.8

25.8
29.0
27.7
31.0
29.6

12
12
13
13
14

EL03
EL04
EL03
EL04
EL03

9.9
8.9
10.8
9.8
11.7

11.1
10.1
12.0
10.9
13.0

12.6
11.5
13.6
12.4
14.6

27.8
26.3
29.4
27.7
30.9

32.8
31.3
34.6
32.9
36.2

14
15
15
16
16

EL04
EL03
EL04
EL03
EL04

10.6
12.5
11.3
13.3
12.0

11.8
13.9
12.6
14.8
13.4

13.3
15.6
14.1
16.5
15.0

29.1
32.2
30.4
33.6
31.6

34.5
37.8
35.9
39.3
37.3

17
17
18
18
19

EL03
EL04
EL03
EL04
EL03

14.1
12.7
14.9
13.4
15.6

15.6
14.1
16.5
14.9
17.2

17.4
15.8
18.2
16.6
19.1

34.8
32.7
36.1
33.9
37.2

40.7
38.7
42.1
40.0
43.4

65

Table 18.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

19
20
20
21
21

EL04
EL03
EL04
EL03
EL04

14.0
16.4
14.7
17.0
15.4

15.6
18.0
16.3
18.7
16.9

17.3
19.9
18.0
20.7
18.8

35.0
38.4
36.0
39.5
37.0

41.2
44.7
42.4
46.0
43.6

22
22
23
23
24

EL03
EL04
EL03
EL04
EL03

17.7
15.9
18.4
16.6
19.0

19.5
17.6
20.2
18.2
20.8

21.5
19.5
22.2
20.1
22.9

40.5
38.0
41.5
39.0
42.5

47.2
44.7
48.4
45.8
49.5

24
25
25
26
26

EL04
EL03
EL04
EL03
EL04

17.1
19.7
17.7
20.3
18.3

18.8
21.5
19.4
22.2
20.0

20.8
23.6
21.4
24.3
22.0

39.9
43.5
40.7
44.5
41.6

46.9
50.6
47.9
51.7
48.8

27
27
28
28
29

EL03
EL04
EL03
EL04
EL03

20.9
18.8
21.5
19.3
22.0

22.8
20.6
23.4
21.1
24.0

24.9
22.6
25.6
23.1
26.2

45.4
42.3
46.2
43.1
47.0

52.7
49.7
53.7
50.5
54.6

29
30
30
30
31

EL04
L-HR
EL03
EL04
L-HR

19.8
42.2
22.6
20.3
37.0

21.6
49.1
24.6
22.1
41.7

23.7
60.1
26.8
24.2
48.0

43.8
****
47.8
44.4
****

51.3
****
55.5
52.0
****

31
31
32
32
32

EL03
EL04
L-HR
EL03
EL04

23.1
20.8
35.3
23.7
21.3

25.1
22.6
39.3
25.7
23.1

27.4
24.8
44.5
28.0
25.3

48.6
45.1
92.0
49.3
45.7

56.3
52.8
****
57.1
53.4

33
33
33
34
34

L-HR
EL03
EL04
L-HR
EL03

34.5
24.2
21.8
34.0
24.7

38.1
26.2
23.6
37.5
26.7

42.8
28.6
25.8
41.8
29.1

84.7
50.0
46.4
80.2
50.6

****
57.8
54.1
99.5
58.5

34
34
35
35
35

EL04
T01
L-HR
EL03
EL04

22.2
59.1
34.8
25.2
22.7

24.1
75.9
38.3
27.3
24.6

26.3
****
42.8
29.6
26.8

47.0
****
81.9
51.2
47.6

54.7
****
****
59.2
55.4

66

Table 18.

Level
35
36
36

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)
T01
EL03
EL04

70.7
25.2
22.8

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

****
27.3
24.7

****
29.7
26.9

67

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

****
51.3
47.6

****
59.3
55.4

Table 19.

Level

Results of Tenability Analysis for Scenario 19.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

B
G
G
G
G

L-HR
OPEN
SW1
L-SR
EL-S

96.5
3.0
19.5
12.1
35.1

****
4.3
30.6
16.1
45.8

****
5.0
56.0
21.9
60.9

****
31.1
****
69.6
****

****
44.0
****
90.7
****

G
G
G
G
G

EL01
EL02
EL03
EL04
T01

5.4
5.4
4.6
4.7
13.1

6.7
6.7
5.7
5.7
17.5

8.7
8.6
7.1
7.2
23.9

38.0
37.8
34.9
35.6
74.1

51.6
51.4
48.2
49.4
96.6

G
G
2
2
2

T02
SW2
F-RM
SW1
EL-S

22.3
15.6
1.0
27.4
53.0

31.0
21.1
1.0
42.9
68.5

44.0
29.5
1.0
84.7
91.8

****
87.7
0.0
****
****

****
****
0.0
****
****

2
2
2
2
2

EL01
EL02
EL03
EL04
SW2

7.7
7.7
1.0
1.0
49.4

9.5
9.6
1.0
1.0
68.4

12.1
12.1
1.0
1.0
****

44.8
44.0
0.4
0.4
****

60.0
58.6
0.7
0.7
****

3
3
3
3
3

SW1
EL-S
EL01
EL02
EL03

33.6
66.6
10.0
10.5
1.0

53.6
86.2
12.3
12.7
1.0

****
****
15.3
15.8
1.0

****
****
50.8
50.1
1.0

****
****
67.6
65.8
1.3

3
3
4
4
4

EL04
SW2
SW1
EL-S
EL01

1.0
74.1
39.4
77.8
12.3

1.0
****
68.4
****
14.9

1.0
****
****
****
18.3

1.0
****
****
****
56.3

1.3
****
****
****
74.6

4
4
4
4
5

EL02
EL03
EL04
SW2
SW1

13.3
1.0
1.0
98.9
45.3

16.0
1.0
1.0
****
93.5

19.5
1.0
1.0
****
****

56.1
1.4
1.4
****
****

73.0
2.1
2.1
****
****

5
5
5
5
5

EL-S
EL01
EL02
EL03
EL04

87.6
14.5
16.3
1.0
1.0

****
17.3
19.3
1.0
1.0

****
21.1
23.3
1.0
1.0

****
61.3
62.0
2.1
2.1

****
81.1
80.2
2.7
2.7

68

Table 19.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

5
6
6
6
6

SW2
SW1
EL-S
EL01
EL02

116.6
51.0
96.4
16.5
19.3

****
****
****
19.6
22.7

****
****
****
23.8
27.1

****
****
****
66.0
67.9

****
****
****
87.2
87.3

6
6
7
7
7

EL03
EL04
SW1
EL-S
EL01

1.0
1.0
56.8
104.4
18.4

1.0
1.0
****
****
21.8

1.0
1.0
****
****
26.2

2.7
2.7
****
****
70.4

3.4
3.4
****
****
93.0

7
7
7
8
8

EL02
EL03
EL04
SW1
EL-S

22.4
1.0
1.0
63.0
111.8

26.1
1.0
1.0
****
****

30.9
1.0
1.0
****
****

73.7
3.4
3.3
****
****

94.4
4.2
4.1
****
****

8
8
8
8
9

EL01
EL02
EL03
EL04
SW1

20.3
25.5
1.0
1.0
93.1

23.8
29.5
1.0
1.0
****

28.6
34.7
1.0
1.0
****

74.5
79.4
4.1
4.0
****

98.5
****
4.9
4.8
****

9
9
9
9
9

EL-S
EL01
EL02
EL03
EL04

118.8
22.0
28.5
1.0
1.0

****
25.7
32.9
1.0
1.0

****
30.8
38.5
1.0
1.0

****
78.5
85.2
4.7
4.6

****
****
****
5.5
5.4

10
10
10
10
10

SW1
EL01
EL02
EL03
EL04

98.8
23.6
31.6
1.0
1.0

****
27.5
36.2
1.0
1.0

****
32.8
42.3
1.5
1.4

****
82.2
90.8
5.3
5.2

****
****
****
6.2
6.1

11
11
11
11
11

SW1
EL01
EL02
EL03
EL04

104.4
25.2
34.6
1.0
1.0

****
29.3
39.6
1.5
1.4

****
34.8
46.0
1.8
1.8

****
85.8
96.5
5.9
5.7

****
****
****
6.8
6.6

12
12
12
12
12

SW1
EL01
EL02
EL03
EL04

110.5
26.7
37.7
1.5
1.4

****
30.9
42.9
1.8
1.8

****
36.7
49.7
2.0
2.0

****
89.2
****
6.5
6.3

****
****
****
7.4
7.2

69

Table 19.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

13
13
13
13
13

SW1
EL01
EL02
EL03
EL04

117.8
28.1
40.6
1.8
1.7

****
32.5
46.1
2.0
1.9

****
38.5
53.4
2.5
2.4

****
92.5
****
7.1
6.9

****
****
****
8.1
7.8

14
14
14
14
15

EL01
EL02
EL03
EL04
EL01

31.2
48.3
2.0
1.9
32.4

36.5
56.0
2.5
2.2
37.8

44.1
67.1
2.9
2.8
45.8

****
****
7.6
7.4
****

****
****
8.6
8.3
****

15
15
15
16
16

EL02
EL03
EL04
EL01
EL02

50.9
2.4
2.1
33.4
53.2

59.1
2.8
2.7
38.9
61.9

71.5
3.2
3.0
47.3
75.5

****
8.2
7.9
****
****

****
9.2
8.9
****
****

16
16
17
17
17

EL03
EL04
EL01
EL02
EL03

2.7
2.6
34.3
55.3
2.9

3.0
2.9
40.0
64.5
3.5

3.6
3.4
48.5
79.2
3.9

8.7
8.4
****
****
9.2

9.7
9.4
****
****
10.3

17
18
18
18
18

EL04
EL01
EL02
EL03
EL04

2.8
35.1
57.2
3.3
3.0

3.2
41.0
66.9
3.8
3.6

3.8
49.7
82.8
4.4
4.0

8.9
****
****
9.8
9.4

10.0
****
****
10.9
10.5

19
19
19
19
20

EL01
EL02
EL03
EL04
EL01

35.9
59.0
3.7
3.5
36.7

41.9
69.2
4.1
3.9
42.7

50.8
86.3
4.8
4.5
51.7

****
****
10.3
9.9
****

****
****
11.4
11.0
****

20
20
20
21
21

EL02
EL03
EL04
EL01
EL02

60.7
3.9
3.8
37.3
62.3

71.4
4.6
4.2
43.3
73.5

89.6
5.0
4.8
52.4
92.9

****
10.8
10.3
****
****

****
12.0
11.5
****
****

21
21
22
22
22

EL03
EL04
EL01
EL02
EL03

4.3
4.0
37.9
63.8
4.7

4.9
4.6
43.9
75.4
5.2

5.5
5.1
53.0
96.2
5.9

11.3
10.9
****
****
11.8

12.4
12.0
****
****
13.0

70

Table 19.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

22
23
23
23
23

EL04
EL01
EL02
EL03
EL04

4.4
38.6
65.2
4.9
4.7

4.9
44.6
77.2
5.6
5.2

5.6
53.7
99.0
6.2
5.9

11.3
****
****
12.2
11.8

12.5
****
****
13.5
13.0

24
24
24
24
25

EL01
EL02
EL03
EL04
EL01

39.2
66.1
5.4
4.9
39.9

45.3
78.2
5.9
5.6
46.0

54.4
****
6.6
6.2
55.1

****
****
12.7
12.2
****

****
****
14.0
13.4
****

25
25
25
26
26

EL02
EL03
EL04
OPEN
EL01

66.8
5.7
5.3
85.1
40.6

78.9
6.3
5.9
****
46.7

****
6.9
6.6
****
55.8

****
13.2
12.7
****
****

****
14.4
13.9
****
****

26
26
26
27
27

EL02
EL03
EL04
EL03
EL04

67.6
6.0
5.7
6.4
5.9

79.7
6.8
6.3
7.0
6.7

****
7.5
7.0
7.8
7.3

****
13.9
13.3
14.3
13.7

****
15.2
14.6
15.6
15.0

28
28
29
29
29

EL03
EL04
OPEN
EL03
EL04

6.7
6.2
18.9
6.9
6.6

7.4
6.9
20.8
7.7
7.1

8.0
7.6
23.2
8.4
7.9

14.7
14.1
47.3
15.1
14.4

16.0
15.4
56.6
16.4
15.7

29
30
30
30
30

T01
OPEN
EL03
EL04
T01

16.9
18.2
7.2
6.8
16.4

18.6
20.0
7.9
7.5
17.9

20.5
22.1
8.7
8.1
19.7

39.4
43.4
15.4
14.8
36.8

45.9
51.1
16.8
16.1
42.2

31
31
31
31
32

OPEN
EL03
EL04
T01
OPEN

17.9
7.6
7.0
16.6
17.5

19.6
8.2
7.8
18.0
19.0

21.5
8.9
8.5
19.8
20.9

40.6
15.8
15.1
36.5
38.3

47.1
17.2
16.5
41.8
43.9

32
32
32
33
33

EL03
EL04
T01
OPEN
EL03

7.8
7.4
16.6
17.4
8.0

8.5
8.0
18.0
18.9
8.8

9.3
8.8
19.8
20.7
9.6

16.2
15.5
35.8
37.1
16.5

17.5
16.9
40.8
42.2
17.9

71

Table 19.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

33
33
34
34
34

EL04
T01
OPEN
EL03
EL04

7.7
16.6
17.4
8.4
7.9

8.3
18.0
18.9
9.0
8.7

9.0
19.7
20.6
9.9
9.4

15.9
35.3
36.4
16.9
16.2

17.2
39.9
41.2
18.3
17.6

34
35
35
35
35

T01
OPEN
EL03
EL04
T01

16.7
17.3
8.7
8.2
16.7

18.1
18.7
9.4
8.9
18.0

19.7
20.4
10.2
9.7
19.6

34.9
35.5
17.3
16.6
34.2

39.3
39.8
18.7
18.1
38.3

36
36
36
36

MECH
ELME
EL03
EL04

54.7
82.8
8.7
8.2

65.8
****
9.5
8.9

81.8
****
10.2
9.7

****
****
17.3
16.6

****
****
18.7
18.1

72

Table 20.

Level

Results of Tenability Analysis for Scenario 20.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

B
B
B
B
B

MECH
L-MR
L-HR
EL02
EL03

77.2
89.2
70.3
118.4
100.1

****
****
****
****
****

****
****
****
****
****

****
****
****
****
****

****
****
****
****
****

B
G
G
G
G

EL04
OPEN
SW1
L-SR
EL-S

96.8
3.0
10.8
9.7
24.5

****
4.3
15.0
12.8
31.5

****
5.1
22.4
17.2
41.2

****
31.7
89.0
58.2
99.4

****
44.4
****
75.4
****

G
G
G
G
G

EL01
EL02
EL03
EL04
T01

6.1
6.2
5.6
5.7
12.0

7.8
7.9
7.0
7.1
16.0

10.2
10.4
9.2
9.4
21.8

41.8
43.1
40.4
42.1
68.5

55.6
57.7
54.5
57.2
88.5

G
G
2
2
2

T02
SW2
F-RM
SW1
EL-S

17.0
11.4
1.0
15.3
36.1

23.2
15.1
1.0
20.9
45.7

32.3
20.7
1.0
30.6
59.2

89.6
66.7
0.0
****
****

****
86.7
0.0
****
****

2
2
2
2
2

EL01
EL02
EL03
EL04
SW2

9.8
10.0
1.0
1.0
29.7

12.4
12.5
1.0
1.0
39.3

15.8
16.0
1.0
1.0
53.5

53.0
53.3
0.3
0.3
****

69.7
70.1
0.5
0.5
****

3
3
3
3
3

SW1
EL-S
EL01
EL02
EL03

19.2
45.2
13.5
14.3
1.0

25.4
56.8
16.6
17.5
1.0

37.2
73.6
20.9
22.0
1.0

****
****
62.5
63.4
1.0

****
****
81.7
82.3
1.4

3
3
4
4
4

EL04
SW2
SW1
EL-S
EL01

1.0
41.8
22.5
52.7
16.8

1.0
55.1
29.4
66.1
20.5

1.0
80.4
43.8
86.0
25.5

1.0
****
****
****
70.7

1.4
****
****
****
92.2

4
4
4
4
5

EL02
EL03
EL04
SW2
SW1

18.7
1.0
1.0
51.3
25.3

22.7
1.0
1.0
71.1
33.4

28.0
1.0
1.0
****
50.2

73.2
1.8
1.8
****
****

94.4
2.4
2.3
****
****

73

Table 20.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

5
5
5
5
5

EL-S
EL01
EL02
EL03
EL04

59.0
19.8
23.3
1.0
1.0

74.1
23.9
27.8
1.0
1.0

97.0
29.6
34.0
1.0
1.0

****
78.0
82.7
2.7
2.6

****
****
****
3.4
3.3

5
6
6
6
6

SW2
SW1
EL-S
EL01
EL02

59.4
27.9
64.6
22.6
27.8

92.3
37.1
81.3
27.1
32.9

****
56.6
****
33.3
39.9

****
****
****
84.6
92.1

****
****
****
****
****

6
6
6
7
7

EL03
EL04
SW2
SW1
EL-S

1.0
1.0
69.0
30.2
69.7

1.0
1.0
****
40.7
87.9

1.0
1.0
****
63.9
****

3.6
3.5
****
****
****

4.4
4.3
****
****
****

7
7
7
7
7

EL01
EL02
EL03
EL04
SW2

25.2
32.3
1.0
1.0
84.9

30.0
38.0
1.0
1.0
****

36.8
45.8
1.0
1.0
****

90.7
****
4.5
4.3
****

****
****
5.4
5.2
****

8
8
8
8
8

SW1
EL-S
EL01
EL02
EL03

32.6
74.3
27.6
36.7
1.0

44.3
94.1
32.7
43.0
1.0

90.3
****
39.9
51.5
1.5

****
****
96.3
****
5.4

****
****
****
****
6.3

8
8
9
9
9

EL04
SW2
SW1
EL-S
EL01

1.0
95.5
34.8
78.6
29.7

1.0
****
47.9
99.8
35.2

1.3
****
95.7
****
42.9

5.2
****
****
****
****

6.1
****
****
****
****

9
9
9
9
10

EL02
EL03
EL04
SW2
SW1

41.0
1.2
1.0
101.6
36.9

47.8
1.7
1.5
****
51.3

57.2
1.9
1.8
****
****

****
6.3
6.0
****
****

****
7.2
6.9
****
****

82.6
31.8
45.3
1.8
1.6

****
37.6
52.6
2.0
1.9

****
45.7
62.8
2.4
2.1

****
****
****
7.1
6.7

****
****
****
8.1
7.7

10
10
10
10
10

EL-S
EL01
EL02
EL03
EL04

74

Table 20.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

10
11
11
11
11

SW2
SW1
EL-S
EL01
EL02

107.1
39.5
86.4
33.7
49.4

****
55.3
****
39.7
57.3

****
****
****
48.4
68.3

****
****
****
****
****

****
****
****
****
****

11
11
11
12
12

EL03
EL04
SW2
SW1
EL-S

2.0
1.9
112.5
42.0
90.0

2.5
2.1
****
59.2
****

2.9
2.7
****
****
****

7.9
7.4
****
****
****

9.0
8.4
****
****
****

12
12
12
12
12

EL01
EL02
EL03
EL04
SW2

35.5
53.5
2.6
2.1
117.6

41.8
61.9
2.9
2.7
****

50.8
73.7
3.5
3.0
****

****
****
8.6
8.2
****

****
****
9.7
9.2
****

13
13
13
13
13

SW1
EL-S
EL01
EL02
EL03

44.4
93.3
37.2
57.5
2.9

63.1
****
43.8
66.4
3.4

****
****
53.2
79.1
3.9

****
****
****
****
9.4

****
****
****
****
10.5

13
14
14
14
14

EL04
SW1
EL-S
EL01
EL02

2.7
46.4
96.1
39.6
64.2

3.0
66.6
****
46.7
74.9

3.6
****
****
57.2
91.2

8.9
****
****
****
****

10.0
****
****
****
****

14
14
15
15
15

EL03
EL04
SW1
EL-S
EL01

3.4
2.9
47.6
97.6
41.1

3.9
3.5
67.9
****
48.4

4.5
4.0
****
****
59.4

10.1
9.5
****
****
****

11.3
10.6
****
****
****

15
15
15
16
16

EL02
EL03
EL04
SW1
EL-S

68.5
3.8
3.4
48.7
98.7

80.4
4.4
3.9
69.2
****

99.1
4.9
4.5
****
****

****
10.8
10.1
****
****

****
12.0
11.3
****
****

16
16
16
16
17

EL01
EL02
EL03
EL04
SW1

42.5
72.5
4.2
3.8
49.9

50.0
85.5
4.8
4.4
70.5

61.5
****
5.5
4.9
****

****
****
11.5
10.7
****

****
****
12.7
11.9
****

75

Table 20.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

17
17
17
17
17

EL-S
EL01
EL02
EL03
EL04

99.9
43.8
76.2
4.7
4.1

****
51.5
90.2
5.3
4.8

****
63.3
****
5.9
5.4

****
****
****
12.1
11.3

****
****
****
13.4
12.5

18
18
18
18
18

SW1
EL-S
EL01
EL02
EL03

51.1
101.0
45.0
79.6
5.1

71.8
****
52.9
94.8
5.8

****
****
65.1
****
6.5

****
****
****
****
12.8

****
****
****
****
14.1

18
19
19
19
19

EL04
SW1
EL-S
EL01
EL02

4.6
52.4
102.2
46.1
82.8

5.1
73.2
****
54.2
99.1

5.8
****
****
66.7
****

11.9
****
****
****
****

13.2
****
****
****
****

19
19
20
20
20

EL03
EL04
SW1
EL-S
EL01

5.6
4.9
53.7
103.4
47.2

6.2
5.6
74.6
****
55.4

6.9
6.2
****
****
68.0

13.4
12.5
****
****
****

14.7
13.8
****
****
****

20
20
20
21
21

EL02
EL03
EL04
SW1
EL-S

85.8
6.0
5.4
55.0
104.5

****
6.7
5.9
76.1
****

****
7.4
6.7
****
****

****
14.0
13.1
****
****

****
15.3
14.3
****
****

21
21
21
21
22

EL01
EL02
EL03
EL04
SW1

48.1
88.7
6.5
5.8
56.3

56.4
****
7.1
6.4
77.6

69.2
****
7.9
7.0
****

****
****
14.6
13.6
****

****
****
16.0
14.9
****

22
22
22
22
22

EL-S
EL01
EL02
EL03
EL04

105.7
48.9
91.4
6.9
6.1

****
57.2
****
7.6
6.8

****
70.1
****
8.3
7.6

****
****
****
15.2
14.1

****
****
****
16.6
15.5

23
23
23
23
23

SW1
EL-S
EL01
EL02
EL03

57.7
106.9
49.7
93.9
7.3

79.2
****
58.0
****
7.9

****
****
70.9
****
8.8

****
****
****
****
15.8

****
****
****
****
17.2

76

Table 20.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

23
24
24
24
24

EL04
SW1
EL-S
EL01
EL02

6.6
59.2
108.2
50.5
95.9

7.2
80.8
****
58.9
****

7.9
****
****
71.7
****

14.6
****
****
****
****

16.1
****
****
****
****

24
24
25
25
25

EL03
EL04
SW1
EL-S
EL01

7.7
6.9
60.7
109.5
51.3

8.5
7.6
82.6
****
59.7

9.2
8.4
****
****
72.6

16.3
15.2
****
****
****

17.8
16.6
****
****
****

25
25
25
26
26

EL02
EL03
EL04
SW1
EL-S

97.3
8.0
7.3
62.3
110.9

****
8.8
7.9
84.4
****

****
9.7
8.8
****
****

****
16.9
15.7
****
****

****
18.3
17.1
****
****

26
26
26
26
27

EL01
EL02
EL03
EL04
SW1

52.2
98.4
8.6
7.7
64.1

60.6
****
9.3
8.4
86.3

73.6
****
10.1
9.1
****

****
****
17.5
16.2
****

****
****
19.0
17.7
****

27
27
27
28
28

EL-S
EL03
EL04
SW1
EL-S

112.3
8.9
8.0
66.0
113.8

****
9.7
8.8
88.6
****

****
10.6
9.6
****
****

****
18.1
16.7
****
****

****
19.5
18.2
****
****

28
28
29
29
29

EL03
EL04
SW1
EL-S
EL03

9.3
8.4
68.2
115.5
9.7

10.0
9.0
91.1
****
10.5

10.9
9.9
****
****
11.3

18.5
17.2
****
****
19.0

20.1
18.7
****
****
20.5

29
30
30
30
30

EL04
SW1
EL-S
EL03
EL04

8.7
70.8
117.3
10.0
9.0

9.5
94.0
****
10.8
9.8

10.3
****
****
11.7
10.6

17.6
****
****
19.4
18.1

19.1
****
****
21.1
19.5

31
31
31
31
31

OPEN
SW1
EL-S
EL03
EL04

24.2
73.8
119.3
10.4
9.3

26.5
97.6
****
11.2
10.0

29.3
****
****
12.0
10.9

55.5
****
****
19.9
18.4

65.5
****
****
21.5
20.0

77

Table 20.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

31
32
32
32
32

T01
OPEN
SW1
EL03
EL04

18.9
23.3
77.6
10.7
9.7

20.5
25.4
****
11.6
10.5

22.3
27.9
****
12.5
11.3

38.2
50.9
****
20.3
18.9

42.7
59.0
****
22.0
20.4

32
33
33
33
33

T01
OPEN
SW1
EL03
EL04

18.4
23.2
82.6
11.0
9.9

19.8
25.3
****
11.9
10.8

21.5
27.7
****
12.8
11.7

36.1
49.7
****
20.8
19.3

40.1
57.3
****
22.4
20.8

33
34
34
34
34

T01
OPEN
SW1
EL03
EL04

18.4
23.0
89.9
11.4
10.3

19.9
25.0
****
12.2
11.1

21.5
27.2
****
13.1
12.0

35.7
47.5
****
21.2
19.7

39.5
54.1
****
22.8
21.3

34
35
35
35
35

T01
OPEN
SW1
EL03
EL04

18.7
23.4
103.5
11.7
10.7

20.1
25.4
****
12.6
11.5

21.8
27.6
****
13.6
12.4

35.9
47.8
****
21.6
20.1

39.7
54.3
****
23.3
21.7

35
36
36

T01
EL03
EL04

19.1
11.8
10.7

20.6
12.7
11.5

22.2
13.6
12.4

36.4
21.6
20.2

40.1
23.3
21.7

78

Table 21.

Level

Results of Tenability Analysis for Scenario 21.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

B
G
G
G
G

L-HR
OPEN
SW1
L-SR
EL-S

96.5
3.0
19.5
12.1
35.2

****
4.3
30.7
16.1
45.8

****
5.0
56.2
21.9
61.0

****
31.1
****
69.7
****

****
44.0
****
90.8
****

G
G
G
G
G

EL01
EL02
EL03
EL04
T01

5.4
5.4
4.6
4.7
13.1

6.7
6.7
5.7
5.7
17.5

8.7
8.6
7.1
7.2
23.9

38.0
37.8
34.9
35.6
74.1

51.6
51.4
48.2
49.4
96.6

G
G
2
2
2

T02
SW2
F-RM
SW1
EL-S

22.3
15.6
1.0
27.5
53.0

31.0
21.1
1.0
43.0
68.5

44.0
29.6
1.0
85.0
91.9

****
87.8
0.0
****
****

****
****
0.0
****
****

2
2
2
2
2

EL01
EL02
EL03
EL04
SW2

7.7
7.7
1.0
1.0
49.5

9.5
9.6
1.0
1.0
68.5

12.1
12.1
1.0
1.0
****

44.8
44.0
0.4
0.4
****

60.0
58.6
0.7
0.7
****

3
3
3
3
3

SW1
EL-S
EL01
EL02
EL03

33.6
66.6
10.0
10.5
1.0

53.7
86.2
12.3
12.7
1.0

****
****
15.3
15.8
1.0

****
****
50.8
50.1
1.0

****
****
67.6
65.8
1.3

3
3
4
4
4

EL04
SW2
SW1
EL-S
EL01

1.0
74.2
39.4
77.8
12.3

1.0
****
68.9
****
14.9

1.0
****
****
****
18.3

1.0
****
****
****
56.3

1.3
****
****
****
74.6

4
4
4
4
5

EL02
EL03
EL04
SW2
SW1

13.3
1.0
1.0
99.0
45.4

16.0
1.0
1.0
****
93.7

19.6
1.0
1.0
****
****

56.1
1.4
1.4
****
****

73.0
2.1
2.1
****
****

5
5
5
5
5

EL-S
EL01
EL02
EL03
EL04

87.6
14.5
16.3
1.0
1.0

****
17.3
19.4
1.0
1.0

****
21.1
23.3
1.0
1.0

****
61.3
62.0
2.1
2.1

****
81.2
80.2
2.7
2.7

79

Table 21.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

5
6
6
6
6

SW2
SW1
EL-S
EL01
EL02

116.7
51.1
96.4
16.5
19.3

****
****
****
19.6
22.7

****
****
****
23.8
27.1

****
****
****
66.0
67.9

****
****
****
87.3
87.3

6
6
7
7
7

EL03
EL04
SW1
EL-S
EL01

1.0
1.0
56.9
104.4
18.4

1.0
1.0
****
****
21.8

1.0
1.0
****
****
26.3

2.8
2.7
****
****
70.4

3.4
3.4
****
****
93.0

7
7
7
8
8

EL02
EL03
EL04
SW1
EL-S

22.4
1.0
1.0
63.3
111.8

26.1
1.0
1.0
****
****

30.9
1.0
1.0
****
****

73.7
3.4
3.3
****
****

94.4
4.2
4.1
****
****

8
8
8
8
9

EL01
EL02
EL03
EL04
SW1

20.3
25.5
1.0
1.0
93.2

23.8
29.5
1.0
1.0
****

28.6
34.7
1.0
1.0
****

74.5
79.5
4.1
4.0
****

98.5
****
4.9
4.8
****

9
9
9
9
9

EL-S
EL01
EL02
EL03
EL04

118.8
22.0
28.5
1.0
1.0

****
25.7
32.9
1.0
1.0

****
30.8
38.5
1.0
1.0

****
78.5
85.2
4.7
4.6

****
****
****
5.5
5.4

10
10
10
10
10

SW1
EL01
EL02
EL03
EL04

99.0
23.6
31.6
1.0
1.0

****
27.5
36.2
1.0
1.0

****
32.8
42.3
1.5
1.4

****
82.2
90.9
5.3
5.2

****
****
****
6.2
6.1

11
11
11
11
11

SW1
EL01
EL02
EL03
EL04

104.6
25.2
34.6
1.0
1.0

****
29.3
39.6
1.5
1.4

****
34.8
46.0
1.8
1.8

****
85.8
96.5
5.9
5.7

****
****
****
6.8
6.6

12
12
12
12
12

SW1
EL01
EL02
EL03
EL04

110.7
26.7
37.7
1.5
1.4

****
30.9
42.9
1.8
1.8

****
36.7
49.7
2.0
2.0

****
89.2
****
6.5
6.3

****
****
****
7.4
7.2

80

Table 21.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

13
13
13
13
13

SW1
EL01
EL02
EL03
EL04

118.1
28.1
40.7
1.8
1.7

****
32.5
46.1
2.0
1.9

****
38.5
53.4
2.5
2.4

****
92.5
****
7.1
6.9

****
****
****
8.1
7.8

14
14
14
14
15

EL01
EL02
EL03
EL04
EL01

31.2
48.4
2.0
1.9
32.4

36.5
56.0
2.5
2.2
37.8

44.1
67.2
2.9
2.8
45.8

****
****
7.6
7.4
****

****
****
8.6
8.3
****

15
15
15
16
16

EL02
EL03
EL04
EL01
EL02

50.9
2.4
2.1
33.4
53.2

59.2
2.8
2.7
39.0
61.9

71.6
3.2
3.0
47.3
75.5

****
8.2
7.9
****
****

****
9.2
8.9
****
****

16
16
17
17
17

EL03
EL04
EL01
EL02
EL03

2.7
2.6
34.3
55.3
2.9

3.0
2.9
40.0
64.5
3.5

3.6
3.4
48.6
79.2
3.9

8.7
8.4
****
****
9.2

9.7
9.4
****
****
10.3

17
18
18
18
18

EL04
EL01
EL02
EL03
EL04

2.8
35.2
57.2
3.3
3.0

3.2
41.0
67.0
3.8
3.6

3.8
49.7
82.8
4.4
4.0

8.9
****
****
9.8
9.4

10.0
****
****
10.9
10.5

19
19
19
19
20

EL01
EL02
EL03
EL04
EL01

35.9
59.0
3.7
3.5
36.7

41.9
69.3
4.1
3.9
42.7

50.8
86.3
4.8
4.5
51.7

****
****
10.3
9.9
****

****
****
11.4
11.0
****

20
20
20
21
21

EL02
EL03
EL04
EL01
EL02

60.7
3.9
3.8
37.3
62.3

71.4
4.6
4.2
43.3
73.5

89.7
5.0
4.8
52.4
93.0

****
10.8
10.3
****
****

****
12.0
11.5
****
****

21
21
22
22
22

EL03
EL04
EL01
EL02
EL03

4.3
4.0
37.9
63.9
4.7

4.9
4.6
44.0
75.5
5.2

5.5
5.1
53.0
96.2
5.9

11.3
10.9
****
****
11.8

12.4
12.0
****
****
13.0

81

Table 21.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

22
23
23
23
23

EL04
EL01
EL02
EL03
EL04

4.4
38.6
65.2
4.9
4.7

4.9
44.6
77.2
5.6
5.2

5.6
53.7
99.1
6.2
5.9

11.3
****
****
12.2
11.8

12.5
****
****
13.5
13.0

24
24
24
24
25

EL01
EL02
EL03
EL04
EL01

39.2
66.1
5.4
4.9
39.9

45.3
78.2
5.9
5.6
46.0

54.4
****
6.6
6.2
55.1

****
****
12.7
12.2
****

****
****
14.0
13.4
****

25
25
25
26
26

EL02
EL03
EL04
OPEN
EL01

66.9
5.7
5.3
85.1
40.6

79.0
6.3
5.9
****
46.7

****
6.9
6.6
****
55.9

****
13.2
12.7
****
****

****
14.4
13.9
****
****

26
26
26
27
27

EL02
EL03
EL04
EL03
EL04

67.6
6.0
5.7
6.4
5.9

79.8
6.8
6.3
7.0
6.7

****
7.5
7.0
7.8
7.3

****
13.9
13.3
14.3
13.7

****
15.2
14.6
15.6
15.0

28
28
29
29
29

EL03
EL04
OPEN
EL03
EL04

6.7
6.2
18.9
6.9
6.6

7.4
6.9
20.8
7.7
7.1

8.0
7.6
23.2
8.4
7.9

14.7
14.1
47.3
15.1
14.4

16.0
15.4
56.6
16.4
15.7

29
30
30
30
30

T01
OPEN
EL03
EL04
T01

16.9
18.2
7.2
6.8
16.4

18.6
20.0
7.9
7.5
17.9

20.5
22.1
8.7
8.1
19.7

39.4
43.4
15.4
14.8
36.8

45.9
51.1
16.8
16.1
42.2

31
31
31
31
32

OPEN
EL03
EL04
T01
OPEN

17.9
7.6
7.0
16.6
17.5

19.6
8.2
7.8
18.0
19.0

21.5
8.9
8.5
19.8
20.9

40.6
15.8
15.1
36.5
38.3

47.1
17.2
16.5
41.8
43.9

32
32
32
33
33

EL03
EL04
T01
OPEN
EL03

7.8
7.4
16.6
17.4
8.0

8.5
8.0
18.0
18.9
8.8

9.3
8.8
19.8
20.7
9.6

16.2
15.5
35.8
37.1
16.5

17.5
16.9
40.8
42.2
17.9

82

Table 21.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

33
33
34
34
34

EL04
T01
OPEN
EL03
EL04

7.7
16.6
17.4
8.4
7.9

8.3
18.0
18.9
9.0
8.7

9.0
19.7
20.6
9.9
9.4

15.9
35.3
36.4
16.9
16.2

17.2
39.9
41.2
18.3
17.6

34
35
35
35
35

T01
OPEN
EL03
EL04
T01

16.7
17.3
8.7
8.2
16.7

18.1
18.7
9.4
8.9
18.0

19.7
20.4
10.2
9.7
19.6

34.9
35.5
17.3
16.6
34.2

39.3
39.8
18.7
18.1
38.3

36
36
36
36

MECH
ELME
EL03
EL04

54.7
82.8
8.7
8.2

65.8
****
9.5
8.9

81.8
****
10.2
9.7

****
****
17.3
16.6

****
****
18.7
18.1

83

Table 22.

Level

Results of Tenability Analysis for Scenario 22.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

B
B
G
G
G

EL-S
EL04
SW1
L-SR
EL-S

105.6
107.9
83.0
103.3
89.6

****
****
88.0
****
93.4

****
****
93.7
****
97.6

****
****
****
****
****

****
****
****
****
****

G
G
G
G
G

EL04
T01
T02
EL05
SW2

90.4
119.8
113.7
110.9
102.2

97.3
****
****
****
****

****
****
****
****
****

****
****
****
****
****

****
****
****
****
****

2
2
2
2
2

SW1
L-SR
CR02
EL-S
EL04

75.9
91.4
102.6
79.9
79.2

80.6
95.3
****
83.3
85.1

85.9
99.6
****
87.0
92.2

****
****
****
****
****

****
****
****
****
****

2
2
2
2
3

T01
T02
EL05
SW2
OPEN

104.1
101.3
100.3
84.7
114.0

****
****
****
89.7
****

****
****
****
95.0
****

****
****
****
****
****

****
****
****
****
****

3
3
3
3
3

SW1
L-SR
CR02
EL-S
EL04

71.3
84.9
99.7
73.9
73.0

75.8
88.7
****
77.2
78.4

80.9
92.7
****
80.7
85.0

****
****
****
****
****

****
****
****
****
****

3
3
3
3
4

T01
T02
EL05
SW2
OPEN

96.8
94.3
93.5
75.3
107.9

****
98.8
98.0
79.6
****

****
****
****
84.5
****

****
****
****
****
****

****
****
****
****
****

4
4
4
4
4

SW1
L-SR
CR02
EL-S
EL04

68.1
79.8
93.8
69.1
68.0

72.3
83.4
****
72.2
73.1

77.0
87.3
****
75.6
79.3

****
****
****
96.4
****

****
****
****
****
****

4
4
4
4
5

T01
T02
EL05
SW2
OPEN

91.1
88.8
88.1
69.6
102.8

99.6
93.1
92.4
73.3
****

****
97.8
97.1
77.4
****

****
****
****
****
****

****
****
****
****
****

84

Table 22.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

5
5
5
5
5

SW1
L-SR
CR02
EL-S
EL04

65.4
75.6
88.9
65.0
63.8

69.4
79.1
98.3
68.0
68.7

73.7
82.8
****
71.3
74.6

99.3
****
****
91.6
****

****
****
****
96.4
****

5
5
5
5
6

T01
T02
EL05
SW2
OPEN

86.3
84.3
83.6
65.5
98.4

94.6
88.5
87.8
68.7
****

****
93.0
92.4
72.4
****

****
****
****
96.6
****

****
****
****
****
****

6
6
6
6
6

SW1
L-SR
CR02
EL-S
L-LR

63.1
72.0
84.8
61.5
117.8

66.8
75.4
94.0
64.5
****

71.0
79.0
****
67.6
****

95.7
****
****
87.4
****

****
****
****
92.1
****

6
6
6
6
6

EL04
T01
T02
EL05
SW2

60.2
82.3
80.5
79.8
62.2

64.9
90.5
84.6
83.8
65.2

70.5
****
89.0
88.2
68.6

****
****
****
****
91.3

****
****
****
****
96.8

7
7
7
7
7

OPEN
SW1
L-SR
CR02
EL-S

94.5
61.2
68.8
81.2
58.4

****
64.7
72.1
90.2
61.3

****
68.6
75.7
****
64.3

****
92.4
97.8
****
83.8

****
97.8
****
****
88.3

7
7
7
7
7

L-LR
EL04
T01
T02
EL05

113.6
57.0
78.8
77.2
76.4

****
61.5
86.8
81.1
80.3

****
67.0
97.1
85.5
84.6

****
****
****
****
****

****
****
****
****
****

7
8
8
8
8

SW2
OPEN
SW1
L-SR
CR02

59.6
91.0
59.4
65.9
78.0

62.4
96.6
62.8
69.2
86.9

65.5
****
66.5
72.7
99.4

86.8
****
89.3
94.6
****

92.2
****
94.7
****
****

8
8
8
8
8

EL-S
L-LR
EL04
T01
T02

55.6
109.8
54.1
75.7
74.2

58.4
****
58.5
83.6
78.1

61.4
****
63.8
93.8
82.3

80.5
****
****
****
****

85.0
****
****
****
****

85

Table 22.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

8
8
8
9
9

EL05
EL06
SW2
OPEN
SW1

73.3
119.9
57.3
87.9
57.8

77.2
****
60.0
93.5
61.1

81.4
****
62.9
99.3
64.6

****
****
83.2
****
86.5

****
****
88.1
****
91.8

9
9
9
9
9

L-SR
CR02
EL-S
L-LR
EL04

63.4
75.1
53.0
106.3
51.5

66.6
83.9
55.8
****
55.8

70.0
96.3
58.7
****
60.9

91.7
****
77.6
****
****

97.0
****
81.9
****
****

9
9
9
9
9

T01
T02
EL05
EL06
SW2

72.9
71.6
70.6
116.4
55.1

80.7
75.4
74.4
****
57.8

90.9
79.5
78.5
****
60.7

****
****
****
****
80.1

****
****
****
****
84.7

10
10
10
10
10

OPEN
SW1
L-SR
CR02
EL-S

85.2
56.3
61.0
72.5
50.7

90.6
59.5
64.2
81.2
53.4

96.3
62.9
67.6
93.6
56.3

****
84.1
89.0
****
74.9

****
89.1
94.3
****
79.2

10
10
10
10
10

L-LR
EL04
T01
T02
EL05

103.2
49.1
70.4
69.1
68.0

****
53.3
78.1
72.9
71.8

****
58.3
88.2
77.0
75.9

****
99.3
****
****
****

****
****
****
****
****

10
10
11
11
11

EL06
SW2
OPEN
SW1
L-SR

113.1
53.2
82.9
54.9
58.9

****
55.9
87.9
58.1
62.0

****
58.7
93.6
61.5
65.3

****
77.4
****
81.9
86.6

****
81.8
****
86.6
91.8

11
11
11
11
11

CR02
EL-S
L-LR
EL04
T01

70.1
48.5
100.4
47.0
68.0

78.8
51.2
****
51.0
75.7

91.1
54.0
****
55.9
85.8

****
72.3
****
96.5
****

****
76.6
****
****
****

11
11
11
11
12

T02
EL05
EL06
SW2
OPEN

66.9
65.7
110.2
51.4
80.5

70.6
69.4
****
54.0
85.5

74.7
73.4
****
56.9
91.1

****
98.6
****
75.1
****

****
****
****
79.2
****

86

Table 22.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

12
12
12
12
12

SW1
L-SR
CR02
EL-S
L-LR

52.9
56.9
67.9
46.5
97.7

56.0
59.9
76.5
49.1
****

59.3
63.3
88.8
51.9
****

79.5
84.4
****
70.0
****

84.2
89.6
****
74.2
****

12
12
12
12
12

EL04
T01
T02
EL05
EL06

44.9
65.8
64.9
63.5
107.5

48.9
73.5
68.6
67.2
****

53.7
83.6
72.6
71.1
****

94.0
****
97.8
96.1
****

****
****
****
****
****

12
13
13
13
13

SW2
OPEN
SW1
L-SR
CR02

49.0
78.3
50.9
55.1
65.9

51.6
83.3
54.0
58.1
74.5

54.4
88.8
57.3
61.4
86.8

72.4
****
77.2
82.5
****

76.4
****
81.8
87.6
****

13
13
13
13
13

EL-S
L-LR
EL04
T01
T02

44.6
95.3
43.0
63.9
63.0

47.1
****
46.9
71.5
66.7

49.9
****
51.6
81.6
70.7

67.8
****
91.6
****
95.9

72.0
****
****
****
****

13
13
13
14
14

EL05
EL06
SW2
OPEN
SW1

61.5
105.1
46.8
76.6
49.1

65.0
****
49.4
81.6
52.1

68.9
****
52.1
87.3
55.3

93.8
****
69.8
****
75.0

****
****
73.8
****
79.6

14
14
14
14
14

L-SR
CR02
EL-S
L-LR
EL04

53.6
64.2
42.8
93.5
41.3

56.6
72.8
45.3
99.7
45.1

59.9
85.2
48.0
****
49.6

81.0
****
65.8
****
89.4

86.2
****
69.8
****
****

14
14
14
14
14

T01
T02
EL05
EL06
SW2

62.2
61.5
59.5
103.0
44.7

69.8
65.2
63.1
****
47.2

80.2
69.2
66.9
****
49.9

****
94.6
91.6
****
67.4

****
****
98.3
****
71.3

15
15
15
15
15

MECH
SW1
L-SR
CR01
EL-S

77.3
47.4
53.8
63.2
41.0

82.7
50.3
56.9
72.0
43.5

88.9
53.4
60.3
84.9
46.2

****
72.9
82.3
****
63.8

****
77.4
87.8
****
67.8

87

Table 22.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

15
15
15
15
16

EL04
T01
T02
SW2
OPEN

39.6
61.1
62.1
42.7
77.0

43.3
69.0
65.9
45.2
82.7

47.8
80.1
70.2
47.8
89.2

87.3
****
97.1
65.1
****

****
****
****
69.0
****

16
16
16
16
16

SW1
L-SR
CR01
EL-S
EL04

45.6
53.2
61.6
39.4
38.0

48.5
56.4
70.5
41.8
41.7

51.6
59.8
83.5
44.5
46.0

70.8
82.2
****
61.9
85.3

75.2
88.0
****
65.9
****

16
16
16
17
17

T01
T02
SW2
OPEN
SW1

58.3
61.5
40.7
76.6
43.9

65.8
65.5
43.2
82.5
46.7

75.8
69.8
45.8
89.2
49.7

****
97.4
62.9
****
68.7

****
****
66.7
****
73.1

17
17
17
17
17

L-SR
CR01
EL-S
EL04
T01

52.5
60.0
37.7
36.5
56.7

55.7
68.9
40.1
40.1
64.2

59.2
81.9
42.7
44.4
74.3

82.1
****
60.0
83.4
****

88.1
****
64.0
****
****

17
17
18
18
18

T02
SW2
OPEN
SW1
L-SR

61.0
38.8
76.8
42.2
52.3

65.0
41.2
83.0
45.0
55.7

69.5
43.8
90.3
47.9
59.3

97.9
60.7
****
66.7
83.0

****
64.5
****
71.0
89.3

18
18
18
18
18

CR01
EL-S
EL04
T01
T02

58.4
36.1
35.0
55.2
61.1

67.3
38.5
38.6
62.7
65.3

80.4
41.0
42.8
72.9
70.0

****
58.2
81.6
****
99.8

****
62.1
****
****
****

18
19
19
19
19

SW2
OPEN
SW1
L-SR
CR01

36.9
79.1
40.5
54.7
56.9

39.3
86.0
43.2
58.4
65.8

41.8
94.4
46.1
62.4
78.9

58.5
****
64.7
88.8
****

62.3
****
68.9
96.2
****

19
19
19
19
19

EL-S
EL04
T01
T02
SW2

34.5
33.7
53.7
64.3
35.1

36.9
37.1
61.2
69.1
37.4

39.4
41.3
71.5
74.6
39.9

56.3
79.9
****
****
56.4

60.2
****
****
****
60.1

88

Table 22.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

20
20
20
20
20

OPEN
SW1
L-SR
CR01
EL-S

95.8
38.8
87.7
55.5
32.9

****
41.5
95.4
64.3
35.3

****
44.3
****
77.4
37.8

****
62.6
****
****
54.5

****
66.8
****
****
58.3

20
20
20
20
21

EL04
T01
T02
SW2
SW1

32.3
52.3
96.4
33.3
37.1

35.8
59.7
****
35.6
39.7

39.8
70.1
****
38.0
42.5

78.3
****
****
54.3
60.6

****
****
****
58.0
64.7

21
21
21
21
21

L-SR
CR01
EL-S
EL04
T01

84.1
54.1
31.3
31.0
50.9

91.6
62.9
33.6
34.5
58.4

****
76.0
36.1
38.4
69.0

****
****
52.7
76.7
****

****
****
56.5
****
****

21
22
22
22
22

SW2
SW1
L-SR
CR01
EL-S

31.5
35.4
80.9
52.8
29.7

33.7
37.9
88.2
61.7
31.9

36.1
40.7
97.1
74.8
34.4

52.3
58.5
****
****
50.8

55.8
62.6
****
****
54.5

22
22
22
23
23

EL04
T01
SW2
SW1
L-SR

29.8
49.7
29.6
33.6
77.9

33.2
57.2
31.8
36.1
85.1

37.1
67.8
34.2
38.7
93.7

75.2
****
50.2
56.3
****

****
****
53.7
60.3
****

23
23
23
23
23

CR01
EL-S
EL04
T01
SW2

51.7
28.0
28.7
48.6
27.8

60.7
30.3
31.9
56.1
29.9

73.9
32.7
35.8
66.8
32.3

****
48.9
73.8
****
48.0

****
52.6
****
****
51.4

24
24
24
24
24

SW1
L-SR
CR01
EL-S
EL04

31.7
75.0
50.8
26.3
27.5

34.2
82.0
59.9
28.6
30.8

36.8
90.5
73.4
30.9
34.6

54.0
****
****
47.0
72.4

58.0
****
****
50.5
****

24
24
25
25
25

T01
SW2
SW1
L-SR
CR01

47.6
25.9
29.8
72.3
50.3

55.3
28.0
32.1
79.2
59.6

66.2
30.3
34.7
87.6
73.7

****
45.8
51.7
****
****

****
49.2
55.5
****
****

89

Table 22.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

25
25
25
25
26

EL-S
EL04
T01
SW2
SW1

24.6
26.4
47.0
23.9
27.7

26.8
29.6
54.8
26.0
30.0

29.1
33.4
66.1
28.3
32.5

44.9
71.0
****
43.5
49.1

48.4
****
****
46.8
52.9

26
26
26
26
26

L-SR
L-HR
EL-S
EL04
T01

69.4
50.7
22.8
25.3
46.5

76.1
60.9
24.9
28.5
54.6

84.3
77.4
27.2
32.2
66.3

****
****
42.8
69.7
****

****
****
46.3
99.8
****

26
27
27
27
27

SW2
SW1
L-SR
L-HR
EL-S

21.9
25.5
66.8
54.6
20.9

24.0
27.8
73.5
67.2
23.0

26.2
30.2
81.7
****
25.3

41.2
46.5
****
****
40.6

44.4
50.1
****
****
44.0

27
27
27
28
28

EL04
T01
SW2
SW1
L-SR

24.3
47.1
19.9
23.1
63.4

27.4
55.9
21.9
25.4
70.0

31.0
68.8
24.0
27.7
77.9

68.4
****
38.7
43.5
****

98.4
****
41.8
47.1
****

28
28
28
28
28

L-HR
EL-S
EL04
T01
SW2

60.7
19.0
23.2
47.6
17.8

79.0
21.0
26.4
57.1
19.7

****
23.2
29.9
71.2
21.7

****
38.3
67.2
****
36.1

****
41.5
97.0
****
39.1

29
29
29
29
29

SW1
L-SR
EL-S
EL04
T01

20.6
59.6
16.9
22.2
48.4

22.7
65.9
18.9
25.4
58.7

25.0
73.6
21.0
28.9
74.8

40.4
****
35.8
65.9
****

43.8
****
39.0
95.6
****

29
30
30
30
30

SW2
SW1
L-SR
EL-S
EL04

15.5
17.8
55.4
14.8
21.2

17.3
19.9
61.4
16.7
24.4

19.3
22.0
68.6
18.7
27.8

33.3
37.0
****
33.2
64.7

36.3
40.2
****
36.2
94.3

30
30
31
31
31

T01
SW2
SW1
L-SR
EL-S

49.8
13.2
14.8
50.5
12.6

61.2
14.9
16.7
56.1
14.3

82.3
16.7
18.8
62.9
16.3

****
30.4
33.2
****
30.4

****
33.2
36.2
****
33.3

90

Table 22.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

31
31
31
32
32

EL04
T01
SW2
SW1
L-SR

20.2
52.5
10.8
11.6
45.0

23.4
65.7
12.3
13.3
50.1

26.7
****
14.0
15.2
56.3

63.5
****
27.3
29.0
97.1

92.8
****
30.0
31.8
****

32
32
32
32
33

EL-S
EL04
T01
SW2
SW1

10.2
19.2
58.1
8.3
8.0

11.8
22.4
76.9
9.7
9.5

13.7
25.7
****
11.2
11.1

27.4
62.3
****
23.9
24.1

30.2
91.1
****
26.4
26.7

33
33
33
33
33

L-SR
EL-S
EL04
T01
SW2

38.6
7.8
18.2
76.8
5.8

43.0
9.2
21.4
****
6.9

48.5
10.9
24.6
****
8.2

85.6
24.2
61.0
****
20.2

****
26.9
89.2
****
22.6

34
34
34
34
34

SW1
L-SR
EL-S
EL04
SW2

4.5
31.0
5.3
17.2
3.5

5.6
34.7
6.5
20.4
4.3

6.8
39.0
7.9
23.6
5.3

18.3
71.3
20.6
59.7
16.1

20.8
83.0
23.2
87.1
18.4

35
35
35
35
35

OPEN
SW1
L-SR
EL-S
EL04

1.0
1.5
1.7
2.9
16.2

1.0
1.9
2.0
3.9
19.3

1.0
2.6
2.8
4.9
22.6

5.0
11.2
11.6
16.7
58.4

6.3
13.2
13.7
19.2
85.0

35
35
35
36
36

T01
T02
SW2
MECH
ELME

6.0
3.0
1.6
10.7
33.9

7.7
4.0
1.9
13.0
38.8

9.6
5.1
2.7
15.5
44.9

23.9
16.9
11.6
33.1
84.6

26.9
19.3
13.7
37.9
****

36
36

EL-S
SW2

15.1
19.6

17.6
22.5

20.3
25.5

39.3
48.8

44.6
56.1

91

Table 23.

Level
35
36
36

Results of Tenability Analysis for Scenario 23.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)
OPEN
MECH
ELME

1.0
10.5
19.0

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

1.0
12.7
22.0

1.0
15.2
25.3

92

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

5.0
32.8
54.5

6.3
37.6
65.2

Table 24.

Level

Results of Tenability Analysis for Scenario 24.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

B
B
B
B
B

MECH
L-SR
L-MR
L-HR
EL-S

38.5
57.4
57.9
54.4
50.9

45.1
67.0
67.5
63.2
57.5

53.9
79.7
79.9
74.6
65.6

****
****
****
****
****

****
****
****
****
****

B
B
B
B
B

EL01
EL02
EL03
EL04
SW2

53.1
62.4
57.8
50.0
30.1

61.8
72.9
67.2
58.0
33.7

72.9
86.5
79.2
68.3
38.0

****
****
****
****
68.1

****
****
****
****
77.6

G
G
G
G
G

OPEN
SW1
L-SR
L-MR
L-HR

9.9
17.6
16.6
15.2
12.5

12.1
20.4
19.2
17.7
14.7

14.6
23.4
22.0
20.3
17.1

32.2
47.4
42.8
39.5
34.3

37.0
55.6
48.9
44.9
38.7

G
G
G
G
G

EL-S
EL01
EL02
EL03
EL04

24.4
16.5
18.6
17.8
17.9

27.4
19.0
21.3
20.4
20.6

30.8
21.9
24.2
23.3
23.4

56.5
43.0
45.8
44.2
44.7

64.5
49.4
52.2
50.4
51.0

G
G
G
2
2

T01
T02
SW2
OPEN
SW1

15.9
18.7
17.9
1.0
1.0

18.4
21.4
20.6
1.0
1.6

21.1
24.3
23.5
1.0
2.0

40.7
46.3
45.4
4.8
10.3

46.2
52.8
52.0
6.1
12.4

2
2
2
2
2

L-SR
CR01
CR02
EL-S
EL01

1.0
1.4
1.0
3.3
1.0

1.5
1.8
1.4
4.1
1.6

1.9
2.4
1.9
5.1
2.0

9.3
10.6
9.1
15.9
10.1

11.2
12.6
11.0
18.2
12.2

2
2
2
2
2

EL02
EL03
EL04
T01
T02

1.8
1.7
1.7
1.6
2.0

2.3
2.0
2.0
2.0
2.7

3.0
2.8
2.8
2.8
3.5

12.7
12.1
12.2
11.6
13.5

14.9
14.3
14.4
13.7
15.8

2
3
3
3
3

SW2
SW1
L-SR
CR02
EL-S

1.0
1.9
18.2
12.9
5.0

1.4
2.6
20.9
15.2
6.0

1.8
3.2
23.8
17.7
7.3

9.1
12.5
49.1
35.3
19.0

10.9
14.7
59.4
40.0
21.4

93

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

3
3
3
3
3

EL01
EL02
EL03
EL04
SW2

2.4
3.8
2.9
2.8
2.8

3.0
4.7
3.7
3.6
3.5

3.9
5.8
4.6
4.5
4.3

13.5
17.2
15.0
14.8
14.0

15.7
19.7
17.3
17.1
16.1

4
4
4
4
4

SW1
L-SR
EL-S
EL01
EL02

2.9
20.3
6.7
3.8
6.3

3.6
23.0
7.9
4.7
7.6

4.5
25.9
9.3
5.7
9.0

14.5
52.7
21.5
16.3
21.6

16.7
64.0
24.1
18.7
24.3

4
4
4
5
5

EL03
EL04
SW2
SW1
L-SR

4.2
3.9
4.8
3.9
22.1

5.1
4.9
5.7
4.8
24.8

6.3
5.9
6.9
5.7
27.8

17.4
17.0
17.8
16.2
56.0

19.9
19.4
20.0
18.5
68.4

5
5
5
5
5

EL-S
EL01
EL02
EL03
EL04

8.2
5.2
9.1
5.6
5.1

9.6
6.2
10.6
6.6
6.2

11.1
7.4
12.3
7.9
7.4

23.7
18.7
25.8
19.6
18.9

26.4
21.2
28.7
22.1
21.4

5
6
6
6
6

SW2
SW1
L-SR
EL-S
EL01

6.8
4.9
23.8
9.7
6.6

7.9
5.8
26.5
11.1
7.7

9.3
6.9
29.5
12.7
8.9

20.8
17.8
59.0
25.7
20.8

23.1
20.1
72.5
28.3
23.3

6
6
6
6
7

EL02
EL03
EL04
SW2
SW1

12.0
6.8
6.3
8.7
5.9

13.7
8.0
7.4
9.9
6.9

15.6
9.4
8.7
11.5
8.1

29.8
21.5
20.6
23.3
19.3

32.9
24.1
23.1
25.5
21.6

7
7
7
7
7

L-SR
EL-S
EL01
EL02
EL03

25.2
10.9
7.8
14.9
8.0

27.9
12.5
9.0
16.8
9.3

31.0
14.2
10.4
18.8
10.8

61.9
27.4
22.7
33.7
23.2

76.7
30.1
25.3
37.0
25.9

7
7
8
8
8

EL04
SW2
SW1
L-SR
EL-S

7.3
10.4
6.9
26.5
12.2

8.5
11.8
7.9
29.3
13.8

9.9
13.4
9.3
32.5
15.5

22.1
25.3
20.6
64.6
28.9

24.6
27.6
22.9
81.0
31.7

94

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

8
8
8
8
8

EL01
EL02
EL03
EL04
SW2

8.9
17.7
9.1
8.3
12.0

10.3
19.7
10.5
9.6
13.5

11.8
21.9
12.0
10.9
15.1

24.3
37.5
24.8
23.4
27.1

27.0
40.9
27.5
26.0
29.3

9
9
9
9
9

SW1
L-SR
EL-S
EL01
EL02

7.8
27.7
13.3
10.0
20.5

9.0
30.6
14.9
11.5
22.7

10.3
33.9
16.8
13.0
24.9

21.8
67.2
30.3
25.9
41.1

24.1
85.5
33.2
28.6
44.8

9
9
9
10
10

EL03
EL04
SW2
SW1
L-SR

10.2
9.1
13.5
8.8
28.9

11.6
10.5
15.0
9.9
31.7

13.2
12.0
16.7
11.4
35.2

26.2
24.6
28.6
22.9
69.8

29.0
27.3
30.9
25.1
90.3

10
10
10
10
10

EL-S
EL01
EL02
EL03
EL04

14.4
11.1
23.3
11.2
10.0

16.0
12.6
25.5
12.7
11.4

17.9
14.2
27.9
14.3
12.9

31.6
27.3
44.6
27.5
25.8

34.5
30.1
48.5
30.3
28.4

10
11
11
11
11

SW2
SW1
L-SR
EL-S
EL01

14.8
9.6
29.9
15.3
12.1

16.4
10.9
32.9
17.0
13.6

18.1
12.3
36.5
18.9
15.3

30.0
23.9
72.4
32.8
28.6

32.3
26.2
95.7
35.8
31.4

11
11
11
11
12

EL02
EL03
EL04
SW2
SW1

25.9
12.1
10.8
16.0
10.5

28.3
13.7
12.3
17.7
11.8

30.8
15.4
13.9
19.4
13.2

48.0
28.8
26.8
31.2
24.8

52.1
31.6
29.5
33.6
27.1

12
12
12
12
12

L-SR
EL-S
EL01
EL02
EL03

31.0
16.2
13.0
28.5
13.0

34.0
18.0
14.6
30.9
14.6

37.7
19.9
16.3
33.6
16.4

75.1
34.0
29.8
51.3
30.0

****
36.9
32.6
55.6
32.8

12
12
13
13
13

EL04
SW2
SW1
L-SR
EL-S

11.6
17.2
11.3
32.0
17.1

13.0
18.8
12.6
35.1
18.9

14.7
20.5
14.1
38.9
20.9

27.8
32.4
25.7
77.9
35.0

30.5
34.8
28.0
****
38.0

95

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

13
13
13
13
13

EL01
EL02
EL03
EL04
SW2

13.9
31.0
13.9
12.3
18.2

15.5
33.6
15.5
13.8
19.8

17.2
36.2
17.3
15.5
21.6

30.9
54.6
31.0
28.7
33.4

33.8
59.0
34.0
31.4
35.9

14
14
14
14
14

SW1
L-SR
EL-S
EL01
EL02

12.0
33.0
17.9
14.7
33.5

13.5
36.1
19.8
16.4
36.1

14.9
40.1
21.7
18.1
38.9

26.5
80.9
36.0
32.0
57.7

28.8
****
39.0
34.9
62.3

14
14
14
15
15

EL03
EL04
SW2
SW1
L-SR

14.7
13.0
19.2
12.8
33.9

16.4
14.6
20.8
14.2
37.2

18.2
16.3
22.5
15.7
41.3

32.1
29.5
34.4
27.3
84.1

35.0
32.3
37.0
29.6
****

15
15
15
15
15

EL-S
EL01
EL02
EL03
EL04

18.7
15.5
35.9
15.5
13.7

20.6
17.2
38.6
17.1
15.2

22.6
19.0
41.5
19.0
16.9

36.9
33.0
60.8
33.0
30.3

40.0
35.9
65.5
36.0
33.1

15
16
16
16
16

SW2
SW1
L-SR
EL-S
EL01

20.1
13.5
34.9
19.5
16.3

21.7
14.9
38.3
21.3
17.9

23.4
16.5
42.5
23.4
19.8

35.4
28.1
87.7
37.8
33.9

37.9
30.3
****
40.9
36.9

16
16
16
16
17

EL02
EL03
EL04
SW2
SW1

38.3
16.2
14.3
20.9
14.2

41.0
17.9
15.9
22.5
15.7

44.0
19.8
17.7
24.2
17.2

63.8
33.9
31.1
36.3
28.7

68.7
37.0
33.9
38.8
31.0

17
17
17
17
17

L-SR
EL-S
EL01
EL02
EL03

35.9
20.1
17.0
40.6
16.9

39.4
22.0
18.7
43.4
18.7

43.8
24.1
20.6
46.4
20.6

92.0
38.6
34.8
66.7
34.8

****
41.7
37.9
71.8
37.9

17
17
18
18
18

EL04
SW2
SW1
L-SR
EL-S

14.9
21.7
14.9
36.9
20.8

16.5
23.3
16.3
40.5
22.7

18.3
24.9
17.9
45.2
24.8

31.8
37.1
29.4
97.2
39.4

34.7
39.7
31.7
****
42.5

96

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

18
18
18
18
18

EL01
EL02
EL03
EL04
SW2

17.7
42.9
17.6
15.5
22.4

19.5
45.7
19.4
17.1
24.0

21.4
48.8
21.3
18.9
25.7

35.6
69.5
35.6
32.5
37.9

38.7
74.8
38.7
35.4
40.5

19
19
19
19
19

SW1
L-SR
EL-S
EL01
EL02

15.5
38.0
21.5
18.4
45.1

16.9
41.8
23.4
20.1
48.0

18.6
46.7
25.5
22.0
51.2

30.1
****
40.2
36.5
72.3

32.4
****
43.3
39.6
77.7

19
19
19
20
20

EL03
EL04
SW2
SW1
L-SR

18.2
16.0
23.1
16.1
39.3

20.0
17.7
24.7
17.6
43.2

22.0
19.5
26.3
19.2
48.5

36.4
33.2
38.6
30.6
****

39.5
36.1
41.3
33.0
****

20
20
20
20
20

EL-S
EL01
EL02
EL03
EL04

22.1
19.0
47.3
18.8
16.6

24.0
20.8
50.3
20.7
18.2

26.1
22.8
53.6
22.7
20.1

40.9
37.3
75.1
37.2
33.8

44.1
40.4
80.6
40.3
36.7

20
21
21
21
21

SW2
SW1
L-SR
EL-S
EL01

23.8
16.8
41.0
22.7
19.6

25.3
18.2
45.2
24.7
21.4

27.0
19.8
51.2
26.8
23.4

39.3
31.4
****
41.6
38.0

42.0
33.8
****
44.8
41.2

21
21
21
21
22

EL02
EL03
EL04
SW2
SW1

49.4
19.5
17.0
24.5
17.4

52.5
21.3
18.8
26.0
18.9

55.8
23.3
20.6
27.8
20.5

77.8
37.9
34.4
40.2
32.1

83.4
41.1
37.3
42.9
34.5

22
22
22
22
22

L-SR
EL-S
EL01
EL02
EL03

43.3
23.3
20.2
51.5
20.0

48.1
25.2
22.0
54.7
21.9

55.2
27.4
24.0
58.1
23.9

****
42.2
38.7
80.4
38.6

****
45.5
41.9
86.2
41.8

22
22
23
23
23

EL04
SW2
SW1
L-SR
EL-S

17.6
25.2
17.9
48.1
23.8

19.3
26.8
19.5
54.9
25.8

21.1
28.5
21.1
66.4
27.9

35.0
41.1
32.8
****
42.9

37.9
43.8
35.2
****
46.2

97

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

23
23
23
23
23

EL01
EL02
EL03
EL04
SW2

20.8
53.6
20.6
18.0
25.9

22.6
56.8
22.5
19.8
27.5

24.7
60.3
24.5
21.7
29.2

39.4
83.0
39.3
35.5
41.9

42.6
88.9
42.5
38.5
44.7

24
24
24
24
24

SW1
L-MR
EL-S
EL01
EL02

18.6
30.1
24.4
21.3
39.0

20.1
32.5
26.4
23.2
42.1

21.7
35.1
28.5
25.2
45.5

33.5
53.3
43.5
40.1
69.6

36.0
57.8
46.8
43.3
76.5

24
24
24
25
25

EL03
EL04
SW2
SW1
L-MR

21.1
18.5
26.6
19.1
30.0

23.0
20.3
28.1
20.7
32.4

25.0
22.1
29.9
22.3
35.0

40.0
36.1
42.7
34.2
52.9

43.2
39.1
45.5
36.6
57.3

25
25
25
25
25

EL-S
EL01
EL02
EL03
EL04

24.8
21.8
37.3
21.7
18.9

26.9
23.7
40.2
23.6
20.7

29.0
25.8
43.3
25.6
22.6

44.1
40.7
65.4
40.6
36.6

47.4
43.9
71.6
43.9
39.6

25
25
26
26
26

T01
SW2
SW1
L-MR
EL-S

40.4
27.1
19.7
30.5
25.3

43.8
28.8
21.2
32.9
27.4

48.2
30.5
22.8
35.5
29.5

88.3
43.4
34.8
53.3
44.6

****
46.3
37.3
57.7
47.9

26
26
26
26
26

EL01
EL02
EL03
EL04
T01

22.4
36.8
22.1
19.4
40.7

24.2
39.6
24.0
21.1
44.0

26.3
42.6
26.1
23.1
48.3

41.3
63.8
41.2
37.1
87.1

44.5
69.6
44.5
40.1
****

26
27
27
27
27

SW2
SW1
L-MR
EL-S
EL01

27.8
20.2
30.9
25.8
22.9

29.4
21.7
33.4
27.8
24.8

31.1
23.4
35.9
30.0
26.9

44.1
35.4
53.8
45.1
41.9

47.0
37.9
58.2
48.5
45.2

27
27
27
27
27

EL02
EL03
EL04
T01
SW2

36.8
22.6
19.8
41.2
28.4

39.5
24.6
21.6
44.6
30.0

42.5
26.7
23.5
48.8
31.8

63.1
41.8
37.6
87.3
44.8

68.7
45.1
40.6
****
47.7

98

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

28
28
28
28
28

SW1
L-MR
EL-S
EL01
EL02

20.7
31.5
26.2
23.4
36.9

22.3
33.8
28.3
25.3
39.6

23.9
36.4
30.5
27.4
42.5

36.0
54.4
45.6
42.5
62.9

38.5
58.8
49.0
45.8
68.3

28
28
28
28
29

EL03
EL04
T01
SW2
SW1

23.1
20.2
41.7
28.9
21.2

25.0
22.0
45.1
30.6
22.8

27.2
23.9
49.4
32.4
24.5

42.4
38.1
87.8
45.5
36.6

45.7
41.1
****
48.4
39.1

29
29
29
29
29

L-MR
EL-S
EL01
EL02
EL03

31.9
26.7
23.9
37.1
23.6

34.4
28.7
25.8
39.8
25.5

36.9
30.9
27.9
42.7
27.7

54.9
46.1
43.1
62.9
42.9

59.3
49.5
46.4
68.2
46.3

29
29
29
30
30

EL04
T01
SW2
SW1
L-MR

20.6
42.3
29.5
21.8
32.5

22.4
45.8
31.2
23.4
34.9

24.4
50.0
32.9
25.0
37.5

38.5
88.5
46.2
37.2
55.5

41.5
****
49.1
39.8
59.9

30
30
30
30
30

EL-S
EL01
EL02
EL03
EL04

27.1
24.4
37.4
24.0
21.0

29.2
26.4
40.1
26.0
22.8

31.4
28.5
43.0
28.1
24.8

46.6
43.7
63.0
43.4
39.0

50.0
47.0
68.2
46.8
42.0

30
30
31
31
31

T01
SW2
OPEN
SW1
L-SR

42.9
30.0
82.0
22.3
40.6

46.4
31.8
94.5
23.9
43.3

50.7
33.6
****
25.6
46.3

89.3
46.8
****
37.8
67.4

****
49.8
****
40.4
73.1

31
31
31
31
31

L-MR
CR01
EL-S
EL01
EL02

32.9
102.4
27.6
24.9
37.8

35.4
****
29.6
26.9
40.4

38.0
****
31.8
29.0
43.3

56.1
****
47.1
44.3
63.2

60.5
****
50.4
47.6
68.4

31
31
31
31
31

EL03
EL04
T01
T02
SW2

24.5
21.4
43.6
48.0
30.6

26.5
23.2
47.1
51.6
32.3

28.6
25.2
51.4
55.5
34.1

44.0
39.4
89.9
83.9
47.5

47.4
42.5
****
93.3
50.4

99

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

32
32
32
32
32

OPEN
SW1
L-SR
L-MR
CR01

64.6
22.8
39.1
33.5
79.8

71.0
24.4
41.7
35.9
88.7

79.7
26.1
44.6
38.5
****

****
38.4
64.2
56.6
****

****
41.0
69.4
61.1
****

32
32
32
32
32

EL-S
EL01
EL02
EL03
EL04

28.0
25.5
38.1
24.9
21.8

30.0
27.4
40.8
26.9
23.6

32.2
29.6
43.7
29.0
25.6

47.5
44.9
63.5
44.5
39.8

50.9
48.2
68.6
47.9
42.9

32
32
32
33
33

T01
T02
SW2
OPEN
SW1

44.3
46.0
31.2
59.9
23.3

47.8
49.2
32.9
65.0
24.9

52.2
52.8
34.7
71.3
26.7

90.6
78.4
48.1
****
39.0

****
86.2
51.1
****
41.6

33
33
33
33
33

L-SR
L-MR
CR01
EL-S
EL01

38.3
33.9
73.4
28.4
25.9

40.9
36.4
80.2
30.5
27.9

43.6
39.0
89.1
32.7
30.1

62.5
57.1
****
48.0
45.5

67.3
61.6
****
51.4
48.9

33
33
33
33
33

EL02
EL03
EL04
T01
T02

38.5
25.3
22.1
75.7
45.0

41.1
27.3
23.9
83.0
48.1

44.0
29.5
25.9
92.6
51.5

63.8
45.0
40.2
****
75.5

68.9
48.4
43.3
****
82.7

33
34
34
34
34

SW2
OPEN
SW1
L-SR
L-MR

31.7
58.7
23.8
38.0
34.4

33.4
63.3
25.5
40.6
36.9

35.3
68.9
27.2
43.2
39.5

48.7
****
39.6
61.8
57.7

51.7
****
42.2
66.4
62.1

34
34
34
34
34

CR01
EL-S
EL01
EL02
EL03

71.5
28.8
26.5
38.9
25.7

77.8
30.9
28.5
41.5
27.8

85.6
33.1
30.7
44.4
29.9

****
48.5
46.1
64.1
45.5

****
51.9
49.5
69.2
49.0

34
34
34
34
35

EL04
T01
T02
SW2
OPEN

22.5
73.7
44.6
32.2
58.1

24.3
80.3
47.6
34.0
62.5

26.3
88.8
50.8
35.8
67.8

40.7
****
74.1
49.4
****

43.8
****
80.8
52.4
****

100

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

35
35
35
35
35

SW1
L-SR
L-MR
CR01
EL-S

24.3
38.0
34.9
70.6
29.3

25.9
40.5
37.4
76.5
31.4

27.7
43.1
40.0
83.8
33.6

40.1
61.4
58.2
****
49.0

42.8
65.9
62.6
****
52.4

35
35
35
35
35

EL01
EL02
EL03
EL04
T01

27.0
39.3
26.1
22.8
72.6

29.0
41.9
28.1
24.7
78.8

31.2
44.8
30.4
26.7
86.7

46.7
64.4
46.0
41.1
****

50.1
69.5
49.4
44.2
****

35
35
36
36
36

T02
SW2
OPEN
SW1
L-SR

44.4
32.8
52.6
24.8
38.1

47.4
34.6
56.8
26.5
40.6

50.6
36.4
61.9
28.2
43.2

73.3
50.0
98.8
40.7
61.3

79.7
53.0
****
43.4
65.7

36
36
36
36
36

L-MR
CR01
EL-S
EL01
EL02

35.4
65.0
29.7
27.6
39.6

37.8
70.6
31.8
29.6
42.3

40.5
77.4
34.0
31.8
45.1

58.7
****
49.4
47.3
64.8

63.1
****
52.9
50.7
69.8

36
36
36
36
36

EL03
EL04
T01
T02
SW2

26.5
23.2
54.7
44.5
33.3

28.6
25.0
60.1
47.4
35.1

30.8
27.0
67.2
50.5
36.9

46.4
41.5
****
72.9
50.6

49.9
44.6
****
79.2
53.7

37
37
37
37
37

OPEN
SW1
L-SR
L-MR
CR01

50.3
25.4
38.2
35.8
62.2

54.1
27.0
40.6
38.3
67.5

58.8
28.7
43.2
40.9
73.8

93.1
41.3
61.2
59.1
****

****
43.9
65.5
63.5
****

37
37
37
37
37

EL-S
EL01
EL02
EL03
EL04

30.2
28.0
40.0
26.9
23.5

32.3
30.1
42.7
28.9
25.4

34.5
32.3
45.5
31.2
27.4

49.9
47.9
65.1
46.9
41.9

53.4
51.3
70.1
50.4
45.0

37
37
37
38
38

T01
T02
SW2
OPEN
SW1

51.2
43.8
33.9
49.3
25.8

55.6
46.7
35.7
52.9
27.5

61.2
49.8
37.6
57.3
29.3

****
71.8
51.3
89.8
41.8

****
77.9
54.4
****
44.5

101

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

38
38
38
38
38

L-SR
L-MR
CR01
EL-S
EL01

38.3
36.3
61.0
30.7
28.6

40.7
38.7
65.9
32.8
30.6

43.3
41.4
71.9
35.0
32.8

61.1
59.5
****
50.4
48.5

65.4
63.9
****
53.9
52.0

38
38
38
38
38

EL02
EL03
EL04
T01
T02

40.4
27.3
23.8
49.9
43.6

43.0
29.3
25.7
53.9
46.4

45.9
31.6
27.8
58.8
49.5

65.4
47.3
42.2
97.7
71.1

70.4
50.9
45.4
****
77.1

38
39
39
39
39

SW2
OPEN
SW1
L-SR
L-MR

34.5
48.8
26.4
38.4
36.6

36.2
52.3
28.0
40.8
39.1

38.1
56.4
29.8
43.4
41.7

52.0
87.4
42.4
61.0
59.8

55.0
98.6
45.1
65.3
64.2

39
39
39
39
39

CR01
EL-S
EL01
EL02
EL03

60.3
31.1
29.1
40.7
27.7

65.1
33.2
31.2
43.4
29.7

70.8
35.5
33.4
46.2
31.9

****
51.0
49.1
65.8
47.7

****
54.4
52.6
70.8
51.3

39
39
39
39
40

EL04
T01
T02
SW2
OPEN

24.2
49.2
43.6
35.0
48.5

26.0
53.0
46.3
36.8
51.9

28.1
57.6
49.3
38.7
55.8

42.6
93.9
70.6
52.6
85.6

45.8
****
76.4
55.7
96.0

40
40
40
40
40

SW1
L-SR
L-MR
CR01
EL-S

26.9
38.6
36.9
60.0
31.6

28.6
40.9
39.4
64.6
33.7

30.4
43.5
42.0
70.1
36.0

43.0
61.0
60.0
****
51.5

45.7
65.2
64.3
****
55.0

40
40
40
40
40

EL01
EL02
EL03
EL04
T01

29.7
41.1
28.0
24.5
48.9

31.7
43.7
30.1
26.4
52.4

33.9
46.6
32.3
28.4
56.8

49.7
66.1
48.2
43.0
91.1

53.2
71.0
51.7
46.2
****

40
40
41
41
41

T02
SW2
OPEN
SW1
L-SR

43.5
35.6
48.3
27.5
38.7

46.3
37.4
51.6
29.1
41.1

49.2
39.3
55.4
30.9
43.7

70.2
53.3
84.2
43.6
61.1

75.9
56.4
94.0
46.4
65.2

102

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

41
41
41
41
41

L-MR
CR01
EL-S
EL01
EL02

37.0
59.9
32.1
30.2
41.4

39.4
64.5
34.2
32.2
44.0

42.0
69.8
36.5
34.5
46.9

59.7
****
52.0
50.2
66.3

64.0
****
55.5
53.8
71.2

41
41
41
41
41

EL03
EL04
T01
T02
SW2

28.4
24.8
48.7
43.6
36.2

30.5
26.7
52.1
46.3
38.0

32.7
28.7
56.2
49.2
39.9

48.6
43.3
89.0
69.9
54.0

52.2
46.5
****
75.5
57.1

42
42
42
42
42

OPEN
SW1
L-SR
L-MR
CR01

48.4
28.0
39.1
37.1
60.0

51.6
29.7
41.5
39.6
64.4

55.3
31.5
44.0
42.1
69.5

83.0
44.3
61.4
59.7
****

92.0
47.1
65.5
63.9
****

42
42
42
42
42

EL-S
EL01
EL02
EL03
EL04

32.6
30.7
41.7
28.7
25.1

34.7
32.8
44.4
30.8
27.0

37.0
35.0
47.2
33.0
29.0

52.6
50.8
66.6
49.0
43.6

56.1
54.4
71.5
52.6
46.9

42
42
42
43
43

T01
T02
SW2
OPEN
SW1

49.0
43.9
36.8
48.5
28.7

52.4
46.7
38.6
51.7
30.3

56.5
49.6
40.6
55.3
32.1

88.5
70.2
54.7
82.2
45.0

****
75.6
57.8
90.8
47.7

43
43
43
43
43

L-SR
L-MR
L-HR
EL-S
EL01

39.5
37.6
59.0
33.1
31.3

41.8
40.0
63.1
35.3
33.4

44.4
42.6
67.9
37.6
35.6

61.7
60.1
****
53.2
51.4

65.8
64.2
****
56.7
55.0

43
43
43
43
43

EL02
EL03
EL04
T01
T02

42.1
29.0
25.4
49.3
44.3

44.7
31.1
27.3
52.6
46.9

47.6
33.4
29.4
56.6
49.8

66.9
49.4
44.0
87.8
70.3

71.7
53.0
47.2
99.3
75.7

43
44
44
44
44

SW2
OPEN
SW1
L-SR
L-HR

37.4
49.1
29.3
39.7
60.4

39.2
52.3
30.9
42.0
64.7

41.2
55.9
32.8
44.6
69.7

55.4
83.1
45.7
61.7
****

58.6
92.0
48.4
65.8
****

103

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

44
44
44
44
44

EL-S
EL03
EL04
T01
T02

33.7
29.4
25.7
49.3
44.4

35.8
31.5
27.6
52.5
47.0

38.1
33.8
29.7
56.3
49.9

53.8
49.8
44.3
86.7
70.0

57.3
53.4
47.5
97.9
75.3

44
45
45
45
45

SW2
OPEN
SW1
L-SR
L-HR

38.0
49.6
29.9
40.1
61.4

39.9
52.7
31.6
42.5
65.8

41.9
56.3
33.5
45.0
70.8

56.2
83.3
46.4
62.2
****

59.4
92.0
49.2
66.2
****

45
45
45
45
45

EL-S
EL03
EL04
T01
T02

34.3
29.7
25.9
49.7
44.8

36.4
31.8
27.9
53.0
47.4

38.7
34.1
29.9
56.8
50.3

54.4
50.2
44.6
86.7
70.3

57.9
53.8
47.9
97.6
75.6

45
46
46
46
46

SW2
OPEN
SW1
L-SR
L-HR

38.7
50.2
30.6
40.6
62.6

40.6
53.3
32.4
43.0
67.0

42.6
56.9
34.1
45.5
72.1

57.0
83.7
47.2
62.7
****

60.2
92.2
50.0
66.7
****

46
46
46
46
46

EL-S
EL03
EL04
T01
T02

34.9
30.0
26.2
50.3
45.3

37.0
32.1
28.1
53.6
47.9

39.3
34.5
30.2
57.3
50.8

55.1
50.5
44.9
87.0
70.8

58.6
54.2
48.2
97.8
76.0

46
47
47
47
47

SW2
OPEN
SW1
L-SR
L-HR

39.4
50.9
31.4
41.2
48.5

41.3
54.0
33.1
43.6
52.1

43.3
57.6
34.9
46.1
56.4

57.8
84.2
48.1
63.3
87.5

61.0
92.7
50.9
67.3
98.1

47
47
47
47
47

EL-S
EL03
EL04
T01
T02

35.5
30.3
26.5
51.0
45.9

37.7
32.5
28.4
54.3
48.6

40.0
34.8
30.5
58.0
51.4

55.8
50.9
45.2
87.5
71.4

59.3
54.6
48.5
98.2
76.6

47
48
48
48
48

SW2
OPEN
SW1
L-SR
L-HR

40.1
51.7
32.1
41.8
42.5

42.0
54.8
33.9
44.2
45.4

44.1
58.4
35.7
46.7
48.7

58.6
84.9
49.0
63.9
72.9

61.9
93.3
51.8
67.9
80.3

104

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

48
48
48
48
48

EL-S
EL03
EL04
T01
T02

36.2
30.6
26.7
51.8
46.6

38.4
32.8
28.7
55.1
49.2

40.7
35.1
30.8
58.8
52.1

56.5
51.3
45.5
88.2
72.0

60.1
54.9
48.8
98.8
77.2

48
49
49
49
49

SW2
OPEN
SW1
L-SR
L-HR

40.8
52.6
33.0
42.5
40.7

42.8
55.7
34.8
44.8
43.4

44.9
59.3
36.6
47.4
46.5

59.6
85.7
49.9
64.6
68.5

62.9
94.1
52.8
68.6
74.9

49
49
49
49
49

EL-S
EL03
EL04
T01
T02

36.9
30.9
27.0
52.7
47.3

39.1
33.1
28.9
56.0
49.9

41.4
35.4
31.0
59.8
52.8

57.3
51.6
45.8
89.1
72.8

60.9
55.3
49.1
99.6
77.9

49
50
50
50
50

SW2
OPEN
SW1
L-SR
L-HR

41.7
53.5
33.9
43.2
39.7

43.7
56.7
35.7
45.6
42.4

45.7
60.3
37.6
48.1
45.3

60.5
86.7
51.0
65.4
66.2

63.9
95.0
54.0
69.4
72.0

50
50
50
50
50

EL-S
EL03
EL04
T01
T02

37.7
31.2
27.2
53.8
48.1

39.8
33.4
29.2
57.0
50.7

42.2
35.7
31.3
60.8
53.6

58.1
51.9
46.1
90.1
73.6

61.7
55.6
49.4
****
78.7

50
51
51
51
51

SW2
OPEN
SW1
L-SR
L-HR

42.5
54.6
35.0
44.0
39.1

44.6
57.8
36.8
46.4
41.7

46.7
61.4
38.7
48.9
44.5

61.6
87.8
52.2
66.3
64.7

65.0
96.1
55.2
70.3
70.2

51
51
51
51
51

EL-S
EL03
EL04
T01
T02

38.5
31.5
27.5
54.9
48.9

40.7
33.7
29.5
58.2
51.6

43.0
36.0
31.6
62.0
54.5

59.1
52.2
46.4
91.4
74.5

62.6
56.0
49.6
****
79.7

51
52
52
52
52

SW2
OPEN
SW1
L-SR
L-HR

43.5
55.9
36.1
44.9
38.7

45.5
59.1
37.9
47.3
41.3

47.7
62.8
39.9
49.8
44.0

62.7
89.2
53.5
67.2
63.6

66.1
97.4
56.5
71.3
68.9

105

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

52
52
52
52
52

EL-S
EL03
EL04
T01
T02

39.4
31.8
27.8
56.2
49.9

41.6
33.9
29.7
59.6
52.6

43.9
36.3
31.8
63.4
55.5

60.0
52.6
46.6
92.9
75.6

63.6
56.3
49.9
****
80.7

52
53
53
53
53

SW2
OPEN
SW1
L-SR
L-HR

44.5
57.4
37.5
45.8
38.4

46.5
60.6
39.3
48.3
40.9

48.7
64.3
41.2
50.8
43.6

64.0
90.8
55.1
68.3
62.8

67.4
99.0
58.1
72.4
67.9

53
53
53
53
53

EL-S
EL03
EL04
T01
T02

40.3
32.0
28.0
57.8
51.0

42.6
34.2
29.9
61.1
53.7

44.9
36.6
32.1
65.1
56.6

61.1
52.9
46.9
94.7
76.7

64.8
56.6
50.2
****
81.9

53
54
54
54
54

SW2
OPEN
SW1
L-SR
L-HR

45.6
58.4
38.9
46.9
38.1

47.7
61.7
40.8
49.4
40.6

49.9
65.5
42.8
51.9
43.2

65.3
92.1
56.9
69.5
62.0

68.8
****
60.0
73.6
66.8

54
54
54
54
54

EL-S
EL03
EL04
T01
T02

41.4
32.3
28.3
47.5
52.2

43.7
34.5
30.2
50.7
54.9

46.0
36.8
32.3
54.4
57.9

62.3
53.2
47.2
80.4
78.1

66.0
56.9
50.5
88.4
83.3

54
55
55
55
55

SW2
OPEN
SW1
L-SR
L-HR

46.8
59.2
40.8
48.1
38.1

48.9
62.7
42.7
50.6
40.6

51.2
66.7
44.7
53.2
43.2

66.8
93.4
59.0
70.9
61.8

70.3
****
62.2
75.0
66.6

55
55
55
55
55

EL-S
EL03
EL04
T01
T02

42.6
32.6
28.5
44.7
53.6

44.9
34.8
30.5
47.7
56.3

47.3
37.1
32.6
51.0
59.3

63.6
53.4
47.5
74.9
79.6

67.3
57.2
50.8
82.0
84.8

55
56
56
56
56

SW2
OPEN
SW1
L-SR
L-HR

48.1
60.1
43.0
49.5
38.2

50.3
63.9
44.9
51.9
40.7

52.6
68.1
47.0
54.6
43.3

68.5
95.3
61.7
72.4
61.8

72.1
****
65.1
76.6
66.6

106

Table 24.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

56
56
56
56
56

EL-S
EL03
EL04
T01
T02

43.9
32.8
28.8
43.7
55.0

46.2
35.0
30.7
46.6
57.9

48.7
37.4
32.8
49.8
60.9

65.2
53.7
47.7
72.7
81.3

68.9
57.5
51.1
79.3
86.6

56
57
57
57
57

SW2
OPEN
SW1
L-SR
L-HR

49.7
61.4
45.9
51.0
38.4

51.9
65.6
48.0
53.6
40.9

54.3
70.1
50.1
56.2
43.5

70.4
98.0
65.4
74.2
62.0

74.0
****
68.9
78.4
66.8

57
57
57
57
57

EL-S
EL03
EL04
T01
T02

45.5
33.1
29.0
43.6
56.8

47.8
35.3
31.0
46.5
59.7

50.3
37.7
33.1
49.6
62.8

66.9
54.0
48.0
72.3
83.4

70.7
57.8
51.3
78.8
88.7

57
58
58
58
58

SW2
OPEN
SW1
L-SR
L-HR

51.5
63.6
50.4
52.9
38.8

53.8
68.2
52.6
55.4
41.2

56.2
73.2
55.0
58.1
43.8

72.6
****
71.4
76.3
62.5

76.3
****
75.3
80.6
67.2

58
58
58
58
58

EL-S
EL03
EL04
T01
T02

47.3
33.4
29.3
44.3
58.9

49.6
35.6
31.2
47.2
61.8

52.1
37.9
33.4
50.4
65.0

69.0
54.3
48.3
73.5
86.0

72.8
58.1
51.6
80.3
91.3

58
59
59
59
59

SW2
MECH
ELME
EL-S
EL03

53.6
66.9
69.6
49.5
33.4

55.9
70.3
73.3
51.9
35.6

58.5
74.1
77.4
54.4
37.9

75.3
99.0
****
71.6
54.3

79.2
****
****
75.5
58.1

59
59
R

EL04
SW2
SW2

29.3
56.2
60.4

31.3
58.7
63.0

33.4
61.3
65.7

48.3
78.7
83.9

51.6
82.7
88.2

107

Table 25.

Level

Results of Tenability Analysis for Scenario 25.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

B
B
B
B
B

MECH
L-SR
L-MR
L-HR
EL-S

41.5
61.6
44.1
37.1
20.7

46.3
68.8
52.0
43.4
23.1

52.0
77.5
61.7
51.5
25.7

88.8
****
****
97.9
43.5

****
****
****
****
47.8

B
B
B
B
B

EL01
EL02
EL03
EL04
SW2

55.8
61.3
51.8
50.6
9.6

62.4
69.2
58.8
56.6
11.2

70.2
78.6
67.1
63.6
13.0

****
****
****
****
26.6

****
****
****
****
29.4

G
G
G
G
G

OPEN
SW1
L-SR
EL-S
EL01

7.1
46.9
16.8
11.6
9.7

9.0
52.1
19.4
13.5
11.7

11.2
58.2
22.2
15.5
13.9

26.9
95.9
42.8
30.2
30.1

30.6
****
48.9
33.3
34.1

G
G
G
G
G

EL02
EL03
EL04
T01
T02

9.6
8.5
8.6
14.8
17.2

11.6
10.5
10.5
17.2
19.7

13.9
12.7
12.8
19.8
22.4

30.1
28.6
28.7
38.2
41.6

34.0
32.4
32.6
43.2
46.9

G
2
2
2
2

SW2
OPEN
SW1
L-SR
CR01

3.7
1.0
1.0
1.0
1.5

4.5
1.0
1.5
1.5
1.9

5.6
1.0
1.9
1.9
2.6

16.2
4.8
9.7
9.4
11.1

18.4
6.1
11.7
11.3
13.1

2
2
2
2
2

CR02
EL-S
EL01
EL02
EL03

1.0
3.3
1.4
2.0
2.0

1.5
4.0
1.9
2.8
2.9

1.9
5.0
2.5
3.6
3.8

9.4
15.6
11.9
14.7
15.5

11.3
17.9
14.2
17.2
18.2

2
2
2
2
3

EL04
T01
T02
SW2
SW1

2.0
1.7
2.0
1.0
2.1

2.8
2.1
2.8
1.4
2.8

3.8
2.9
3.6
1.9
3.6

15.3
11.9
13.6
9.0
12.8

17.9
14.0
15.8
10.9
15.0

3
3
3
3
3

L-SR
CR02
EL-S
EL01
EL02

18.4
13.6
5.5
2.1
3.2

21.0
15.9
6.6
2.8
4.0

23.8
18.5
7.9
3.6
5.1

46.5
36.5
19.6
13.8
16.9

54.8
41.4
22.1
16.1
19.5

108

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

3
3
3
4
4

EL03
EL04
SW2
SW1
L-SR

2.8
2.7
4.5
3.6
21.3

3.6
3.5
5.5
4.4
23.9

4.6
4.6
6.8
5.3
26.7

16.5
16.3
18.4
15.5
51.1

19.2
18.9
20.9
17.7
60.5

4
4
4
4
4

EL-S
EL01
EL02
EL03
EL04

7.6
3.0
4.5
3.3
3.3

8.9
3.8
5.5
4.2
4.1

10.4
4.8
6.8
5.3
5.3

22.9
15.4
19.0
17.4
17.2

25.5
17.9
21.7
20.1
19.9

4
5
5
5
5

SW2
SW1
L-SR
EL-S
EL01

8.0
4.9
23.7
9.6
3.9

9.6
5.9
26.3
11.0
4.8

11.3
7.0
29.2
12.7
5.9

24.0
17.9
55.3
25.7
17.0

26.5
20.1
65.6
28.4
19.5

5
5
5
5
6

EL02
EL03
EL04
SW2
SW1

5.8
3.9
3.8
11.4
6.4

7.0
4.9
4.8
13.0
7.5

8.4
6.0
5.9
14.9
8.7

21.1
18.3
18.1
27.9
19.9

23.8
21.1
20.8
30.5
22.1

6
6
6
6
6

L-SR
EL-S
EL01
EL02
EL03

25.7
11.3
4.8
7.3
4.5

28.4
12.9
5.8
8.6
5.5

31.4
14.7
6.9
10.0
6.8

59.0
28.1
18.4
23.1
19.2

70.6
30.8
21.0
26.0
21.9

6
6
7
7
7

EL04
SW2
SW1
L-SR
EL-S

4.4
14.2
7.7
27.6
12.9

5.5
15.9
8.9
30.3
14.6

6.7
17.9
10.3
33.4
16.4

19.0
31.0
21.7
62.5
30.1

21.7
33.8
23.9
75.4
33.0

7
7
7
7
7

EL01
EL02
EL03
EL04
SW2

5.7
8.7
5.0
4.9
16.6

6.8
10.1
6.1
6.0
18.4

7.9
11.8
7.4
7.3
20.4

19.8
25.2
20.1
19.8
33.6

22.4
28.0
22.8
22.5
36.5

8
8
8
8
8

SW1
L-SR
EL-S
EL01
EL02

9.0
29.2
14.4
6.6
10.2

10.3
31.9
16.1
7.7
11.7

11.7
35.2
18.0
8.9
13.4

23.2
65.9
32.0
21.1
27.1

25.5
80.3
35.0
23.7
30.1

109

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

8
8
8
9
9

EL03
EL04
SW2
SW1
L-SR

5.6
5.6
18.6
10.2
30.7

6.8
6.7
20.5
11.6
33.5

8.0
7.9
22.4
13.0
36.9

20.8
20.6
35.9
24.7
69.1

23.6
23.3
38.9
26.9
85.6

9
9
9
9
9

EL-S
EL01
EL02
EL03
EL04

15.7
7.4
11.7
6.1
6.0

17.5
8.6
13.3
7.3
7.2

19.5
9.9
15.1
8.7
8.6

33.7
22.2
29.1
21.6
21.3

36.7
24.9
32.1
24.4
24.1

9
10
10
10
10

SW2
SW1
L-SR
EL-S
EL01

20.4
11.4
32.0
17.0
8.2

22.2
12.8
35.0
18.8
9.4

24.1
14.3
38.6
20.8
10.8

37.8
25.9
72.3
35.3
23.3

41.0
28.2
91.3
38.3
26.1

10
10
10
10
11

EL02
EL03
EL04
SW2
SW1

13.2
6.7
6.6
21.9
12.5

14.9
7.9
7.8
23.7
13.9

16.7
9.4
9.2
25.6
15.5

31.0
22.3
22.1
39.6
27.1

34.1
25.1
24.8
42.8
29.3

11
11
11
11
11

L-SR
EL-S
EL01
EL02
EL03

33.3
18.1
8.9
14.7
7.2

36.4
20.0
10.2
16.4
8.5

40.1
22.1
11.7
18.4
9.9

75.6
36.7
24.4
32.9
23.1

97.7
39.8
27.1
36.1
25.9

11
11
12
12
12

EL04
SW2
SW1
L-SR
EL-S

7.0
23.3
13.5
34.6
19.2

8.3
25.1
14.9
37.7
21.1

9.8
27.0
16.6
41.6
23.2

22.7
41.2
28.2
79.0
38.0

25.5
44.5
30.4
****
41.2

12
12
12
12
12

EL01
EL02
EL03
EL04
SW2

9.7
16.2
7.7
7.6
24.5

11.0
18.0
9.0
8.8
26.3

12.5
20.0
10.5
10.3
28.2

25.4
34.8
23.7
23.4
42.6

28.2
38.0
26.6
26.2
46.1

13
13
13
13
13

SW1
L-SR
EL-S
EL01
EL02

14.5
35.8
20.2
10.4
17.7

15.9
39.0
22.2
11.8
19.5

17.6
43.0
24.3
13.3
21.6

29.2
82.6
39.3
26.4
36.6

31.4
****
42.5
29.2
39.9

110

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

13
13
13
14
14

EL03
EL04
SW2
SW1
L-SR

8.2
8.0
25.6
15.4
36.9

9.6
9.3
27.4
16.8
40.3

11.1
10.8
29.3
18.5
44.5

24.4
24.1
44.0
30.1
86.5

27.3
26.9
47.5
32.4
****

14
14
14
14
14

EL-S
EL01
EL02
EL03
EL04

21.2
11.0
19.1
8.7
8.5

23.2
12.5
21.0
10.0
9.8

25.3
14.1
23.1
11.6
11.4

40.4
27.3
38.4
25.1
24.7

43.7
30.1
41.8
27.9
27.5

14
15
15
15
15

SW2
SW1
L-SR
EL-S
EL01

26.6
16.2
38.0
22.1
11.8

28.4
17.7
41.5
24.1
13.2

30.4
19.4
45.9
26.3
14.8

45.2
31.0
90.9
41.5
28.1

48.9
33.3
****
44.9
31.0

15
15
15
15
16

EL02
EL03
EL04
SW2
SW1

20.6
9.2
8.9
27.5
17.0

22.6
10.6
10.3
29.4
18.6

24.7
12.1
11.9
31.3
20.2

40.2
25.7
25.2
46.4
31.8

43.7
28.6
28.1
50.1
34.1

16
16
16
16
16

L-SR
EL-S
EL01
EL02
EL03

39.2
22.9
12.4
22.0
9.7

42.8
25.0
13.9
24.0
11.0

47.4
27.2
15.6
26.2
12.7

96.2
42.5
29.0
42.0
26.3

****
46.0
31.8
45.5
29.2

16
16
17
17
17

EL04
SW2
SW1
L-SR
EL-S

9.4
28.4
17.8
40.3
23.8

10.8
30.2
19.3
44.0
25.8

12.4
32.2
20.9
48.9
28.0

25.8
47.5
32.5
****
43.5

28.7
51.3
34.9
****
47.0

17
17
17
17
17

EL01
EL02
EL03
EL04
SW2

13.0
23.4
10.1
9.8
29.2

14.5
25.5
11.5
11.2
31.0

16.2
27.8
13.2
12.8
33.1

29.8
43.7
26.8
26.4
48.5

32.7
47.3
29.8
29.3
52.4

18
18
18
18
18

SW1
L-SR
EL-S
EL01
EL02

18.5
41.5
24.5
13.6
24.8

20.0
45.4
26.6
15.1
26.9

21.7
50.6
28.9
16.9
29.3

33.3
****
44.5
30.5
45.4

35.7
****
48.0
33.5
49.1

111

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

18
18
18
19
19

EL03
EL04
SW2
SW1
L-SR

10.6
10.2
29.9
19.2
42.8

12.0
11.7
31.8
20.7
46.9

13.7
13.3
33.9
22.3
52.5

27.4
26.9
49.5
34.0
****

30.4
29.8
53.5
36.4
****

19
19
19
19
19

EL-S
EL01
EL02
EL03
EL04

25.3
14.2
26.2
10.9
10.6

27.4
15.8
28.4
12.5
12.1

29.6
17.5
30.7
14.1
13.8

45.3
31.3
47.1
28.0
27.4

48.9
34.2
50.9
30.9
30.4

19
20
20
20
20

SW2
SW1
L-SR
EL-S
EL01

30.7
19.8
44.3
25.9
14.8

32.6
21.4
48.7
28.1
16.4

34.7
22.9
54.7
30.4
18.1

50.4
34.6
****
46.2
32.0

54.4
37.1
****
49.8
35.0

20
20
20
20
21

EL02
EL03
EL04
SW2
SW1

27.6
11.4
11.0
31.3
20.5

29.8
12.9
12.5
33.3
22.0

32.2
14.6
14.2
35.4
23.7

48.8
28.5
28.0
51.3
35.5

52.6
31.5
30.9
55.4
38.0

21
21
21
21
21

L-SR
EL-S
EL01
EL02
EL03

46.3
26.6
15.3
28.9
11.8

51.2
28.8
16.9
31.2
13.3

58.2
31.1
18.7
33.6
15.0

****
47.0
32.7
50.4
29.0

****
50.6
35.7
54.4
32.0

21
21
22
22
22

EL04
SW2
SW1
L-SR
EL-S

11.4
32.2
21.1
49.5
27.3

12.9
34.1
22.7
55.4
29.5

14.6
36.2
24.3
64.4
31.8

28.4
52.4
36.3
****
47.8

31.4
56.6
38.8
****
51.4

22
22
22
22
22

EL01
EL02
EL03
EL04
SW2

15.8
30.3
12.2
11.8
32.9

17.5
32.6
13.7
13.3
34.9

19.3
35.0
15.5
15.0
37.1

33.3
52.1
29.5
28.9
53.5

36.3
56.1
32.5
31.9
57.7

23
23
23
23
23

SW1
EL-S
EL01
EL02
EL03

21.8
27.9
16.4
31.6
12.6

23.4
30.1
18.0
33.9
14.1

25.0
32.4
19.9
36.5
15.9

37.0
48.5
34.0
53.7
30.0

39.6
52.2
37.0
57.7
33.1

112

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

23
23
24
24
24

EL04
SW2
SW1
L-SR
EL-S

12.1
33.7
22.4
54.1
28.5

13.7
35.7
23.9
61.3
30.7

15.5
37.9
25.6
74.1
33.0

29.4
54.5
37.7
****
49.2

32.4
58.8
40.3
****
52.9

24
24
24
24
24

EL01
EL02
EL03
EL04
SW2

17.5
34.7
12.9
12.5
34.4

19.2
37.2
14.6
14.0
36.4

21.1
39.9
16.3
15.8
38.6

35.7
58.7
30.5
29.8
55.4

39.0
63.5
33.5
32.8
59.7

25
25
25
25
25

OPEN
SW1
L-SR
CR01
EL-S

45.6
22.9
38.1
58.9
28.9

49.4
24.5
40.8
64.6
31.1

54.0
26.1
43.6
71.7
33.5

91.8
38.3
63.1
****
49.7

****
40.9
68.1
****
53.4

25
25
25
25
25

EL01
EL02
EL03
EL04
T01

17.9
35.7
13.3
12.8
43.5

19.7
38.2
14.9
14.4
46.9

21.6
41.0
16.7
16.2
51.0

36.3
60.0
30.9
30.2
85.8

39.5
64.9
34.0
33.2
****

25
25
26
26
26

T02
SW2
OPEN
SW1
L-SR

42.4
35.0
46.3
23.4
38.7

45.5
37.0
50.1
24.9
41.4

48.9
39.2
54.8
26.7
44.2

73.6
56.1
92.8
38.9
63.7

80.7
60.4
****
41.5
68.6

26
26
26
26
26

CR01
EL-S
EL01
EL02
EL03

59.7
29.5
18.3
36.5
13.7

65.4
31.7
20.0
39.1
15.3

72.6
34.0
22.0
41.9
17.1

****
50.3
36.8
61.2
31.3

****
54.0
40.1
66.2
34.4

26
26
26
26
27

EL04
T01
T02
SW2
OPEN

13.2
44.2
42.9
35.6
47.2

14.8
47.6
46.0
37.7
51.0

16.6
51.8
49.5
39.9
55.8

30.6
86.6
74.0
56.8
94.2

33.6
****
81.1
61.1
****

27
27
27
27
27

SW1
L-SR
CR01
EL-S
EL01

23.9
39.2
60.7
29.9
18.7

25.5
41.8
66.5
32.1
20.4

27.2
44.7
73.8
34.5
22.4

39.5
64.2
****
50.8
37.2

42.1
69.1
****
54.5
40.5

113

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

27
27
27
27
27

EL02
EL03
EL04
T01
T02

37.3
14.0
13.5
44.9
43.6

39.9
15.7
15.1
48.4
46.7

42.7
17.5
16.9
52.6
50.2

62.3
31.8
31.0
87.7
74.7

67.4
34.9
34.1
****
81.8

27
28
28
28
28

SW2
OPEN
SW1
L-SR
CR01

36.2
48.1
24.5
39.7
61.8

38.3
52.0
26.0
42.4
67.6

40.5
56.9
27.8
45.2
75.1

57.5
95.8
40.1
64.7
****

61.9
****
42.7
69.6
****

28
28
28
28
28

EL-S
EL01
EL02
EL03
EL04

30.4
19.0
38.0
14.4
13.8

32.7
20.8
40.7
16.0
15.5

35.0
22.8
43.5
17.9
17.3

51.3
37.7
63.3
32.2
31.4

55.1
41.0
68.5
35.3
34.5

28
28
28
29
29

T01
T02
SW2
OPEN
SW1

45.6
44.3
36.9
49.0
25.0

49.1
47.4
38.9
53.0
26.6

53.4
50.8
41.2
58.0
28.3

88.8
75.4
58.2
97.4
40.7

****
82.4
62.6
****
43.4

29
29
29
29
29

L-SR
CR01
EL-S
EL01
EL02

40.2
62.9
30.9
19.3
38.7

42.8
68.8
33.2
21.1
41.4

45.7
76.4
35.6
23.2
44.3

65.3
****
51.9
38.1
64.2

70.2
****
55.6
41.4
69.5

29
29
29
29
29

EL03
EL04
T01
T02
SW2

14.7
14.1
46.4
44.9
37.5

16.4
15.8
49.9
48.0
39.6

18.2
17.6
54.2
51.6
41.8

32.6
31.8
89.9
76.1
59.0

35.7
34.9
****
83.1
63.4

30
30
30
30
30

OPEN
SW1
L-SR
CR01
EL-S

50.0
25.6
40.7
64.0
31.5

54.1
27.2
43.4
70.0
33.7

59.2
28.9
46.2
77.7
36.0

99.0
41.4
65.8
****
52.4

****
44.1
70.7
****
56.2

30
30
30
30
30

EL01
EL02
EL03
EL04
T01

19.7
39.4
15.0
14.5
47.2

21.5
42.0
16.7
16.1
50.7

23.5
44.9
18.6
17.9
55.1

38.5
65.1
33.0
32.2
91.1

41.8
70.5
36.2
35.2
****

114

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

30
30
31
31
31

T02
SW2
OPEN
SW1
L-SR

45.6
38.2
51.0
26.2
41.2

48.8
40.3
55.2
27.8
43.9

52.3
42.5
60.4
29.5
46.7

76.8
59.7
****
42.0
66.3

83.8
64.2
****
44.7
71.2

31
31
31
31
31

CR01
EL-S
EL01
EL02
EL03

65.2
31.9
20.0
40.0
15.4

71.3
34.2
21.8
42.7
17.0

79.2
36.6
23.8
45.6
18.9

****
53.0
38.9
66.0
33.4

****
56.8
42.2
71.4
36.6

31
31
31
31
32

EL04
T01
T02
SW2
OPEN

14.8
47.9
46.3
38.8
52.1

16.4
51.6
49.5
40.9
56.3

18.3
56.0
53.0
43.2
61.6

32.5
92.3
77.5
60.5
****

35.6
****
84.5
64.9
****

32
32
32
32
32

SW1
L-SR
CR01
EL-S
EL01

26.8
41.7
66.4
32.5
20.3

28.4
44.4
72.7
34.7
22.1

30.1
47.3
80.7
37.1
24.2

42.7
66.9
****
53.6
39.2

45.4
71.8
****
57.3
42.6

32
32
32
32
32

EL02
EL03
EL04
T01
T02

40.6
15.7
15.0
48.8
47.0

43.3
17.4
16.7
52.5
50.2

46.3
19.3
18.6
56.9
53.7

66.8
33.8
32.9
93.6
78.2

72.3
37.0
36.0
****
85.3

32
33
33
33
33

SW2
OPEN
SW1
L-SR
CR01

39.5
53.2
27.4
42.2
67.7

41.6
57.6
29.0
44.9
74.1

43.9
63.0
30.7
47.8
82.3

61.2
****
43.4
67.4
****

65.7
****
46.1
72.4
****

33
33
33
33
33

EL-S
EL01
EL02
EL03
EL04

33.0
20.6
41.1
16.0
15.4

35.3
22.4
43.9
17.7
17.0

37.7
24.5
46.8
19.7
18.9

54.2
39.6
67.5
34.2
33.3

57.9
42.9
73.1
37.4
36.4

33
33
33
34
34

T01
T02
SW2
OPEN
SW1

53.2
47.8
40.1
54.4
28.0

57.7
51.0
42.3
58.9
29.6

63.3
54.5
44.6
64.4
31.4

****
79.1
62.0
****
44.1

****
86.2
66.5
****
46.9

115

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

34
34
34
34
34

L-SR
CR01
EL-S
EL01
EL02

42.8
69.1
33.5
20.8
41.7

45.5
75.7
35.8
22.7
44.4

48.4
84.0
38.2
24.8
47.4

68.0
****
54.7
39.9
68.3

73.0
****
58.5
43.3
74.0

34
34
34
34
34

EL03
EL04
T01
T02
SW2

16.4
15.7
54.5
48.6
40.8

18.0
17.4
59.1
51.8
42.9

20.0
19.2
64.9
55.3
45.3

34.6
33.6
****
79.9
62.7

37.8
36.7
****
86.9
67.2

35
35
35
35
35

OPEN
SW1
L-SR
CR01
EL-S

53.0
28.6
43.3
67.8
34.1

57.6
30.3
46.0
74.3
36.4

63.1
32.0
48.9
82.5
38.8

****
44.8
68.6
****
55.3

****
47.6
73.6
****
59.1

35
35
35
35
35

EL01
EL02
EL03
EL04
T01

21.1
42.2
16.7
15.9
55.6

23.0
44.9
18.4
17.7
60.3

25.0
48.0
20.3
19.6
66.3

40.2
69.0
35.0
34.0
****

43.5
74.7
38.2
37.1
****

35
35
36
36
36

T02
SW2
OPEN
SW1
L-SR

49.3
41.4
47.0
29.3
43.9

52.6
43.6
51.1
30.9
46.6

56.1
45.9
56.1
32.7
49.5

80.7
63.5
91.9
45.5
69.2

87.8
68.0
****
48.3
74.2

36
36
36
36
36

CR01
EL-S
EL01
EL02
EL03

60.9
34.6
21.4
42.6
16.9

66.6
36.9
23.2
45.4
18.7

73.7
39.3
25.3
48.5
20.7

****
56.0
40.5
69.6
35.3

****
59.7
43.9
75.4
38.5

36
36
36
36
37

EL04
T01
T02
SW2
OPEN

16.3
55.6
50.1
42.0
44.5

17.9
60.2
53.4
44.3
48.2

19.9
66.0
56.9
46.7
52.7

34.3
****
81.6
64.3
85.5

37.5
****
88.6
68.8
97.6

37
37
37
37
37

SW1
L-SR
CR01
EL-S
EL01

29.9
44.5
57.6
35.2
21.7

31.6
47.2
62.8
37.5
23.5

33.4
50.1
69.2
39.9
25.6

46.3
69.8
****
56.6
40.8

49.1
74.8
****
60.4
44.1

116

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

37
37
37
37
37

EL02
EL03
EL04
T01
T02

43.0
17.3
16.6
55.4
50.9

45.8
19.0
18.3
60.0
54.2

48.9
21.0
20.2
65.6
57.8

70.2
35.7
34.7
****
82.4

76.1
38.9
37.8
****
89.4

37
38
38
38
38

SW2
OPEN
SW1
L-SR
CR01

42.7
42.6
30.6
45.0
55.2

44.9
46.2
32.3
47.7
60.0

47.3
50.3
34.0
50.6
65.8

65.0
80.7
47.0
70.4
****

69.6
91.3
49.9
75.4
****

38
38
38
38
38

EL-S
EL01
EL02
EL03
EL04

35.8
21.9
43.3
17.6
16.8

38.0
23.8
46.2
19.3
18.6

40.5
25.9
49.3
21.3
20.5

57.2
41.1
70.7
36.1
35.0

61.0
44.4
76.6
39.3
38.2

38
38
38
39
39

T01
T02
SW2
OPEN
SW1

54.8
51.7
43.4
41.0
31.2

59.3
55.0
45.6
44.3
32.9

64.7
58.6
48.0
48.1
34.7

****
83.2
65.8
76.1
47.8

****
90.2
70.4
85.5
50.6

39
39
39
39
39

L-SR
CR01
EL-S
EL01
EL02

45.5
53.0
36.4
22.2
43.6

48.2
57.5
38.7
24.0
46.5

51.1
62.7
41.1
26.1
49.6

70.9
97.7
57.8
41.3
71.1

75.8
****
61.7
44.8
77.1

39
39
39
39
39

EL03
EL04
T01
T02
SW2

17.9
17.1
53.6
52.3
44.0

19.7
18.8
57.9
55.5
46.3

21.6
20.8
63.0
59.1
48.7

36.4
35.3
98.8
83.7
66.6

39.7
38.5
****
90.7
71.1

40
40
40
40
40

OPEN
SW1
L-SR
CR01
EL-S

41.1
31.9
46.1
53.0
36.9

44.4
33.6
48.8
57.5
39.3

48.2
35.4
51.8
62.7
41.7

76.0
48.6
71.5
97.5
58.5

85.3
51.4
76.5
****
62.3

40
40
40
40
40

EL01
EL02
EL03
EL04
T01

22.5
43.9
18.2
17.4
54.1

24.4
46.8
19.9
19.1
58.5

26.5
49.9
21.9
21.0
63.7

41.7
71.4
36.8
35.7
99.5

45.1
77.4
40.0
38.8
****

117

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

40
40
41
41
41

T02
SW2
OPEN
SW1
L-SR

53.2
44.7
41.4
32.6
46.7

56.5
46.9
44.7
34.3
49.5

60.2
49.4
48.4
36.1
52.4

84.7
67.3
76.3
49.4
72.2

91.7
71.9
85.6
52.3
77.2

41
41
41
41
41

CR01
EL-S
EL01
EL02
EL03

53.3
37.6
22.8
44.3
18.5

57.7
39.9
24.7
47.1
20.2

63.0
42.3
26.8
50.3
22.2

97.8
59.1
42.0
71.8
37.1

****
63.0
45.4
77.8
40.4

41
41
41
41
42

EL04
T01
T02
SW2
OPEN

17.7
54.8
53.9
45.3
41.3

19.4
59.3
57.2
47.6
44.6

21.4
64.6
60.8
50.1
48.3

36.0
****
85.4
68.1
75.7

39.2
****
92.4
72.7
84.8

42
42
42
42
42

SW1
L-SR
CR01
EL-S
EL01

33.3
47.3
53.1
38.2
23.0

35.0
50.0
57.5
40.5
25.0

36.9
53.0
62.6
43.0
27.1

50.2
72.8
96.9
59.8
42.3

53.1
77.8
****
63.7
45.7

42
42
42
42
42

EL02
EL03
EL04
T01
T02

44.6
18.7
17.9
54.9
54.5

47.5
20.6
19.7
59.5
57.8

50.6
22.6
21.7
64.9
61.4

72.2
37.4
36.3
****
86.0

78.2
40.7
39.5
****
92.9

42
43
43
43
43

SW2
OPEN
SW1
L-SR
EL-S

45.9
35.7
34.0
46.0
38.8

48.3
38.5
35.8
48.6
41.1

50.8
41.5
37.6
51.4
43.6

68.9
62.7
51.0
70.3
60.5

73.5
68.6
53.9
74.9
64.4

43
43
43
43
43

EL01
EL02
EL03
EL04
T01

23.4
45.0
19.3
18.5
48.9

25.3
47.8
21.2
20.3
52.4

27.4
51.0
23.2
22.3
56.3

42.7
72.5
38.3
37.2
83.6

46.1
78.5
41.7
40.4
92.3

43
43
44
44
44

T02
SW2
OPEN
SW1
L-SR

51.2
46.6
55.1
34.8
45.8

54.2
49.0
58.6
36.5
48.4

57.5
51.5
62.6
38.4
51.2

80.0
69.7
92.0
51.8
69.8

86.1
74.3
****
54.8
74.2

118

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

44
44
44
44
44

EL-S
EL03
EL04
T01
T02

39.5
19.6
18.7
55.5
50.8

41.8
21.4
20.5
58.9
53.7

44.3
23.5
22.6
62.9
56.8

61.2
38.6
37.4
93.7
78.6

65.1
42.1
40.7
****
84.4

44
45
45
45
45

SW2
OPEN
SW1
L-SR
EL-S

47.3
56.5
35.6
46.5
40.1

49.7
60.0
37.3
49.1
42.5

52.2
64.0
39.2
51.9
45.0

70.5
93.7
52.7
70.5
62.0

75.1
****
55.7
75.0
65.9

45
45
45
45
45

EL03
EL04
T01
T02
SW2

19.8
18.9
56.4
51.6
48.0

21.7
20.8
59.9
54.5
50.4

23.7
22.8
63.9
57.6
53.0

38.9
37.7
94.9
79.4
71.3

42.3
41.0
****
85.2
75.9

46
46
46
46
46

OPEN
SW1
L-SR
EL-S
EL03

55.3
36.4
47.3
40.9
20.0

59.2
38.2
49.9
43.2
21.9

63.6
40.0
52.7
45.8
23.9

93.6
53.7
71.3
62.8
39.2

****
56.7
75.8
66.7
42.6

46
46
46
46
47

EL04
T01
T02
SW2
OPEN

19.1
56.1
52.4
48.7
48.0

20.9
59.8
55.3
51.2
52.6

23.0
64.1
58.5
53.8
57.8

37.9
95.3
80.3
72.2
89.2

41.2
****
86.1
76.8
99.5

47
47
47
47
47

SW1
L-SR
EL-S
EL03
EL04

37.3
48.0
41.7
20.3
19.4

39.1
50.7
44.0
22.1
21.2

41.0
53.5
46.6
24.2
23.2

54.7
72.2
63.6
39.4
38.2

57.8
76.7
67.6
42.9
41.4

47
47
47
48
48

T01
T02
SW2
OPEN
SW1

45.2
53.2
49.5
46.0
38.3

49.4
56.2
52.0
50.4
40.1

54.3
59.4
54.6
55.5
42.0

86.1
81.3
73.1
87.5
55.9

96.6
87.1
77.8
97.7
58.9

48
48
48
48
48

L-SR
EL-S
EL03
EL04
T01

48.9
42.5
20.5
19.6
43.3

51.5
44.8
22.4
21.4
47.2

54.3
47.4
24.4
23.4
51.8

73.1
64.5
39.7
38.4
83.2

77.6
68.5
43.1
41.7
93.4

119

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

48
48
49
49
49

T02
SW2
OPEN
SW1
L-SR

54.2
50.3
45.4
39.4
49.8

57.1
52.8
49.6
41.2
52.4

60.3
55.5
54.7
43.1
55.2

82.3
74.1
87.0
57.1
74.1

88.1
78.8
97.2
60.2
78.6

49
49
49
49
49

EL-S
EL03
EL04
T01
T02

43.3
20.7
19.8
42.7
55.1

45.7
22.6
21.6
46.5
58.1

48.3
24.7
23.6
51.0
61.4

65.5
39.9
38.6
82.2
83.3

69.5
43.3
41.9
92.3
89.2

49
50
50
50
50

SW2
OPEN
SW1
L-SR
EL-S

51.2
44.6
40.5
50.7
44.3

53.8
48.7
42.4
53.4
46.7

56.5
53.6
44.3
56.2
49.2

75.1
86.0
58.4
75.1
66.5

79.8
96.2
61.6
79.7
70.5

50
50
50
50
50

EL03
EL04
T01
T02
SW2

20.9
19.9
42.7
56.2
52.2

22.8
21.8
46.5
59.2
54.7

24.9
23.8
50.9
62.5
57.5

40.2
38.8
82.3
84.5
76.3

43.6
42.1
92.5
90.4
81.0

51
51
51
51
51

OPEN
SW1
L-SR
EL-S
EL03

43.5
41.8
51.7
45.2
21.1

47.4
43.7
54.4
47.7
23.0

51.9
45.7
57.3
50.3
25.1

84.0
60.0
76.3
67.6
40.4

94.1
63.1
80.8
71.6
43.8

51
51
51
51
52

EL04
T01
T02
SW2
OPEN

20.2
42.4
57.4
53.2
42.7

22.0
46.1
60.4
55.8
46.4

24.0
50.5
63.6
58.6
50.8

39.1
81.8
85.8
77.5
82.3

42.4
92.0
91.6
82.2
92.4

52
52
52
52
52

SW1
L-SR
EL-S
EL03
EL04

43.2
52.8
46.3
21.3
20.4

45.1
55.5
48.8
23.2
22.2

47.2
58.4
51.4
25.3
24.3

61.6
77.5
68.8
40.6
39.3

64.9
82.1
72.9
44.1
42.6

52
52
52
53
53

T01
T02
SW2
OPEN
SW1

42.1
58.6
54.3
42.1
44.8

45.7
61.6
56.9
45.8
46.8

50.0
64.9
59.7
50.0
48.9

81.0
87.1
78.8
80.9
63.6

91.2
93.0
83.5
91.0
66.9

120

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

53
53
53
53
53

L-SR
EL-S
EL03
EL04
T01

54.0
47.5
21.5
20.6
41.8

56.7
49.9
23.4
22.5
45.4

59.6
52.6
25.5
24.5
49.5

78.8
70.1
40.8
39.5
80.2

83.4
74.2
44.3
42.9
90.3

53
53
54
54
54

T02
SW2
OPEN
SW1
L-SR

59.9
55.5
41.7
46.7
55.3

63.0
58.1
45.3
48.7
58.0

66.3
61.0
49.4
50.8
61.0

88.6
80.2
79.8
65.8
80.3

94.5
85.0
89.8
69.2
84.9

54
54
54
54
54

EL-S
EL03
EL04
T01
T02

48.8
21.7
20.8
41.5
61.4

51.2
23.7
22.7
45.0
64.5

53.9
25.7
24.7
49.1
67.9

71.5
41.1
39.8
79.4
90.3

75.7
44.5
43.1
89.5
96.2

54
55
55
55
55

SW2
OPEN
SW1
L-SR
EL-S

56.8
41.4
48.9
56.8
50.2

59.5
44.9
51.0
59.5
52.7

62.4
48.9
53.1
62.5
55.3

81.8
78.8
68.5
81.9
73.2

86.6
88.7
72.0
86.6
77.3

55
55
55
55
55

EL03
EL04
T01
T02
SW2

21.9
21.0
41.3
63.0
58.3

23.9
22.9
44.8
66.2
61.0

25.9
24.9
48.8
69.6
64.0

41.3
40.0
78.7
92.2
83.5

44.7
43.3
88.7
98.1
88.4

56
56
56
56
56

OPEN
SW1
L-SR
EL-S
EL03

41.2
51.7
58.4
51.7
22.2

44.6
53.8
61.2
54.3
24.1

48.6
56.0
64.1
57.0
26.2

77.9
71.9
83.7
74.9
41.5

87.7
75.5
88.5
79.1
45.0

56
56
56
56
57

EL04
T01
T02
SW2
OPEN

21.2
41.2
64.9
60.0
41.0

23.1
44.6
68.0
62.8
44.4

25.2
48.6
71.5
65.7
48.3

40.2
78.0
94.3
85.5
77.1

43.6
88.0
****
90.4
86.8

57
57
57
57
57

SW1
L-SR
EL-S
EL03
EL04

55.2
60.2
53.5
22.4
21.5

57.5
63.0
56.1
24.3
23.3

59.9
66.0
58.8
26.4
25.4

76.5
85.8
77.0
41.8
40.5

80.3
90.6
81.2
45.2
43.8

121

Table 25.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

57
57
57
58
58

T01
T02
SW2
OPEN
SW1

41.0
66.9
61.9
40.5
60.7

44.4
70.2
64.7
43.8
63.1

48.3
73.7
67.8
47.5
65.7

77.3
96.7
87.8
75.4
83.7

87.1
****
92.8
84.7
88.0

58
58
58
58
58

L-SR
EL-S
EL03
EL04
T01

62.3
55.6
22.6
21.7
40.6

65.2
58.2
24.5
23.6
43.9

68.2
61.0
26.6
25.7
47.7

88.2
79.4
42.0
40.7
75.8

93.1
83.7
45.5
44.1
85.2

58
58
59
59
59

T02
SW2
MECH
ELME
EL-S

69.3
64.1
76.8
80.4
58.0

72.6
67.0
80.9
84.7
60.7

76.2
70.1
85.4
89.5
63.6

99.6
90.5
****
****
82.3

****
95.6
****
****
86.7

59
59
59
R

EL03
EL04
SW2
SW2

22.6
21.7
66.9
71.4

24.6
23.6
69.8
74.6

26.7
25.7
73.0
77.9

42.0
40.8
93.8
99.5

45.5
44.1
99.0
****

122

Table 26.

Level

Results of Tenability Analysis for Scenario 26.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

B
B
B
B
B

MECH
L-SR
L-MR
L-HR
EL-S

37.7
55.0
38.4
34.6
22.6

43.2
62.9
45.0
40.2
25.1

49.9
72.5
53.5
47.5
27.9

91.1
****
****
93.5
47.0

****
****
****
****
52.0

B
B
B
B
B

EL01
EL02
EL03
EL04
SW2

53.3
52.0
47.5
46.6
11.1

60.5
59.8
54.5
53.0
12.9

69.1
69.2
62.9
60.8
14.9

****
****
****
****
29.3

****
****
****
****
32.3

G
G
G
G
G

OPEN
SW1
L-SR
EL-S
EL01

7.0
18.0
14.2
13.3
10.7

8.9
20.8
16.6
15.4
12.8

11.0
23.8
19.1
17.6
15.1

26.6
48.0
37.5
33.3
31.7

30.3
56.3
42.5
36.9
35.8

G
G
G
G
G

EL02
EL03
EL04
T01
T02

10.8
9.9
10.0
14.1
16.6

12.8
11.9
12.1
16.5
19.1

15.2
14.2
14.4
19.0
21.9

31.8
30.5
30.9
37.0
41.7

35.9
34.5
35.0
41.8
47.3

G
2
2
2
2

SW2
OPEN
SW1
L-SR
CR01

4.6
1.0
1.0
1.0
1.4

5.7
1.0
1.5
1.4
1.9

6.9
1.0
1.9
1.9
2.4

18.6
4.8
9.8
9.2
10.7

21.1
6.1
11.8
11.0
12.7

2
2
2
2
2

CR02
EL-S
EL01
EL02
EL03

1.0
3.0
1.1
1.8
1.8

1.4
3.9
1.7
2.4
2.3

1.9
4.8
2.2
3.1
3.0

9.2
15.2
10.8
13.3
13.2

11.0
17.5
12.9
15.7
15.6

2
2
2
2
3

EL04
T01
T02
SW2
SW1

1.8
1.6
1.9
1.0
1.9

2.3
2.0
2.7
1.3
2.6

3.0
2.8
3.4
1.8
3.2

13.2
11.6
13.3
8.8
12.4

15.5
13.7
15.5
10.6
14.5

3
3
3
3
3

L-SR
CR02
EL-S
EL01
EL02

17.6
13.0
4.9
2.2
3.3

20.2
15.2
6.0
2.9
4.1

23.0
17.7
7.2
3.7
5.2

46.1
35.4
18.6
13.4
16.5

55.0
40.2
21.1
15.7
19.0

123

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

3
3
3
4
4

EL03
EL04
SW2
SW1
L-SR

2.7
2.7
3.0
3.0
20.0

3.4
3.3
3.9
3.8
22.7

4.3
4.2
4.8
4.7
25.5

15.1
14.9
15.1
14.6
50.1

17.5
17.3
17.2
16.8
60.1

4
4
4
4
4

EL-S
EL01
EL02
EL03
EL04

6.8
3.4
5.0
3.6
3.5

7.9
4.1
6.1
4.5
4.4

9.4
5.1
7.5
5.5
5.4

21.5
15.7
19.6
16.7
16.5

24.0
18.0
22.2
19.2
19.0

4
5
5
5
5

SW2
SW1
L-SR
EL-S
EL01

5.6
4.2
22.1
8.4
4.6

6.7
5.0
24.7
9.7
5.5

7.9
6.1
27.6
11.3
6.6

19.4
16.6
53.8
23.9
17.7

21.7
18.9
64.8
26.5
20.1

5
5
5
5
6

EL02
EL03
EL04
SW2
SW1

7.0
4.5
4.4
7.9
5.4

8.3
5.5
5.3
9.2
6.3

9.8
6.7
6.5
10.8
7.5

22.5
18.2
17.9
22.8
18.4

25.3
20.8
20.4
25.1
20.6

6
6
6
6
6

L-SR
EL-S
EL01
EL02
EL03

23.9
9.9
5.7
8.9
5.4

26.5
11.4
6.7
10.4
6.5

29.5
12.9
7.9
12.0
7.7

57.2
25.9
19.5
25.4
19.6

69.3
28.6
22.0
28.2
22.2

6
6
7
7
7

EL04
SW2
SW1
L-SR
EL-S

5.2
10.0
6.5
25.5
11.3

6.2
11.6
7.6
28.1
12.8

7.5
13.2
8.8
31.2
14.5

19.2
25.4
20.0
60.3
27.7

21.8
27.7
22.2
73.7
30.5

7
7
7
7
7

EL01
EL02
EL03
EL04
SW2

6.8
11.0
6.3
6.0
12.0

7.9
12.6
7.4
7.1
13.6

9.2
14.4
8.8
8.4
15.3

21.1
28.2
21.0
20.4
27.5

23.7
31.1
23.6
23.1
29.9

8
8
8
8
8

SW1
L-SR
EL-S
EL01
EL02

7.5
26.9
12.6
7.8
13.0

8.7
29.6
14.1
9.0
14.7

10.0
32.8
15.9
10.4
16.6

21.4
63.4
29.4
22.6
30.9

23.6
78.3
32.2
25.3
33.9

124

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

8
8
8
9
9

EL03
EL04
SW2
SW1
L-SR

7.1
6.8
13.7
8.6
28.2

8.3
7.9
15.4
9.8
31.0

9.7
9.3
17.1
11.1
34.2

22.2
21.6
29.4
22.6
66.3

24.8
24.2
31.8
24.9
83.3

9
9
9
9
9

EL-S
EL01
EL02
EL03
EL04

13.7
8.8
15.0
7.9
7.6

15.4
10.0
16.8
9.2
8.8

17.2
11.5
18.8
10.7
10.2

30.9
24.1
33.5
23.3
22.6

33.7
26.7
36.7
26.0
25.3

9
10
10
10
10

SW2
SW1
L-SR
EL-S
EL01

15.3
9.5
29.4
14.8
9.7

16.9
10.8
32.3
16.5
11.0

18.7
12.2
35.6
18.4
12.6

31.0
23.8
69.2
32.2
25.3

33.5
26.0
88.7
35.1
28.1

10
10
10
10
11

EL02
EL03
EL04
SW2
SW1

17.0
8.7
8.3
16.7
10.5

18.9
10.0
9.5
18.4
11.8

21.0
11.5
11.0
20.1
13.2

36.0
24.3
23.6
32.4
24.8

39.3
27.1
26.3
35.0
27.1

11
11
11
11
11

L-SR
EL-S
EL01
EL02
EL03

30.6
15.8
10.6
18.9
9.5

33.5
17.5
12.0
20.9
10.8

37.0
19.5
13.6
23.1
12.4

72.2
33.4
26.5
38.5
25.3

95.0
36.4
29.3
41.9
28.1

11
11
12
12
12

EL04
SW2
SW1
L-SR
EL-S

8.9
17.9
11.3
31.7
16.7

10.2
19.6
12.7
34.7
18.5

11.8
21.4
14.2
38.3
20.5

24.5
33.8
25.8
75.3
34.6

27.2
36.4
28.1
****
37.6

12
12
12
12
12

EL01
EL02
EL03
EL04
SW2

11.5
20.9
10.2
9.6
19.0

12.9
22.9
11.6
10.9
20.8

14.5
25.2
13.2
12.5
22.5

27.6
40.9
26.3
25.4
35.0

30.5
44.4
29.1
28.1
37.6

13
13
13
13
13

SW1
L-SR
EL-S
EL01
EL02

12.1
32.7
17.6
12.3
22.8

13.6
35.8
19.4
13.7
24.9

15.1
39.6
21.4
15.4
27.2

26.7
78.6
35.7
28.7
43.3

29.0
****
38.7
31.6
46.9

125

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

13
13
13
14
14

EL03
EL04
SW2
SW1
L-SR

10.9
10.2
20.1
12.9
33.7

12.3
11.6
21.8
14.4
36.9

13.9
13.2
23.5
15.9
40.8

27.2
26.2
36.1
27.5
82.1

30.1
29.0
38.8
29.8
****

14
14
14
14
14

EL-S
EL01
EL02
EL03
EL04

18.4
13.0
24.6
11.5
10.8

20.3
14.6
26.8
13.0
12.2

22.3
16.2
29.1
14.7
13.8

36.7
29.7
45.5
28.1
27.0

39.8
32.6
49.3
30.9
29.8

14
15
15
15
15

SW2
SW1
L-SR
EL-S
EL01

21.0
13.7
34.7
19.2
13.8

22.7
15.1
38.0
21.1
15.3

24.5
16.7
42.1
23.1
17.0

37.1
28.3
86.2
37.6
30.7

39.9
30.6
****
40.8
33.6

15
15
15
15
16

EL02
EL03
EL04
SW2
SW1

26.4
12.1
11.4
21.9
14.4

28.6
13.7
12.8
23.6
15.9

31.0
15.4
14.5
25.3
17.5

47.8
28.9
27.7
38.1
29.1

51.7
31.8
30.5
40.9
31.3

16
16
16
16
16

L-SR
EL-S
EL01
EL02
EL03

35.7
19.9
14.5
28.1
12.8

39.1
21.9
16.0
30.5
14.3

43.4
23.9
17.8
32.9
16.0

90.9
38.5
31.6
50.0
29.7

****
41.7
34.5
54.0
32.6

16
16
17
17
17

EL04
SW2
SW1
L-SR
EL-S

11.9
22.7
15.1
36.8
20.7

13.4
24.4
16.6
40.3
22.6

15.1
26.1
18.1
44.8
24.7

28.4
39.0
29.7
96.9
39.4

31.2
41.8
32.1
****
42.6

17
17
17
17
17

EL01
EL02
EL03
EL04
SW2

15.1
29.9
13.4
12.5
23.5

16.8
32.2
14.9
14.0
25.1

18.6
34.8
16.7
15.7
26.8

32.4
52.1
30.4
29.1
39.8

35.4
56.2
33.3
32.0
42.7

18
18
18
18
18

SW1
L-SR
EL-S
EL01
EL02

15.8
37.8
21.4
15.8
31.6

17.2
41.5
23.3
17.5
33.9

18.8
46.3
25.4
19.3
36.5

30.4
****
40.2
33.2
54.2

32.7
****
43.4
36.3
58.4

126

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

18
18
18
19
19

EL03
EL04
SW2
SW1
L-SR

13.9
13.0
24.1
16.4
39.0

15.5
14.5
25.8
17.9
42.8

17.3
16.2
27.6
19.5
48.0

31.1
29.7
40.6
31.0
****

34.1
32.6
43.5
33.4
****

19
19
19
19
19

EL-S
EL01
EL02
EL03
EL04

22.0
16.5
33.2
14.5
13.5

23.9
18.1
35.7
16.0
15.0

26.1
19.9
38.3
17.9
16.8

41.0
34.0
56.2
31.8
30.4

44.2
37.1
60.5
34.8
33.2

19
20
20
20
20

SW2
SW1
L-SR
EL-S
EL01

24.8
16.9
40.3
22.6
17.0

26.5
18.5
44.4
24.6
18.7

28.2
20.1
50.0
26.7
20.6

41.3
31.6
****
41.7
34.8

44.3
34.0
****
45.0
37.9

20
20
20
20
21

EL02
EL03
EL04
SW2
SW1

34.8
15.0
13.9
25.4
17.6

37.3
16.6
15.6
27.0
19.1

40.0
18.5
17.3
28.8
20.7

58.2
32.5
31.0
42.1
32.4

62.6
35.5
33.9
45.1
34.8

21
21
21
21
21

L-SR
EL-S
EL01
EL02
EL03

42.2
23.2
17.6
36.4
15.5

46.7
25.2
19.4
38.9
17.1

53.2
27.4
21.2
41.7
19.0

****
42.4
35.5
60.2
33.1

****
45.7
38.6
64.7
36.2

21
21
22
22
22

EL04
SW2
SW1
L-SR
EL-S

14.4
26.1
18.1
44.9
23.8

16.0
27.8
19.7
50.4
25.8

17.8
29.6
21.3
58.8
27.9

31.5
43.0
33.1
****
43.1

34.4
46.0
35.5
****
46.4

22
22
22
22
22

EL01
EL02
EL03
EL04
SW2

18.2
37.9
16.0
14.9
26.8

19.9
40.6
17.7
16.5
28.5

21.8
43.3
19.6
18.3
30.2

36.2
62.1
33.7
32.1
43.8

39.3
66.7
36.8
35.0
47.0

23
23
23
23
23

SW1
L-SR
EL-S
EL01
EL02

18.7
56.3
24.3
18.7
39.5

20.3
70.5
26.4
20.5
42.1

21.9
****
28.5
22.4
44.9

33.7
****
43.7
36.9
64.0

36.2
****
47.1
40.0
68.7

127

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

23
23
23
24
24

EL03
EL04
SW2
SW1
L-SR

16.5
15.3
27.4
19.2
51.8

18.2
16.9
29.1
20.8
60.0

20.0
18.8
30.9
22.5
78.8

34.3
32.6
44.6
34.3
****

37.4
35.6
47.8
36.9
****

24
24
24
24
24

EL-S
EL01
EL02
EL03
EL04

24.8
19.4
41.7
16.9
15.7

26.9
21.2
44.4
18.7
17.4

29.0
23.2
47.3
20.6
19.2

44.3
37.8
67.2
34.9
33.1

47.7
41.1
72.2
38.0
36.1

24
25
25
25
25

SW2
OPEN
SW1
L-SR
CR01

28.0
44.9
19.7
36.4
57.7

29.7
49.0
21.3
39.0
63.7

31.6
54.3
22.9
41.9
71.2

45.3
96.1
34.9
61.9
****

48.6
****
37.4
67.2
****

25
25
25
25
25

EL-S
EL01
EL02
EL03
EL04

25.2
19.9
42.9
17.4
16.1

27.3
21.8
45.7
19.1
17.8

29.5
23.8
48.7
21.0
19.6

44.8
38.5
69.1
35.4
33.6

48.2
41.7
74.3
38.6
36.6

25
25
25
26
26

T01
T02
SW2
OPEN
SW1

40.0
41.1
28.5
44.1
20.1

43.3
44.3
30.2
48.0
21.7

47.3
47.8
32.1
52.9
23.4

82.7
73.8
46.0
91.2
35.4

99.2
81.7
49.2
****
37.9

26
26
26
26
26

L-SR
CR01
EL-S
EL01
EL02

35.6
56.5
25.7
20.4
43.8

38.1
62.1
27.7
22.2
46.7

40.8
69.0
29.9
24.3
49.8

59.8
****
45.3
39.1
70.7

64.6
****
48.7
42.3
76.1

26
26
26
26
26

EL03
EL04
T01
T02
SW2

17.8
16.5
40.4
40.1
29.0

19.6
18.2
43.7
43.1
30.8

21.5
20.0
47.7
46.5
32.6

36.0
34.1
82.3
70.6
46.5

39.1
37.0
97.8
77.7
49.8

27
27
27
27
27

OPEN
SW1
L-SR
CR01
EL-S

44.7
20.6
35.6
57.1
26.1

48.6
22.2
38.2
62.7
28.2

53.4
23.9
40.9
69.6
30.4

91.5
35.9
59.6
****
45.7

****
38.4
64.4
****
49.2

128

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

27
27
27
27
27

EL01
EL02
EL03
EL04
T01

20.9
44.7
18.2
16.9
41.0

22.7
47.6
20.0
18.6
44.3

24.8
50.8
21.9
20.5
48.3

39.6
72.2
36.5
34.5
83.0

42.9
77.8
39.6
37.5
98.4

27
27
28
28
28

T02
SW2
OPEN
SW1
L-SR

40.4
29.6
45.4
21.1
35.8

43.4
31.3
49.3
22.7
38.3

46.7
33.2
54.1
24.4
41.0

70.4
47.2
92.1
36.4
59.7

77.3
50.4
****
39.0
64.4

28
28
28
28
28

CR01
EL-S
EL01
EL02
EL03

57.8
26.5
21.3
45.5
18.7

63.4
28.6
23.2
48.5
20.4

70.4
30.8
25.2
51.7
22.4

****
46.2
40.2
73.5
37.0

****
49.6
43.5
79.3
40.1

28
28
28
28
29

EL04
T01
T02
SW2
OPEN

17.2
41.6
40.7
30.1
46.0

18.9
44.9
43.7
31.9
50.0

20.8
48.9
47.0
33.7
54.9

34.9
83.7
70.5
47.8
92.8

37.9
99.2
77.3
51.0
****

29
29
29
29
29

SW1
L-SR
CR01
EL-S
EL01

21.6
36.0
58.6
26.9
21.7

23.2
38.6
64.2
29.0
23.6

24.8
41.3
71.2
31.3
25.7

37.0
59.8
****
46.7
40.7

39.5
64.4
****
50.1
44.0

29
29
29
29
29

EL02
EL03
EL04
T01
T02

46.2
19.0
17.6
42.2
41.1

49.2
20.8
19.3
45.5
44.0

52.6
22.8
21.2
49.6
47.3

74.8
37.4
35.3
84.5
70.6

80.7
40.6
38.4
****
77.3

29
30
30
30
30

SW2
OPEN
SW1
L-SR
CR01

30.7
46.7
22.0
36.3
59.3

32.4
50.7
23.7
38.8
65.0

34.3
55.6
25.4
41.5
71.9

48.4
93.4
37.5
60.0
****

51.7
****
40.1
64.6
****

30
30
30
30
30

EL-S
EL01
EL02
EL03
EL04

27.4
22.1
46.8
19.5
17.9

29.5
24.0
50.0
21.2
19.7

31.7
26.1
53.4
23.2
21.6

47.2
41.2
76.0
37.9
35.8

50.6
44.5
82.0
41.1
38.8

129

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

30
30
30
31
31

T01
T02
SW2
OPEN
SW1

42.8
41.5
31.2
47.4
22.6

46.2
44.4
33.0
51.3
24.2

50.3
47.7
34.9
56.3
25.9

85.3
70.8
49.1
94.0
38.1

****
77.4
52.3
****
40.7

31
31
31
31
31

L-SR
CR01
EL-S
EL01
EL02

36.6
60.0
27.8
22.5
47.5

39.1
65.7
29.9
24.4
50.7

41.8
72.7
32.2
26.5
54.2

60.2
****
47.6
41.6
77.1

64.8
****
51.1
45.0
83.2

31
31
31
31
31

EL03
EL04
T01
T02
SW2

19.8
18.3
43.4
41.9
31.8

21.7
20.0
46.8
44.8
33.6

23.6
21.9
50.9
48.0
35.5

38.4
36.2
86.1
71.0
49.7

41.6
39.2
****
77.6
53.0

32
32
32
32
32

OPEN
SW1
L-SR
CR01
EL-S

48.0
23.1
36.9
60.8
28.3

52.0
24.7
39.4
66.4
30.4

57.0
26.4
42.1
73.4
32.6

94.5
38.7
60.5
****
48.1

****
41.3
65.0
****
51.6

32
32
32
32
32

EL01
EL02
EL03
EL04
T01

22.9
48.1
20.2
18.7
44.1

24.8
51.3
22.0
20.4
47.5

26.9
54.9
24.0
22.3
51.7

42.1
78.1
38.8
36.6
87.0

45.4
84.4
42.1
39.6
****

32
32
33
33
33

T02
SW2
OPEN
SW1
L-SR

42.3
32.4
48.6
23.6
37.3

45.2
34.1
52.6
25.2
39.8

48.5
36.0
57.6
26.9
42.4

71.3
50.3
94.9
39.2
60.7

77.8
53.7
****
41.9
65.3

33
33
33
33
33

CR01
EL-S
EL01
EL02
EL03

61.4
28.8
23.2
48.7
20.6

67.1
30.8
25.2
51.9
22.4

74.1
33.1
27.3
55.6
24.4

****
48.6
42.5
79.1
39.3

****
52.1
45.9
85.4
42.5

33
33
33
33
34

EL04
T01
T02
SW2
OPEN

19.0
48.7
42.8
32.9
49.4

20.8
52.9
45.7
34.7
53.4

22.7
58.4
48.9
36.7
58.4

37.0
****
71.7
51.0
95.7

40.1
****
78.1
54.4
****

130

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

34
34
34
34
34

SW1
L-SR
CR01
EL-S
EL01

24.1
37.6
62.3
29.2
23.6

25.8
40.1
67.9
31.3
25.5

27.5
42.8
74.9
33.6
27.6

39.8
61.1
****
49.1
42.9

42.5
65.6
****
52.6
46.3

34
34
34
34
34

EL02
EL03
EL04
T01
T02

49.3
20.9
19.3
49.4
43.3

52.6
22.8
21.1
53.8
46.2

56.2
24.8
23.0
59.3
49.4

80.0
39.7
37.4
****
72.1

86.5
43.0
40.4
****
78.5

34
35
35
35
35

SW2
OPEN
SW1
L-SR
CR01

33.5
50.3
24.7
38.0
63.3

35.3
54.4
26.3
40.5
69.0

37.3
59.4
28.0
43.2
76.1

51.7
96.9
40.4
61.5
****

55.1
****
43.1
66.0
****

35
35
35
35
35

EL-S
EL01
EL02
EL03
EL04

29.7
23.9
49.8
21.3
19.7

31.8
25.9
53.2
23.1
21.4

34.0
28.0
56.8
25.2
23.4

49.6
43.3
80.8
40.2
37.8

53.1
46.7
87.4
43.4
40.8

35
35
35
36
36

T01
T02
SW2
OPEN
SW1

50.4
43.8
34.0
49.2
25.2

54.8
46.7
35.9
53.1
26.8

60.4
49.9
37.9
57.8
28.6

****
72.6
52.4
92.4
41.1

****
78.9
55.7
****
43.7

36
36
36
36
36

L-SR
CR01
EL-S
EL01
EL02

38.5
61.7
30.1
24.2
50.3

41.0
67.1
32.3
26.2
53.7

43.7
73.6
34.5
28.3
57.4

62.0
****
50.2
43.6
81.6

66.5
****
53.6
47.0
88.3

36
36
36
36
36

EL03
EL04
T01
T02
SW2

21.7
19.9
51.4
44.5
34.7

23.5
21.8
55.8
47.4
36.5

25.6
23.7
61.5
50.6
38.5

40.6
38.1
****
73.2
53.1

43.9
41.2
****
79.6
56.4

37
37
37
37
37

OPEN
SW1
L-SR
CR01
EL-S

47.5
25.8
38.9
59.5
30.6

51.1
27.4
41.4
64.4
32.8

55.4
29.1
44.0
70.3
35.0

87.1
41.7
62.4
****
50.7

98.5
44.3
66.8
****
54.2

131

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

37
37
37
37
37

EL01
EL02
EL03
EL04
T01

24.6
50.6
22.0
20.3
51.6

26.5
54.0
23.9
22.1
56.0

28.6
57.8
25.9
24.0
61.5

44.0
82.3
41.0
38.5
****

47.4
89.1
44.3
41.6
****

37
37
38
38
38

T02
SW2
OPEN
SW1
L-SR

44.9
35.2
46.2
26.3
39.2

47.8
37.1
49.7
28.0
41.7

51.0
39.1
53.7
29.7
44.4

73.6
53.7
83.2
42.3
62.6

79.9
57.2
93.4
45.0
67.1

38
38
38
38
38

CR01
EL-S
EL01
EL02
EL03

57.8
31.1
24.9
50.8
22.3

62.4
33.3
26.8
54.3
24.2

67.9
35.5
28.9
58.1
26.3

****
51.2
44.3
82.8
41.4

****
54.7
47.7
89.7
44.7

38
38
38
38
39

EL04
T01
T02
SW2
OPEN

20.6
51.4
45.1
35.8
44.9

22.4
55.5
48.0
37.7
48.2

24.4
60.6
51.2
39.7
52.0

38.9
98.3
73.6
54.4
79.5

42.0
****
79.9
57.9
88.6

39
39
39
39
39

SW1
L-SR
CR01
EL-S
EL01

26.9
39.5
56.3
31.6
25.2

28.6
41.9
60.6
33.8
27.2

30.3
44.6
65.6
36.0
29.3

43.0
62.7
99.5
51.8
44.7

45.6
67.1
****
55.3
48.1

39
39
39
39
39

EL02
EL03
EL04
T01
T02

50.9
22.7
20.9
50.5
45.0

54.4
24.6
22.7
54.4
47.9

58.3
26.7
24.7
59.0
51.1

83.2
41.8
39.2
94.0
73.2

90.2
45.1
42.3
****
79.3

39
40
40
40
40

SW2
MECH
SW1
L-SR
CR01

36.4
44.3
27.5
39.7
55.5

38.3
47.5
29.1
42.2
59.6

40.4
51.0
30.9
44.8
64.4

55.2
77.3
43.6
62.8
96.9

58.6
85.8
46.3
67.2
****

40
40
40
40
40

EL-S
EL01
EL02
EL03
EL04

32.1
25.6
51.1
23.0
21.2

34.3
27.5
54.6
24.9
23.0

36.6
29.7
58.5
27.0
25.0

52.3
45.0
83.6
42.2
39.6

55.9
48.5
90.6
45.5
42.7

132

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

40
40
40
41
41

T01
T02
SW2
OPEN
SW1

50.1
45.1
37.0
44.4
28.0

53.8
47.9
38.9
47.6
29.8

58.1
51.0
41.0
51.1
31.5

91.2
72.9
55.9
77.1
44.3

****
78.9
59.3
85.4
47.0

41
41
41
41
41

L-SR
CR01
EL-S
EL01
EL02

40.1
55.6
32.7
25.9
51.4

42.6
59.7
34.8
27.9
54.9

45.2
64.5
37.1
30.0
58.8

63.2
96.6
52.9
45.4
84.0

67.6
****
56.4
48.9
91.1

41
41
41
41
41

EL03
EL04
T01
T02
SW2

23.3
21.5
50.5
45.5
37.6

25.2
23.3
54.1
48.4
39.6

27.4
25.3
58.4
51.5
41.6

42.5
39.9
91.0
73.3
56.6

46.0
43.1
****
79.2
60.1

42
42
42
42
42

OPEN
SW1
L-SR
CR01
EL-S

44.7
28.7
40.6
55.9
33.2

47.9
30.4
43.1
60.0
35.4

51.4
32.1
45.7
64.8
37.7

77.3
45.0
63.7
96.7
53.5

85.4
47.7
68.1
****
57.1

42
42
42
42
42

EL01
EL02
EL03
EL04
T01

26.3
51.9
23.6
21.8
51.0

28.2
55.4
25.6
23.6
54.7

30.4
59.3
27.7
25.6
59.0

45.8
84.5
42.9
40.2
91.3

49.3
91.6
46.3
43.4
****

42
42
43
43
43

T02
SW2
OPEN
SW1
L-SR

46.0
38.2
42.9
29.3
40.2

48.9
40.2
45.9
31.0
42.7

52.0
42.3
49.2
32.8
45.3

73.7
57.3
72.8
45.7
62.9

79.6
60.8
79.8
48.4
67.0

43
43
43
43
43

EL-S
EL01
EL02
EL03
EL04

33.8
26.7
52.4
24.0
22.1

35.9
28.6
55.9
26.0
24.0

38.2
30.8
59.8
28.1
26.0

54.1
46.2
85.0
43.5
40.7

57.7
49.7
92.1
46.9
43.9

43
43
43
44
44

T01
T02
SW2
OPEN
SW1

49.3
45.1
38.9
49.5
29.9

52.6
47.9
40.8
52.6
31.7

56.4
50.8
42.9
56.2
33.5

85.6
71.7
58.1
83.6
46.4

95.6
77.2
61.6
92.6
49.2

133

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

44
44
44
44
44

L-SR
EL-S
EL03
EL04
T01

40.2
34.4
24.4
22.5
49.5

42.6
36.5
26.3
24.3
52.7

45.1
38.8
28.5
26.4
56.5

62.5
54.7
43.9
41.1
86.1

66.6
58.3
47.3
44.3
97.0

44
44
45
45
45

T02
SW2
OPEN
SW1
L-SR

44.8
39.5
50.2
30.7
40.7

47.5
41.5
53.3
32.4
43.1

50.4
43.7
56.9
34.2
45.7

70.7
58.9
84.2
47.2
63.0

76.0
62.4
93.1
50.0
67.1

45
45
45
45
45

EL-S
EL03
EL04
T01
T02

34.9
24.7
22.7
50.2
45.4

37.1
26.6
24.6
53.4
48.0

39.5
28.8
26.7
57.1
50.9

55.4
44.2
41.4
86.6
71.2

59.0
47.7
44.6
97.5
76.4

45
46
46
46
46

SW2
OPEN
SW1
L-SR
EL-S

40.2
51.0
31.4
41.3
35.6

42.2
54.1
33.1
43.7
37.8

44.4
57.8
34.9
46.3
40.1

59.7
85.0
48.1
63.7
56.1

63.3
93.9
50.9
67.8
59.7

46
46
46
46
46

EL03
EL04
T01
T02
SW2

24.9
22.9
51.0
46.1
40.9

26.9
24.8
54.2
48.8
42.9

29.1
26.9
58.0
51.7
45.1

44.6
41.7
87.5
71.9
60.5

48.1
44.9
98.3
77.2
64.1

47
47
47
47
47

OPEN
SW1
L-SR
EL-S
EL03

51.9
32.2
42.0
36.3
25.2

55.0
33.9
44.4
38.5
27.2

58.7
35.8
47.0
40.8
29.4

86.0
49.0
64.4
56.8
44.9

94.9
51.8
68.5
60.4
48.4

47
47
47
47
48

EL04
T01
T02
SW2
OPEN

23.2
51.9
46.8
41.7
52.8

25.1
55.2
49.5
43.7
56.0

27.2
58.9
52.4
45.9
59.7

42.0
88.5
72.7
61.5
87.0

45.2
99.4
78.0
65.1
95.9

48
48
48
48
48

SW1
L-SR
EL-S
EL03
EL04

33.0
42.7
37.0
25.5
23.5

34.8
45.1
39.2
27.5
25.4

36.7
47.7
41.6
29.7
27.4

50.0
65.2
57.6
45.2
42.2

52.8
69.3
61.3
48.7
45.5

134

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

48
48
48
49
49

T01
T02
SW2
OPEN
SW1

52.9
47.6
42.5
52.0
34.0

56.2
50.3
44.6
55.4
35.8

60.0
53.2
46.8
59.3
37.6

89.7
73.5
62.4
86.7
51.0

****
78.8
66.1
95.6
53.9

49
49
49
49
49

L-SR
EL-S
EL03
EL04
T01

43.5
37.7
25.7
23.7
46.6

45.9
39.9
27.7
25.6
50.0

48.5
42.3
29.9
27.7
53.9

66.1
58.5
45.5
42.5
81.8

70.2
62.1
49.0
45.7
91.0

49
49
50
50
50

T02
SW2
OPEN
SW1
L-SR

48.5
43.3
50.5
35.0
44.3

51.2
45.5
54.1
36.8
46.8

54.1
47.7
58.2
38.7
49.4

74.5
63.5
85.9
52.2
67.0

79.8
67.1
94.6
55.2
71.1

50
50
50
50
50

EL-S
EL03
EL04
T01
T02

38.6
26.0
23.9
43.0
49.4

40.8
28.0
25.8
46.2
52.1

43.1
30.2
27.9
49.8
55.0

59.4
45.8
42.7
75.6
75.5

63.0
49.3
46.0
83.6
80.8

50
51
51
51
51

SW2
OPEN
SW1
L-SR
EL-S

44.2
49.8
36.1
45.2
39.4

46.4
53.6
37.9
47.7
41.7

48.7
57.7
39.9
50.3
44.0

64.6
85.7
53.5
68.0
60.3

68.3
94.4
56.5
72.1
64.0

51
51
51
51
51

EL03
EL04
T01
T02
SW2

26.2
24.1
41.8
50.4
45.2

28.3
26.0
44.9
53.1
47.4

30.5
28.1
48.4
56.1
49.7

46.1
43.0
73.2
76.6
65.8

49.6
46.3
80.8
81.9
69.5

52
52
52
52
52

OPEN
SW1
L-SR
EL-S
EL03

49.6
37.4
46.1
40.4
26.5

53.4
39.2
48.6
42.6
28.5

57.7
41.2
51.3
45.0
30.7

86.0
55.0
69.0
61.4
46.3

94.8
58.0
73.2
65.1
49.9

52
52
52
52
53

EL04
T01
T02
SW2
OPEN

24.4
41.4
51.4
46.3
49.6

26.3
44.4
54.2
48.5
53.5

28.4
47.8
57.2
50.8
57.9

43.2
72.1
77.7
67.1
86.8

46.5
79.5
83.1
70.8
95.6

135

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

53
53
53
53
53

SW1
L-SR
EL-S
EL03
EL04

38.8
47.2
41.4
26.7
24.6

40.7
49.7
43.7
28.7
26.5

42.7
52.4
46.1
30.9
28.6

56.7
70.2
62.5
46.6
43.5

59.8
74.4
66.3
50.1
46.8

53
53
53
54
54

T01
T02
SW2
OPEN
SW1

41.3
52.6
47.4
49.2
40.5

44.3
55.4
49.7
53.1
42.4

47.6
58.4
52.0
57.5
44.4

71.8
79.1
68.5
86.7
58.6

79.1
84.4
72.3
95.6
61.8

54
54
54
54
54

L-SR
EL-S
EL03
EL04
T01

48.4
42.5
26.9
24.8
41.4

50.9
44.8
29.0
26.8
44.4

53.6
47.3
31.2
28.8
47.7

71.5
63.8
46.8
43.8
71.9

75.7
67.6
50.4
47.0
79.2

54
54
55
55
55

T02
SW2
OPEN
SW1
L-SR

53.9
48.7
48.7
42.5
49.7

56.7
51.0
52.5
44.4
52.2

59.8
53.4
56.9
46.5
54.9

80.5
70.0
86.5
61.0
73.0

85.9
73.9
95.5
64.2
77.2

55
55
55
55
55

EL-S
EL03
EL04
T01
T02

43.8
27.2
25.0
41.3
55.4

46.1
29.2
27.0
44.3
58.2

48.6
31.4
29.1
47.6
61.3

65.2
47.1
44.0
71.6
82.2

69.0
50.6
47.3
78.9
87.6

55
56
56
56
56

SW2
OPEN
SW1
L-SR
EL-S

50.1
48.3
44.9
51.1
45.2

52.5
52.0
46.9
53.7
47.6

54.9
56.4
49.0
56.4
50.0

71.8
86.4
64.0
74.6
66.8

75.7
95.5
67.3
78.9
70.7

56
56
56
56
56

EL03
EL04
T01
T02
SW2

27.4
25.3
41.3
57.0
51.7

29.5
27.2
44.2
59.9
54.1

31.7
29.3
47.5
63.0
56.6

47.3
44.3
71.3
84.0
73.7

50.9
47.5
78.4
89.5
77.7

57
57
57
57
57

OPEN
SW1
L-SR
EL-S
EL03

48.2
48.0
52.7
46.8
27.7

51.9
50.1
55.3
49.2
29.7

56.2
52.4
58.1
51.7
31.9

86.5
68.0
76.5
68.7
47.6

96.1
71.6
80.8
72.6
51.2

136

Table 26.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

57
57
57
57
58

EL04
T01
T02
SW2
OPEN

25.5
41.3
58.8
53.6
48.5

27.5
44.2
61.8
56.0
52.3

29.6
47.5
64.9
58.6
56.6

44.5
71.1
86.2
76.0
87.8

47.8
78.2
91.7
80.1
98.0

58
58
58
58
58

SW1
L-SR
EL-S
EL03
EL04

52.9
54.7
48.7
27.9
25.8

55.2
57.3
51.1
29.9
27.7

57.6
60.1
53.7
32.1
29.8

74.5
78.7
70.9
47.9
44.8

78.4
83.1
74.8
51.4
48.1

58
58
58
59
59

T01
T02
SW2
MECH
ELME

41.6
61.0
55.7
68.9
71.7

44.6
64.0
58.2
72.4
75.5

47.8
67.2
60.9
76.3
79.7

71.5
88.8
78.7
****
****

78.7
94.4
83.0
****
****

59
59
59
59
R

EL-S
EL03
EL04
SW2
SW2

50.9
27.9
25.8
58.4
62.7

53.4
29.9
27.7
61.0
65.4

56.0
32.2
29.8
63.8
68.3

73.5
47.9
44.8
82.1
87.5

77.5
51.4
48.1
86.5
92.1

137

Table 27.

Level

Results of Tenability Analysis for Scenario 27.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

B
B
B
B
B

MECH
L-SR
L-MR
L-HR
EL-S

41.5
61.6
44.1
37.1
20.7

46.3
68.8
52.0
43.4
23.1

52.0
77.4
61.7
51.5
25.7

88.8
****
****
97.9
43.5

****
****
****
****
47.8

B
B
B
B
B

EL01
EL02
EL03
EL04
SW2

55.8
61.3
51.8
50.6
9.6

62.4
69.2
58.8
56.6
11.2

70.1
78.6
67.1
63.6
13.0

****
****
****
****
26.6

****
****
****
****
29.4

G
G
G
G
G

OPEN
SW1
L-SR
EL-S
EL01

7.1
46.9
16.8
11.6
9.7

9.0
52.1
19.4
13.5
11.7

11.2
58.2
22.2
15.5
13.9

26.9
95.9
42.8
30.2
30.1

30.6
****
48.9
33.3
34.1

G
G
G
G
G

EL02
EL03
EL04
T01
T02

9.6
8.5
8.6
14.8
17.2

11.6
10.5
10.5
17.2
19.7

13.9
12.7
12.8
19.8
22.4

30.1
28.6
28.7
38.2
41.6

34.0
32.4
32.6
43.2
46.9

G
2
2
2
2

SW2
OPEN
SW1
L-SR
CR01

3.7
1.0
1.0
1.0
1.5

4.5
1.0
1.5
1.5
1.9

5.6
1.0
1.9
1.9
2.6

16.2
4.8
9.7
9.4
11.1

18.4
6.1
11.7
11.3
13.1

2
2
2
2
2

CR02
EL-S
EL01
EL02
EL03

1.0
3.3
1.4
2.0
2.0

1.5
4.0
1.9
2.8
2.9

1.9
5.0
2.5
3.6
3.8

9.4
15.6
11.9
14.7
15.5

11.3
17.9
14.2
17.2
18.2

2
2
2
2
3

EL04
T01
T02
SW2
SW1

2.0
1.7
2.0
1.0
2.1

2.8
2.1
2.8
1.4
2.8

3.8
2.9
3.6
1.9
3.6

15.3
11.9
13.6
9.0
12.8

17.9
14.0
15.8
10.9
15.0

3
3
3
3
3

L-SR
CR02
EL-S
EL01
EL02

18.4
13.6
5.5
2.1
3.2

21.0
15.9
6.6
2.8
4.0

23.8
18.5
7.9
3.6
5.1

46.5
36.5
19.6
13.8
16.9

54.8
41.4
22.1
16.1
19.5

138

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

3
3
3
4
4

EL03
EL04
SW2
SW1
L-SR

2.8
2.7
4.5
3.6
21.3

3.6
3.5
5.5
4.4
23.9

4.6
4.6
6.8
5.3
26.7

16.5
16.3
18.4
15.5
51.1

19.2
18.9
20.9
17.7
60.5

4
4
4
4
4

EL-S
EL01
EL02
EL03
EL04

7.6
3.0
4.5
3.3
3.3

8.9
3.8
5.5
4.2
4.1

10.4
4.8
6.8
5.3
5.3

22.9
15.4
19.0
17.4
17.2

25.5
17.9
21.7
20.1
19.9

4
5
5
5
5

SW2
SW1
L-SR
EL-S
EL01

8.1
4.9
23.7
9.6
3.9

9.6
5.9
26.3
11.0
4.8

11.3
7.0
29.2
12.7
5.9

24.0
17.9
55.3
25.7
17.0

26.5
20.1
65.7
28.4
19.5

5
5
5
5
6

EL02
EL03
EL04
SW2
SW1

5.8
3.9
3.8
11.4
6.4

7.0
4.9
4.8
13.0
7.5

8.4
6.0
5.9
14.9
8.7

21.1
18.3
18.1
28.0
19.9

23.8
21.1
20.8
30.5
22.2

6
6
6
6
6

L-SR
EL-S
EL01
EL02
EL03

25.7
11.3
4.8
7.3
4.5

28.4
12.9
5.8
8.6
5.5

31.4
14.7
6.9
10.0
6.8

59.0
28.1
18.4
23.1
19.2

70.6
30.8
21.0
26.0
21.9

6
6
7
7
7

EL04
SW2
SW1
L-SR
EL-S

4.4
14.2
7.7
27.6
12.9

5.5
15.9
8.9
30.3
14.6

6.7
17.9
10.3
33.4
16.4

19.0
31.0
21.7
62.6
30.1

21.7
33.8
23.9
75.4
33.0

7
7
7
7
7

EL01
EL02
EL03
EL04
SW2

5.7
8.7
5.0
4.9
16.6

6.8
10.1
6.1
6.0
18.4

7.9
11.8
7.4
7.3
20.4

19.8
25.2
20.1
19.8
33.6

22.4
28.0
22.8
22.5
36.5

8
8
8
8
8

SW1
L-SR
EL-S
EL01
EL02

9.0
29.2
14.4
6.6
10.2

10.3
31.9
16.1
7.7
11.7

11.7
35.2
18.0
8.9
13.4

23.2
65.9
32.0
21.1
27.1

25.5
80.3
35.0
23.7
30.1

139

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

8
8
8
9
9

EL03
EL04
SW2
SW1
L-SR

5.6
5.6
18.6
10.2
30.7

6.8
6.7
20.5
11.6
33.5

8.0
7.9
22.4
13.0
36.9

20.8
20.6
35.9
24.7
69.1

23.6
23.3
38.9
26.9
85.6

9
9
9
9
9

EL-S
EL01
EL02
EL03
EL04

15.7
7.4
11.7
6.1
6.0

17.5
8.6
13.3
7.3
7.2

19.5
9.9
15.1
8.7
8.6

33.7
22.2
29.1
21.6
21.3

36.7
24.9
32.1
24.4
24.1

9
10
10
10
10

SW2
SW1
L-SR
EL-S
EL01

20.4
11.4
32.0
17.0
8.2

22.2
12.8
35.0
18.8
9.4

24.1
14.3
38.6
20.8
10.8

37.8
26.0
72.3
35.3
23.3

41.0
28.2
91.3
38.3
26.1

10
10
10
10
11

EL02
EL03
EL04
SW2
SW1

13.2
6.7
6.6
21.9
12.5

14.9
7.9
7.8
23.7
13.9

16.8
9.4
9.2
25.7
15.5

31.0
22.3
22.1
39.6
27.1

34.1
25.1
24.8
42.8
29.3

11
11
11
11
11

L-SR
EL-S
EL01
EL02
EL03

33.3
18.1
8.9
14.7
7.2

36.4
20.0
10.2
16.5
8.5

40.1
22.1
11.7
18.4
9.9

75.6
36.7
24.4
32.9
23.1

97.7
39.8
27.1
36.1
25.9

11
11
12
12
12

EL04
SW2
SW1
L-SR
EL-S

7.0
23.3
13.5
34.6
19.2

8.3
25.1
14.9
37.7
21.1

9.8
27.0
16.6
41.6
23.2

22.7
41.2
28.2
79.0
38.0

25.5
44.5
30.4
****
41.2

12
12
12
12
12

EL01
EL02
EL03
EL04
SW2

9.7
16.2
7.7
7.6
24.5

11.0
18.0
9.0
8.8
26.3

12.5
20.0
10.5
10.3
28.2

25.4
34.8
23.7
23.4
42.6

28.2
38.0
26.6
26.2
46.1

13
13
13
13
13

SW1
L-SR
EL-S
EL01
EL02

14.5
35.8
20.2
10.4
17.7

15.9
39.0
22.2
11.8
19.5

17.6
43.0
24.3
13.3
21.6

29.2
82.6
39.3
26.4
36.6

31.4
****
42.5
29.2
39.9

140

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

13
13
13
14
14

EL03
EL04
SW2
SW1
L-SR

8.2
8.0
25.6
15.4
36.9

9.6
9.3
27.4
16.8
40.3

11.1
10.8
29.3
18.5
44.5

24.4
24.1
44.0
30.1
86.5

27.3
26.9
47.5
32.4
****

14
14
14
14
14

EL-S
EL01
EL02
EL03
EL04

21.2
11.1
19.1
8.7
8.5

23.2
12.5
21.0
10.0
9.8

25.3
14.1
23.2
11.6
11.4

40.4
27.3
38.4
25.1
24.7

43.7
30.1
41.8
27.9
27.5

14
15
15
15
15

SW2
SW1
L-SR
EL-S
EL01

26.6
16.2
38.0
22.1
11.8

28.4
17.7
41.5
24.1
13.2

30.4
19.4
45.9
26.3
14.8

45.3
31.0
91.0
41.5
28.1

48.9
33.3
****
44.9
31.0

15
15
15
15
16

EL02
EL03
EL04
SW2
SW1

20.6
9.2
8.9
27.5
17.0

22.6
10.6
10.3
29.4
18.6

24.7
12.1
11.9
31.3
20.2

40.2
25.7
25.2
46.4
31.8

43.7
28.6
28.1
50.1
34.1

16
16
16
16
16

L-SR
EL-S
EL01
EL02
EL03

39.2
22.9
12.4
22.0
9.7

42.8
25.0
13.9
24.0
11.0

47.4
27.2
15.6
26.3
12.7

96.2
42.6
29.0
42.0
26.3

****
46.0
31.9
45.5
29.2

16
16
17
17
17

EL04
SW2
SW1
L-SR
EL-S

9.4
28.4
17.8
40.3
23.8

10.8
30.2
19.3
44.1
25.8

12.4
32.2
20.9
48.9
28.0

25.8
47.5
32.5
****
43.5

28.7
51.3
34.9
****
47.0

17
17
17
17
17

EL01
EL02
EL03
EL04
SW2

13.0
23.4
10.1
9.8
29.2

14.5
25.5
11.5
11.2
31.0

16.2
27.8
13.2
12.8
33.1

29.8
43.7
26.8
26.4
48.6

32.7
47.3
29.8
29.3
52.4

18
18
18
18
18

SW1
L-SR
EL-S
EL01
EL02

18.5
41.5
24.5
13.6
24.8

20.0
45.4
26.6
15.1
26.9

21.7
50.6
28.9
16.9
29.3

33.3
****
44.5
30.5
45.4

35.7
****
48.0
33.5
49.1

141

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

18
18
18
19
19

EL03
EL04
SW2
SW1
L-SR

10.6
10.2
29.9
19.2
42.8

12.0
11.7
31.8
20.7
46.9

13.7
13.3
33.9
22.3
52.5

27.4
26.9
49.5
34.0
****

30.4
29.8
53.5
36.4
****

19
19
19
19
19

EL-S
EL01
EL02
EL03
EL04

25.3
14.2
26.2
10.9
10.7

27.4
15.8
28.4
12.5
12.1

29.7
17.5
30.7
14.1
13.8

45.4
31.3
47.1
28.0
27.4

48.9
34.2
50.9
30.9
30.4

19
20
20
20
20

SW2
SW1
L-SR
EL-S
EL01

30.7
19.8
44.3
25.9
14.8

32.6
21.4
48.7
28.1
16.4

34.7
22.9
54.8
30.4
18.1

50.5
34.6
****
46.2
32.0

54.5
37.1
****
49.8
35.0

20
20
20
20
21

EL02
EL03
EL04
SW2
SW1

27.6
11.4
11.0
31.4
20.5

29.8
12.9
12.5
33.3
22.0

32.2
14.6
14.2
35.4
23.7

48.8
28.5
28.0
51.3
35.5

52.6
31.5
30.9
55.4
38.0

21
21
21
21
21

L-SR
EL-S
EL01
EL02
EL03

46.4
26.7
15.3
28.9
11.8

51.2
28.8
16.9
31.2
13.3

58.2
31.1
18.7
33.6
15.0

****
47.0
32.7
50.4
29.0

****
50.6
35.7
54.4
32.0

21
21
22
22
22

EL04
SW2
SW1
L-SR
EL-S

11.4
32.2
21.1
49.5
27.3

12.9
34.1
22.7
55.4
29.5

14.6
36.2
24.3
64.4
31.8

28.4
52.4
36.3
****
47.8

31.4
56.6
38.8
****
51.4

22
22
22
22
22

EL01
EL02
EL03
EL04
SW2

15.8
30.3
12.2
11.8
32.9

17.5
32.6
13.7
13.3
34.9

19.3
35.0
15.5
15.0
37.1

33.3
52.1
29.5
28.9
53.5

36.4
56.1
32.5
31.9
57.7

23
23
23
23
23

SW1
EL-S
EL01
EL02
EL03

21.8
27.9
16.4
31.6
12.6

23.4
30.1
18.0
33.9
14.1

25.0
32.4
19.9
36.5
15.9

37.0
48.5
34.0
53.7
30.0

39.6
52.2
37.0
57.8
33.1

142

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

23
23
24
24
24

EL04
SW2
SW1
L-SR
EL-S

12.1
33.7
22.4
54.2
28.5

13.7
35.7
23.9
61.3
30.7

15.5
37.9
25.6
74.2
33.0

29.4
54.5
37.7
****
49.2

32.4
58.8
40.3
****
52.9

24
24
24
24
24

EL01
EL02
EL03
EL04
SW2

17.5
34.7
12.9
12.5
34.4

19.2
37.3
14.6
14.0
36.4

21.1
40.0
16.3
15.8
38.6

35.7
58.7
30.5
29.8
55.4

39.0
63.5
33.5
32.8
59.7

25
25
25
25
25

OPEN
SW1
L-SR
CR01
EL-S

45.6
22.9
38.1
58.9
28.9

49.4
24.5
40.8
64.6
31.2

54.0
26.1
43.6
71.7
33.5

91.8
38.3
63.2
****
49.7

****
40.9
68.1
****
53.4

25
25
25
25
25

EL01
EL02
EL03
EL04
T01

17.9
35.7
13.3
12.8
43.5

19.7
38.2
14.9
14.4
46.9

21.6
41.0
16.7
16.2
51.1

36.3
60.1
30.9
30.2
85.8

39.5
64.9
34.0
33.2
****

25
25
26
26
26

T02
SW2
OPEN
SW1
L-SR

42.4
35.0
46.3
23.4
38.7

45.5
37.0
50.1
24.9
41.4

49.0
39.2
54.8
26.7
44.2

73.6
56.1
92.8
38.9
63.7

80.8
60.4
****
41.5
68.6

26
26
26
26
26

CR01
EL-S
EL01
EL02
EL03

59.7
29.5
18.3
36.6
13.7

65.4
31.7
20.0
39.1
15.3

72.6
34.0
22.0
41.9
17.1

****
50.3
36.8
61.2
31.3

****
54.0
40.1
66.2
34.4

26
26
26
26
27

EL04
T01
T02
SW2
OPEN

13.2
44.2
42.9
35.6
47.2

14.8
47.6
46.0
37.7
51.1

16.6
51.8
49.5
39.9
55.8

30.6
86.6
74.0
56.8
94.2

33.6
****
81.1
61.2
****

27
27
27
27
27

SW1
L-SR
CR01
EL-S
EL01

23.9
39.2
60.7
29.9
18.7

25.5
41.9
66.5
32.1
20.5

27.2
44.7
73.8
34.5
22.4

39.5
64.2
****
50.8
37.2

42.1
69.1
****
54.5
40.5

143

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

27
27
27
27
27

EL02
EL03
EL04
T01
T02

37.3
14.0
13.5
44.9
43.6

39.9
15.7
15.1
48.4
46.7

42.8
17.5
16.9
52.6
50.2

62.3
31.8
31.0
87.7
74.7

67.4
34.9
34.1
****
81.8

27
28
28
28
28

SW2
OPEN
SW1
L-SR
CR01

36.2
48.1
24.5
39.7
61.8

38.3
52.0
26.0
42.4
67.7

40.5
56.9
27.8
45.2
75.1

57.5
95.8
40.1
64.7
****

61.9
****
42.8
69.6
****

28
28
28
28
28

EL-S
EL01
EL02
EL03
EL04

30.5
19.0
38.0
14.4
13.8

32.7
20.8
40.7
16.0
15.5

35.0
22.8
43.5
17.9
17.3

51.4
37.7
63.3
32.2
31.4

55.1
41.0
68.5
35.3
34.5

28
28
28
29
29

T01
T02
SW2
OPEN
SW1

45.6
44.3
36.9
49.0
25.0

49.1
47.4
38.9
53.0
26.6

53.4
50.9
41.2
58.0
28.3

88.8
75.4
58.2
97.4
40.7

****
82.4
62.6
****
43.4

29
29
29
29
29

L-SR
CR01
EL-S
EL01
EL02

40.2
62.9
30.9
19.3
38.7

42.8
68.8
33.2
21.1
41.4

45.7
76.4
35.6
23.2
44.3

65.3
****
51.9
38.1
64.2

70.2
****
55.6
41.4
69.5

29
29
29
29
29

EL03
EL04
T01
T02
SW2

14.7
14.1
46.4
44.9
37.5

16.4
15.8
49.9
48.0
39.6

18.2
17.6
54.2
51.6
41.9

32.6
31.8
89.9
76.1
59.0

35.7
34.9
****
83.1
63.4

30
30
30
30
30

OPEN
SW1
L-SR
CR01
EL-S

50.0
25.6
40.7
64.0
31.5

54.1
27.2
43.4
70.1
33.7

59.2
28.9
46.2
77.8
36.0

99.0
41.4
65.8
****
52.5

****
44.1
70.7
****
56.2

30
30
30
30
30

EL01
EL02
EL03
EL04
T01

19.7
39.4
15.0
14.5
47.2

21.5
42.1
16.7
16.1
50.7

23.5
45.0
18.6
17.9
55.1

38.5
65.1
33.0
32.2
91.1

41.8
70.5
36.2
35.2
****

144

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

30
30
31
31
31

T02
SW2
OPEN
SW1
L-SR

45.6
38.2
51.0
26.2
41.2

48.8
40.3
55.2
27.8
43.9

52.3
42.6
60.4
29.5
46.8

76.8
59.7
****
42.0
66.3

83.8
64.2
****
44.7
71.3

31
31
31
31
31

CR01
EL-S
EL01
EL02
EL03

65.2
31.9
20.0
40.0
15.4

71.4
34.2
21.8
42.7
17.0

79.2
36.6
23.9
45.6
18.9

****
53.0
38.9
66.0
33.4

****
56.8
42.2
71.4
36.6

31
31
31
31
32

EL04
T01
T02
SW2
OPEN

14.8
47.9
46.3
38.8
52.1

16.4
51.6
49.5
40.9
56.3

18.3
56.0
53.0
43.2
61.6

32.5
92.3
77.5
60.5
****

35.6
****
84.6
65.0
****

32
32
32
32
32

SW1
L-SR
CR01
EL-S
EL01

26.8
41.7
66.4
32.5
20.3

28.4
44.4
72.7
34.7
22.1

30.1
47.3
80.7
37.1
24.2

42.7
66.9
****
53.6
39.2

45.4
71.8
****
57.4
42.6

32
32
32
32
32

EL02
EL03
EL04
T01
T02

40.6
15.7
15.0
48.8
47.0

43.3
17.4
16.7
52.5
50.2

46.3
19.3
18.6
56.9
53.7

66.8
33.8
32.9
93.6
78.2

72.3
37.0
36.0
****
85.3

32
33
33
33
33

SW2
OPEN
SW1
L-SR
CR01

39.5
53.2
27.4
42.2
67.7

41.6
57.6
29.0
44.9
74.1

43.9
63.0
30.7
47.8
82.3

61.2
****
43.4
67.4
****

65.7
****
46.1
72.4
****

33
33
33
33
33

EL-S
EL01
EL02
EL03
EL04

33.0
20.6
41.1
16.0
15.4

35.3
22.4
43.9
17.7
17.0

37.7
24.5
46.9
19.7
18.9

54.2
39.6
67.5
34.2
33.3

58.0
43.0
73.2
37.4
36.4

33
33
33
34
34

T01
T02
SW2
OPEN
SW1

53.2
47.8
40.1
54.4
28.0

57.7
51.0
42.3
58.9
29.7

63.3
54.5
44.6
64.5
31.4

****
79.1
62.0
****
44.1

****
86.2
66.5
****
46.9

145

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

34
34
34
34
34

L-SR
CR01
EL-S
EL01
EL02

42.8
69.1
33.6
20.8
41.7

45.5
75.7
35.8
22.7
44.5

48.4
84.0
38.2
24.8
47.4

68.0
****
54.7
39.9
68.3

73.0
****
58.5
43.3
74.0

34
34
34
34
34

EL03
EL04
T01
T02
SW2

16.4
15.7
54.5
48.6
40.8

18.0
17.4
59.1
51.8
42.9

20.0
19.2
64.9
55.3
45.3

34.6
33.6
****
79.9
62.8

37.8
36.7
****
87.0
67.3

35
35
35
35
35

OPEN
SW1
L-SR
CR01
EL-S

53.0
28.6
43.3
67.8
34.1

57.6
30.3
46.0
74.3
36.4

63.2
32.0
48.9
82.5
38.8

****
44.8
68.6
****
55.3

****
47.6
73.6
****
59.1

35
35
35
35
35

EL01
EL02
EL03
EL04
T01

21.1
42.2
16.7
15.9
55.6

23.0
45.0
18.4
17.7
60.3

25.0
48.0
20.3
19.6
66.3

40.2
69.0
35.0
34.0
****

43.6
74.7
38.2
37.1
****

35
35
36
36
36

T02
SW2
OPEN
SW1
L-SR

49.3
41.4
47.0
29.3
43.9

52.6
43.6
51.2
30.9
46.6

56.1
45.9
56.1
32.7
49.5

80.7
63.5
91.9
45.5
69.2

87.8
68.0
****
48.3
74.2

36
36
36
36
36

CR01
EL-S
EL01
EL02
EL03

60.9
34.6
21.4
42.7
16.9

66.6
36.9
23.3
45.4
18.7

73.7
39.4
25.3
48.5
20.7

****
56.0
40.5
69.6
35.3

****
59.8
43.9
75.4
38.5

36
36
36
36
37

EL04
T01
T02
SW2
OPEN

16.3
55.6
50.1
42.0
44.5

17.9
60.2
53.4
44.3
48.3

19.9
66.0
56.9
46.7
52.7

34.3
****
81.6
64.3
85.6

37.5
****
88.6
68.8
97.7

37
37
37
37
37

SW1
L-SR
CR01
EL-S
EL01

29.9
44.5
57.6
35.2
21.7

31.6
47.2
62.8
37.5
23.5

33.4
50.1
69.2
39.9
25.6

46.3
69.8
****
56.6
40.8

49.1
74.8
****
60.4
44.2

146

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

37
37
37
37
37

EL02
EL03
EL04
T01
T02

43.0
17.3
16.6
55.4
50.9

45.8
19.0
18.3
60.0
54.2

48.9
21.0
20.2
65.6
57.8

70.2
35.7
34.7
****
82.4

76.1
38.9
37.8
****
89.5

37
38
38
38
38

SW2
OPEN
SW1
L-SR
CR01

42.7
42.7
30.6
45.0
55.2

44.9
46.2
32.3
47.7
60.0

47.4
50.3
34.0
50.6
65.8

65.1
80.7
47.0
70.4
****

69.6
91.3
49.9
75.4
****

38
38
38
38
38

EL-S
EL01
EL02
EL03
EL04

35.8
21.9
43.4
17.6
16.8

38.0
23.8
46.2
19.3
18.6

40.5
25.9
49.3
21.3
20.5

57.2
41.1
70.7
36.1
35.0

61.0
44.4
76.6
39.3
38.2

38
38
38
39
39

T01
T02
SW2
OPEN
SW1

54.8
51.7
43.4
41.0
31.2

59.3
55.0
45.6
44.3
32.9

64.7
58.6
48.0
48.1
34.7

****
83.2
65.8
76.1
47.8

****
90.2
70.4
85.5
50.6

39
39
39
39
39

L-SR
CR01
EL-S
EL01
EL02

45.5
53.0
36.4
22.2
43.7

48.2
57.5
38.7
24.1
46.5

51.1
62.7
41.1
26.1
49.6

70.9
97.7
57.8
41.3
71.1

75.9
****
61.7
44.8
77.1

39
39
39
39
39

EL03
EL04
T01
T02
SW2

17.9
17.1
53.6
52.3
44.0

19.7
18.8
57.9
55.6
46.3

21.6
20.8
63.0
59.1
48.7

36.4
35.3
98.8
83.7
66.6

39.7
38.5
****
90.7
71.2

40
40
40
40
40

MECH
SW1
L-SR
CR01
EL-S

41.1
31.9
46.1
53.0
36.9

44.4
33.6
48.8
57.5
39.3

48.2
35.5
51.8
62.7
41.7

76.0
48.6
71.5
97.6
58.5

85.3
51.4
76.5
****
62.3

40
40
40
40
40

EL01
EL02
EL03
EL04
T01

22.5
44.0
18.2
17.4
54.1

24.4
46.8
19.9
19.1
58.5

26.5
49.9
21.9
21.1
63.7

41.7
71.5
36.8
35.7
99.5

45.1
77.4
40.0
38.9
****

147

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

40
40
41
41
41

T02
SW2
OPEN
SW1
L-SR

53.3
44.7
41.4
32.6
46.7

56.6
46.9
44.7
34.3
49.5

60.2
49.4
48.4
36.1
52.4

84.7
67.4
76.3
49.4
72.2

91.7
71.9
85.6
52.3
77.2

41
41
41
41
41

CR01
EL-S
EL01
EL02
EL03

53.3
37.6
22.8
44.3
18.5

57.7
39.9
24.7
47.2
20.2

63.0
42.4
26.8
50.3
22.2

97.8
59.1
42.0
71.8
37.1

****
63.0
45.4
77.8
40.4

41
41
41
41
42

EL04
T01
T02
SW2
OPEN

17.7
54.8
53.9
45.3
41.3

19.4
59.3
57.2
47.6
44.6

21.4
64.6
60.8
50.1
48.3

36.0
****
85.4
68.1
75.7

39.2
****
92.4
72.7
84.8

42
42
42
42
42

SW1
L-SR
CR01
EL-S
EL01

33.3
47.3
53.1
38.2
23.0

35.0
50.0
57.5
40.5
25.0

36.9
53.0
62.6
43.0
27.1

50.2
72.8
96.9
59.8
42.3

53.1
77.8
****
63.7
45.7

42
42
42
42
42

EL02
EL03
EL04
T01
T02

44.6
18.7
17.9
54.9
54.5

47.5
20.6
19.7
59.5
57.8

50.6
22.6
21.7
64.9
61.4

72.2
37.4
36.3
****
86.0

78.2
40.7
39.5
****
92.9

42
43
43
43
43

SW2
OPEN
SW1
L-SR
EL-S

45.9
35.7
34.0
46.0
38.8

48.3
38.5
35.8
48.6
41.1

50.8
41.5
37.6
51.4
43.6

68.9
62.7
51.0
70.3
60.5

73.5
68.6
53.9
74.9
64.4

43
43
43
43
43

EL01
EL02
EL03
EL04
T01

23.4
45.0
19.3
18.5
48.9

25.3
47.9
21.2
20.3
52.4

27.4
51.0
23.2
22.3
56.3

42.7
72.6
38.4
37.2
83.6

46.1
78.6
41.7
40.4
92.3

43
43
44
44
44

T02
SW2
OPEN
SW1
L-SR

51.2
46.6
55.1
34.8
45.8

54.2
49.0
58.6
36.5
48.4

57.5
51.5
62.6
38.4
51.2

80.0
69.7
92.0
51.8
69.8

86.1
74.3
****
54.8
74.2

148

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

44
44
44
44
44

EL-S
EL03
EL04
T01
T02

39.5
19.6
18.7
55.5
50.8

41.8
21.4
20.5
58.9
53.7

44.3
23.5
22.6
62.9
56.8

61.2
38.6
37.4
93.8
78.6

65.1
42.1
40.7
****
84.4

44
45
45
45
45

SW2
OPEN
SW1
L-SR
EL-S

47.3
56.5
35.6
46.5
40.1

49.7
60.0
37.3
49.1
42.5

52.3
64.0
39.2
51.9
45.0

70.5
93.7
52.7
70.5
62.0

75.1
****
55.7
75.0
65.9

45
45
45
45
45

EL03
EL04
T01
T02
SW2

19.8
18.9
56.4
51.6
48.0

21.7
20.8
59.9
54.5
50.4

23.7
22.8
63.9
57.6
53.0

38.9
37.7
94.9
79.4
71.3

42.3
41.0
****
85.2
76.0

46
46
46
46
46

OPEN
SW1
L-SR
EL-S
EL03

55.3
36.4
47.3
40.9
20.0

59.2
38.2
49.9
43.2
21.9

63.6
40.0
52.7
45.8
24.0

93.6
53.7
71.3
62.8
39.2

****
56.7
75.8
66.7
42.6

46
46
46
46
47

EL04
T01
T02
SW2
OPEN

19.1
56.1
52.4
48.7
48.0

20.9
59.9
55.3
51.2
52.6

23.0
64.1
58.5
53.8
57.8

37.9
95.3
80.3
72.2
89.2

41.2
****
86.1
76.8
99.5

47
47
47
47
47

SW1
L-SR
EL-S
EL03
EL04

37.3
48.0
41.7
20.3
19.4

39.1
50.7
44.0
22.1
21.2

41.0
53.5
46.6
24.2
23.2

54.7
72.2
63.6
39.4
38.2

57.8
76.7
67.6
42.9
41.4

47
47
47
48
48

T01
T02
SW2
OPEN
SW1

45.2
53.2
49.5
46.0
38.3

49.4
56.2
52.0
50.4
40.1

54.3
59.4
54.6
55.5
42.0

86.1
81.3
73.1
87.5
55.9

96.6
87.1
77.8
97.7
58.9

48
48
48
48
48

L-SR
EL-S
EL03
EL04
T01

48.9
42.5
20.5
19.6
43.3

51.5
44.8
22.4
21.4
47.2

54.3
47.4
24.4
23.4
51.8

73.1
64.5
39.7
38.4
83.2

77.6
68.5
43.1
41.7
93.4

149

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

48
48
49
49
49

T02
SW2
OPEN
SW1
L-SR

54.2
50.3
45.4
39.4
49.8

57.1
52.8
49.6
41.2
52.4

60.3
55.5
54.7
43.1
55.2

82.3
74.1
87.0
57.1
74.1

88.1
78.8
97.2
60.2
78.6

49
49
49
49
49

EL-S
EL03
EL04
T01
T02

43.3
20.7
19.8
42.7
55.1

45.7
22.6
21.6
46.5
58.1

48.3
24.7
23.6
51.0
61.4

65.5
39.9
38.6
82.2
83.3

69.5
43.3
41.9
92.3
89.2

49
50
50
50
50

SW2
OPEN
SW1
L-SR
EL-S

51.2
44.6
40.5
50.7
44.3

53.8
48.7
42.4
53.4
46.7

56.5
53.6
44.3
56.2
49.2

75.2
86.0
58.4
75.1
66.5

79.9
96.2
61.6
79.7
70.5

50
50
50
50
50

EL03
EL04
T01
T02
SW2

20.9
19.9
42.7
56.2
52.2

22.8
21.8
46.5
59.2
54.7

24.9
23.8
50.9
62.5
57.5

40.2
38.8
82.3
84.5
76.3

43.6
42.1
92.5
90.4
81.0

51
51
51
51
51

OPEN
SW1
L-SR
EL-S
EL03

43.5
41.8
51.7
45.3
21.1

47.4
43.7
54.4
47.7
23.0

51.9
45.7
57.3
50.3
25.1

84.0
60.0
76.3
67.6
40.4

94.1
63.1
80.9
71.7
43.8

51
51
51
51
52

EL04
T01
T02
SW2
OPEN

20.2
42.4
57.4
53.2
42.7

22.0
46.1
60.4
55.8
46.4

24.0
50.5
63.6
58.6
50.8

39.1
81.8
85.8
77.5
82.3

42.4
92.0
91.6
82.2
92.4

52
52
52
52
52

SW1
L-SR
EL-S
EL03
EL04

43.2
52.8
46.3
21.3
20.4

45.1
55.5
48.8
23.2
22.2

47.2
58.4
51.4
25.3
24.3

61.6
77.5
68.8
40.6
39.3

64.9
82.1
72.9
44.1
42.6

52
52
52
53
53

T01
T02
SW2
OPEN
SW1

42.1
58.6
54.3
42.1
44.8

45.7
61.6
56.9
45.8
46.8

50.0
64.9
59.7
50.0
48.9

81.0
87.1
78.8
80.9
63.6

91.2
93.0
83.6
91.0
66.9

150

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

53
53
53
53
53

L-SR
EL-S
EL03
EL04
T01

54.0
47.5
21.5
20.6
41.8

56.7
49.9
23.4
22.5
45.4

59.6
52.6
25.5
24.5
49.5

78.8
70.1
40.8
39.5
80.2

83.4
74.2
44.3
42.9
90.3

53
53
54
54
54

T02
SW2
OPEN
SW1
L-SR

59.9
55.5
41.7
46.7
55.3

63.0
58.2
45.3
48.7
58.0

66.3
61.0
49.4
50.8
61.0

88.6
80.2
79.8
65.8
80.3

94.5
85.0
89.8
69.2
85.0

54
54
54
54
54

EL-S
EL03
EL04
T01
T02

48.8
21.7
20.8
41.5
61.4

51.2
23.7
22.7
45.0
64.5

53.9
25.7
24.7
49.1
67.9

71.6
41.1
39.8
79.4
90.3

75.7
44.5
43.1
89.5
96.2

54
55
55
55
55

SW2
OPEN
SW1
L-SR
EL-S

56.8
41.4
48.9
56.8
50.2

59.5
44.9
51.0
59.5
52.7

62.4
48.9
53.1
62.5
55.4

81.8
78.8
68.5
81.9
73.2

86.6
88.7
72.0
86.6
77.3

55
55
55
55
55

EL03
EL04
T01
T02
SW2

21.9
21.0
41.3
63.0
58.3

23.9
22.9
44.8
66.2
61.0

25.9
24.9
48.8
69.6
64.0

41.3
40.0
78.7
92.2
83.5

44.7
43.3
88.7
98.1
88.4

56
56
56
56
56

OPEN
SW1
L-SR
EL-S
EL03

41.2
51.7
58.4
51.7
22.2

44.6
53.8
61.2
54.3
24.1

48.6
56.0
64.1
57.0
26.2

77.9
71.9
83.7
75.0
41.5

87.7
75.5
88.5
79.1
45.0

56
56
56
56
57

EL04
T01
T02
SW2
OPEN

21.2
41.2
64.9
60.0
41.0

23.1
44.6
68.0
62.8
44.4

25.2
48.6
71.5
65.7
48.3

40.2
78.0
94.3
85.5
77.1

43.6
88.0
****
90.4
86.8

57
57
57
57
57

SW1
L-SR
EL-S
EL03
EL04

55.3
60.2
53.5
22.4
21.5

57.5
63.0
56.1
24.3
23.3

59.9
66.1
58.8
26.4
25.4

76.5
85.8
77.0
41.8
40.5

80.3
90.6
81.2
45.2
43.8

151

Table 27.

Level

Continued.

Visibility of
30. m
(98 ft)
at Time
Zone
(min)

Visibility of
15. m
(49 ft)
at Time
(min)

Visibility of
8. m
(25 ft)
at Time
(min)

FED of
0.5 at
Time
(min)

FED of
1.0 at
Time
(min)

57
57
57
58
58

T01
T02
SW2
OPEN
SW1

41.0
66.9
61.9
40.5
60.7

44.4
70.2
64.7
43.8
63.1

48.3
73.7
67.8
47.6
65.7

77.3
96.7
87.8
75.4
83.7

87.2
****
92.8
84.7
88.0

58
58
58
58
58

L-SR
EL-S
EL03
EL04
T01

62.3
55.6
22.6
21.7
40.6

65.2
58.2
24.5
23.6
43.9

68.3
61.0
26.6
25.7
47.7

88.2
79.4
42.0
40.7
75.8

93.1
83.7
45.5
44.1
85.2

58
58
59
59
59

T02
SW2
MECH
ELME
EL-S

69.3
64.1
76.8
80.4
58.0

72.6
67.0
80.9
84.7
60.7

76.2
70.1
85.4
89.5
63.6

99.6
90.5
****
****
82.3

****
95.6
****
****
86.7

59
59
59
R

EL03
EL04
SW2
SW2

22.6
21.7
66.9
71.4

24.6
23.6
69.8
74.6

26.7
25.7
73.0
77.9

42.0
40.8
93.8
99.5

45.5
44.1
99.0
****

152

Appendix G
The Basis for Egress Provisions in U.S. Building Codes

InterFlam ’04

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The Basis for Egress Provisions in U.S. Building Codes
Richard W. Bukowski, P.E., FSFPE and Erica Kuligowski
NIST Building and Fire Research Laboratory
Gaithersburg, Maryland 20899 USA
Abstract
Some of the earliest public safety-from-fire regulations in the US are requirements for egress stairs adopted by New
York City in 18601. One of the first model regulations promulgated by the National Fire Protection Association
(NFPA) was the 1927 Building Exits Code, predecessor of the Life Safety Code. Thus the need to move occupants out
of harms’ way in building fires has long been central to fire safety regulations.
The need to move occupants to a safe place was underscored in numerous historical fire disasters. Locked exits
contributed to the high number of fatalities (150) in the 1911 Triangle Shirtwaist Factory fire and exit doors that
opened inwards blocked by crowds was cited in the 492 fatalities of the Cocoanut Grove fire (1942)2. Incidents like
these resulted in public outcry for stronger code provisions but even today egress problems leading to high numbers of
deaths persist. The 100 fatalities at the Station Club in Rhode Island in 2003 provide the most recent example. Since
the Rhode Island fire, NFPA and other code authorities are reviewing current requirements for level of safety,
especially for assembly spaces.
These current prescriptive codes used for building design contain a list of egress specifications depending upon certain
aspects of the building, such as the type of occupancy, the configuration of the space, the presence of sprinklers, and
the type of construction of the building. These code specifications aid the designer in providing a certain level of life
safety for their building, but little effort has been put into quantifying this level of life safety in terms of egress times.
This paper attempts to describe the prescriptive design process for specific types of buildings. Secondly, by applying
some assumptions to the egress specifications listed in the codes, an estimate of resulting egress times for maximum
occupant loads were performed for specific occupancies. The egress times were obtained using multiple calculation
methods and include estimates of pre-movement time, time to exit the occupied room, and time spent to travel one
flight of stairs. Lastly, additional egress issues, such as merging flows and the use of elevators for occupant egress, are
discussed.

History of Egress Provisions in Regulations
Some of the earliest public safety-from-fire regulations in the US are requirements for
egress stairs adopted by New York City in 18601. One of the first model regulations
promulgated by the National Fire Protection Association (NFPA) was the 1927 Building
Exits Code, predecessor of the Life Safety Code. Thus the need to move occupants out of
harms’ way in building fires has long been central to fire safety regulations.
The need to move occupants to a safe place was underscored in numerous historical fire
disasters. Locked exits contributed to the high number of fatalities (150) in the 1911
Triangle Shirtwaist Factory fire and exit doors that opened inwards blocked by crowds
was cited in the 492 fatalities of the Cocoanut Grove fire (1942)2. Incidents like these
resulted in public outcry for stronger code provisions but even today egress problems
leading to high number of deaths persist. The 100 fatalities at the Station Club in Rhode
Island in 2003 provide the most recent example.
Basic Principles of Egress Safety
The basic concept of occupant egress implemented in building regulations involves the
provision of a properly designed means of egress that is continuous and unobstructed
from any point in the building to the outside. Proper design includes the width of the
spaces and doors, direction of door swing, lighting and marking, protection from the fire
and its effects, and geometry of stairs or ramps, among others. Limits on travel distances

InterFlam ’04

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to reach a means of egress and on common paths of travel, dead ends, and the provision
of alternate means of egress if the primary path is blocked by fire are also basic concepts
of egress design.
The means of egress described in building regulation consists of three parts. The exit
access is the corridor, aisle, balcony, gallery, room, porch, or portion of a roof over
which an occupant must travel to reach the exit. The exit is a door leading to the outside
or through a protected passageway to the outside, a smokeproof tower, protected
stairway, exit passageway, enclosed ramp, escalator, or moving walkway within a
building. The exit discharge is the door to the outside, although some regulations allow
not more than half the exits to discharge onto a floor with an unobstructed path to the
outside, and is protected by sprinklers and a 2-hr separation from floors below.
It must further be possible for all the occupants using the exit discharge to reach a safe
place away from the building. Thus if exits discharge to a yard or alley these must lead
to a safe place and have the capacity to carry all occupants and to protect them from the
effects of the fire as they move away from the building. In Japanese building regulations3
the means of egress includes the entire path to a safe place of sufficient capacity to
accommodate the entire population of all buildings intended to evacuate to that place.
Thus Japanese cities are dotted with parks that serve as gathering places for occupants of
multiple buildings. Those parks utilize perimeter trees intended to protect people in the
park from thermal radiation from fires in surrounding buildings from which they
evacuated.
Designing an Egress System
The objective of the egress system design is to allow the unimpeded evacuation of the
building population without exposure to fire or smoke. Prescriptive building regulations
address this by specifying a population density (people per unit floor area) for each
building use group, called the occupant load factor. When multiplied by the floor area,
the occupant load is obtained on which the egress system design is based (unless there is
reason to believe that the actual load will be greater or the owner desires a greater
allowance).
The means of egress is then designed to accommodate that occupant load by specifying
an egress width per occupant served. Values are specified for stairs and for other egress
components, sprinklered and unsprinklered, and with special values for type-H (high
hazard) and type-I (institutional) building uses to allow for higher egress speeds (high
hazard) and greater number of wheelchairs or evacuation in patient beds (institutional),
respectively.
The width of the egress system at each floor is sized to accommodate the number of
occupants on that floor only. There is an additional requirement that the egress system
width cannot become narrower in the direction of egress travel and beyond any
convergence of two or more egress systems from different directions, the capacity cannot
be less than the sum of the capacities. These requirements are intended to account for the

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accumulation of flows from multiple floors.
For very tall buildings, it was recognized that the accumulating flow from a large number
of floors would result in congestion in the stairways and a reduction of flow speeds.
Widening the stairway to increase the capacity has a serious economic impact that could
make tall buildings impractical. Thus the concept of phased evacuation was developed
where occupants are evacuated from the (3) floors closest to the fire first, while others
wait their turn. Such systems require a voice communication system to manage the
process by voice messages from a fire command center staffed by the fire service, and
(e.g., in New York City) fire wardens on each floor directing the flow.
Egress System Performance
Egress systems designed in accordance with these rules are considered to allow all
building occupants to get to a safe place, “in time.” Unfortunately, “in time” is not
quantified. In the last 20 years, the engineering concept of Available Safe Egress Time
(or ASET) vs. Required Safe Egress Time (RSET) has become popular. ASET is defined
as the time available for safe egress before conditions within a space or building become
untenable4. RSET is defined as the time required for the occupants in a structure to
evacuate without harm. Time available is normally estimated by fire modeling and the
application of tenability limits for human tolerance to fire effects. Time required is
estimated by traffic flow calculations for speed of people movement through the egress
system.
With use, the ASET/RSET methodologies became more refined. The time required
calculations began to include other, significant components such as pre-movement times
and behavioral rules to account for many situations where people do not immediately
evacuate. Human factors research documented large variability in movement speeds4 and
toxicology research showed large differences in individual tolerance to smoke depending
on age and pre-existing physiological conditions. Recently questions have been raised
about sub-lethal effects5 that are difficult to estimate and unethical to measure, further
clouding the picture.
Because of the large variability in movement speeds, it is possible for individual designs
to pass or fail by selection of a characteristic speed or by the application of an
appropriately large factor of safety. A safety factor of 24 is generally recommended in
the fire protection engineering literature6. Thus it would be of value to establish a
benchmark for what might be considered adequate escape time. The prescriptive
regulatory system for egress system design implies such a benchmark value as follows.
Prescriptive Egress Specifications
Traditional building codes specify the design of egress systems by first estimating the
number of occupants in an area to be evacuated, second determining the (combined)
width of the exit system needed for that number of occupants, and third dividing that
width among the number of exits needed to achieve the travel distance limits.
In current building codes, design occupant densities (called loads) range from 46.5 m2

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(500 ft2) (gross13 – the area within the confining perimeter walls of the building) per
occupant (aircraft hangers, warehouses) to 0.46 m2 (5 ft2) (net13 – the actual occupied
space only) per occupant (assembly, standing space). Common values are 9.3 m2 (100
ft2) (gross) per occupant (business, industrial) or 18.6 m2 (200 ft2) (gross) per occupant
(residential). By multiplying these loads by the floor area, the number of people to be
evacuated is obtained.
With the exception of hazardous and health care occupancies, both the IBC7 (without
sprinkler protection) and NFPA 50008 (sprinklered or not) specify the same egress system
width of 7.6 mm (0.3 in) per occupant in exit stairways and 5 mm (0.2 in) per occupant
elsewhere. The IBC reduces egress capacity where sprinklered to 5 mm (0.2 in) per
occupant in stairs and 3.8 mm (0.15 in) elsewhere. The egress capacity of the exit system
is the smallest capacity of any component. For example, a 0.86 m (34 in) (clear width)
door leading into a 1.1 m (44 in) (clear) stair have capacities of 170 (0.86 m/5 mm) and
147 (1.1 m/7.6 mm) respectively. Thus the exit capacity is the smaller of the two, or 147.
The minimum number of exits specified in both model codes is two for populations up to
500, three from 501 to 1000, and four if over 1000.
Finally, building codes specify maximum travel distances to an exit by occupancy. The
IBC specifies 61 m (200 ft) (unsprinklered) and 76 m (250 ft) (sprinklered) for most
occupancies, except for business which is allowed 91.4 m (300 ft) if sprinklered. NFPA
5000 specifies travel distances without sprinklers of 30.5 m (100 ft) (hotels, apartments,
mercantile), 45.7 m (150 ft) (health care, educational) or 61 m (200 ft) (business,
industrial, assembly). When fully sprinklered, these increase to 61 m (200 ft) (hotel,
apartments, educational), 76 m (250 ft) (mercantile, industrial, assembly) and 91.4 m
(300 ft) (business). While most buildings will require two or more exits, the travel
distance requirement only applies to the distance from any point to the closest (single)
exit. The distance to any other exit(s) is unregulated.
An unforeseen problem may exist involving travel distances of the occupants to the
“main entrance” of assembly occupancies. For assembly occupancies, there exists a
requirement that the “main entrance” of the building must be designed for half of the
egress capacity. The travel distance requirement, however, applies only to the closest
(single) exit from any point of occupancy in the building. The question that arises is
whether or not a specific travel distance should be required for the “main entrance” of the
building, especially since the exit is designed for use by half of the building population.
For example, an assembly space with 650 m2 (7,000 ft2) (net) will contain a design
occupant load of 1000 people. The code requires 3 exits and sprinklers, which results in
a travel distance limit of 76 m (250 ft). The “main entrance” is designed for half of the
population (500 occupants), and the two other exits of the building include a larger exit
designed for 400 occupants and a smaller exit designed for 100 occupants. If the smallest
exit is 76 m (250 ft) away from the furthest occupied space in the building, the travel
distance requirement for the building is met. The other two exits, the larger exit and the
“main entrance” are not required to meet any travel distance requirements. In this
example, 90% of the required egress capacity can be in exits that require excessively long

InterFlam ’04

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travel distances to reach.
Benchmarking the Intent of the Codes
By applying some assumptions to the specifications previously listed, it is possible to
estimate the resulting egress times for maximum occupant loads by occupancy. In each
case the occupant load can be estimated by assuming a square compartment with exits in
opposite corners so that the diagonal dimension is the maximum travel distance. This
establishes an area that, when multiplied by the occupant load, gives the number of
occupants to be evacuated.
Egress times are generally taken to be the time between notification of the occupants of
the need to evacuate (initiation of the fire alarm system) and the time the occupants get
into the stairway or a protected stairway access (this is not the normal exit access corridor
but rather an extension of the stairway meeting the same fire and smoke protection
requirements).
The time required to evacuate these occupants is the pre-movement time plus the time
required to move the (maximum) travel distance plus the time required to pass through
the door. Table A9 presents estimates of pre-movement times for various occupancies
and type of warning system. Also, other references provide alternatives for premovement times, which were obtained from fire drills, experiments, and post-fire
analysis10,11,12.
Walking speeds on horizontal surfaces vary with density and fall within the range of 1.19
m/s (235 ft/min) at 0.54 people/m2 (0.05 people/ft2) to 0.63 m/s (125 ft/min) at 2.17
people/m2 (0.2 people/ft2)4. While walking speeds vary with exposure to smoke, it is
reasonable to assume that codes would be based on no smoke exposure due to the limited
data on this interaction. Travel speeds and flow rates are typically restricted by flow
through doorways. The maximum rate of flow through doors is given in the literature as
1.3 persons/s-m of effective width (24 people/min-ft)4.

InterFlam ’04

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Table A – Estimated Delay Time to Start Evacuation
Occupancy Type
Offices, commercial and industrial buildings, schools, colleges,
and universities (Occupants awake and familiar with the building,
the alarm system, and evacuation procedure)
Shops, museums, leisure-sport centers, and
other assembly buildings (Occupants awake but may be
unfamiliar with building, alarm system, evacuation procedure)
Dormitories, residential mid- and high-rise (Occupants may be
asleep but are predominantly familiar with the building, alarm
system, evacuation procedure)
Hotels and boarding houses (Occupants may be asleep and
unfamiliar with building, alarm system, evacuation procedure)
Hospitals, nursing homes, and other institutional (A significant
number of occupants may require assistance)

4/28/2004

W1
W2
W3
(min) (min) (min)
<1

3

>4

<2

3

>6

<2

4

>5

<2

4

>6

<3

5

>8

W1: live directives using voice communication system from a control room with closed-circuit television facility or
live directives in conjunction with well-trained, uniformed staff that can be seen and heard by all occupants in the
space.
W2: nondirective voice messages (pre-recorded) and/or informative warning visual display with trained staff.
W3: warning system using fire alarm signal and staff with no relevant training

The building codes specify that egress doors cannot be less than 0.8 m (32 in) (clear) nor
more than 1.2 m (48 in) (clear) in width (per leaf). Door capacities range from 160
persons for a 0.8 m door to 240 persons for a 1.2 m door with a differential of 10 people
per 51 mm (2 in) of width.
Egress stairs cannot be less than 1.1 m (44 in) in width with no maximum. Design
capacities for stairs range from 147 people for a 1.1 m (44 in) stair to 220 people for a
1.67 m (66 in) stair with a differential of 13 people per 102 mm (4 in) of width.
Horizontal Movement
Tables B1 and B2 show estimates of the worst-case egress times for each occupancy
type; assembly without fixed seating, business, and residential (open space). Each egress
time is the combination of the travel time to the stairwell door and the time for all of the
occupants to go through the door into the stairwell. Prescriptive codes consider the
occupant to reach safety as soon as they enter the stairwell. In the tables, egress times are
separated first into occupancy type, and then second into whether or not the occupancy is
sprinklered (S refers to sprinklered spaces and N refers to nonsprinklered (or
unsprinklered) spaces in each table). Both designations ultimately affect the travel
distances and number of occupants in a space, as shown in the table.
For each occupancy type, a square room is configured so that the diagonal dimension is
equivalent to the travel distance. Then, the dimensions of the compartment are used to
calculate the number of occupants in the space according to the Life Safety Code13 (Table
7.3.1.2). The “travel time” is used to represent the longest possible distance traveled by

InterFlam ’04

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an occupant to reach the stairway door. As shown in Figure 1, this longest distance with
all exits available is the distance along the side of the
compartment (shown by the arrows in the figure).
This provides a conservative estimate of travel time
for that space. The speeds used to calculate travel
time for each occupancy reflect the actual density of
the space and were obtained from Pauls’ density
correlations in the SFPE handbook14.
The next calculation in Table B1, specifically, shows
the time for all of the distributed occupants to travel
through their designated door. Each occupancy has a
different number of exit doors depending upon the
number of occupants in the space. The “through
Figure 1: Square compartment
door” time is calculated by dividing the number of
occupants through the door by the calculated flow
(maximum specific flow x effective door width) in persons/minute. The door calculation
takes into account that occupants will maintain a boundary layer of 150 mm (6 in) from
each side of the doorway.
Table B1 – Estimates of worst-case egress times using SFPE Handbook values
Assembly
Business
Residential
Sb
NSc
S
NS
S
NS
Travel distance
76
61
91.4
61
61a
30.5a
(diagonal dimension–
(250)
(200)
(300)
(200)
(200)
(100)
Fig. 1) in meters (ft)
Compartment side
54.3
43.6
65.2
43.6
43.6
21.6
dimensions in m (ft)
(178)
(143)
(214)
(143)
(143)
(71)
Occupant #
6336
4090
458
205
102
25
(load x area)
Travel time (s)
85
69
55
37
37
18
Exit doors, # x width
14x2.4
9x2.4
2x1.17
2x0.8
2x0.8
2x0.8
in m (people per set
(452)
(455)
(229)
(103)
(51)
(13)
of doors)
Through door (s)
162
163
202
155
77
20
a
Travel distance shown is from the door to any individual living unit to the exit.
Additional travel time would be required for travel within the living unit.
b
Refers to a Sprinklered space; cRefers to a Nonsprinklered space
For Table B2, as a variation to the calculations made in Table B1, it is assumed that the
doors act as turnstiles. From video tapes of egress through doors taken by Fruin15, it can
be seen that each exiting person places his/her hand on the door before leaving the
building. Nelson16 speculates that this behavior limits the flow through each door to
about 50 to 60 persons per minute. This applies to the full range of door widths from 0.8
m (32 in) to 1.2 m (48 in). For the assembly space, a 2.4 m (96 in) door represents a twoleaf set of 1.2 m (48 in) wide doors, which would indicate a flow of 100 to 120 persons

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per minute. For all calculations in Table B2, a midrange value of 55 persons per minute
per door was used to achieve times through the door. For example, in the assembly
space, 452 people will pass through a two-leaf set of 1.2 m (48 in) doors, which
corresponds to a flow of 110 people per minute. For sprinklered assembly spaces, the
result is 247 seconds to flow 452 people through the 2-1.2 m (48 in) doors.
Table B2 – Estimates of worst-case egress times using Nelson and Fruin turnstile values
(each door allows 55 persons/minute)
Assembly
Business
Residential
b
c
S
NS
S
NS
S
NS
Travel distance in
76
61
91.4
61
61a
30.5a
meters (ft)
(300)
(200)
(200)
(250)
(200)
(100)
Compartment side
54.3
43.6
65.2
43.6
43.6
21.6
dimensions in m (ft)
(178)
(143)
(214)
(143)
(143)
(71)
Occupant #
6336
4090
458
205
102
25
(load x area)
Travel time (s)
85
69
55
37
37
18
Exit doors, # x width
14x2.4
9x2.4
2x1.17
2x0.8
2x0.8
2x0.8
in m (people per set
(452)
(455)
(229)
(103)
(51)
(13)
of doors)
Through door (s)
247
248
250
112
56
14
a
Travel distance shown is from the door to any individual living unit to the exit.
Additional travel time would be required for travel within the living unit.
b
Refers to a Sprinklered space; cRefers to a Nonsprinklered space
By using the turnstile approach in Table B2, it can be seen that the flows become
restricted in the larger density spaces. This causes a longer time through the door.
Again, as with the calculations made in Table B1, these can be considered as
conservative estimates of egress times for movement without the presence of fire effects.
Assumptions lead to alternative approach to calculate egress times
There are three assumptions made to calculate the horizontal travel time and time through
the door shown in Tables B1 and B2. It should be understood that these calculations are
approximations of general situations and certain assumptions needed to be made to
complete the calculations for each case. The first assumption involves an even
distribution of occupants to the doors leading to the stairwells.
The second and third assumptions correspond to the addition of the “travel time” and the
“through door” time to achieve the evacuation time for each room. There is an
assumption made that “travel time” and “through door” time do not overlap. In the case
where a queue forms after some period of time during the evacuation, the addition of
these two values (travel and through door time) produces an evacuation time that is
overly conservative. While the most remote occupant travels to the doorway, other
occupants closer to the door leave the room. At some point, the remote occupant reaches
a queue, meaning that they have not walked the entire travel distance. Once they reach
the queue, the “through door” calculation dominates the evacuation time. Also, not all

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occupants are part of the queue, as was assumed in the “through door” calculation, since
some leave while others join the queue.
The third assumption made is that “travel” and “through door” times both have values
that are nonzero. This is not always the case. For lower density spaces, such as the
residential unsprinklered, if a queue never forms, the evacuation time should equal the
“travel” time of the most remote occupant in the space. For the very high density spaces,
such as the assembly spaces, a queue forms immediately. In the case of assembly spaces,
the evacuation time is equivalent to the “through door” time only.
Because of the previous assumptions made about the addition of travel time and time
through the door, several evacuation simulations were run using the Simulex* model17 to
correct these assumptions. The purpose of these evacuation simulations was to note how
long occupants travel to the door unimpeded before a queue would form at the door, at
which time the “through door” egress time dominates the total egress time from the room.
Each occupancy (sprinklered and unsprinklered) was drawn using TurboCAD and
imported into Simulex. The room for each occupancy was equipped with exits at
opposing corners (except for the Assembly spaces which had doors all around the space)
separated by the maximum travel distance along the diagonal. Simulex allows the user to
input a travel speed and body size for each occupant in the simulation. For each run, all
occupants moved at 1.2 m/s (235 ft/min) unimpeded and contained the “median” adult
body size (average of men and women). The occupants were spaced evenly throughout
the room and moved immediately with the start of the simulation. The model, Simulex,
was used only to track the unimpeded movement of the occupants from their starting
position to the doorway. Overall, these Simulex runs were used to obtain the amount of
time that occupants walked through the door before a queue formed. The results were as
follows:
Table C - Simulated time before a queue developed at the doors

Time (s) before queue at door

Assembly
S
NS
!0
!0

Business
S
NS
12
12

Residential
S
NS
16
"

A time of 0 seconds corresponds to a queue developing almost instantaneously in the
assembly spaces. This was expected due to the fact that the assembly spaces were packed
at an allowable density of 0.46 m2/person (5 ft2/person). On the other hand, the
unsprinklered residential space never formed a queue at the door, which is described as
an infinite time in Table C. This was also expected due to the size of the space and the
low number of occupants that needed to evacuate. For the business (sprinklered and
unsprinklered) spaces and the sprinklered residential space, there was a recognized time
*

Certain commercial entities, equipment, or materials may be identified in this document in order to
describe an experimental procedure or concept adequately. Such identification is not intended to imply
recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended
to imply that the entities, materials, or equipment are necessarily the best available for the purpose.

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before queuing began, and for the rest of the evacuation, the time through the door
dominated. This shows that for these occupancies in this example, the evacuation time is
a mix of the travel time and the time through the door. The appropriate evacuation time
can be calculated, given the information in Table C.
Since Table C displays the time before queuing begins for
the three occupancies (Business Sprinklered, Business
Unsprinklered, and Residential Sprinklered), the number of
people that pass through the door in that amount of time
can be calculated. The time before the queue forms and
the speed of the occupants at the specific density is known,
and from this information, the distance that the occupants
traveled to evacuate before a queue formed can be
calculated. As shown in Figure 2, an arc is drawn in front
of each doorway, with the radius consisting of the distance
traveled by the occupants before queuing. Essentially, this
arc is drawn to show the position of the occupants that left
before queuing began. By solving for the area of the arc,
the number of occupants residing in this arc space (using
the density of the space) can be found and used as the number of occupants evacuating
during the pre-queuing time. These occupants are then subtracted out from the
population. Lastly, the time for the rest of the occupants to move through the door is
calculated using two different methods; the effective width method and the turnstile
method. These values are shown in Table B3.
Figure 2: Arc display of
occupants who leave the
room before queuing occurs

Table B3 – Estimates of egress times without overlapping travel time and time through
the doorway.
Assembly
Business
Residential
S
NS
S
NS
S
NS
76
61
91.4
61
61
30.5
Travel distance in meters (ft)
(250)
(200)
(300) (200)
(200) (100)
Compartment side dimensions in m
54.3
43.6
65.2
43.6
43.6
21.6
(ft)
(178)
(143)
(214) (143)
(143)
(71)
Occupant # (load x area)
6336
4090
458
205
102
25
Time (s) before queue at door
0
0
12
12
16
! (18)
# of occupants evacuating during
0
0
17
17
15
13
pre-queue per door
(452)
(455)
(212)
(86)
(36)
(0)
(# of occupants left at time of queue)
Through door (s) for queuing
162
163
188
129
54
18a
occupants – effective width method
Through door (s) for queuing
247
248
231
94
39
18a
occupants – turnstile method
a
These values are equivalent to the travel time assuming that occupants are traveling at the
unimpeded speed of 1.2 m/s (235 ft/min) (at least one traveling the entire “travel time”
distance).

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For all occupancies, except for the residential unsprinklered, horizontal travel time was
not explicitly included in the egress times from each space. This is because the egress
times are dominated by the time through the door, as shown in the Simulex runs of each
occupancy (except for residential unsprinklered). Because of this, the total egress time
for the space is calculated by adding the “time before queue at door” and the “through
door” time (depending upon the calculation method preferred).
Overall
If a more conservative evacuation time is preferred, it is recommended to add the travel
time to the door and the time through the door for the business occupancy (sprinklered
and unsprinklered) and the sprinklered residential occupancy.
Stairs
While prescriptive codes generally designate occupants as safe when they enter the
protected egress stair, evacuation often requires that the occupants travel down stairs to
the level of exit discharge. From the literature, the maximum flow rate in a (7/11) egress
stair is estimated to be 1 person/s-m (18.5 people/min-ft) of effective width. Thus
typical/maximum flow rates for 1.1 m (44 in) to 1.67 m (66 in) egress stairs range from
49 to 83 people per min. This does not include the effect of congestion in the stairs that
results from accumulating flows from several floors accessing the stairs.
Table D shows the time for travel on the stairs from one floor to another (including one
landing in between flights). The times were obtained by assuming that the calculated
flow (people/min) from one section of the building is equal to the calculated flow on the
next section, except for the unsprinklered residential. For the unsprinklered residential
occupancy, since no queue has formed at the door, unimpeded speed was used to
calculate movement on the staircase. For all other occupancies, the occupants travel from
the doorway into the stairwell with the same calculated flow, but different widths, and
therefore, different specific flows. It is assumed that they travel from the room at a
specific flow of 1.3 people/m-s (24 people/ft-min). The Life Safety code specifies 7.6
mm/person (0.3 in/person) of stair width, which was used to calculate the appropriate
stair width for each occupancy, sprinklered or unsprinklered. By solving for the specific
flow for the staircase, the appropriate travel speed can be obtained from the SFPE
handbook4 in order to calculate the travel times for the section of stair. Stair travel
distance was estimated by first, multiplying the vertical distance of the floor by the
diagonal travel distance conversion factor found in Nelson’s chapter of the SFPE
Handbook, Table 3-14.34, and second, adding travel distance of the 2 landings. The
calculated range of times for stair travel from one floor to another (assuming a 3.7 m (12
ft) ceiling height – slab to slab and (7/11) stairs) was 12-25 seconds, depending upon the
occupancy and method of calculation.

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Table D – Travel times on Stairs
Travel distance in room (m)
People per door/stair
Stair width (m)
Travel dist on Stairs (m)
Time on each flight (s) –
effective width method
Time on each flight (s) –
turnstile method

Assembly
S
NS
76
61
452
455
3.4
3.47
20.5
20.5

Business
S
NS
91.4
61
229
103
1.7
1.1
13.7
11.2

Residential
S
NS
61
30.5
51
13
1.1
1.1
11.2
11.2

25

25

16

13

13

12

22

22

15

18

18

12

Due to the number of occupants evacuating the three occupancies, especially in the case
of the assembly space, the stairwells used in Table D are quite wide. The Life Safety
Code specifies that handrails need to be placed 1.5 m (60 in) apart in order to provide
support for occupants descending wider staircases. This handrail specification affects
both the sprinklered and unsprinklered assembly spaces and the sprinklered business
space. The calculations provided in Table D account for boundary layers (150 mm (6 in))
around the walls of the staircase, but not the handrails placed in the middle of the stair.
Boundary layers from walls are used in evacuation calculations to account for lateral
body sway in the stair9. For this estimation of stair time, it is assumed that the occupants
will allow their bodies to get within millimeters of the handrail, negating the need for
additional boundary layers around handrails. It is possible that the presence of handrails
in the center of a staircase can negatively affect the flow of occupants during egress, but
there lacks a sufficient amount of data on this topic to include such in the estimation.
Thus the benchmark egress times on the initial floor implied in current building codes
range from approximately 5.5 minutes (sprinklered assembly) to 0.3 min (unsprinklered
residential), depending upon the method of calculation used and the type of occupancy.
When added to the alarm time for the initial notification of the occupants (generally on
the order of one minute from sustained ignition of the first item), estimated premovement times (Table A) and descent times (per floor times number of floors, Table D)
as appropriate, these can be used to benchmark egress system performance for systems
designed by calculation.
Congestion and Merging Flows on Stairs
Merging flows occur when occupants from a floor and the stairwell above enter the
stairwell section simultaneously during downward flow. This can also occur during
upward flow if occupants are traveling from basement levels of the building. In a highrise building, congestion points occur at each entrance into the stairway from all floors of
the building.
During merging flows, it is likely for researchers to witness the phenomenon of deference
behavior. Deference behavior describes how occupants from the floors above yield to the

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occupants entering the stairwell from their floor. This behavior is often seen on airplanes
where the rows leave before the passengers already waiting in the plane aisle.
Merging flows and congestion frequently occur in high-rise buildings during full or total
evacuation of the structure. Currently all US model building codes (International
Building Code and NFPA5000) design tall buildings, particularly door and stair widths,
based on a partial or phased evacuation plan for the building. The code specifies that the
width of the stairs depends on the number of occupants on a particular floor, irrespective
of building zones or the entire building population. This would result in congestion in
high-rise buildings if the entire population evacuates simultaneously. Since 9/11, New
York City has imposed a requirement for an evacuation drill (the entire population
evacuating to the street) annually. It is reported that occupants of surrounding buildings
seeing the evacuation themselves, then evacuate their buildings. Situations like this result
in the opinion that the process for evacuation of tall buildings needs to be rethought.
Elevators
Currently there are no building codes that permit elevators to be used as a means of
occupant egress, and ASME A17.118 requires signs at all elevators warning that they shall
not be used in fires. NFPA 5000 permits protected elevators as a secondary means of
egress for air traffic control towers and the City of Las Vegas accepted elevators as a
primary means of occupant egress from Stratosphere Tower based on a performancebased design19.
US codes require accessible elevators as part of a means of egress that may be used by
the fire service to evacuate people with disabilities. These elevators must comply with
the emergency operation requirements of ASME A17.1 (Phase II emergency operation by
the fire service), be provided with emergency power, be accessible from an area of refuge
or a horizontal exit (unless the building is fully sprinklered), and operate in a smoke
protected hoistway. Phase II operation involves the use of an elevator by a firefighter for
fire service access or for rescue of people with disabilities performed under manual
control (with the use of a special key).
According to a survey20 by the International Organization for Standardization technical
committee on elevators (ISO TC178), there are twelve countries that require firefighter
lifts, generally in buildings that exceed 30 m (98 ft) in height. Standards for firefighter
lifts generally describe a firefighting shaft consisting of protected elevators, enclosed
lobbies on each floor and an associated stairway, all of which have at least 1-hr fire
resistance and smoke protection. Firefighters use the elevator to move their people and
equipment to two floors below the fire, from which point they advance up the stairs,
which contain a standpipe and provide a protected path for retreat. These firefighter lifts
can be used to provide evacuation assistance for occupants with disabilities after
suppression activities are underway.
NIST studies have shown that the use of protected elevators to supplement stairs for
occupant egress (not just for people with disabilities) can result in a significant reduction

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in total egress times, especially for taller buildings21. Given the observation that
occupants may resist certain evacuation approaches, such as phased evacuation, protected
elevators is clearly the most promising to address the problem without incurring huge
penalties in decreased leasable space.
Conclusions
Based on the preceding analysis, the longest egress times expected in buildings designed
in accordance with current (prescriptive) U.S. codes would occur in larger, assembly
occupancies without fixed seating (the so-called festival seating) having the maximum
occupant densities. Benchmark egress times would be approximately 4 minutes premovement, 5 minutes to get into the stairs, and 0.5 (25/60 s) minutes per floor to get to
the level of exit discharge.
In an office (business occupancy) egress times might be 3 minutes pre-movement, 5
minutes to get into the stairs, and 0.3 minutes per floor to get to the level of exit
discharge. In residential occupancies egress times might be 4 minutes pre-movement
(but with much higher variability since there is likely additional delays to assist family
members, obtain pets and valuables, etc.), 2 minutes to get into the stairs, and 0.3 minutes
per floor to get to the level of exit discharge. These times attempt to account for queuing
entering the stairs but do not include delays due to congestion within stairs that would be
expected to increase with building height.
These times represent estimates of the egress performance implied by egress system
designs prescribed in current U.S. model building codes. These should not be taken as
requirements nor even as the performance intended by the code developers, since this is
the first attempt to quantify what might be expected from means of egress complying
with the minimum requirements of the codes. The intent of this paper is simply to
provide benchmarks that can be compared against performance-based egress analyses.

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References
1

1984 Fire Almanac, NFPA Quincy, MA 02269.
Reily, E., “Third Code Revolution: A Brief History of US Building Codes,” Sprinkler Age, 10, 7, July
1991.
3
Building Standard Law of Japan, Official Translation by the Architectural Institute of Japan, Tokyo.
4
Nelson, H.E. and Mowrer, F.W. (2002), “Section 3, Chapter 14 Emergency Movement,” The SFPE
Handbook of Fire Protection Engineering, 3rd Edition, National Fire Protection Association, Quincy, MA.
5
Gann, R.G., Averill, J.D., Johnsoon, E.L., Nyden, M.R., & Peacock, R.D., “Smoke Component Yields
from Room-scale Fire Tests,” National Institute of Standards and Technology, NIST TN 1453, 159 pp.,
April 2003.
6
Bukowski, R. W., “Predicting the Fire Performance of Buildings: Establishing Appropriate Calculation
Methods for Regulatory Applications,” Proc AsiaFlam ’95, International Conference on Fire Science and
Engineering, March 15-16, 1995, Kowloon Hong Kong, pp 9-18.
7
International Building Code, 2003 edition, International Code Council, Inc., Falls Church, VA 22041.
8
Building Construction and Safety Code (NFPA 5000-2003), National Fire Protection Assn., Quincy, MA
02269.
9
Proulx, G. (2002), “Movement of People: The Evacuation Timing, Section 3 Chapter 13,” The SFPE
Handbook of Fire Protection Engineering 3rd ed., P.J. DiNenno ed., NFPA, Quincy, MA.
10
Fahy, R.F. & Proulx, G., “Toward Creating a Database on Delay Times to Start Evacuation and Walking
Speeds for Use in Evacuation Modeling,” Proceedings of the Second International Symposium on Human
Behaviour in Fire, Boston, Mass., USA (2001).
11
Brennan, P. “Timing Human Response in Real Fires,” Proceedings of the Fifth International Symposium
on Fire Safety Science, Melbourne, Australia (1997).
12
Shields, T.J., Boyce, K.E., and Silcock, G.W.H., “Towards the Characterization of Large Retail Stores,”
Proceedings of the First International Symposium on Human Behaviour in Fire, Belfast, UK (1998).
13
Life Safety Code (NFPA 101-2003), National Fire Protection Assn., Quincy, MA 02269.
14
Pauls, J. (1995), “Movement of People, Section 1 Chapter 15,” The SFPE Handbook of Fire Protection
Engineering 2nd Edition, P.J. DiNenno, ed., NFPA, Quincy, MA.
15
Fruin, J.J., Pedestrian Planning and Design, Revised Edition, Elevator World, Inc., Mobile, AL, Fruin,
J.J., ed, 211 p., 1987.
16
Nelson, H.E. (1990), “FPETOOL User’s Guide,” NISTIR 4439, National Institute of Standards and
Technology, Gaithersburg, MD.
17
IES, “Simulex: Evacuation Modeling Software,” Integrated Environmental Solutions, Inc., March, 2001.
18
Safety Code for Elevators and Escalators ASME A17.1 2000, American Society of Mechanical
Engineers, New York, NY.
19
Bukowski, R.W., “Protected Elevators for Egress and Access During Fires in Tall Buildings,” Proc of the
CIB-CTBUH Conf on Tall Buildings, 20-23 October 2003, Kuala Lumpur Mayalasia.
20
Comparison of Worldwide Lift (Elevator) Safety Standards – Firefighters Lifts (Elevators), ISO/TR
16765:2002(E), ISO, Geneva, Switzerland.
21
Klote, J.H., Alvord, D.M., Levin, B.M., and Groner, N.E. (1992), “Feasibility and Design Considerations
of Emergency Evacuation by Elevators,” NISTIR 4870, National Institute of Standards and Technology,
Gaithersburg, MD.
2

Appendix H
Is There a Need to Enclose Elevator Lobbies in Tall
Buildings?

Is There A Need to
ENCLOSE ELEVATOR LOBBIES
IN TALL BUILDINGS?
by Richard W. Bukowski, P.E., FSFPE

S

everal proposals have been submitted in recent years
to model building code organizations to require
enclosure of elevator lobbies in order to restrict the
movement of smoke to other parts of buildings via hoistways. A significant development in this area occurred
recently when the National Institute of Standards and Technology (NIST)—which was already involved with a
consortium of industry representatives, codes and standards
developers, and other interested parties in a study of the
protection of elevators for occupant evacuation and fire
service access1—was asked by the U.S. General Services
Administration (GSA) to research the conditions under
which enclosed elevator lobbies were called for. This article
will provide an overview of the progress made to date on
this line of research.

Background
Vertical shafts in tall buildings are subject to something called
“stack effect,” which describes an induction of airflow resulting from differences in temperature between the inside and
outside of the shaft. When the outside temperature is colder,
the induced flow is upward (normal stack effect); when the
outside temperature is warmer, the flow is downward (reverse
stack effect). While firestopping is effective in limiting the
upward spread of flames through vertical openings and shafts,
smoke is far harder to stop because even small leakages can
allow it to pass. This has led to the use of smoke management
systems which employ pressure differences to block smoke
flow even through small cracks2.
There are several examples of fires in which smoke
spread in shafts has been implicated in deaths on upper
floors, with perhaps the most infamous being the November
21, 1980, conflagration at the MGM Grand in Las Vegas.
Although the flames were confined to the casino area on the
26 Building Safety Journal August 2005

first floor of the structure, 61 of the 85 casualties occurred
on upper (above the 20th) floors due to smoke spread up
elevator hoistways and seismic joints between the building
core and wings.3
It is not surprising that such tragedies are frequently cited
as substantiation for proposals to enclose elevator lobbies.
However, the potential for smoke flow in hoistways is a
function not only of leakage of the elevator doors but also
of the strength of the stack flow, fire temperature (buoyancy
flows) and the height of the shaft. Each of these factors was
taken into account in NIST’s analysis of the potential flows
under varying conditions in order to identify those situations where significant shaft flows might be expected.

Shaft Flow Analysis
NIST contracted with John H. Klote, Inc.—which is a well
known for its expertise in the fields of both smoke management and elevators—for the analysis. Klote’s report contains the details of the scenarios examined and the results
obtained for each4 and was summarized in a paper presented
at the 2004 ASME Workshop on Use of Elevators in Fires
and Other Emergencies.5

Scenarios Studied
A number of primary variables were identified for study,
including building size and configuration (five types),
extent of fire (three types), lobby enclosure (two conditions), weather (winter or summer), and two alternate
methods of preventing smoke flow in the shaft. This
resulted in the 27 scenarios shown in Table 1, which were
then evaluated using a combination of numerical models
and NIST’s Consolidated Model of Fire Growth and Smoke
Transport (CFAST)6 and CONTAM multizone airflow and
contamination transport analysis software programs.7

Table 1. Scenarios Examined.
SCENARIO

BUILDING1

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27

A
A
A
A
B
B
B
B
C
C
C
C
C
D
D
D
D
D
D
D
D
D
D
E
E
E
E

FIRE
TYPE2
SP
FDR
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDF
FDR
FDR
FDR
FDR
FDF
FDF
FDF
FDF
FDF
FDF

FIRE
FLOOR3
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
36
36
2
2
2
2

ENCLOSED
ELEV. LOBBY
Y
Y
Y
N
Y
N
N
N
Y
N
N
N
N
Y
N
N
N
Y
N
N
N
Y
N
Y
N
N
N

WEATHER4
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-W
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
W-NW
S-NW
S-NW
W-NW
W-NW
W-NW
W-NW

ALTERNATIVE
METHODS5
none
none
none
none
none
none
TB
JPC
none
none
none
TB
JPC
none
none
TB
JPC
none
none
TB
JPC
none
none
none
none
TB
JPC

1. See Table 2.
2. SP is a sprinklered fire, FDR is a fully developed room fire, FDF for fully developed floor fire.
3. FDR fires are located in a conference room on the floor indicated, FDF fires are located in the open floor plan space on that floor.
4. W-NW for winter with no wind, S-NW for summer with no wind, W-W for winter with wind.
5. TB for temporary barriers over elevator car doors. JPC for judicious positioning of cars within hoistways.

Building Characteristics
The buildings considered were all office use and were assumed to have typical floor heights of 4.0 meters (13.1 feet) except
for the ground floors, which were assumed to have heights of 6.0 meters (19.7 feet). Total building heights ranged from 6
to 58 floors. The number of elevators and their arrangements were typical for the building’s sizes and configurations—see
Table 2. The buildings were based on several actual GSA office buildings previously studied.8
Table 2. Building Characteristics.

A

NUMBER
OF STORIES*
6

PASSENGER
ELEVATORS
1 bank of 3 elevators

SERVICE
ELEVATOR
None

B

13

1 bank of 6 elevators

None

C

16

1 bank of 6 elevators

None

D

35

3 banks of 6 elevators:
low, medium & high rise

2

E

58

3 banks of 8 elevators:
low, medium & high rise

2

BUILDING

* Does not include mechanical penthouse.

Flow Paths
Buildings are surprisingly leaky, and these leaks are characterized in the smoke management literature.9 Leakages occur
through construction cracks and around doors, especially elevator doors. Values typical of reasonably tight construction were
assumed for this study and are displayed in Table 3. Hoistway vents required by the building codes and increased leakage
due to warpage of some doors by the heat of the fire are included.10
(continued)
August 2005 Building Safety Journal

27

Elevator Lobbies in Tall Buildings (continued)
Table 3. Flow Coefficients and Equivalent Leakage Areas for Building Flow Paths.
COMPONENT
Exterior wall
Exterior wall below grade5
Interior wall
Elevator wall
Floor
Roof5
Closed doors
Single door
Double door
Elevator doors6
Large elevator doors7
Warped single door
Warped double door
Open doors
Single door
Double door
Shaft equivalent area8
Stairwell
3-car passenger elevator
4-car passenger elevator
2-car service elevator
Open elevator vent9
3-Car passenger elevator
4-Car passenger elevator
2-Car service elevator
Roll down barriers
Shafts with cars in place
3-car passenger elevator
4-car passenger elevator

PATH
TYPE1
O
O
O
O
O
O

PATH
IDENTIFIER2
W-EXT
W-UG
W-INT
W-EL
FLOOR
ROOF

FLOW
COEFFICIENT3
0.65
0.65
0.65
0.65
0.65
0.65

T
T
T
T
T
T

DR-SI
DR-DO
DR-EL42
DR-EL48
DR-SI-W
DR-DO-W

0.65
0.65
0.65
0.65
0.65
0.65

AREA4
m /m2 (ft2/ft2)
0.00017
0.000085
0.00011
0.00084
0.000052
0.000026
m2
ft2
0.016
0.17
0.027
0.29
0.047
0.50
0.049
0.53
0.043
0.46
0.070
0.75

T
T

DR-SI-O
DR-DO-O

0.35
0.35

1.95
3.90

21
42

O
O
O
O

STAIR
EL-P3
EL-P4
EL-S2

0.60
0.60
0.06
0.60

2.3
230
360
160

25
2500
3900
1700

O
O
O
T

EL-P3V
EL-P4V
EL-S2V
ROLL

0.32
0.32
0.32
0.65

0.70
1.05
0.52
0.011

7.5
11.3
5.6
0.12

O
O

EL-P3C
EL-P4C

0.65
0.65

6.5
9.1

70
98

2

1. O indicates an orifice path for which flow is in one direction, T indicates a two-directional flow path. The two-directional flow is used for doors, and the
leakage is uniformly distributed over the height of the door.
2. The path identifiers are used with CONTAMW for data input.
3. The flow coefficient is defined as m A-1 (2 ρ p)-1/2 where m is the mass flow through the path, ρ is the density of gas flowing in the path, and p is the
pressure difference across the path.
4. Areas for walls and floors are listed as area of flow path per unit of area of wall or of floor as appropriate.
5. Due to lack of experimental data, the flow areas of the exterior wall below grade and the roof were estimated at half that of the exterior wall and floor,
respectively.
6. This elevator door is 1.07 m (3.5 ft) wide. It is used for all passenger elevators in this study except for that in Building E.
7. This elevator door is 1.22 m (4.0 ft) wide. It is used for the passenger elevators in Building E and the service elevators.
8. Shaft equivalent areas are used to calculate the pressure losses due to friction in shafts. For more information, see chapter 6 of Klote and Milke (2002).
9. Vent area was calculated at 3.5% of the shaft area but not less than 0.28 m2 (3 ft2).

L

Weather
Because stack effect is driven by the difference between inside and outside temperatures, typical environmental conditions
needed to be taken into account. The following representative conditions were used in the calculations.
• winter outdoor temperature: -16°C (3°F)
• summer outdoor temperature: 35°C (95°F)
• wind speed: 11 meters per second (25 miles per hour)
Interior Temperature
Interior temperatures in buildings are normally maintained in a narrow range around 23°C (73°F), so that was the value used
in the calculations.

Limiting the Spread of Smoke in Shafts
The spread of smoke in shafts can be limited by sealing leakages and/or by producing pressure differences that result in airflows in the desired direction. The recognition that many leakages are hidden or difficult to seal leads to the use of active
smoke management techniques, particularly for egress stairways, but there are some other techniques that might be
effective in reducing leakages into elevator hoistways to low levels.
28 Building Safety Journal August 2005

Methodology
Fires on a lower floor during winter and on an upper floor
in summer were examined to determine the quantity of
smoke that might spread to the upper or lower floors,
respectively, by means of the hoistways (heat is not a significant hazard long distances from a fire source because
temperatures rapidly diminish to near ambient level through
entrainment and heat losses to the surroundings). It was
assumed that all exterior and interior stairway doors were
closed. Windows to the exterior were also assumed to be
closed except for in the case of a fully developed floor fire,
the intense heat of which can break the glass.
The hazards of smoke obscuration and toxic potency were
assessed using engineering criteria frequently employed in
11
building performance analysis. A fire (heat release rate)
curve representative of the scenario being considered was
first chosen—see Figure 1 for the heat release rates selected.
Then the CFAST fire model was used to determine the

burning rate as affected by the geometry and ventilation,
resulting in the production over time of energy, smoke particulates and combustion gasses. Consumption of oxygen
and its effect on burning rate and combustion chemistry was
also computed.
The energy and mass produced moves through the building by buoyancy and building flows, including stack effect.
These were calculated by the model CONTAM, resulting in
estimates of temperature, smoke density and gas concentrations over time in spaces remote from the fire. The exposure
of evacuating occupants would change as they moved from
space to space, but the analysis used the more conservative
approach of evaluating the exposure of stationary occupants
in order to take into account those with disabilities or otherwise unable to escape.

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'$""
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"

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Landing doors for both passenger and freight elevators
are known to be particularly leaky because they open laterally by a mechanism carried on the elevator cars. Gaps, the
provision of safety mechanisms to prevent the doors from
closing on passengers, and the tendency of sliding doors to
jam when subjected to pressure differences all tend to exacerbate the leakage problem. As a result, solutions to reduce
smoke leakage into hoistways generally involve the provision of an enclosed lobby (creating an air lock with an entry
door capable of far better sealing against infiltration) or by
a roll-down barrier that covers the normal elevator door.
Both of these approaches were evaluated.
Suggestions have been made that hoistways themselves
could be blocked during a fire by an extendable or inflatable
barrier, mounted either within them or on the bottoms of the
cars, that would be deployed when needed. This approach
has many limitations (e.g., interference by the elevator
cables unless the car is above the barrier), but it was decided
to examine the potential for positioning a car near the
neutral plane to partially block the hoistway and reduce the
flow in the shaft. If found to be effective, this could be done
for no additional cost beyond programming elevator controllers appropriately. Therefore, the study also evaluated
the “judicious” positioning of elevator cars near the neutral
plane to limit shaft flow.
Another new technology is a type of elevator door seal
that is intended to be tight enough to restrict smoke leakage
into hoistways. These type of seals are currently being
tested in Japan (where they originate) and the U.S. In the
past, however, similar seals were found to be problematic
because they required adjustments to door closing forces
that increased the hazard of passengers becoming struck. It
remains to be seen if the newer seals will perform better.

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"

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&=""

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2+3/'456
4C6'788'?;*'?.;;*'?+*/@

Figure 1. Heat release rates.

Results
As expected, sprinklered fires were not shown to represent
a significant hazard to occupants because the sprinklers
activated and extinguished the fires before they could
release significant energy or mass. Little or no smoke or
gasses entered the hoistways, and none reached remote
locations in any building regardless of height or other conditions examined.
(continued)
August 2005 Building Safety Journal

29

Elevator Lobbies in Tall Buildings (continued)
Fully developed room fires (flashovers) released significant energy and mass, and strong fire-induced flows drove
those products to the hoistways. Enclosed lobbies prevented
any substantial portion of that mass or energy from entering
the hoistways, but the absence of a lobby resulted in untenable conditions in terms of reduced visibility and toxicity on
the upper floors of the tallest building, which had the greatest stack effect.
Where the fire spread to the entire floor, enclosed lobbies
continued to provide some protection, allowing sufficient
smoke to exceed visibility limits at remote locations in all of
the buildings but limiting toxicity to less than the limiting
value for the time studied. In addition, times at which visibility limits were exceeded occurred significantly later
when lobbies were present. The increases in time to untenable visibility increased by 50 percent to 200 percent for
lobbies enclosed by normal construction and by 0 percent to
20 percent with the use of roll down barriers due to their
greater leakage characteristics (temporary barriers with
better leakage characteristics would be expected to perform
better). Without lobbies, tenability conditions for both visibility and toxicity were exceeded at locations remote from
the fire in all buildings regardless of height.
The “judicious” positioning of elevator cars had no effect
on smoke flow in the hoistways because the leakage area
around cars is quite large.

Discussion
It may therefore be concluded from the study results that
enclosed elevator lobbies are not necessary in buildings
with operational fire sprinkler systems. From a risk management perspective, this means that the need for enclosed
elevator lobbies depends on the probability that a sprinkler
system will not work (operational reliability) and the consequences (expected losses) of such a failure.

Sprinkler System Reliability
Data on in-service failures of wet pipe sprinkler systems in
U.S. Department of Energy (DOE) facilities show operational reliabilities of 99.2 percent,12 but these systems are
subject to testing and maintenance programs more rigorous
than those typically performed on commercial systems.
Studies of commercial sprinkler systems installed per industry standards indicate an operational reliability of about 95
percent,13 so the decision whether or not to incorporate
enclosed lobbies might be based on a 5-percent probability
of sprinkler system failure unless a maintenance program
comparable to the DOE’s is in place.
Statistics indicate that most sprinkler system failures are
due to impaired water supplies such as closed valves,
blocked pipes, impaired sources, etc., which tend to affect
sections of or the entire system. As such, system reliability
can be increased by active monitoring of water supplies and
controls. The general consensus is that problems with individual sprinkler heads are rare. However, it may well be
asserted that current data do not accurately reflect the
upsurge in the use of quick-response heads, and the fact that
several models of these have been involved in recent recalls
underscores the need to update field reliability data for light
hazard systems commonly used in business and residential
occupancies.
Consequences of Failure
Minimal stack effect was produced in shafts—including
hoistways—in low-rise buildings (less than 7 stories or 75feet high), so the spread of smoke and fire gasses to upper
floors may be considered to be of no great concern even
when there are no operational sprinklers. While smoke from
fully developed floor fires exceeded tenability limits in lowrise buildings without elevator lobbies, this occurred long
after such buildings would be expected to be fully evacuated. A risk manager might therefore conclude that enclosed
lobbies are not needed in low-rise buildings, particularly
when sprinklered.
In taller buildings, which experience greater stack effect
and require more time for occupant egress, untenable conditions are reached much sooner if lobbies are not provided
and if sprinkler system failure allows a fire to grow to room

30 Building Safety Journal August 2005

flashover or full floor involvement. A risk manager may
therefore decide to provide enclosed elevator lobbies in
high-rise buildings even when sprinklered unless the sprinklers can be shown to have operational reliabilities similar
to that achieved by DOE systems. Elevator lobbies should
be of 2-hour fire-resistance rated construction (1-hour rated
in fully sprinklered buildings) and have direct access to an
egress stair. ◆
Richard W. Bukowski, P.E., FSFPE, is a Senior Engineer
and Coordinator of Standards and Codes for the National
Institute of Standards and Technology Building and Fire
Research Laboratory, chairs several committees and task
groups for the National Fire Protection Association
(NFPA), is Coordinator of the International Council on
Building Standards and Documentation (CIB) Working
Commission 14: Fire, and is active in the work of CIB
TG50: Tall Buildings. He is also the U.S. representative to
ISO TAG8, which advises the International Organization
for Standardization (ISO) Technical Management Board
and provides oversight to all ISO Technical Committees
working in the building and fire areas, and served on the
committee that developed the International Code Council
Performance Code™ for Buildings and Facilities and on
NFPA’s Standards Council.
Bukowski is a Fellow of the Society of Fire Protection
Engineers and a licensed Professional Engineer in the
States of Illinois and Maryland. His professional awards
include being was named 1997 Automatic Fire Alarm
Association Person of the Year and 2003 Commerce
Department Federal Engineer of the Year by the National
Society of Professional Engineers.

References

1. Bukowski, R.W., “Protected Elevators for Egress and
Access During Fires in Tall Buildings, Strategies for
Performance in the Aftermath of the World Trade Center.”
Proceedings of the International CIB-CTBUH Conference
on Tall Buildings. CIB Publication No. 290. F. Shafii, R.
Bukowski and R. Klemencic (Eds.). pp 187–192, 2003.
2. NFPA 92, Recommended Practice for Smoke Control
Systems. National Fire Protection Association.
3. Best, R. and D.P. Demers, “Investigation Report on the
MGM Grand Hotel Fire—Las Vegas, Nevada, November
21, 1980,” Fire Journal 76(1), pp 19–37, January 1982.
4. Klote, J.H., “Hazards Due to Smoke Migration through
Elevator Shafts,” NIST GCR04-864-I, Volume 1: Analysis
and Discussion, and NIST GCR04-864-II Volume 2:
Results of Tenability Calculations. National Institute of
Standards and Technology, 2004.
5. Klote, J.H., “Analysis of the Consequences of Smoke
Migration through Elevator Shafts,” Workshop on Use of
Elevators in Fires and Other Emergencies, Conference

Proceedings. Co-sponsors: ASME International, the
National Institute of Standards and Tech-nology, the
International Code Council, the National Fire Protection
Association, the U.S. Architectural and Transportation
Barriers Compliance Board, and the International Association of Fire Fighters.
6. Peacock, R.D., et al., NIST Technical Note 1299, CFAST,
the Consolidated Model of Fire Growth and Smoke Transport. National Institute of Standards and Technology,
1993.
7. Dols, W.S. and G.N. Walton, NISTIR 6921, CONTAMW
2.0 User Manual. National Institute of Standards and
Technology, 2002.
8. Klote, J.H., et al., NISTIR 4770, Staging Areas for
Persons with Mobility Limitations. National Institute of
Standards and Technology, 1992.
9. Klote, J.H. and J.A. Milke, Principles of Smoke Management. Amercan Society of Heating, Refrigerating and AirConditioning Engineers, 2002.
10. VanGeyn, M, National Fire Door Fire Test Project Technical Report 6285, Positive Pressure Furnace Fire Tests.
Fire Protection Research Foundation, 1994.
11. Purser, D.A., “Toxicity Assessment of Combustion Products,” SFPE Handbook of Fire Protection Engineering.
Third Edition. P.J. DiNenno (Ed.). National Fire Protection Association, 2002.
12. Bukowski, R.W., E.K. Budnick and C.F. Schemel,
“Estimates of the Operational Reliability of Fire Protection Systems,” International Conference on Fire Research
and Engineering, Third Proceedings, pp 87–98. Cosponsors: the Building and Fire Research Laboratory, the
National Institute of Standards and Technology, and the
Society of Fire Protection Engineers.
13. Maybee, W.W., “Sprinkler Performance Update,
1952–1986,” Sprinkler Quarterly, pp 49–51, Spring 1987.
August 2005 Building Safety Journal

31

Appendix I
Protected Elevators and the Disabled

SFPE Fire Protection Engineering

Page 1 of 10

8/31/2005

Protected Elevators and the Disabled
Richard W. Bukowski, P.E., FSFPE
NIST, Building and Fire Research Laboratory
Gaithersburg, Maryland 20899 USA
It was 1989 and I was giving a talk to local federal agencies on the newly-released
HAZARD I software and its promise for performance-based design for fire safety. After
the talk several attendees came up to talk to me, including a gentleman in an electric
wheelchair. He told me that he worked on the 10th floor of a nearby, high-rise office
building and that when he first came to work there the safety officer did not really know
what to do with him. He was instructed that in case of a fire evacuation, he was to go to
the stairway. If there was someone there to open the door (he was quadriplegic and could
not grip nor turn the knob) he should proceed onto the top landing. Otherwise he should
wait at the stairway door for assistance. He told me that it was clear to him that they
wanted to know where to go to collect the body.
It was just the next year, 1990, when the Americans with Disabilities Act (ADA) was
passed to provide equal access to public buildings for all Americans. The objective of the
ADA regulations was to permit people with disabilities access to the places where we
live, work, and play with little thought of how they would get out in case of emergency.
Fifteen years later we are still addressing this important issue.
The purpose of this article is to present the issues that need to be addressed in the
development of elevators that can be used in fires to safely evacuate occupants,
particularly those with limited mobility that affects their ability to use stairs.
Accessibility
The ADA accessibility requirements are intended to
result in public buildings that can be accessed and
used by people with a range of limitations including
vision, hearing, and mobility. The guidelines provide
for signs that include Braille markings, strobe lights
and other visible warnings, and doors with powered
openers that are wide enough for wheelchairs.
Smaller changes in elevation require ramps or
platform lifts that eliminate barriers to wheelchair
users.
Building codes contain special provisions for an
accessible means of egress that either leads out of the
building (including through a horizontal exit) or to an
area of refuge, which may be served by an accessible
elevator. Elevators are the primary means of routine
ingress and egress for all occupants in most buildings
and under most conditions, except during fires.
Elevators are posted with signs warning that they are

Accessible elevators are required
by the Building Codes and ADA
requirements

SFPE Fire Protection Engineering

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8/31/2005

not to be used during a fire. Occupants and firefighters are relegated to stairways that
may have only the capacity to carry the occupants from a few floors at a time, without the
counterflow of firefighters trying to move up carrying equipment. And what about those
people with disabilities (including both disabilities as defined by the ADA and those
occupants who needed assistance to exit long distances) who now represent 6% to 10% of
the occupant load?
Elevator Safety
While lifts for goods have been in use for thousands
of years it is only since the development in 1854 of
the automatic safety brake by Elisha Graves Otis
that the passenger elevator became a reality. Often
cited as the safest mode of human transportation,
millions of people ride elevators daily without
incident. This laudable safety record has been
achieved through the pervasive safety culture of the
elevator industry and the committees who write the
safety codes that govern the design, installation,
operation, maintenance, and inspection of passenger
elevators. In the U.S., this is the American Society
of Mechanical Engineers (ASME) A17.1
Committee.
The issue addressed by Otis’ brake was a failure of
the lifting rope causing the car to fall. Doors or
gates on the landing opening and car prevented
people from falling out or getting their body parts
caught between the car and shaft wall. Additional
improvements in safety and reliability over the
years have led to the admirable safety performance
of modern elevators.
A fundamental industry assumption is that
entrapment in an elevator is a fail-safe condition
Safety brakes located under the car are
and a special system has been implemented to
triggered by an overspeed governor in
ensure that trapped passengers can be extracted
the machine room (drawing courtesy
Mitsubishi)
quickly and safely. Every elevator is equipped
with a telephone to summon help, and every elevator maintenance contractor has
technicians on call 24/7 to respond. Even in major incidents such as the 2003 blackout in
the Northeast U.S. and Canada, hundreds of entrapment calls were cleared in only a few
hours. The acceptance of temporary entrapment leads to the common arrangement that,
if the many safety controls on an elevator sense something is going wrong, the elevator
controller shuts the system down. In recent times it has been recognized that there are
two conditions where entrapment is not a safe condition – during an earthquake or during
a fire.

SFPE Fire Protection Engineering

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8/31/2005

Door Restrictors
A more recent safety device required on passenger elevators is called a door restrictor.
These are devices that restrict the ability of a passenger to force open the car door unless
the floor of the car is within at least 75 mm but not more than 450 mm (3 in to 18 in)
above or below the level of the landing. Passengers have been known to force open the
doors and fall down the hoistway if the car became stuck or even to “joyride” on the top
of the car, especially since the roof hatch began to be locked from the inside. These door
restrictors have been successful at eliminating many injuries and deaths (according to
decreases in reports of deaths and injuries from falling down shafts all of which occur in
elevators not retrofit with door restrictors), but became an issue in the WTC Towers on
September 11, 2001. There were several cases of occupants entrapped in cars that were
not close enough to the landing to release the restrictor. The industry is now studying
ways of releasing restrictors in an emergency that would not lose their safety function in
other circumstances.
Elevators and Earthquakes
The vertical and lateral motions associated with a seismic event can affect the operational
safety of an elevator. In an earthquake it is possible for the elevator or its counterweight
(for traction elevators) to be jarred out of their guide rails. The most dangerous result is
where the car runs into the counterweight. Thus the elevator code requires that all
elevators located in Seismic Zone 2 or greater are designed with greater clearances,
retainer brackets where the car and counterweight attach to the rails and with seismic
switches set to activate at an acceleration of 0.15 g. Activation of the switch causes the
car to stop, and move in the direction away from the counterweight to the next available
landing where the doors open and the car is locked out of service until the system is
manually reset. This can only be done from the machine room by an elevator technician
after determining that the system can operate safely [ASME 2004].
Elevators and Fires
Beyond the direct impacts on the safe operation of the elevator, there are several
interactions between the elevator system and the building during a fire. One is the
hoistway as a vertical shaft spreading smoke through the building. Most landing doors
open horizontally and are far leakier than other types of doors. The shaft itself is subject
to what is known as stack effect, which is a vertical airflow resulting from differences in
indoor to outdoor temperatures and the height of the shaft. This shaft flow draws air into
or out of the shaft through the landing doors depending on the position of the landing
relative to the neutral plane and the direction of the shaft flow. [Klote and Milke 1992]
Stack effect flows are driven by differences in indoor and outdoor temperatures with
upward flows in winter (outdoors colder than indoors) and downward in summer
(outdoors warmer than indoors). The greater the difference, the greater the flow;
therefore stack effect is larger in more extreme climates and for taller shafts. Even
without a fire, stack effect flows can cause problems in tall buildings, resulting in strong
flows and noise at landing doors near the top and bottom of the shaft. These flows can
cause jamming of landing doors and may require seasonal door adjustments by elevator
technicians. During a fire, stack effect flows can carry smoke and fire gases to remote

SFPE Fire Protection Engineering

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parts of the building. For example, in the MGM Grand [Fire Journal 1981] and DuPont
Plaza [Klem 1987] fires which both occurred near the ground floor level, there were
fatalities on upper floors due only to smoke carried up elevator shafts by stack effect
flows.
It is important to note that both examples occurred in unsprinklered (at least in the area of
the fire) buildings. A recent analytical study by the author [Bukowski 2005] showed that
stack effect flows sufficient to create safety problems on upper floors would not be likely
in fully sprinklered buildings (with working sprinkler systems) or in buildings not tall
enough (less than 75 feet under less than extreme weather conditions) to produce strong
shaft flows. In some mission critical applications it might be appropriate to provide for
the small likelihood of a failure of the sprinkler system. [Bukowski 2005]
Elevators and Water
Water from fire sprinklers or hose streams can result in safety problems for elevators
during fires. Water can enter the hoistway and cause electrical shorts in safety controls
causing them to fail. Water on the drum of the elevator machine can cause the car to slip
although the safety brake would stop a car from overspeed or falling down the shaft.
To address this situation, elevators protected by sprinklers in the hoistway or machine
room are equipped with a shunt breaker to deenergize main power before a sprinkler
activates. Connected to a heat detector that would activate before the sprinkler, the shunt
breaker activation removes power and stops the elevator, but can result in entrapment.
The shunt breaker will not protect the system from water from sprinklers or hose streams
at landings leaking into the hoistway.
Firefighters Emergency Operation
In the mid-1970’s the elevator industry
developed firefighters emergency operation
to improve the safety of the system during
fires. Smoke detectors are installed in the
elevator lobby within 6.4 m (21 ft) of any
landing door on each floor. The smoke
detectors protect the elevator system by
detecting any encroachment of the fire and
triggering Phase I recall. Here the elevator
cars are sent immediately to the designated
landing which is generally the level of exit
discharge. There the elevators stop, the
doors open, and the elevators are locked out
of service. If a fire is detected on the
designated landing, the cars are sent to
A fire operation instruction panel is required in every
elevator fitted for this service (courtesy ASME )
an alternate floor.
Upon their arrival, firefighters are able to place individual cars back into manual service
by use of a firefighters key, in what is called Phase II operation. While operating in this

SFPE Fire Protection Engineering

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8/31/2005

mode, a light on the car control panel marked with the symbol of a firefighters hat is
illuminated. In this mode, the controls in the car operate in a special manner designed to
protect the firefighter operating the car. For example, the car will move to a selected
floor but the doors will not open. Depressing the door open button opens the doors but
only as long as the button is depressed. Thus, if smoke enters the car and the firefighter
reacts by jumping back, the door will close.
Additional smoke detectors installed at the top of the hoistway and in the machine room
monitor the system integrity. If activated, the firefighters hat light in the car begins to
flash warning the operator that the system may become erratic and to move to a safe
location.
It is generally accepted by the experts that as long as the system is operating in normal
service (before Phase I activates) the elevators are safe to use, even if there is a fire in the
building. Such a fire would need to be sufficiently remote from the elevator lobby so as
to not have activated a lobby smoke detector triggering Phase I recall.
Elevator Assisted Egress
In the wake of the September 11, 2001 attacks on the World Trade Center Towers, the
concept of protected elevators for occupant egress and for fire service access from tall
buildings received new interest. The primary issues are the need for more rapid egress
from very tall buildings and additional capacity to support simultaneous evacuation of
occupants who were now reluctant to await a phased evacuation. Since even minimal
additional egress capacity by stairs has a very large cost penalty in lost leasable space,
use of the elevators that are already present is a logical approach. But arguably the most
important issue is to provide for self-evacuation of people with disabilities and those for
whom evacuation down long stairways presents significant difficulties.
1993 and 2001 WTC Evacuations
In the 1993 bombing at the World Trade Center, it was found that many more occupants
experienced difficulties than just those with traditional disabilities. People with
temporary disabilities such as broken legs, people with asthma, pregnancy, or obesity all
reported difficulties in mobility or stamina that limited their own evacuation abilities and
that of others behind them in the stairways.
Recently Bukowski and Kuligowski [Bukowski and Kuligowski 2004] benchmarked
evacuation times for egress systems designed in accordance with modern building codes.
They found for office occupancies that it requires about 5 minutes to empty a floor and ½
to 1 minute per floor to egress down stairs without delays for queuing, congestion, or
resting (total evacuation times would further need to include pre-evacuation times).
Based on this benchmark, the World Trade towers would have required 1 to 2 hours
(without congestion delays). Observed evacuation time in the 1993 bombing and total
evacuation time in 2001 estimated for a full occupant load of 25,000 by state-of-the-art
egress models that included queuing and congestion was about double the best case times
or about 4 hours. [Fahy and Proulx, 2002]

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One crucial observation from 2001 involves the evacuation of 2 World Trade Center
(South Tower) in the 16 minutes between the aircraft strike on the North Tower and the
strike on the South Tower. Having seen what happened to the North Tower, many of the
occupants in the South Tower decided to evacuate. Since their building was undamaged
many used their normal procedure of elevators. NIST estimated that about 3000 people
evacuated from above the (eventual) aircraft strike zone using the stairs or elevators
[Averill 2005]. After the South Tower was hit NIST estimated that only 18 additional
occupants escaped from above the impact region.
Protected Elevators
NIST has been working on the development of protected (also called hardened or Phase
III) elevators in cooperation with the elevator industry, fire alarm industry, and key codes
and standards organizations in the hope of developing the needed technology and code
provisions to put these into practice. This work is making slow but steady progress and
should be ready for demonstration in a year or two.
Early work focused on the issues discussed previously including water sensitivity and
protection of the elevator system from the fire. Enclosed and (real time) monitored
lobbies would provide a protected space for occupants to await the elevator as well as an
additional layer of passive protection for the hoistway. Information displays and
communication to the fire command station would provide reassurance to those waiting,
and direct access to a stair would provide a second way out for those capable of using it.
It is expected that people with disabilities would be given priority access to the elevator
cars. [Bukowski 2003]
An important benchmark of elevator evacuation performance can be seen in the typical
design objective for elevator systems. The number, capacity, and speed of elevators are
typically designed to move 15 % of the total occupant load of the building in 5 minutes.
This means that a typical system utilizing an efficient evacuation protocol (e.g., ignoring
hall and car calls and operating in a shuttle mode between a 3-floor fire zone and the
level of exit discharge) would be capable of evacuating the entire occupant load of 3
floors of a 20 story building or 6 floors of a 40 story building in 5 minutes.
Layers of Protection
In order to protect the elevator system from compromise by the fire and provide a
protected space in which to wait, protected elevator systems would incorporate enclosed
lobbies on each floor above the level of exit discharge and would be found in fully
sprinklered buildings. In a 1993 report done for GSA, Klote et al [Klote 1993] found that
separate staging areas were not needed in fully sprinklered buildings since the entire
building remains tenable as long as the sprinkler system is operational and the fire is not
shielded from the sprinkler. The addition of protected lobbies adds an additional layer of
protection, not only for the elevator, but also for occupants awaiting the arrival of the
elevator. This is particularly important for occupants who cannot use the stairs and who
need to be protected in place until they can egress using the elevators or be assisted by
others.

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Hoistway pressurization
Another function of the lobby is to prevent smoke from exposing people waiting for the
elevator as well as to prevent smoke from entering the hoistway. While the lobby
enclosure can be made smoke tight, the door will be opened repeatedly as occupants
enter, so a pressurization system would be needed. Based on prior NIST work, it is
important to minimize pressure differences across the landing door that might lead to
jamming [Klote 1982]. Thus, a system where the hoistway is pressurized and a positive
pressure of the lobby (with respect to the rest of the floor) is produced by leakage through
the landing door, will provide the desired result. Pressurization of the order of 12 Pa
(0.05 inches of water) is a reasonable design value [Klote and Milke 1992].
Real-Time Monitoring
An important layer of protection is the
ability of the fire service to monitor
the conditions within the lobbies,
hoistway and machine room in real
time to ensure that there are no threats
to people or systems. These
monitoring functions will be carried
out by the fire alarm system and
displayed in the fire command station
on a special fire service display. These
displays comply with National Fire
Protection Association (NFPA) and
National Electrical Manufacturers
Association (NEMA) standards so that
Conditions in lobbies and status of elevators can be
they are consistent in form and
displayed in real time in the building fire command
operation across all equipment
station
manufacturers. All conditions and
functionality critical to the safe and reliable operation of the system are monitored.
Information systems
Crucial to the safety and peace of mind of occupants using the system is the provision of
real time information on the system status. Displays in the lobbies will show waiting
occupants that the elevators are in service and how long they will need to wait to be
served. People who are capable of using the stairs will be free to do so if they feel the
wait is too long, either taking the stairs to a lower level to reenter and await an elevator,
or all the way to the street. Should it be necessary to take the elevators out of service, the
lobby display would indicate that those capable should use the stairs and others could
communicate directly with the fire command station to request assistance.
Evacuation mode
Elevators are the most efficient at moving people in “shuttle mode” where the times
associated with deceleration, loading, and acceleration are minimized. Thus it has been
proposed to establish an evacuation mode of operation that will optimize system
performance.

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In general, evacuation mode would be triggered on a general alarm in the building. All
elevators would be captured and returned to the level of exit discharge to unload any
passengers. An automatic message in the elevators would explain that there is an
emergency reported in the building and the elevators are being put into service to assist in
evacuation. Signs on the discharge level would warn people not to enter. One (predesignated) car would be held for fire service access and the rest would go into
evacuation service; moving to the first priority floor group (fire floor, one above and one
below). Destination buttons in the car (Car calls) would be disabled and the buttons that
summon the elevator to a floor (hall calls) would register where occupants are awaiting
the elevator for egress but would not direct service.
Once the first priority group of floors is evacuated, the system would serve additional
floor groups in a logical order until all occupants have been evacuated. If Phase I recall
is activated at any time in the process, evacuation mode would end, but cars could be put
into Phase II service if the fire service considers it safe to do so.
Mobility Impaired Occupants
The evacuations of the World Trade Center towers
in 1993 and in 2001 provided some common
lessons regarding egress of people with impaired
mobility. First, there are more people who have
difficulty in moving long distances down stairs in
very tall buildings than those who usually come to
mind. People with temporary disabilities (broken
legs/sprains using canes or crutches, pregnant, or
those injured in the initiating event), asthmatic or
other respiratory conditions, obese or other
conditions that limit stamina, all have been
observed to require extra time and frequent rest
stops. In the WTC evacuation 6% of the survivors
reported having some pre-existing condition that
limited their mobility. If you add to that, people
injured by the initiating event or just after
beginning to evacuate the number could be higher.
Even women in high heels and men in new dress
This smokeproof elevator is installed at
shoes were reported to have caused backups in
an Italian residential facility for mobility
stairs by moving more slowly [Averill 2005].
impaired people to provide access and
egress. The glass hoistway enclosure
While 6% is not unreasonable for traditional
permits
the fire service to determine if the
disabilities, designing for a disabled population of
elevator is in use. (courtesy CNR)
10% would be conservative for many buildings.
In some buildings such as residences for the elderly, the proportion could be considerably
higher. A recent paper [Sekizawa 2004] mentions a fire in Japan where 80% of the
elderly occupants were unable to evacuate down the stairs and used the elevators
successfully.

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In the September 11, 2001 evacuation, first responders moving down stairs in WTC 1
after the collapse of WTC 2 found 40 to 60 mobility impaired occupants on the 12th floor
where they had been moved. About 20 of these occupants were being assisted down the
stairs just prior to the collapse of WTC 1. It is unclear how many of these or the 20 to 40
others who had been staged on the 12th floor perished [Picciotto 2002].
Conclusions
Protected elevators that can provide for unassisted egress of occupants with disabilities
can result in significant reductions in total evacuation times for tall buildings and more
efficient flows in stairs by people capable of using them. Considering the optimum flow
rates down stairs of 30 seconds per floor without congestion or the need to stop and rest,
elevators designed to move 15% of the occupant load in 5 minutes could evacuate 60
floors (including wait times) in the same time it takes for occupants to descend 60 floors,
or 30 minutes.
By reducing stair flow impediments through the use of elevators for up to half the
population it should be possible to totally evacuate buildings of any height in the order of
30 minutes. Those using the elevators would include all people with disabilities and
those highest in the building, while the stairs would be used by the most physically
capable from the lower floors. This approach is used by the 88-story Petronas Towers in
Kuala Lumpur, Malaysia where a total evacuation time in a drill was reported to be 32
minutes, utilizing a combination of stairs and elevators. [Arliff 2003]
References
Arliff, A., Review of Evacuation Procedures for the Petronas Twin Towers, Proc CIBCTBUH Conference on Tall Buildings, Kuala Lumpur Malaysia 2003.
ASME, Safety Code for Elevators and Escalators, ASME A17.1-2004 Section 84.10.1.3, ASME New York, NY 2004.
Averill, J., et al, Federal Building and Fire Safety Investigation of the World Trade
Center Disaster: Occupant Behavior, Egress, and Emergency Communications, NCSTAR
1-7, NIST Gaithersburg, MD 20899 2005.
Bukowski, R.W., Is There a Need to Enclose Elevator Lobbies in Tall Buildings,
Building Safety Journal, Vol III, No. 4, ICC Whittier, CA, August 2005.
Bukowski, R.W., Protected Elevators for Egress and Access During Fires in Tall
Buildings, Proc CIB-CTBUH Conference on Tall Buildings, Kuala Lumpur Malaysia
2003.
Bukowski, R.W. and Kuligowski, E.D., The Basis for Egress Provisions in U.S.
Building Codes, Proc InterFlam 2004, Interscience Communications, London, 2004.
Fire Journal, Fire at the MGM Grand, NFPA Fire Journal, Vol. 75, No. 2, 33-36, March
1981.
Klem, T., 97 Die in Arson Fire at DuPont Plaza Hotel, Fire Journal, Vol. 81, No. 3, 7477, 79,+, May/June 1987.
Klote, J. H., Elevators as a Means of Fire Escape. American Society of Heating
Refrigerating and Air Conditioning Engineers Transactions, Vol. 89, No. 2, 1-16, 1983.
NBSIR 82-2507; 37 p. May 1982.

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Klote, J.H., Nelson, H.E., Deal, S., and Levin, B.M., Staging Areas for Persons with
Mobility Limitations, NISTIR 4770, Nat Inst Stand Tech, 18p, Jan 1993.
Klote, J.H. and Milke, J.A., Design of Smoke Management Systems, ASHRAE 1992.
Fahy, R. and Proulx, G., A Comparison of the 1993 and 2001 Evacuations of the World
Trade Center, Proc Fire Risk and Hazard Assessment Research Application Symposium,
Fire Prot. Res. Foundation, Quincy, MA July 24-26, 2002.
Picciotto, R., Last Man Down, Berkley Publishing, NY, NY 2002
Sekizawa, A., Nakahama, S., Notake, H., Ebihara, M., and Ikehata, Y., Study on
Feasibility of Evacuation Using Elevators in High-Rise Buildings, Proc ASME
Workshop on Emergency Use of Elevators, Atlanta GA March 2-4 2004.

Appendix J
Elevator Controls

It is important that all parties, from rescue
personnel to building designers understand
the intent of the fire service operation
provisions of ASME A17.1, Safety Code for
Elevators and Escalators.

Elevator

controls

THE DEVELOPMENT OF THE PASSENGER ELEVATOR is tied directly
to the emergence of tall buildings. While various types of freight lifts
were found in warehouses and factories before the advent of the highrise, these were considered too dangerous to move people.
In 1854, however, Elisha Graves Otis demonstrated an automatic
safety brake that changed the landscape. Within a few years, his steam
elevators had eliminated one of the major limits to building height.

By Richard Bukowski, P.E.
Russell Fleming, P.E.
Jeffrey Tubbs, P.E.
Christopher Marrion, P.E.
Jill Dirksen
Chris Duke
Debbie Prince
Lee F. Richardson
Lieutenant Dave Beste, and
Dottie Stanlaske

NFPA JOURNAL MARCH/APRIL 2006

43

But, while elevators proved to be one of the
safest forms of transportation, there were
instances where people were killed while using
elevators during building fires. Heat sometimes activated call buttons bringing cars to
the fire floor where smoke prevented the
doors from closing (light beams are in modern
day elevators to detect people in the doorway)
and water in the shaft sometimes shorted out
electrical safety devices or may have caused
failure of braking systems. Thus, the use of
elevators for occupant egress or fire department access was discouraged.

In 1973, the elevator industry
developed a system that
recalls elevators and takes
them out of service if smoke is
detected in the lobbies,
machine room, or hoistway.
In 1973, the elevator industry developed a
system that recalls elevators and takes them
out of service if smoke is detected in the lobbies, machine room, or hoistway. Mandated
in the American Society of Mechanical Engineers (ASME) A17.1, Safety Code for Elevators
and Escalators,1 for all automatic passenger elevators, this system involves two distinct
phases of emergency operation.
In Phase I, the detection of smoke or heat
causes the elevators to be recalled to the ground
floor, unless this is where smoke was detected.
The doors open, and the elevators are locked
out of service. Responding fire fighters may use
the elevators under manual control of a fire
fighter in the car using a special fire fighter key
in what is called Phase-II operation.
While Phase II operation is used to evacuate
people with mobility impairments, some fire
department standard operating procedures for
high-rise fire fighting rely on stairs for access,
staging, and operations. ASME A17.4, Guide for
Emergency Personnel,2 contains detailed instructions for fire fighters’ service operation.
In the 1980s, the United Kingdom developed BS5588 part 53, a standard for fire
fighter lifts. It describes a fire-fighting shaft
consisting of an elevator, protected lobbies on
44

NFPA JOURNAL MARCH/APRIL 2006

each floor with direct access to one of the
required stairs, and standpipes, all enclosed in
fire resistant construction. According to a survey4 by the International Organization for
Standardization (ISO) committee responsible
for ISO/TC178 elevator standards, this system
is used in a few countries, generally former
British colonies, for buildings greater than 18
meters (60 feet). Recently, BS5588 part 5 has
been adopted as CEN Standard EN 81-73 for
use throughout the European Union.
Also in the 1980s, the Federal Aviation
Administration (FAA) was interested in providing a secondary means of egress from air
traffic control towers. Because a contro l
tower’s footprint is so small, it is not possible
to provide two remote stairs, but any tower of
significant height has an elevator and stairs.
The FAA contacted the National Institute of
Standards and Technology (NIST), and a
cooperative project launched with the elevator

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industry, coordinated through the National
Elevator Industry Institute, resulted in
changes in the 1997 edition of NFPA 101®, Life
Safety Code®5, that were subsequently incorporated into NFPA 5000®, Building and
Construction Safety Code®. In addition to the technical requirements for the equipment and
components, NFPA criteria also limits the
number of occupants in the tower and requires
periodic drills.
While requirements exist for elevators for
emergency use by fire fighters and people with
mobility impairments, there are currently no
codes or standards for egress elevators for use
by building occupants. There are, however,
egress elevators accepted under performancebased design provisions based on engineering
analysis. An example of where such elevators
can be found is the Stratosphere Tower in Las
Vegas, Nevada.
Atop the 800-foot (250-meter) Stratosphere
Tower is an 11-story building, known as the
Pod. The Pod has an emergency staircase that
is considered impractical for use in emergency
conditions. Thus the four double-deck elevators designed for emergency use. One is
reserved for the fire department, and the others are used under manual control to evacuate
all occupants from the two lower floors of the
Pod, which were designed as areas of refuge.
Occupancy of the tower is limited to the number of people that can be evacuated by the
elevators in one hour.6
New demands for protected elevators

The attacks on the World Trade Center on
September 11, 2001, showed that access by fire
fighters to incidents on upper floors of tall
buildings was problematic. Fire fighters in
their protective clothing and carrying the normal gear for high-rise firefighting that includes
hose packs and forced entry tools require
about 2 minutes per floor to ascend stairs.
Once they arrive at the fire scene, they are
likely to require rest before they can begin suppression operations. Logistics is also an issue,
especially re-supplying oxygen tanks that have
a practical capacity of 15 minutes to 20 minutes, depending on the level of exertion.
Clearly, using elevators to move people and
equipment to a staging area, which is normally
two floors below the fire floor, is the only reasonable approach. Although many in the fire
service did not trust the safety of elevators
during a fire incident, some departments

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began to cautiously incorporate elevator
access into their high-rise firefighting procedures after 9/11, requiring inspection of the
hoistway for signs of smoke and sometimes
stationing a fire fighter in the machine room.
In the summer of 2003, NIST approached
the ASME A17 committee with a proposal to
explore the development of protected elevators for fire service access and for occupant
egress in collaboration with the A17 code committee, elevator industry, and fire service.
These groups agreed and organized a workshop to explore issues and barriers. A call for
papers resulted in a range of speakers, most of
whom supported the concept. Breakout
groups identified many issues and some ideas
on features that should be incorporated into
any such system.
Based on these results, the ASME A17 committee established two task groups under the
Emergency Operations Committee to develop
recommendations for fire-service access elevators and for occupant egress elevators.
A key finding from the workshop was that
the incorporation of fire fighters emergency
service operation in the 1980s resulted in systems that could continue to operate safely
during a fire and would safely take the elevators out of service before there was any risk of
entrapment from an effect of the fire. However, many fire departments would manually
initiate recall of the elevators on their arrival to
control access and to ensure that there were no
trapped occupants. While this practice would
not materially affect fire service access, it
would affect the use of the elevators for occupant egress.
The ASME A17 task groups followed a formal hazard analysis using an ISO standard for
risk assessment without the step of assigning
probabilities. While tedious, this process is
thorough and results in a detailed record of the
conditions the committee considered and the
mitigation of all hazards identified.
Protecting elevators

The ASME A17 task groups largely addressed
the safety issues associated with fire service
access elevators by adding real-time monitoring of critical systems from the fire command
station that the building codes alre a d y
required as the incident command location for
high-rise buildings. This allows the fire service
to monitor the safety and functionality of the
systems and to warn fire fighters by radio if

NFPA JOURNAL MARCH/APRIL 2006

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the safety of the elevator is in doubt. The task
groups also identified other improvements
that would make it less likely that the fire or
firefighting operations might cause the systems to fail, including better protecting the
power to the system, monitoring the internal
temperature of the controller, and protecting
some critical components in the hoistway
from water damage. Finally, the groups provided arrangements to facilitate self-rescue in
case of entrapment.
Far more complicated are the arrangements
and protocols needed to evacuate occupants
by elevator. Unlike the fire service, elevator
occupants are not trained or equipped to deal
with emergencies. The only thing that can be
assumed is familiarity with the normal use of
the elevators, as these are the primary means
of daily ingress and egress. Thus, while some
degree of proactive management of the evacuation by the fire service is provided, the use of
elevators for evacuation must be as close to
“normal” as possible, with some allowance for
guidance by informational messages.

The current ASME A.17 requirements
for fire fighter emergency operation
are considered effective in maintaining safe operation, even during a fire.
The task groups’ concept of occupant
egress elevators included protecting the entire
bank of cars to take advantage of the system’s
full handling capacity. This is an elevator
industry term describing the design of the system for normal operation where the number,
size, and speed of the cars, number of floors
served, and occupant load are all considered
to achieve a specific service objective.
The elevators in an office building are
designed with a handling capacity of 8 percent
to 10 percent (downpeak 5), meaning that 8
percent to 10 percent of the entire population
of the building can be collected from various
floors and transported to the ground floor in
five minutes. Apartment buildings are typically designed for a handling capacity of 4
percent to 5 percent (downpeak 5), and some
high-end offices, such as the new WTC 7
46

NFPA JOURNAL MARCH/APRIL 2006

owned by Silverstein Properties in New York
City, are being designed for 12.5 percent,
meaning shorter waits for an elevator at 5 p.m.
The handling capacity calculation is standardized throughout the elevator industry and is
discussed in design manuals such as the Vertical Transportation Handbook.7
The current AS ME A17 requirements for
fire fighter emergency operation are considered effective in maintaining safe operation,
even during a fire. If the elevators are to be
used for occupant egress, it is important to
keep them in service for as long as possible.
This led the task groups to observe that
enclosed and protected lobbies are needed on
every floor, not only to provide a protected
space for occupants to wait, but also to protect
the elevator lobby from smoke or fire exposure that will initiate elevator recall. Previous
work by NIST showed that elevator-landing
doors are particularly susceptible to jamming
with relatively small pre s s u re differe n c e s
across them. However, a system in which the
hoistway is pressurized and the lobby has a
positive pressure with respect to the rest of the
building by leakage can provide smoke protection for the hoistway and lobby without
causing problems with the landing doors.
Provision of real-time environmental monitoring of the lobbies and two - w ay
communication with the fire command station
would also be specified. Dynamic signs, which
the fire alarm industry calls textural notification appliances, would be provided in each
lobby to give information to waiting occupants. In most modern systems, the elevator
controller’s dispatch software can provide realtime estimates of the time before an elevator
car arrives at that floor, and this will be specified as part of the system.
Evacuation protocol

To provide the needed efficiencies in quickly
moving occupants, a new operational protocol
is being developed and recommended. Since
elevators are most efficient when the number
of starts and stops is minimized, the elevators
would operate in a shuttle mode in the evacuation protocol. The cars would not respond to
car calls—that is, floor buttons in the car—and
hall calls, or call buttons in the lobby, would
only register that there are occupants waiting
there. First priority would be given to collecting occupants on the fire floor, one floor
above, and two floors below, and taking them

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ELEVATOR CONTROL

to the main lobby. Note that the initial evacuation zone extends two floors below the fire so
that the lobby normally used by the fire fighters for staging would be unoccupied by the
time they arrive.
Once the fire zone was empty, the elevator
evacuation would proceed from the highest
floors downw a rd. People on lower flo o r s
would be told the length of wait for an elevator and they might choose to start down the
exit stair that would be accessible from the
lobby. If any of these occupants needed to
rest, they could enter a lobby and do so, or
wait for an elevator.
By taking advantage of all the handling
capacity of the system, it is unnecessary to
restrict access to the evacuation elevators to
just people with limited mobility. Since the
lower floors would be the last to be served,
there is incentive for most occupants on those
floors to egress by the stairs. By starting with
the upper floors, the occupants who require
the longest egress times by stairs would be
evacuated first, dramatically lowering the total
egress time for even the tallest buildings.
Many of the features described here are
already being implemented in tall buildings
outside the United States. For example, the
Petronas Towers in Kuala Lumpur reports
that incorporating elevators into the egress
plan has resulted in total evacuation times in
both towers of about 20 minutes. Taipei 101,
which is currently the tallest building in the
world at 101 occupied stories, reports a total
evacuation time for the tower and the very
large podium area at the base of just under
one hour.
Addressing user needs

The fire service must be confident that an elevator is safe and reliable and that they can
escape or be rescued quickly by their colleagues if they become entrapped. The fire
service has the opportunity to train with the
elevator systems and, when the practice
becomes more common, they will have an
opportunity to use them during real fires.
Monitoring critical systems at the fire command station in real time makes them
confident that incident command can relay
warnings by radio if needed and will know
quickly if an entrapment occurs.
Occupant egress elevators provide a different set of challenges. Using them for
emergency egress should be as close to using

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them for normal egress as possible, and a
steady stream of information is needed. This
can be addressed primarily by incorporating
dynamic signage, operated from the fire alarm
system, in each elevator lobby to provide a
high level of reliability. Again, monitoring critical systems in real-time and having two-way
communication capabilities would supplement
information transfer and increase reliability.
The occupant egress elevator further
addresses the needs of people with various disabilities by providing a means of egress they
can use with all other building occupants without outside assistance. By protecting all the
elevators, the normal design capacity of the
system would be sufficient for use by everyone, with the backup of the fire service access
elevators to help those who need it after suppression operations have begun. If additional
capacity were needed, the fire service could
press any occupant egress elevators into service under manual control.
Recognizing the potential benefits of protected elevators in federal buildings and
elsewhere, the U.S. General Services Administration (GSA) is providing funding that
supplements NIST’s investment in these activities and has agreed to incorporate such
systems in a future federal building as a
demonstration of the technology. NIST welcomes the opportunity to work with GSA to
advance technologies beneficial to government
workers and to the public.
Fire sprinklers and elevators

Rules relating to sprinkler installation in elevator shafts and machinery rooms have long
been a source of conflict, but there have been
significant efforts to coordinate the requirements of NFPA 13, Installation of Sprinkler
Systems, with those of ASME A17, Safety Code for
Elevators and Escalators.
The most notable took place following the
February 1991 Symposium on Elevators and
Fire, jointly sponsored by ASME, NFPA, and
the Council of American Building Officials. The
organizations established a code coordination
committee that met in late 1991 and 1992 and
reached several key points of agreement:
Summary of requirements

1. Sprinklers in Elevator Pits: It was agreed that
sprinklers in elevator pits are a good idea
because this is a likely location of fire due to the
accumulation of debris. Although the accumula-

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tion of water in the pit is a potential concern,
this concern can take place re ga rdless of
whether sprinkler protection is provided.
2. Sprinklers in Hoistways: It was agreed
that sprinklers are not necessary at the tops of
hoistways if the hoistway is noncombustible
and the elevator car is constructed in accordance with the flame spread and smoke
development requirements of ASME A17.1.
3. Sprinklers in Machine Rooms: It was
agreed that sprinklers may not be necessary in
an elevator machine room if it is located at the
top of a building and contains nothing other
than elevator equipment. It was further
agreed that concern over water discharge and
p ower-disconnect re q u i rements can be
addressed by requiring means to automatically disconnect the main line power supply to
the affected elevator upon or prior to the
application of water.
These points of agreement we re largely
adopted into the 1994 edition of NFPA 13
through a major rewrite of Section 4.5.5. The
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NFPA JOURNAL MARCH/APRIL 2006

NFPA 13 requirements have changed very little
since that time. Now contained in Section 8.14.5
of the 2002 edition of NFPA 13, the rules make
specific accommodations for elevators.
Pit sprinklers: Sidewall sprinklers are to be
placed within 2 feet (61 centimeters) of the
floor of an elevator pit, without regard to the
normal distances required below a ceiling. The
NFPA 13 Annex suggests placing the sidewall
sprinklers near the side of the pit below the
elevator doors and taking care to avoid interference with the elevator toe guard. The pit
sprinklers can be omitted for enclosed, noncombustible shafts that do not contain
combustible hydraulic fluids. Since sprinklers
at the base of the shaft are not expected to discharge onto operating components of the
elevator, they can be connected directly to the
building sprinkler system with no special valving or delay mechanism.
Hoistway sprinklers: Upright or pendent
sprinklers are required at the tops of elevator
hoistways, except noncombustible hoistways

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ELEVATOR CONTROL

for passenger elevators with car enclosure
materials meeting ASME A17.1.
Machine room sprinklers: The standard
has no special rules for elevator machine
rooms, except to require that machine room,
sprinklers and sprinklers at the tops of hoistw ays be of ordinary or intermediate
temperature rating. In other words, high temp e r a t u re rated sprinklers that would be
delayed in operation are not permitted. Sprinkler protection of elevator machine rooms is
expected as part of a complete sprinkler system since these spaces are not specifically
excluded from the need for sprinklers.
An Annex section in NFPA 13 discusses the
ASME A17.1 requirement that power to the
elevators be shut down upon or before the
application of water in elevator machine
rooms or hoistways, and suggests this can be
accomplished by a sufficiently sensitive detection system or by using devices that effect
power shutdown immediately upon sprinkler
activation, such as a waterflow switch with no
time delay.
The NFPA Committee on Automatic Sprinklers is now completing work on the next, 2007,
edition of NFPA 13. One of the proposals
accepted in this cycle allows the option of sidewall sprinklers at the top of hoistways rather
than upright or pendent sprinklers. A proposal
that would have required the hoistway sprinklers to be part of a preaction system was
rejected on the basis that there are other ways to
meet the ASME A17.1 requirements. Another
proposal would have eliminated sprinklers from
the elevator machine room under certain conditions of smoke detection, signage prohibiting
storage, and control of combustible contents, as
now permitted in the Commonwealth of Massachusetts. The Technical Committee rejected
this proposal on the basis that “buildings are to
be fully sprinklered which includes these types
of spaces. Storage can occur in these types of
spaces regardless of signage.” The Committee is
aware that reliance on housekeeping practices
has historically been an inadequate substitute
for complete sprinkler protection.
In the view of the fire sprinkler community,
the current rules represent a reasonable
a p p roach to elevator protection. Unfortunately, continued lack of consistency in the
application and enforcement of these rules can
create problems that go beyond the lack of
p rotection. Disagreements among multiple
authorities having jurisdiction for an elevator

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installation have led in some instances to lastminute changes in protection, with
consequences of improper valving, inadequate
protection against freezing, or other problems.
At the least, it is necessary that elevator protection issues be discussed at the project planning
stage. Ideally, those discussions will lead to
recognition that sprinkler protection in accordance with NFPA 13 is reasonable and proper.
Elevator smoke control

Deadly fires, such as the 1980 MGM Grand
Hotel and Casino fire8 and the 1988 First
Interstate Building fire,9 have shown that
unprotected elevators can provide a significant
path for vertical smoke movement from fires
through building.
Several factors, including the lack of sprinkler protection on the fire floor, elevator doors
that did not provide an effective smoke barrier,
as well as the combined effects of the natural
buoyancy of hot smoke and the stack effect,
resulted in smoke spread through the elevator
hoistways to upper levels. A properly designed
smoke management system could have helped
to mitigate smoke movement through the elevator shafts in these high-rise buildings.
Designers have several alternatives when
designing smoke management systems for elevator shafts10, including pressurize the elevator
hoistway; pressurize the elevator lobby; and
exhausting the fire floor, which creates a positive pressure in the elevator hoistway relative
to the fire floor.
Passive systems

These methods can be used individually or in
combination.
Pressurize Ho i s t wa y : Some jurisdictions
require hoistway pressurization when elevator
lobbies are not provided. In general, dedicated
supply fans are used to pressurize hoistways to
a minimum pressure 0.05 inches (0.13 centimeters) of water column. Since the elevator
machine room in cable elevators is open to the
hoistway through the cable sleeves, these
rooms can be pressurized along with the shaft.
Elevator doors are typically not tight-fitting
and tend to be a major source of leakage in the
shaft, as do vents. Doors and vents, as well as
other sources of leakage, must be accounted
for in the design.
In addition, the piston effect may need to be
considered if elevators are expected to be used
by responders or others during as fire event.

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49

Pressurize Elevator Lobby: If an elevator lobby is
provided, this lobby can be pressurized along
with the elevator shaft. A second design goal
for these types of system is that the opening
f o rce for the elevator lobby doors cannot
exceed 30 pounds (13.6 kilograms) at the latch
side when it is operating and the pressure
should not interfere with the opening or closing
of the elevator doors. This approach typically
allows smaller fans, since the leakage air is
lower, but a duct system is necessary to distribute air to the various floors.
Exhaust Fire Floor: Exhausting the fire floor
has a similar effect as pressurizing the hoistway
or lobby; however, these systems tend to be
larger, more costly and more complicated than
elevator pressurization systems. The goal of
this approach is to limit smoke to the fire floor.
Passive Systems: Smoke tight elevator hoistways and/or lobbies can be an effective means
of limiting smoke movement. If protected lobbies are not provided, doors on hold-open
devices or deployable smoke barriers can be
installed across the elevator doors to maintain
an effective smoke barrier. Given the effect i veness of quick-response sprinklers, the
requirement for smoke-tight separations is a
constant topic of debate.
Design considerations

When designing smoke management systems
for elevators, as well as other areas, it is helpful to understand the stack effect, a
phenomenon that occurs when there are temperature differences between the air outside
the elevator shaft and the air in the rest of the
building. Where the air outside the shaft is
cooler than the air inside it, buoyancy causes
the hot interior air to flow toward the top of
an elevator shaft, while air from the lower
areas of the building or outside the building
enters the shaft towards the bottom to replace
the hot air. This causes a general upward flow
that can help push smoke into the shaft.
When the temperature difference is reversed,
the opposite flow results.
Other design considerations include the piston effects, wind effects, and normal HVAC
effects that need to be taken into consideration.
As elevators travel up within the shaft, air from
within the top of the shaft is pressurized and air
in the bottom of the shaft is de-pressurized.
Pressures are reversed when elevators are moving down. Wind velocity may also influence the
design, as the wind will increase pressure on the
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NFPA JOURNAL MARCH/APRIL 2006

side being impacted by the wind and decrease
pressure on the downstream side of the building. Normal HVAC is typically shutdow n
during emergency operation. Klote11 describes
methods for accounting for the piston effect and
wind velocity.
Consideration should be also be given to
providing automatic sprinklers when designing these systems, as the 0.05 inches of water
column assumes that a large fire would not
occur within the space. Additionally, emergency power is necessary for required life
safety systems.
Although the design of smoke management
systems presents challenges, smoke management techniques can increase the level of
elevator safety in high-rise buildings. With the
recent discussions about the use of elevators
for evacuation, it is perhaps even more critical
to consider smoke management solutions for
elevators now than ever before.
Elevator sump pumps

Elevator sump pits are intended to keep water
away from the equipment at the bottom of an
elevator shaft if the hoistway fire suppression
system is activated. Just allow the water to
drain into the elevator sump pit, and the
equipment stays dry and functional. It’s as
simple as that. Or is it?
Anyone designing an elevator sump pump
system must consider not only removing discharged sprinkler water, but also preventing
any oil that has leaked from the elevator’s
hydraulic lift from entering the sewer system.
If the hydraulic system works properly, it generally releases only a small amount of oil. If
the system fails, however, a sizable volume
could be lost. This oil, combined with the volume of water discharged by one sprinkler,
provides a design challenge for the engineer.
In an effort to keep oil from leaking into their
sewer systems, some states are trying require
the design and installation of large sum pits
below elevator shaft floors from which water
may be pumped out and disposed of later.
Unfortunately, a blanket requirement mandating that a sump pit contain a pump is not
necessarily the right way to design the system.
Section 2.2.2.5 of the 2000 edition of ASME
A17.1 requires all elevator pits with Firefighters’ Emergency Operations (FEO) to have a
drain or sump pump. ASME A17.1 also
requires a connection to the emergency power
supply and protection of circuits to ensure that

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ELEVATOR CONTROL

accidental grounding or short-circuiting does
not occur after an emergency has begun.
Instead of a sump pump, an oil separator or
some other device can be used to remove oil
from the elevator shaft, thus preventing discharge into the sanitary sewer. However, an
oversized oil separator is a maintenance issue,
and an undersized oil separator will not
remove oil effectively.
Replacing the oil separator with a system
called an “oil minder” could help resolve the
issue. The oil minder concept relies on the fact
that oil floats on water. As water is pumped
from the bottom of the pit and the water level
falls, the oil minder’s sensing device detects
the oil and shuts off the pump, thus allowing
the water out and keeping the oil in.
This controversy has been a long time in
the making, but a blanket requirement to provide an elevator sump pump creates more
design issues than it solves.
Pros and cons of elevator door restrictors

When entering an elevator, most passengers
do not realize they have agreed to be securely
locked in that elevator cab until the car
reaches its destination. Should the elevator
lose power before reaching its destination, all
methods of self-evacuation are mechanically
prohibited. This applies equally to emergency
personnel and the public.
Door restrictors, which ASME A17.1
requires on passenger elevators, are mechanical devices designed to prevent a passenger
from opening the elevator car or hoistway
doors more than 4 inches (10.2 centimeters)
when the elevator car is outside the “unlocking zone.” ASME defines the unlocking zone
as “a zone extending from the landing floor
level to a point not less than 75 millimeters (3
inches) or more than 450 millimeters (18
inches) above and below the landing.”
The requirement for door restrictors was
implemented to pre vent passengers from
falling into an open hoistway underneath the
elevator platform while trying to evacuate
from an elevator that is stuck between floors.
Is this a real concern? Unfortunately, it is.
Picture yourself in an elevator that has
stopped 5 feet (1.5 meters) above the landing.
If you could open the elevator car door, you
would have access to the hoistway door interlock, which is typically easy to open from this
position. Once you opened the standard hoistway door, you would discover that you now

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had access to an opening 2 feet (0.6 meters)
high from which you could try to exit the elevator. What you wouldn’t be able to see is the
unprotected space underneath the platform
and platform guard. If you were to lower yourself backward from the elevator, your feet
would tend to push into the hoistway. If you
were to jump forward, you would risk falling
backward into the hoistway.
So why not lock passengers in the elevator?
Imagine being trapped inside an elevator that

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51

lost power only 19 inches (0.5 centimeters)
above a landing in the World Trade Center on
September 11, 2001. Or imagaine being an
emergency responder who found himself
trapped and unable to override the door
restrictor. This is not exactly farfetched.
In the attacks on the World Trade Center in
1993 and 2001, many people found themselves
trapped inside elevators. In 1993, there were no
door restrictors on the elevators. By September
11, 2001, however, about half of the elevators
had been retrofitted with these devices. On that
day, the few successful escapes that are known
to have taken place were from those elevators
that had not yet been equipped with the door
restrictor devices.
On May 18, 2004, Alan Reiss, Deputy
Director of Aviation at The Port Authority of
New York and New Jersey testified before the
9/11 Commission, saying “Another item that
should be looked at is the elevator code
requirement that door restrictors must lock
the elevator doors closed when the elevator is
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NFPA JOURNAL MARCH/APRIL 2006

not level with a landing. This is a requirement
of the current codes, and such devices were
being installed as elevators were modernized
at the World Trade Center. These devices are
meant to improve safety and prevent accidental falls into the shaft, but they have the
potential consequence of trapping individuals
in an elevator when it is stuck between floors,
preventing escapes such as took place in both
1993 and 2001.”
Recently, Northwest Territories in Canada
modified the CSA B44-04, Elevator Safety
Code, to allow extended platform guards as an
alternative to door restrictors in some cases.
Platform guards are sheet metal extensions
mounted directly from the car sill and supported to restrict hoistway access below the car
platform. The code modification to Requirement 2.15.9.5 states that “A platform guard
may be used as an alternative to the requirement set out in 2.12.5.1 if the platform
guard...is installed so that the hoistway opening space below the platform guard is limited

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ELEVATOR CONTROL

to not more than 250 milimeters (9.8 inches)
between the floor and the bottom of the platform guard, regardless of the location of the
elevator car when it is stopped.”
While this alternative certainly prevents
falling into the hoistway and allows for selfevacuation if necessary, the pit depth on many
existing elevators is insufficient to accommodate this extended guard length. In addition,
the platform guard does not prevent injuries
during the unassisted evacuation of an elevator that has stopped significantly above or
below the landing, other than the falling scenario described above.
So if power is lost while traveling in an elevator, how likely is it that you will be
prevented from getting out of the elevator? In
a building with the typical 10-foot (3-meter)
floor-to-floor height and a maximum unlocking zone of 18 inches (45.7 centimeters) above
and below the floor, the elevator car doors
will be mechanically restricted during 70 percent of the hoistway travel. The probability
increases to 95 percent where the minimum
unlocking zone of 3 inches (7.6 centimeters)
above and below the floor is employed.
In any case, there is a significant potential of
being locked in the elevator should there be a
loss of power. This is a fact of which most passengers, including the public and emergency
responders, are probably unaware.
Emergency operation overview

ASME A17.1, Safety Code for Elevators and Escalators, includes special provisions for elevator
operation during fire emergencies. These are
identified as Phase I Emergency Recall Operation and Phase II Emergency In-Car Operation.
Phase I Emergency Recall Operation is
used to take elevators out of normal service.
This prevents building occupants from going
to the fire floor and also makes the elevators
available for use by firefighters. Recall operation can be activated manually by firefighters
from the key-operated “FIRE RECA L L”
switch located at the designated level. Manual
activation causes the elevator(s) to return nonstop to the designated level.
Recall operation can also be activated automatically by the fire alarm system in response
to the actuation of specific fire alarm initiating
devices. These initiating devices are those
re q u i red at each elevator lobby, elevator
machine room, and elevator hoistway when
sprinklers are installed in those hoistways.

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The use of smoke detectors is required unless
environmental conditions require the use of
another type of automatic initiating device
such as a heat detector. Automatic activation
of recall operation causes the elevator to
return nonstop to either the “designated level”
or the “alternate level” as determined by the
building configuration and the location of the
first of these initiating devices to actuate. The
designated level is typically the level where
firefighters would normally arrive. The alternate level is used when the first initiating
device to actuate is located at the designated
level, either in the lobby or in the machine
room if it is located at the designated level.
Note that only these specific fire alarm initiating devices can activate recall operation. Fire
alarm signals from devices in other building
locations do not result in elevator recall.
Each elevator car is equipped with a special
visual signal (fire hat) that will illuminate when
Phase I Emergency Recall Operation is activated manually or automatically. This visual
signal remains activated until elevator operation is restored to automatic operation.
Once Phase I Emergency Recall Operation
has been activated and elevator cars have
returned to the appropriate level, Phase II
Emergency In-Car Operation can be activated.
Phase II operation is activated
manually by firefighters from the key-operated
“FIRE OPERATION” switch located in each
elevator car. Once activated fire fighters have
control of the elevator.
There is a potential that operation of the elevator could be adversely affected during a fire
event. To help warn firefighters of this potential,
the special visual signal (fire hat) used to indicate that activation of Phase I Emergency Recall
Operation is caused to illuminate intermittently
(flashing instead of steady illumination). The
trigger for this intermittent illumination is when
Phase I Emergency Recall Operation is activated automatically by a fire alarm initiating
device located in elevator machine room or
hoistway, since a fire in these locations could
impact the operation of the elevator. It should
be noted that when the visual signal is flashing,
Phase II Emergency In-Car Operation is still
permitted and fire fighters are allowed to continue using the elevator at there own discretion
based on their knowledge of the fire conditions.
ASME A17.1 also includes special provisions for automatic elevator shutdown when
elevator equipment is located where the appli-

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53

cation of water from automatic fire sprinklers
could cause unsafe elevator operation. The
use of heat detectors located in proximity to
the sprinkler heads is one means used to
achieve elevator shutdown. Heat detector
operation causes the main line power to the
elevator to be automatically disconnected.
This is typically referred to as “shunt trip”
due to the name of the mechanism used to
operate the main line power circuit breaker.
When elevator shutdown occurs the elevator
will stop in place due to the failsafe operation
of the elevator braking mechanism.
Because of the potential of entrapment associated with shunt trip operation, revisions
processed for the 2006 edition of ASME A17.1
will require the heat detectors used for shunt
trip to initiate Phase I Emergency Recall Operation and delay the removal of power and the
release of water to allow the completion of
recall. Note that if the elevators are already
operating on Phase II Emergency In-Car Operation, the recall operation will not occur, but
s h u t d own and water release will still be
delayed. If the elevator is on Phase II operation, the delay will allow the car to go to the
next selected floor. Once the car has stopped at
the floor all registered calls are canceled and
shunt trip will activate. As a warning to fire
fighters of the impending elevator shutdown,
the heat detectors used for this operation will
also cause the special visual signal (fire hat) to
illuminate intermittently. Note that in the case
of impending elevator shutdown, once the elevator car has stopped at a landing, it will
remain at the landing and car calls will not register. While the new shunt trip provisions
should greatly minimize the risk of entrapment,
it should be recognized that complete elimination of this risk may not be possible.
Elevators and the fire service

Although elevators normally operate flawlessly, they can fail. Their safe operation
should not be taken for granted.
In many jurisdictions, building owners test
Firefighters’ Emergency Operation (FEO)
monthly in accordance with Section 8.6.10.1
of the 2004 edition of ASME A17.1. And
authorities having jurisdiction over elevator
licensing requirements should also test FEO
regularly. In addition, those jurisdictions that
have adopted NFPA 1, Uniform Fire Code™,
should also be testing and assuring at each elevator has an FEO. Since fire fighters cannot
54

NFPA JOURNAL MARCH/APRIL 2006

be certain when F EO was last tested or the
quality of the inspection, however, they should
confirm that the elevator is operating properly
before using it during a fire.
An elevator’s FEO consists of a Phase I and
a Phase II.
Phase I is activated by the Phase I key
switch or by a fire alarm initiating device
(FAID). The FAIDs that initiate Phase I recall
are located at each floor the elevator serves,
typically in the elevator lobby; in the elevator
machine room; and in the elevator hoistway,
when required. When Phase I is activated, the
elevator ceases normal operation, illuminates
the fire fighter helmet pictograph, and returns
the elevator non-stop to the designated level
or, if the FAID initiating Phase I is on the designated level, to an alternate landing. This
keeps the public from taking an elevator to the
fire floor and renders the car call buttons, corridor call buttons, and automatic door
reopening devices inoperative.
Once recalled, the elevator will not operate
until it is reset or the Phase II switch located in
the elevator is placed in the “on” position.
Upon arrival at a fire, fire fighters should
confirm that all elevators have recalled to the
designated or alternate recall floor. This can
normally be done from the fire control room.
If the elevators have not been recalled, they
should be recalled manually using the Phase I
key switch in the fire control room. If an elevator does not manually recall, fire fighters
must search for it to confirm that no one is
trapped inside or above the fire floor.
When a fire occurs at the elevator’s designated recall landing, the elevators may
automatically recall to an alternate floor. Once
at the alternate floor, the elevator can still be
recalled manually to the designated landing by
activating the Phase I key switch in the elevator lobby or, when applicable, by activating
both the Phase I key switch in the elevator
lobby and the key switch in the fire control
room. The Phase I key switch in the elevator
lobby should only be activated when fire fighters know that the designated level is safe.
Before using the elevator, fire crews should
check the hoistway for fire, water, or smoke
and make sure the helmet pictograph is not
flashing. In newer elevators, the flashing pictograph indicates that the elevator may
malfunction and possibly trap the fire fighters
in the elevator. After checking the hoistway
and pictograph, the Phase II key switch must

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ELEVATOR CONTROL

be placed in the “on” position.
Before traveling to an upper floor, fire fighters must test the “door open” and “door
close” buttons to confirm that they operate
properly. Both buttons require constant pressure in Phase II operation and must be
depressed until the door is completely closed
or opened. If the button is released before the
doors are fully closed or open, they will automatically reverse direction.
Once the doors have been tested, a floor
can be registered. While traveling to the
selected floor, fire fighters should depress the
“call cancel” button to ensure that all car calls
cancel and the elevator stops at or before the
next available landing. Before leaving the elevator, fire fighters should test the “hold”
position of the Phase II key switch to confirm
it is operating properly.
ASME A17.1 requires all equipment necessary for the operation of Phase II to be located
in the main car-operating panel behind a
locked cover, labeled “Firefighters’ Operation,” that can be opened with the fire service
key. ASME A17.1 also requires a “run/stop”
switch behind the cover that will cancel all
registered calls and cut power to the elevator
when placed in the “stop” position.

more be equipped with a feature that, when
initiated, will return the elevator to the main
floor or another designated floor of the building. This feature is commonly referred to as
Phase I Emergency Recall Operation and can
be started with a key-switch or by a fire alarm
initiating device.
Beginning in 1981, ASME A17.1 further
required all automatic elevators with Phase I
Emergency Recall Operation to be equipped
with a feature that allows fire fighters or other
authorized personnel to operate the elevator
during an emergency from within the car. This
feature is commonly referred to as Phase II
Emergency In-Car Operation.

Training

One of the most reliable methods of
ensuring that elevator equipment will function
correctly is to verify that it has been properly
maintained and inspected. ASME A17.1
requires that the Phase I Recall of all elevators
with FEO be tested monthly using the lobby
key switch and that the Phase II Emergency
Operation be tested a minimum of a one-floor
run. Deficiencies found during the monthly
testing procedure must be corrected.
A record of the test results, usually in the
form of a test log located in the elevator
machine room, must be made available to elevator personnel and the authority having
jurisdiction. A sample monthly fire service test
log may be downloaded without charge at
www.naesai.org.
Many elevator inspection agencies train fire
service personnel how to use the Phase I and
Phase II Emergency Recall Operation. If such
training is not available, however, fire fighters
can follow some basic instructions to ensure
that the Phase I and Phase II features are operating properly:
To recall the elevators, fire fighters should
insert the key into the designated level key-

To prevent injuries and deaths, every fire
department should develop, implement, and
strictly enforce of standard operating procedures that specifically address elevator use
during fires. Every fire fighter and fire inspector should be trained to operate FEO,
including Phase I and Phase II, emergency
power activation, and fire fighter self-rescue.
Fire fighters, fire inspectors, and building
owners must become familiar with the codes
specific to elevator FEO. They must be diligent about testing and inspecting its operation
and take time to research and implement an
elevator-training program. Not only will this
increase the reliability of the elevators, but it
might save the life of a fire fighter.
Emergency operation on an elevator

In the event of a fire, the Firefighters’ Emergency Operation (FEO) on an elevator may
prove invaluable in controlling the fire and
safely evacuating the building.
Since 1973, ASME A17.1 Safety Code for Eleva t o rs and Es c a l a t o rs, 12,13 has re q u i red that
elevators travelling 25 feet (7.2 meters) or

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One of the most reliable
methods of ensuring that
elevator equipment will
function correctly is to verify
that it has been properly
maintained and inspected

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55

operated switch, turn the switch to the “on”
position, and remove the key. All elevators
should return to the designated level and park
with the doors open. Then the fire fighters
should enter the elevator and push a car button to ensure that the elevator will not leave
the floor.
Once this has been verified, the emergency
responders can initiate Phase II by inserting
the key in the key-switch, turning the switch
to the “on” position, and verifying that the
key can be removed when the switch is in that
position. The responder can then press the
desired floor button. If more than one floor
button is pressed, the elevator will travel to
the first available floor and all other floor calls
will be cancelled.
To cancel the floor selection, the responder
can press the “Call Cancel” button. The elevator will go to the next available floor, and
the doors will stay closed until the next step
has been initiated.
Once the car has arrived at the floor, the fire
fighter should press and hold the “door open”
button to open the car door. If the button is
released before the doors fully open, the doors
will close. This allows the doors to close immediately if there is a fire or smoke at that floor.
To hold the car at the floor once the doors
have opened, fire fighters can turn the key in the
car to the “hold” position and remove the key.
This will ensure that the car will stay at the landing until Phase II is initiated again or the in-car
switch has been turned to the “off” position.
To close the elevator door, fire fighters can
press and hold the “door close” button. If the
button is released before the doors are fully
closed, the doors will reopen.
Finally, to return the car to the recall floorturn the Phase II key to the “off” position.
The car doors will close automatically, and
the elevator will return to the recall floor.

PostScript Picture
Logo flame only

tors), ISO/TR 16765:2002(E), International
Organization for Standardization, Geneva,
Switzerland, 2002.
5. NFPA 101®, Life Safety Code®, 2000, National
Fire Protection Association, Quincy, MA.
6. Quiter, J. R. Application of Performance
Based Concepts at the Stratosphere Tower, Las
Vegas, Nevada. Rolf Jensen and Associates,
Inc., Deerfield, IL. Fire Risk and Hazard Assessment Symposium. Re s e a rch and Pr a c t i c e :
Bridging the Gap. Proceedings. National Fire
Protection Research Foundation. June 26-28,
1996, San Francisco, CA, 118-126 pp, 1996.
7. Vertical Transportation Handbook,
George R. Strakosch, Editor, John Wiley &
Sons, Inc., New York, New York, 1999.
8. Best, R. and Demers, D., Investigation
Report on the MGM Grand Hotel Fire, Las
Vegas, Nevada. Revised Report, Jan 1982.
NFPA, Quincy, MA, 1982.
9. Isner, M. and Klem. T., Fire Investigation
Report: World Trade Center Explosion and
Fire, New York, New York, February 26.
NFPA, Quincy, MA, 1993.
10. NFPA, Recommended Practice for Smoke-Cont rol Systems, (NFPA 92A), National Fi re
Protection Association, Quincy, MA, 2006.
11. Klote, J., Principles of Smoke Management (NFPA 92B), American Society of
Heating, Refrigeration, and Air-Conditioning
Engineers, Atlanta, GA, 2002.
12. ASME A17.1-2004 Safety Code for Elevators and Escalators: Section 2.27—Emergency
Operation and Signaling Devices
13. ASME A17.2-2004 Guide for Inspection of
Elevators, Escalators, and Moving Walks.
About the authors
RICHARD W. BUKOWSKI P.E., FSFPE is Standards
and Codes Coordinator for the Building and Fire
Research Laboratory of the National Institute of Stan-

56

Endnotes

dards and Technology and Senior Engineer in the

1. S afety Code for Elevators and Escalators,
ASME A17.1-2000, American Society of
Mechanical Engineers, New York, 2000.
2. Guide for Emergency Personnel, ASME A17.41999, ibid
3. Fire Precautions in the Design, Construction,
and Use of Buildings, BS 5588 Part 5 1991, Code
of Practice for Firefighting Lifts and Stairs, British
Standards Institution, London.
4. Comparison of Worldwide Lift (elevator)
Safety Standards – Fire fighters Lifts (eleva-

Integrated Performance Assessment Group. Mr.

NFPA JOURNAL MARCH/APRIL 2006

Bukowski is very active within the U.S. and international
standards communities. He is a member of the Standards Council of the National Fire Protection
Association, which is the body that administers the
NFPA's standards development process and issues all
NFPA documents. Mr. Bukowski is Coordinator of the
International Council on Building Standards and Documentation (CIB), Working Commission 14: Fire, and is
active in the work of CIB TG37: Performance-based
Building Regulatory Systems and CIB TG50: Tall Build-

WWW.NFPAJOURNAL.ORG

ELEVATOR CONTROL
ings. He was appointed by ANSI as U.S representative

for the World Trade Center assessment.

to ISO TAG8, which advises the ISO Technical Management Board and provides oversight to all ISO Technical
Committees working in the building and fire areas. He is

CHRIS DUKE is the owner CNY Elevator Consultants in

a member of the NFPA, member of the Research Sec-

Syracuse, New York. He is a member of the A17.1

tion, Building Fire Safety Systems Section, and

Repair, Renovation, and Replacement Committee and

Education Section, a Fellow of the Society of Fire Pro-

the A17.1 Existing Installations Committee.

tection Engineers, and is a licensed Professional
Engineer in the states of Illinois and Maryland.
DEBBIE PRINCE is a Code Specialist employed with
Motion Control Engineering, Inc. since March 1987;
RUSSELL P. FLEMING, P.E. is the executive vice-pres-

she’s a member of A17 Electrical and Emergency Oper-

ident for the National Fire Sprinkler Association and a

ations committees.

member of several NFPA technical committees including the NFPA 13 technical committee. He is also a
regular columnist for the NFPA Journal® and a former

JILL DIRKSEN is the Managing and Technical Director

member of the NFPA Board of Directors.

for the American Society of Plumbing Engineers. Prior
to her employment with the association, she worked at
Albert Kahn Associates in Detroit, Michigan. She has

JEFFREY TUBBS, P.E. is an Associate Principal and

held many board positions on local ASPE chapter level

staff group leader of their Westborough, MA office. Jeff

and serves as Co-Chairman on the ASPE standard com-

has a broad range of experience with unique projects;

mittee for Hot Water Temperature and Control.

he has focused upon providing innovative, pragmatic
solutions in the context of both prescriptive and performance codes throughout the U.S. and internationally.

LEE F. RICHARDSON is a senior electrical engineer at

Jeff holds positions on various fire and life safety com-

NFPA where he is responsible for several standards,

mittees, including secretary of ASHRAE TC5.6: Control

which include NFPA 72®, National Fire Alarm Code®. He

of Fire and Smoke, and member of the NFPA smoke

is also the co-editor of the National Fire Alarm Hand-

Management committee (Responsible for NFPA 92A,

book and a member of the ASME A17.1 Emergency

92B and 204) and the Assembly Occupancy Commit-

Operations Committee. He is also a frequent contributor

tee, and an alternate member on ICC’s Code

to the NFPA Journal.

Technology Committee. Jeff led Arup’s efforts to assist
the NIST’s National Construction Safety Team investigation of the February 20, 2002 fire at the West Warwick

DAVE BESTE is a Lieutenant at the Bellevue, Washing-

Station Nightclub with egress issues.

ton, Fire Department and a former Elevator Constructor.
He is a member of the ASME A17.1 Emergency Operations Committee, an affiliate member of the

CHRISTOPHER MARRION, P.E. is an Associate Princi-

International Association of Fire Chief’s (IAFC) Fire and

pal with Arup in their New York City office, where he

Life Safety Section, and has developed and instructs

leads the N.Y. Arup Fire group. Chris has worked for

Elevator Safety and Rescue for Fire Fighters.

various fire engineering consulting firms in the United
States, United Kingdom, Hong Kong, and Europe for
the last 15 years. He has been involved with various

DOTTIE STANLASKE is the Executive Director for

committees in the fire industry, including SFPE/NIST—

NAESA International (National Association of Elevator

National R&D Roadmap for Fire Safety Design And

Safety Authorities). In her role of Executive Director, Ms.

Retrofit of Structures Workshop—Steering Committee;

Stanlaske represents NAESA at various national and inter-

New York City Department of Buildings—New NYC Bldg

national codes and standards, and industry association

Code Committees for Egress and Fire Protection Sys-

meetings,including the ASME A17 Elevator and Escalator

tems; SFPE Performance-Based Design

Safety Code Committees, and the International Standards

Committee—Steering Committee; SFPE Design Basis

Organization, ISO Technical Committee 178. She is a vet-

Fires Committee—Chair; ICC/SFPE Enforcer’s Guide to

eran of the elevator industry having held positions of

Performance Based Design Review; and NFPA 72,

increasing responsibility in labor, supervision and manage-

Appendix B—Engineering Guide for Automatic Fire

ment for Beckwith and Otis Elevator companies. She is

Detection—Chair. Chris was also a member of the

also a former elevator inspector for various states includ-

FEMA/ASCE Building Performance Assessment Team

ing Massachusetts and Washington.

WWW.NFPAJOURNAL.ORG

NFPA JOURNAL MARCH/APRIL 2006

57

Appendix K
Emergency Egress Strategies for Buildings

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Emergency Egress Strategies for Buildings
Richard W. Bukowski, P.E., FSFPE
NIST Building and Fire Research Laboratory
Gaithersburg, Maryland 20899 USA
INTRODUCTION
The primary strategy for the safety of building occupants in emergencies
(especially fires) is by facilitating their relocation to a safe place. In other than a few
institutional occupancies (health care and detentional) this generally involves the use of
stairs as part of a protected means of egress (MOE) for vertical evacuation. For tall
buildings with large populations, providing sufficient stair capacity for simultaneous
egress has been considered impractical by code making organizations, so the strategy of
phased evacuation has been employed. To this point in time, little attention has been paid
to the special needs of people with disabilities and other (permanent or temporary)
physical limitations in moving on stairs.
In the aftermath of September 11, 2001 new attention is being paid to many issues,
especially emergency egress from tall buildings. A number of experts have called for a
fundamental rethinking of egress strategies including all of the possible components that
might be employed. In September 2006 a workshop was organized in Atlanta by CIB
W14:Fire and TG50:Tall Buildings, with one of the discussion topics devoted to this
issue. This paper is intended to continue that discussion.
PERFORMANCE METRICS FOR EGRESS
In performance design, the usual performance metric for egress systems is that of
timed egress analysis. Here a range of calculation methods from simple hand
calculations to sophisticated computer simulations that may include behavioral rules of
human interaction are used to estimate the Required Safe Egress Time (or RSET). Fire
models or calculational methods estimate the time available before escaping occupants
are exposed to untenable conditions, Available Safe Egress Time (ASET) and as long as
RSET is less than ASET, safety is assumed to be achieved.
A problem is that the design parameter for means of egress in regulation is that of
capacity. MOE components are rated by the number of people (total) per unit width.
Thus there is no direct connection between regulatory design requirements and the
critical performance metric of egress time. A detailed discussion of the basis for egress
systems design in regulation can be found in Bukowski and Kuligowski 1 .
COMPONENTS OF A MEANS OF EGRESS
A MOE consists of an exit access (normally a common use corridor leading to the
exit), the exit itself (normally a stair), and an exit discharge (normally a door to the
outside or into a protected corridor leading to the outside). Egress stairs may incorporate

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areas of rescue assistance which are part of enlarged landings providing space for people
(especially with disabilities) to move out of the flow to rest or await assistance. Egress
stairs may also incorporate transfer corridors that are used to shift the vertical alignment
of the stair horizontally, to go around equipment or to maintain minimum required stair
separation at floors where the building floor area changes.
This separation into a horizontal travel component on the originating floor, a vertical
component to travel from the originating floor to the level of exit discharge (or other safe
location), and a horizontal component to travel to the building perimeter would be
common to any egress system. Further, the horizontal components are unlikely to be of a
length that an occupant would require more than a few minutes to traverse, so any
improvements to them would be unlikely to provide any significant impact on overall
performance of the MOE, although their reliability might be improved.
STAIRS
Stairs are the primary means of vertical travel during fire emergencies and are
generally effective and reliable, but with several significant shortcomings. Most building
regulations require at least two independent stairs so that a single event cannot block
access to both. This independence comes from the location of the stairs remote from
each other. In some locations scissor stairs (two, intertwined stairs in a common shaft)
are popular since they minimize the building space required. The disadvantage is that
they are not remote and can both be easily compromised by openings in the separating
partition. However, when counted as a single stair they provide additional stair capacity
in a better configuration than a single, wider stair since there is better access to handrails
as people descend.
Another shortcoming of stairs in high rise buildings is that standard firefighting
procedures involve the designation of one of the stairs as the attack stair, in which the fire
hose is extended to permit its advance onto the fire floor. Once the hose is extended in
the stair and charged with water it is nearly impossible for occupants to pass from above.
Further, once the door to the fire floor is opened to advance the hose, smoke may enter
the stair and contaminate the floors above. Thus it may be necessary to delay firefighting
until all occupants clear the stair above the fire floor.
This was observed in the fire in the 52-story Boston Prudential Center on January 2,
1986 2 . The fire began on the 14th floor while the floor was undergoing a tenant fitout
with an estimated 1500 occupants in the building. The 14th floor door to stairway B
failed early in the fire, permitting smoke and fire to make this stair untenable above the
12th floor. This left only stair A for both occupant egress and fire attack. The fire
department could not begin to attack the fire until evacuation was complete – about one
hour. The fire severity was somewhat limited by the fact that the fire floor was
unfinished and the fuel consisted primarily of stored construction materials. If the fire
floor door to stair A had also failed, any remaining occupants above the fire would have
been trapped.

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A conservative estimate of the time needed for most occupants to descend undamaged
and smoke-free egress stairs is about one floor per minute a . But a growing proportion of
the population has difficulty in traveling on stairs and a small number of people cannot
use any stairs without assistance. In general, the number of people who have difficulty
with stairs increases with building height. These people include those with obvious
mobility impairments (wheelchair, walker, and crutch users) but increasingly include
people with respiratory or cardiac conditions, obesity, and those with temporary
conditions ranging from pregnancy to sprains.
Today there are buildings under construction and planned where stairs are impractical for
anyone in the upper reaches of a building 250 to 350 floors in height. For stairs used as a
means of egress in fires, the record has been very good but not without incident. The
most frequent problem is contamination of a stair by smoke due to a door not closed or to
(usually pre-existing) breaches in the stair enclosure. Stair enclosures compromised by
the initiating event (as was the case at the World Trade Center in both the 1993 and 2001
attacks) are rare, but stair enclosures are only required by regulation to exhibit fire
resistance, with no requirements for structural integrity nor impact resistance. Such
requirements are only now being considered in response to NIST’s WTC
recommendations 3 . For example, New York City has adopted a building code
requirement 4 for egress stair enclosures to comply with level 2 performance for impact
resistance under ASTM C 1629 5 .
As mentioned above, any stairs represent significant challenges for some people with
disabilities. With some conditions, a person’s wheelchair provides critical life support
and the person may not survive for long if separated from it. Such chairs are usually
quite heavy and difficult for even several people to carry down stairs. Evacuation chairs
that can be used to convey many wheelchair users or others with mobility limitations
down stairs cannot accommodate these life support devices. These evacuation chairs or
even just the physical support of another can allow some people with disabilities to
traverse some stairs, but this requires people willing to assist, is fatiguing if the distance
traversed is long, and can slow the flow of people in the stair. All these shortcomings
need to be considered when determining RSET.
The most detailed studies of flow on stairs were performed by Templar in 1975 6 and
influenced the regulatory requirements still in place today. Although Templar found that
the current 1100 mm (44 in) minimum stair was “adequate,” a 1400 mm (56 in) stair was
“preferable.” Recently Pauls 7 has challenged the applicability of these to modern society
due to the increased trend to obesity and lower stamina. Larger people need more stair
width to maintain the same flow, move more slowly, and are capable of traversing fewer
flights of stairs before resting. Pauls’ hypothesis is supported by recent studies of drills8
and fire evacuations 9 showing travel speeds down stairs decreasing to a quarter of what
was observed in Templar’s work. Since the costs to the owner in lost rent over the life of
a

Reported flow rates down stairs are often in the range of (20 to 30) seconds per floor but can slow as
building height increases. Rates of 50 seconds per floor were reported in the 2001 World Trade Center
evacuation. Ambiguity of cues, debris in the stairs, or the presence of impaired occupants can slow flows
even further. Thus a rule of thumb estimate of one minute per floor is reasonable.

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the building for space used by wider stairs can be very high, even significant construction
costs of alternate approaches to these problems may be cost effective.
Recently, proposals have been submitted to both US model building code organizations
to increase the minimum width of required egress stairs from 1100 mm (44 in) to 1400
mm (56 in) where the stair serves a cumulative occupant load of more than 2000
people 10 . The US General Services Administration estimated that the cost of
construction of this wider stair is increased by about 21 %, and that the cost in lost rental
of the space occupied by the wider stair is $250 000 to $500 000 per year for a 50 story (2
stairway) office building, depending on geographic location 11 .
CORE ARRANGEMENT
Most tall buildings are designed with a core area which contains the elevators,
stairs, and shafts in which the utilities run vertically through the building. The core
usually serves as the building’s spine and often plays a significant role in the structural
system. Because the core is most often infrastructure and common use space it is less
likely to generate revenue for the owner. The designers spend a great effort to “optimize”
the core design, meaning to make it as small as possible, maximizing the revenue
producing space on each floor.
The exit access is generally arranged just outside and surrounding the core, with the
stairway doors facing outward and cross corridors providing access to elevator lobbies.
This exposes the exit access to the exterior of the building, protected only by any
partitions that may provide for separation of spaces. In its new 7 World Trade Center 12 ,
the architects (SOM) moved the exit access to the center of the core such that the
(reinforced concrete) core protects the access corridor and creates a refuge area on each
floor. While this makes the core larger the protected space can shelter the floor
occupants from external, natural and man-made hazards with direct access to the stairs
and elevators. The cost-benefit of such arrangements needs to be examined.
An aspect of egress system design associated with the arrangement of the core is
remoteness. Buildings are required to have at least two, independent exits, separated by a
minimum distance; usually not less than one third of the diagonal dimension of the space
served. Remoteness is intended to ensure that no single incident can block access to both
stairs. Some regulations permit the separation distance to be measured along a walking
path between exits, which can allow exits to be adjacent but separated by a perpendicular
wall of at least half the required dimension in length. If the initiating event compromises
this wall, the remoteness is defeated.
OCCUPANT EGRESS ELEVATORS
Elevators are the normal means of vertical transport in any building taller than a
few stories. However during fires, the safety of elevators can be affected by the fire itself
and by water from sprinklers and fire hoses, so the policy worldwide is not to use

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elevators during fires. Elevators are also taken out of service during earthquakes when
the lateral acceleration exceeds a level that might compromise further safe operation.
In the 1980’s the elevator industry developed Firefighters Emergency Operation (FEO)
that is now required in building regulations worldwide. In FEO, detection of smoke in
the elevator lobby on any floor or in the machine room results in the elevators being
immediately recalled to the designated landing (generally the level of exit discharge) and
taken out of service. The responding fire brigade can use a special key to re-activate
individual cars to be driven manually by a firefighter. In this mode, hall calls are
ignored and the in-car controls operate somewhat differently to provide enhanced safety.
Most regulations permit the fire brigade to use elevators being driven by a firefighter to
be used to assist people with disabilities in evacuation.
While there are currently no regulations that generally permit occupant egress elevators
there are a growing number of systems being approved worldwide under performancebased or alternate solutions provisions. Much of this recent acceptance is associated with
an intensive effort in the US by NIST, the American Society of Mechanical Engineers
(ASME) and the elevator industry to develop requirements for occupant egress elevators,
as documented in a number of publications 13, 14 , 15 .
The prospect of using the elevators for occupant egress in fires is being enthusiastically
embraced by building owners, designers, and regulators for several reasons. First, it
permits the location of assembly occupancies (bars, restaurants, and observation decks)
on upper floors of tall buildings without the building-code-mandated penalty of larger
stairs running the full height of the building to accommodate the occupant load. This is
premium space based on the views available from the top. An example is 30 St. Mary
Axe in London, which incorporates a bar and restaurant on the top floor and protected
elevators running between the assembly space and street level. Second, egress elevators
directly address the needs of people with disabilities for self-evacuation. Developers of
high-rise condominiums for the elderly see egress elevators as a significant marketing
advantage. An example is Petronas Properties in Kuala Lumpur and Marriott Corp. in the
US, both of whom are developing high rise condominium properties marketed to older
residents. Third, integrating egress elevators into the evacuation procedures of very tall
buildings has a very significant impact on total egress times. An example is Taipei 101
where the total evacuation time was reduced from 2 hours to 57 minutes when elevators
were incorporated into the evacuation plan16 .
FIRE SERVICE ACCESS ELEVATORS
While fire service access elevators are not a part of the means of egress they do
have a significant impact on occupant egress in tall buildings. For any building of
sufficient height that egress has not completed before the fire service begins to move into
position to begin operations, there is a conflict between occupants leaving and firefighters
entering resulting from counterflow in the stairs. NIST studies of the WTC evacuation
and of drills in federal buildings indicate that counterflow has little effect on occupant
evacuation but significant impact on fire service access, delaying the start of operations

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and separating firefighting teams. Transferring fire service access to protected elevators
eliminates counterflow along with numerous additional advantages to operational
efficiency 17 .
It should be noted that the use of fire service access elevators does not eliminate the issue
of the fire department taking over an attack stairway which is then blocked for occupant
use from above by the charged hose. This would still occur because the fire attack would
still be made from the stair – however the impact is greatly lessened if the occupants are
using elevators for egress or if there are additional stairs.
ELEVATOR EGRESS STRATEGIES
When incorporating elevators into fire evacuation it is important to exploit their
strengths while protecting their weaknesses. The typical design metric for elevators in a
modern high rise commercial building is to provide sufficient car capacity and speed to
be capable of moving 10 % of the total population of the building in 5 minutes during
peak times at the start and end of the work day. Thus, any high rise building is able to
move its entire population by elevators in one hour or less with the elevators provided for
normal use.
Elevators are most efficient when operating in shuttle mode (avoiding time needed for
accelerating and decelerating smoothly). Further, it makes sense to use the elevators to
move those with the longest distance to go, first. Occupants of lower floors (without
disabilities) have a choice to use the stairs. Another consideration is that it is unlikely
that any large building will initiate a complete evacuation on an automatic alarm due to
the potential for significant business disruption without cause. But there is recent
experience with occupants of large buildings initiating a full scale evacuation on their
own if they suspect something is wrong in their building. This and other issues are being
studied in a survey of high rise building occupants attitudes regarding building
evacuation 18 .
Thus, an elevator evacuation protocol is likely to begin with an initial alarm summoning
the fire department and taking the designated fire service elevator out of service to await
fire department arrival at the designated landing. The remaining elevators will go into
evacuation mode where they collect occupants of the fire zone (fire floor and two floors
above and below) to shuttle them to the level of exit discharge. The elevators would then
wait at the designated level for a decision by the incident commander for partial or
complete evacuation or for a return to normal service. Waiting at the designated level
prevents arriving people from taking the elevators to upper floors during the fire.
A decision for total evacuation would initiate a second phase of the evacuation protocol
where the elevators would collect occupants from the highest floors first, shuttling them
to the level of exit discharge and returning for another load, working their way down
from the top. Hall calls would register people awaiting pickup but would not alter the
sequence. People with disabilities would not be given any priority since all occupants are
accommodated equally in this system.

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Enclosed lobbies on every floor would provide a protected space in which to wait and
serve to protect the hoistway from smoke/fire (delaying the initiation of Phase I recall)
and from water intrusion from sprinklers or hose streams. Real time signs in every lobby
would report system status in real time including how long before cars would arrive to
evacuate that floor. The signs at the level of exit discharge would warn not to enter as the
elevators are in evacuation mode. Conditions in the lobbies and machine room would be
monitored in real time from the incident command. Once staging is completed, the fire
service elevator can be used to pick up the injured or stragglers. All of this can be
accomplished with commercially available systems.
REFUGE FLOORS
In several Asian countries (China, Singapore) tall buildings must be provided with
refuge floors every 20 to 25 floors. These are usually mechanical floors (no normally
occupied space) with at least 50 % of the floor area configured as an area of refuge (2-hr
separations to equipment spaces, no fuel load, space to hold all occupants of the floors
between refuge floors at 0.3 m2 or 3 ft2per person). They are required to be open on two
opposite sides so that smoke will not accumulate. Refuge floors provide a protected
space for occupants to rest or to await assistance, or to cross between stairways 19 .
Requirements for refuge floors are relatively new and are currently found in only a few
buildings. No real evacuations have occurred but there is some experience from drills
that indicates there may be a problem when people reach a refuge floor and decide to wait
there rather than continuing the evacuation20 . Occupants accumulate on the refuge floor
such that additional arriving occupants cannot enter. This may be an artifact of a drill
where the occupants know they are not in danger and that they will be returning to their
floor after the drill. Also, a study using cfd models showed the open sides could permit
smoke to enter from an external fire plume originating on a lower floor 21 . Recent
revisions require drencher systems on the open sides.
The World Financial Center currently under construction in Shanghai incorporates refuge
floors and also utilizes two observation elevators running on the outside of the super
columns on diagonal corners of the building. These elevators were originally designed to
provide express service only to the observation deck on the top floor. These observation
elevators were modified to stop at each of the refuge floors to be used for occupant egress
in fires. Thus the furthest an occupant would need to travel in the stairs is 25 floors (13
floors if procedures were to suggest using the closest refuge floor even if it was above
your position). Occupants not capable of using the stairs to reach a refuge floor would be
picked up by a firefighter driving an interior elevator under FEO.
ACTIVE EVACUATION MANAGEMENT
Increasingly, experts are saying that occupant evacuation proceeding during fire
department operations should be actively managed, since those operations can result in
risks to occupants due to changing conditions. This was seen in the Cook County office

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building fire 22 and others where suppression operations make the attack stairway
untenable above the fire floor. Such active management involves monitoring in real time
to identify conditions that require a modification to the evacuation, and a means to
communicate instructions.
Monitoring would likely involve the installation of video cameras in the stairways (one
proposal submitted to the ICC in the US is for cameras every five floors). Some concerns
have been raised about the workload of monitoring all these cameras. With modern
security cameras and software it is unnecessary for a person to monitor the images. The
software monitors the image and, as long as there are people moving down the stairs the
image is in background. Should there be no people or no movement for a preset time the
image is brought forward for the operator. This would allow rapid identification of
blockages without undue distraction. These cameras can also identify smoke in the stair
which would require redirection of occupants through the voice communication systems
already present under current codes.
COMMUNICATION SYSTEMS FOR EGRESS MANAGEMENT
Since the early 20th Century fire alarm systems have been provided in buildings to
notify occupants of the need to evacuate. Once the alarm was sounded there was no
further need for communication since the action was simply to leave the building as
quickly as possible. This changed in the mid-1980’s when phased evacuation was
introduced for tall buildings where the egress system could not support simultaneous
evacuation. It was felt that where occupants were asked to wait for their turn to evacuate,
it is necessary to provide a means of making pre-recorded and live, voice messages until
the evacuation was complete. This communication was carried out from a fire command
center specifically arranged for the fire department to conduct incident command.
New York City adopted Local Law 5-1973 which required voice communication systems
for new, high rise (defined as exceeding 100 feet or 30.5 m in height) office buildings and
extended this requirement to new mercantile and all high rise hotel occupancies through
Local Law 16-1984. In the U.S., the National Fire Protection Association’s Technical
Committee on Protective Signaling Systems developed NFPA 72F (High Rise Voice
Communication Systems, which was published in 1988 and then incorporated as a
chapter in the consolidated National Fire Alarm Code, NFPA 72 (1993 and subsequent).
Total evacuation of tall buildings has been a rare event, but as society becomes more risk
averse we may find that it occurs more frequently. Also, fire is not the only condition
that might trigger a total evacuation. Severe weather, chemical spills, earthquakes, major
water leaks, workplace violence, and large-scale power outages are only some of the
conditions that have led to building evacuations. In some cases the emergency action is
to shelter within the building, which may involve some relocation. The complexity of
getting occupants to take the desired action makes an even stronger case for
communication systems and proactive evacuation management.

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Human factors research clearly shows that people will generally make the right decisions
when provided with the (clear and unambiguous) information upon which to base those
decisions 23 . Events such as the 1993 and 2001 World Trade Center evacuations as well
as evacuations and drills carried out in other tall buildings show the range of things that
can go wrong when evacuating large number of people. These all demonstrate the need
to actively manage evacuations, including monitoring the process to identify problems,
and communications systems to give directions that resolve these problems.
Today, emergency communication systems are common, even in smaller buildings.
These initially provide to specific areas (individual floors or fire zones, stairs, and
elevators) or to the entire building, pre-recorded or digitally generated voice instructions
initially, and the ability for the incident commander to issue live instructions during the
incident. Current discussions include the provision of cameras in refuge areas and stairs
to provide the incident commander the ability to monitor the evacuation process and to
quickly identify problems. To reduce monitoring workload these would be arranged to
only display their image if the system detected no people or people not moving in the
stairs, or if a call were placed from the location to the command center.
Dynamic signs are being discussed to provide textural information in real time. These
could display the time before elevators arrive at a given floor as part of an elevator
evacuation system, or to give directions at key points in the egress system on which
direction to go. Such dynamic signs have been installed in the new WTC 7 building on
the transfer floor, within the egress stairs to instruct occupants on which street exits to
use. These signs can display any messages entered from either the fire command or
security center of the building.
Another experimental information system developed by the US General Services
Administration is a text pager that is issued to any hearing impaired occupant and
available to hearing impaired visitors at the security desk. This system can display
messages and instructions in real time during any incident and vibrates to get the user’s
attention. The only problems noted in technology studies is getting people to carry them
and recovering units issued to visitors.
PERFORMANCE GOALS FOR EGRESS SYSTEMS
In its recommendations for changes to codes, standards, and practices resulting
from the WTC collapse investigation, NIST recommends that buildings be designed for
“timely, complete evacuation.” The point is not that total, simultaneous evacuation will
become the norm or will even be common; but it is reasonable to expect that every
building will need to be completely evacuated a small number of times over its lifetime.
In the recommendations, timely is not defined. Recent experience with the use of
elevators for occupant egress in very tall buildings indicates that it is possible to evacuate
the entire population of any building of any height within one hour, without any changes
to the number, size, or speed of the elevators that would be present if they were not used
for evacuation. Thus, the goal of being able to evacuate a building in one hour or less is
achievable as an RSET.

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In modeling of occupant egress it is recommended that a safety factor of 2 by applied
when dealing with the uncertainties of human behavior 24 . In keeping with this
conservative approach it is reasonable to double the time available and to require a
minimum of 2 h of ASET (available safe egress time) and this is a common requirement
today for the fire resistance of the primary structural frame in sprinklered high rise
buildings. The result should represent a reasonable and conservative performance goal
for complete evacuation (including people with disabilities) within one hour. In addition
this permits people with disabilities to self-evacuate with every one else and without the
need for assistance or special devices.
CONCLUSIONS
From this discussion it appears obvious that protected elevators will become a
primary means of vertical travel in tall buildings. Assuming regulatory agreement with
the performance goal of total evacuation in one hour or less, occupant egress elevators
would be required in buildings taller than about 50 stories and fire service access
elevators in buildings taller than (6 to 9) stories. At the estimated one floor per minute
rate, buildings of up to 50 stories can be evacuated in one hour or less using stairs alone.
Most fire departments report a preference to use elevators to access fires above the sixth
floor. Discussion and consensus is needed on the role of stairs, refuge floors,
communication systems, and procedures for egress, relocation, or protection in place in
the range of incidents that may be encountered in any building. In some cases, formal
threat assessment may be needed to identify scenarios that need to be considered.
Where protected elevators are provided for occupant egress much of the occupant load
would be carried by the elevators. Thus there may be less need for wider stairs, and the
avoided costs of wider stairs should be more than adequate to cover the additional costs
for protecting the elevators and adding monitoring. Owners then would be free to place
assembly occupancies high in the buildings without the need for increasing stair capacity.
People with disabilities would be afforded the ability to self-evacuate with all other
occupants without the need for special arrangements or equipment. In an event where
the incident commander decides to require simultaneous evacuation of a building, the
entire population should be capable of clearing the building in an hour or less. An hour
should be an achievable RSET even for very tall buildings and it should be well within
the practical ability of safety designs to provide a protected environment (ASET) of two
hours in which to carry out an evacuation including a conservative factor of safety of 2
for variation in human behavior and capability.
REFERENCES
1

Bukowski, R.W. and Kuligowski, E.D., The Basis for Egress Provisions in U.S. Building Codes,
InterFlam 2004, Edinburgh, UK, July 2004.
2
Klem, T. and Kyte, G., Fire at the Prudential Building, Fire Command, 53, No. 3, 14-19, March 1986.
3
NCSTAR 1 Final Report on the Collapse of the World Trade Center Towers, Chapter 9
Recommendations, Nat Inst Stand Tech, Gaithersburg, MD 20899 2005.
4
Local Law 26-2004, Ammendments to the Building Code of New York City, New York City Department
of Buildings, 2004.

InterFlam 2007

5

Page 11 of 11

final3/14/2007

Standard Classification for Abuse-Resistant Nondecorated Interior Gypsum Panel Products and FiberReinforced Cement Panels, ASTM C 1629/C 1629M-05, ASTM International, West Conshohocken, PA.
6
Templar, J., The Staircase, Studies of Hazards, Falls, and Safer Design, MIT Press, Atlanta, GA 1992.
7
Pauls, J., Selected Human Factors Aspects of Egress System Design, presentation at CIB TG50 and W14
Joint Symposium on Tall Buildings and Fire, September 2006, proceedings available at
http://www.cibworld.nl/
8
Averill, J. and Peacock, R., SFPE PED Conference proceedings (in press)
9
Averill, J., Mileti, D., Peacock, R., Kuligowski, E., Groner, N., Proulx,G., Reneke, P., and Nelson, H.,
Occupant Behavior, Egress, and Emergency Communications, NCSTAR 1-7, NIST, Gaithersburg, MD
2005, available at http://wtc.nist.gov/
10
Life Safety Code, NFPA 101-2006, Table 7.2.2.2.1.2 (B), Nat Fire Prot Assn, Quincy, MA 02269
11
David Frable, GSA, private communication.
12
Details of the design of 7 WTC can be viewed on the Silverstein Properties website
http://silversteinproperties.com/
13
Bukowski, R.W., Protected Elevators for Egress and Access During Fires in Tall Buildings, Strategies for
Performance in the Aftermath of the World Trade Center. CIB-CTBUH Conference on Tall Buildings.
Proceedings. Task Group on Tall Buildings: CIB TG50. CIB Publication No. 290. October 20-23, 2003,
Kuala Lumpur, Malaysia, Shafii, F.; Bukowski, R.; Klemencic, R., Editors, 187-192 pp, 2003.
14
Bukowski, R. et al, Elevator Controls, NFPA Journal, Nat Fire Protect Assoc., Quincy, MA 100, No 2,
March/April 2006
15
Bukowski, R., Protected Elevators and the Disabled, Fire Protection Engineering, SFPE, Bethesda, MD,
Issue 28, Fall, 2005.
16
Hsiung, K., Wen, W., Chien, S., and Shih, B., A Research of the Elevator Evacuation Performance for
Taipei 101 Financial Center, Proc 6th International Conference on Performance-based Codes and Fire
Safety Design Methods, 14-16 June 2006, SFPE Bethesda, MD 2006.
17
Kuligowski, E.D. and Bukowski, R.W., Design of Occupant Egress Systems for Tall Buildings, Use of
Elevators in Fires and Other Emergencies Workshop Proceedings. Co-Sponsored by American Society of
Mechanical Engineers (ASME International); National Institute of Standards and Technology (NIST);
International Code Council (ICC); National Fire Protection Association (NFPA); U.S. Access Board and
International Association of Fire Fighters (IAFF). March 2-4, 2004, Atlanta, GA, 1-12 pp, 2004, 2004.
18
Fire Protection Research Foundation Project on High Rise Occupants and Evacuation, Fire Protection
Research Foundation, Quincy, MA 02269.
19
Code of Practice for the Provision of Means of Escape in Case of Fire, Part II, Section 21 Refuge Floors,
Hong Kong Building Authority, 1996.
20
Meacham, B., Refuge Floors in Tall Buildings: The Asian Experience, presentation at CIB TG50 and
W14 Joint Symposium on Tall Buildings and Fire, September 2006, proceedings available at
http://www.cibworld.nl/
21
Yuen, K., Lo, S., and Yeoh, G., Numerical Simulation of Wind-Smoke Effect on Designated Refuge
Floor in High Rise Buildings, Proc InterFlam “99, Volume 2. June 29-July 1, 1999, Edinburgh, Scotland,
Interscience Communications Ltd., London, England, 1273-1279 pp, 1999
22
Proulx, G. and eid, I., Occupant Behavior and Evacuation during the Chicago Cook County
Administration Building Fire, Journal of Fire Protection Engineering, SFPE Bethesda, MD, 16, No 4, 2006.
23
Proulx, G. and Koroluk, W., Fires Mean People Need Fast, Accurate Information, NRCC-41088, CABA
Home and Building Automation Quarterly, 17-19, Summer 1997.
24
Nelson, H.E. and Morwer, F. W., Emergency Movement, SFPE Handbook of Fire Protection
Engineering, 3rd ed., SFPE Bethesda, MD, 2002.

Appendix L
Emergency Egress from Buildings, Part 1: History and
Current Regulations for Egress Systems Design

Emergency Egress from Buildings
Part 1: History and Current Regulations for Egress Systems Design
Richard W. Bukowski, P.E., FSFPE
NIST Building and Fire Research Laboratory
Gaithersburg, Maryland 20899 USA
INTRODUCTION
For most of history buildings were short enough that stairs provided for access were
sufficient for rapid egress in the event of fire. Even in single stair (mostly residential)
buildings, experience showed that this stair was sufficient for fire egress as long as the
fire did not expose or block access to the stair. Fire resistant apartment doors shielded
the stair from most fires and exterior fire escapes provided a second egress path
beginning early in the 20th Century.
The 1854 invention of the elevator safety brake enabling the passenger elevator is
credited with facilitating increases in building height and the first so-called skyscraper in
Chicago in 1885. These buildings utilized steel frames protected by masonry or tile and
were dubbed “fireproof construction” providing a (possibly false) sense of security. By
1914 authorities had begun to question these arrangements as evidenced by a move to
change the term “fireproof” to “fire-resistive,” and description of egress provisions in
regulations as “exceedingly deficient.” 1
Model building regulations in the US started with the National Building Code published
by the National Board of Fire Underwriters (NBFU) following the Great Fire of Boston
(1872). Property loss claims from this fire resulted in more than 70 insurance companies
being driven into bankruptcy, causing insurance interests to form the NBFU and to
develop building fire safety rules aimed at reducing property losses in fires. These rules
became the first model building code, called the National Building Code (NBC), and first
published in 1905. The NBFU was able to tie compliance with their rules to their
Municipal Grading Schedule on which insurance rates are based. Cities needed favorable
rates to attract investment, so they were motivated to adopt regulations consistent with
the National Building Code 2 . The first (1905) edition of the NBC required exit stairs to
have a minimum width of 20 in (510 mm) * .
The purpose of this paper is to document current regulatory requirements for means of
egress in fires, their origins and scientific basis, and the approaches used in other
countries. Then the paper will present an argument for why these approaches and
requirements should be re-evaluated to reflect changes both in buildings and in their
occupants. Finally the paper will make some suggestions for reasonable revisions to

*

This paper will cite primary dimensions in the units found in the code cited. Thus U.S. codes will show
English units first and non-U.S. will show metric first. Unit conversions are approximate because the paper
cites the equivalent values found in the building regulations of various countries which are normally round
numbers.

design practice along with a more holistic philosophy that takes better account of human
behavior and is based on a more appropriate performance metric.
ORIGINS OF THE 44 INCH EXIT STAIR IN THE US
In the 1913 National Fire Protection Association (NFPA) Proceedings3 , the Committee
on Fireproof (later, Fire-Resistive) Construction reported a number of recommendations,
including one for minimum 44-in exit stairs (unobstructed width except that handrails
would be permitted to intrude not more than 3 ½ in on each side). That same year NFPA
formed their Committee on Safety to Life. That committee’s first activity was to conduct
a comprehensive review of fire safety issues and regulatory approaches found in building
codes and local regulations in several, geographically diverse cities. At the NFPA’s 1914
meeting they reported that,
“… existing laws are exceedingly deficient in this very important matter of egress. A
number of states report frankly that they have no real legislation upon the subject,
many City Ordinances are of the most indefinite character, and in some the
matter is simply left to the discretion of the fire department or other officials.”
In the 1914 NFPA Proceedings, section on egress, the Safety to Life Committee cites the
1913 NFPA Annual Meeting report of the Committee on Fire-Resistive Construction in
which they said was presented,
“… a splendid set of specifications for the construction of a standard building. Egress
received detailed attention; -- specifications for smoke-proof towers, for stairs,
for horizontal exits, and for the capacity of vertical and horizontal exits were
included.”
The committee also cites the 1913 laws of the New York State Department of Labor
which, “… as regards fundamentals appear to agree entirely with the requirements of
our Committee …” Extracting from the referenced New York statute, they cite,
“a. For buildings erected in the future, a minimum of 22 inches of stair width
shall be required for not to exceed 14 persons on any one floor.
b. On buildings already erected this figure is reduced to 18 inches as a minimum.
c. A 44-inch stair in new buildings permits 28 persons to be housed on each floor
above the first one.
d. In arriving at this decision the idea has been that all of the persons on all floors
shall be able to remain in the stair tower without any movement, a person
requiring about 22 inches in width, and one person to stand on every other stair.”
They further characterize the New York laws’ stair geometry (7 ¾ in riser height by 10 in
tread) as “good”, and that they recommend a minimum 44 inch wide stair for new
buildings as this width is
“reported sufficient to prevent three persons from forming an arch and blocking traffic.”
EXIT CAPACITY
The above explains why the US designs exits for “capacity” and why the capacity is
based on the population of a single floor. The exit is sized to “store” people, motionless

within the protected exit enclosure, such that the population of one floor will fit within
one flight of the stair, with each person in a space 22 inches wide and standing on every
other step.
This philosophy was recognized in the 1935 National Bureau of Standards (NBS now
NIST) publication, Design and Construction of Building Exits 4 . Developed by the
Department of Commerce Building Code Committee, this report included survey data on
exit sizes and configurations drawn from eight cities chosen, “… with a view to covering
places varying in size and sufficiently distributed to give a fair cross section of building
construction.” The survey included population counts on typical floors and compiled
data on movement of people in buildings (railway terminals and schools). Studies of the
flow of occupants of government buildings during fire drills were conducted and the data
presented as discharge rates for stairs (as a function of width and stair geometry), ramps,
and doorways.
The data were used to suggest possible approaches to calculating minimum width of exits
necessary to provide for occupant safety. These included (note that the descriptive text is
paraphrased from the 1935 report):
1. Capacity Method, which is based on the concept of storing occupants on the stairs
within a protected stair enclosure, and allowing for the subsequent safe and
orderly evacuation of the building. It recognized that travel down a long series of
stairs in high buildings is exhausting even to normal persons. Objections of
building owners over the loss of rentable space are noted as well as the comment
by some authorities that people may not stand still in stairways, even in high
buildings.
2. Flow Method, which is based on the concept that people will move down the
stairs at a typical flow, assumed to be 45 persons per 22 in unit of width per
minute and 60 persons per minute through doorways. It is stated that this method
is usually coupled with an assumed time in which it is safe to exit the building and
that this method calls for considerably less stairway width than the capacity
method. However they felt that it would be limited to a few occupancies and to
buildings of low to moderate height since continuous movement down stairways
in high buildings cannot be expected without serious effects on some occupants.
3. Combined Method suggests the flow method for lower buildings shifting to the
capacity method for taller buildings also accounting for type of construction and
use. Once again they point out that tall buildings would require a disproportionate
amount of space devoted to stairways as compared with useable floor area.
4. Probability Method considers only the population of the six, most densely
populated floors since it is improbable that simultaneous evacuation of all floors
of a large building is needed. This is the first time that phased evacuation (as
currently practiced in tall buildings) is suggested.
5. Floor Area Method relates area to units of exit width needed as a function of
construction type and use. Like the probability method, simultaneous evacuation
of all floors is not considered but the number of floors considered varies with
occupancy.

In the end, the 1935 report suggests that the needs of the vast majority of buildings can be
met with the provision of two, two-unit-width (44 in) stairs. The capacity method
(occupants waiting within the exit enclosure) is appropriate for low buildings with a
gradual shift to the flow method for taller buildings where people will be less comfortable
waiting in the stair. For tall buildings the floor area method has some application as these
are of fire resistive construction and only those near the floor of origin are initially at risk
but six floors is not sufficient for larger buildings. They suggest half of the floors should
be considered.
EARLY THOUGHTS ON ELEVATORS AS A MEANS OF EGRESS
Both the 1914 NFPA ProceedingsError! Bookmark not defined. and the 1935 NBS report discuss
the possible use of elevators for egress from tall buildings. In 1914 the Committee on
Safety to Life expressed the opinion that, “… elevator shafts properly enclosed and with
openings adequately protected have decided value from an escape standpoint, and are
absolutely necessary in high buildings.” They cited as “… loss of life possibilities in
many modern so-called fireproof buildings …” the common practice of unenclosed stair
and elevator shafts that might permit a fire in lower stories that, “… spread with
unexpected speed could result in a loss of life which would stagger the civilized world.”
The Committee called for enclosing elevator shafts, improving the fire resisting powers
of elevator doors, ensuring the integrity of the electric current applied to elevators, and
“drilling” elevator operators in emergency procedures, including that persons in the upper
stories shall first be taken to the ground.
The 1935 NBS report discusses a credit for elevators against required aggregate exit
width. They discount automatic elevators as unsuitable as their “…capacity and rate of
speed is not great.” And “… they are not subject to a single will as in the case of an
elevator operator, but to demands from many tenants.” While there was a suggestion in
the formulae of the flow method that five elevators might be equal to a single unit of exit
stair width for some construction types and use, in the end they concluded that the
uncertainties were such that no direct credit be given for elevators but to recognize their
availability in high buildings.
EARLY REGULATORY APPROACHES IN THE US
The 1914 report of the Committee on Safety to Life included detailed recommendations
for the design and arrangement of egress stairs and fire escapes with the intent that this
material would be incorporated by others into building regulations. No code or standard
was produced by the Committee until the 1927 publication of the first edition of the
NFPA Building Exits Code (NFPA 101-T) 5 which later became the Life Safety Code.
The 1927 edition of NFPA 101-T defined stairs as Class A, B, or C. Class A stairs were
the main stair of a newly-constructed Assembly occupancy, and were 44 in (1100 mm)
wide (handrails could intrude not more than 3 ½ in (89 mm) on each side) with a rise of
not more than 7 in (178 mm) and a tread of not less than 10 ½ in (267 mm). Class B
stairs were for new construction of all stairs not required to be Class A, and for existing

construction where Class A stairs would be required if new. Class B stairs were the same
width as Class A but the rise was permitted to be not more than 7 ¾ in (197 mm) with a
tread of not less than 9 ½ in (241 mm). Class C stairs covered existing stairs in existing
buildings and were at least 36 in (0.9 m) wide (not less than 32 in, 0.81 m between
handrails, but stairs less than 44 in (1100 mm) wide only required a handrail on one side).
Occupant load on a floor dictates required capacity (total width of stairs in number of 22
in units) required in a minimum of two stairs located “as remote as practical.”
The 1935 NBS report included recommended code language in an appendix that did not
follow any of the five methods for calculating minimum exit widths discussed previously.
They explained that tentative requirements were drawn up and compared against the
results of the field studies. Eventually a consensus of the Committee was reached and
was presented in the recommended code language.
The suggested code requirements largely followed the capacity method for at least two
stairs of two (22 in, 550 mm) units of exit width each, with the floor area method used
(by means of occupancy load factors consistent with those found in current regulations)
to determine aggregate width. No suggestions of maximum egress time (including no
references to fire resistance times associated with construction types, building height, and
use) that might facilitate the use of the flow method, and no mention of partial evacuation
of tall buildings as discussed in the probability and floor area methods was made. These
recommendations were consistent with those in the 1927 edition of NFPA 101-T, but this
is not surprising since the Committee on Safety to Life was represented on the NBS
Committee. The requirements suggested in the NBS report and NFPA 101 were adopted
in the model codes and building regulations throughout the US until the mid-1980’s when
the 22 in (550 mm) unit of exit width was abandoned for assessing exit capacity in units
of people per inch, but retaining the 44 in (1100 mm) minimum width. This method
provides similar results for aggregate exit width but provides more capacity credit for
fractions of the 22 in unit.
SCIENTIFIC STUDIES OF FLOW RATE
The 1935 NBS report included field surveys of discharge rates down exit stairs and
through doors for various government buildings during drills and for subway and rail
terminals at rush hours. The data collected were discussed by the Committee and a
consensus reached that there was a clear correlation between width and flow. The
committee agreed that, “… rates of 45 persons per 22-inch unit per minute for travel
down stairways, and 60 persons per 22-inch unit per minute through doorways, which
had been in use on the basis of earlier observations, were sufficiently confirmed to
warrant their retention in connection with the requirements under development.”
Almost from the start there were issues raised with the assumed flow rate on stairs of 45
persons per minute per (22 in) unit of exit width. Togawa 6 in Japan conducted research
in the 1940’s and 50’s, that showed for densities above 1 person per square meter (10
square feet) that flow rates decreased significantly. His data suggested a flow rate of 26
persons per minute per (22 in) unit of exit width.

Pauls has published extensively on this topic and continues to be the scientific conscience
of stair design in the US codes. Pauls 7 and Fruin 8 both discussed the concept of effective
width of a stair, which is generally 0.3 m (1 ft) narrower than the actual width due to the
natural tendency of people to keep a distance from walls and handrails. Fruin further
spoke of the personal space (buffer) around people that increases their effective space
requirement. Pauls found that for people walking on stairs their body sways from side to
side and they desire sufficient space so that they do not make contact with the person
beside them. Pauls work confirmed that of Togawa finding that flow rate in stairs at
typical densities is about 27 persons per minute per (22 in) unit of exit width. Extensive
studies in Russia also confirmed the effects of density on flow rates including the values
suggested by Pauls and Togawa, as reported in a 1969 book by Predtechenskii and
Milinskii 9 .
From the data collected by NIST in the investigation of the World Trade Center (WTC)
collapse on September 11, 2001, the flow rate in the stairways can be estimated10 . For
WTC 1, there were approximately 7900 survivors who exited the building over the 102
minutes between the aircraft strike and the collapse. The building had three stairs, two at
44 in (1100 mm) and one at 56 in (1400 mm). Assuming the occupants used the stairs
equally, there were 2630 people in each 2-unit wide stair who exited in 102 minutes, or
13 people per minute per unit of exit width. The NIST study found that the egress flow
decreased by about 80 % in the last 20 minutes before collapse. If one assumes the 2630
people exited in 82 minutes, the flow rate would be 16 people per minute per unit of exit
width. These estimates support the argument that current flow rates may be significantly
less than the rate suggested by Pauls and Togawa in the 1970’s and one third the rate
proposed in 1914Error! Bookmark not defined..
SCIENTIFIC STUDIES OF EXIT WIDTH
Clearly, the current 44 in (1100 mm) minimum exit stair width is intended to support two,
22 in queues of occupants either standing still (capacity method) or moving down the
stair (or a single queue of occupants moving down and being passed by firefighters
moving up, known as counterflow). The 22 in dimension for the width of a person was
offered in 1914 as originating with soldiers standing in a lineError! Bookmark not defined..
Challenges to the adequacy of the 22 in dimension include the need to provide for body
sway as people move down the stair (Pauls), and the need to allow for some personal
space (Fruin, Predtechenskii and Milinskii). Recently, the adequacy of the basic 22 inch
dimension is being questioned in light of the increasing size and weight of the typical
person, especially in the US. The 22 inch dimension refers to the width of a person at the
shoulders, which is assumed to be the widest part. Predtechenskii and Milinskii suggest
that 4 in (100 mm) be added to each side to allow for a personal buffer except that for
low obstructions (like handrails) the additional space is not needed since one’s shoulders
are at a higher level and will extend over the obstruction.

From anthropometric data for
modern Americans, the width at
the hip is approaching the width at
the shoulder, and it seems that this
exception may no longer be valid.
Thus, with the shoulder width of
the 97.5th percentile adult male
reaching 20 in (510 mm) 11 and
allowing the 4 in on each side for
handrail and personal space, the
new unit of exit width should be
28 in (700 mm) and the minimum
stair width 56 in (1400 mm), see
Fig 1.
Arguably the most comprehensive
studies of movement on stairs were
conducted by Templer, beginning with
his doctoral research 12 and including Figure 1 Anthropometric data for adults
Reprinted with permission from NFPA 101® the Life Safety
work at NBS 13 in the 1980’s. Templer Code®, copyright © 2006 National Fire Protection Association
observed the movement of many
individuals up and down stairs of varying width and tread geometry, tabulating variables
ranging from quantitative (speed, number of stumbles) to qualitative (perceived comfort).
From this work Templer concluded that the minimum width of an egress stair should be
56 in (1400 mm).
SCIENTIFIC STUDIES OF TREAD GEOMETRY
One of the earliest studies of stair geometry was conducted by an architect in France
named Francois Blondel 14 . Blondel was primarily interested in comfort rather than safety
and observed that the main stairs of classic cathedrals were comfortable to use and
accommodated large numbers of people attending services. He made measurements and
found that the ratio of stair height to tread depth was a constant, and he related this
dimension to the length of the human gait. His formula was 2R+G=24 in, where R is the
rise and G is the going (or run). Templer adjusted Blondel’s formula for the use of the
old (pre French Revolution) inch and a modern gait more like 28 in (71 cm) and arrived
at a modern (metric) formula, 2R+G=710. The so-called 7/11 stair geometry commonly
required in US codes meets the relation 2R+G=635.
Templer 15 summarizes a number of research studies of stair geometry and safety. Many
such studies were conducted by observing people moving up or down stairs in buildings.
Observations in subway or train stations at rush hours provided data for higher population
densities. A few studies were conducted in laboratory settings on specially constructed
stair sections where the geometries and stair angle could be varied systematically.
Templer himself conducted several of these studies, including some at NBS.

Most of the studies reviewed concluded that the measure of Total Energy Cost per Meter
Rise is a useful metric for the evaluation of stair design for normal use and comfort;
however stair safety is more closely related to the likelihood of missteps which is a
function of how the stair relates to the human gait. In both cases the effect is different for
ascent and descent, with descent being more hazardous.
When ascending a stair a person walks on the ball of the foot with less of the foot placed
on the step. Shorter treads (goings) and higher risers produce fewer missteps. When
descending a stair the heel and most of the foot needs to be placed on the tread. Too
much of the front of the foot extending over the nosing results in rotation of the foot and
a fall, or a distorted gait while trying to place more foot on the tread. Tread depths of at
least 11 in (280 mm) are recommended to accommodate the 95th percentile foot, but
considering only gait and accident history treads (goings) of at least 9 in (230 mm) are
required. Riser heights of 6.3 in to 7.2 in (160 mm to 183 mm) had the fewest missteps.
Other dimensions apply to curved stairs 16 .
Other factors relevant to stair safety include lighting, slip resistance, single steps (most
codes prohibit flights of fewer than three steps), handrails, and inability to detect the edge
of the tread due to lack of contrast.
REVIEW OF INTERNATIONAL CODE REQUIREMENTS FOR EGRESS
STAIRS
The building regulations summarized below are from countries that are widely disbursed
and culturally different, and should be representative of any range of methods used to
treat egress. Where the original code documents are published in languages other than
English, the codes used were official translations published in English, so they can be
presumed accurate.
Characteristics of egress stair design include the factors previously discussed as well as
the minimum number of egress stairs provided, maximum travel distance to a stair, width
of doors and passageways, interior finish, lighting and marking, headroom, and handrails.
All of the codes examined address all of these characteristics and all are reasonably
consistent in requirements. For example, all require handrails on both sides of an egress
stair and a center handrail when stair width exceeds 1800 mm (71 in). It is interesting to
note that, while all the codes require a minimum of two egress stairs from every floor,
many of the codes address specific conditions in which a single stairway is permitted, and
some are quite liberal in this regard. Design occupant loads are generally consistent
among most building regulations in the world.
United States
In the United States model building regulations are developed by private sector, nonprofit organizations and are adopted by State and local governments with modifications
that reflect local needs and practices. Two such model codes exist but the requirements
of both are reasonably consistent, especially with respect to egress system design. A

detailed review of current US building code requirements for egress system design is
provided by Bukowski and Kuligowski 17 .
In the US codes, the minimum width for an egress stair is 1100 mm (44 in) except that a
space served by no more than 50 people can have a 900 mm (36 in) stair. The capacity of
a stair (number of people served per floor) is 0.3 in per person unsprinklered and 0.2 in
per person sprinklered. Thus, for the 1100 mm (44 in) stair the capacity is 147
unsprinklered and 220 sprinklered. As an example, the design occupant load for offices
specified in US building regulations is 10 m2 per person (100 ft2 per person).
Australia
In Australia the legal responsibility for regulation of buildings rests with the States and
Territories. Since 1996 a national model building code, the Building Code of Australia
(BCA) has been developed under a mutual agreement (and funding) by the Australian
Building Codes Board, and is adopted with local modifications by the States and
Territories. The local modifications are published as individual annexes in the BCA
document.
The BCA 2006 18 is a performance-based code that includes prescriptive requirements
drawn from the predecessor code as deemed-to-satisfy requirements within the published
code document. While it is common to use performance analysis to address such issues
as travel distances, remoteness requirements, or fire resistance requirements for shaft
enclosures, stair geometries and minimum widths generally comply with the prescriptive
rules.
The minimum clear width (between handrails) of a required exit stair serving a storey or
mezzanine accommodating up to 100 people is 1000 mm (39 in). Stairs serving a storey
that accommodates more than 100 but not more than 200 must have an aggregate width
of at least 1000 mm (39 in) plus 250 mm (10 in) for each 25 people (or fraction thereof)
in excess of 100, and stories accommodating more than 200 must have an aggregate
width of 2000 mm (78 in) plus 500 mm (20 in) for every 75 people (or fraction thereof)
in excess of 200 unless the stair or ramp is steeper than 1 in 12, when the additional 500
mm (20 in) is for every 60 people in excess of 200. Design occupant loads are similar to
the US codes. For example, for offices the design load is 10 m2 per person which is
identical to the US 100 ft2 per person.
Stair geometry is specified as a range for both the riser (rise) and going (tread), along
with a range of the ratio of twice the riser plus the going (Blondel’s formula). The values
specified are a riser between 115 mm and 190 mm (4.5 in and 7.5 in), a going between
250 mm and 355 mm (10 in and 14 in) and the ratio (2R+G) between 510 and 700.
United Kingdom
The UK building regulations apply to England and Wales but not in Scotland or Ireland.
In 1985 UK adopted a performance-based code and converted its prescriptive rules to

Approved Documents which represent deemed-to-satisfy rules. Approved Document B 19
deals with Fire Safety.
Section 5 deals with Design for Vertical Escape for buildings other than Dwellings, with
minimum stair widths for simultaneous evacuation on Table 7 and for phased evacuation
in Table 8. Table 7 lists the maximum capacity (number of persons served) as a function
of stair width and number of floors. Stair widths range from 1000 mm (39 in) to 1800
mm (71 in) with the provision that stairs wider than 1800 mm must be divided by a
handrail. Thus the minimum permitted width is 1000 mm (39 in). For a stair of 1100
mm equivalent to the US minimum 44 in stair, 260 people can be accommodated on two
floors, increasing by 40 people for each additional floor. For phased evacuation 120
people per floor can be accommodated by a 1100 mm (44 in) stair with an additional 10
people for each 100 mm (4 in) in width. Design occupant loads in Approved Document
B are somewhat more conservative than in other codes, for example offices are 6 m2 (60
ft2) per person.
Some insights into the development of the table appear in the supporting text in
Approved Document B. Provision 4.25 presents an alternative to using Table 7 for stairs
1100 mm (44 in) or wider to determine number of persons served (P) for simultaneous
evacuation by applying the formula P=200w+50(w-0.3)(n-1). Note 5 to this formula
explains that 200w represents the number of persons estimated to have left the stair after
2.5 min of evacuation and the second term represents the number accommodated on the
stair at that time. This implies that they are assuming a flow of 45 persons per minute per
510 mm (22 in) of width and a storage capacity of 50 people per (meter minus 0.3, which
may represent Fruin’s boundary space) in each story of stairway. This appears to follow
the 1935 NBS recommendation for a combination of the flow method and the capacity
method with the assumption that the first 2.5 min of evacuation time is safe.
It is also interesting to note that Approved Document B suggests that buildings in excess
of 30 m (100 ft) in height be designed for phased evacuation. This has somewhat
different stair capacity requirements but also suggests that the capacity should be
provided by the stairs remaining after any one is discounted as being used by the fire
service for fire attack. Appropriate arrangements are to be worked out for specific
building conditions in consultation with the fire brigade. This is in addition to a
requirement that buildings in excess of 30 m (100 ft) in height be equipped with a
firefighting shaft including a protected elevator dedicated to emergency response service.
Spain
Spain has a national building regulation developed by the Ministry of Housing and issued
by Royal Decree. Like Australia, Spain recently adopted a performance-based building
regulation that includes deemed-to-satisfy requirements within the code that are based on
the traditional rules. Because Spain is a Member State of the European Union (EU) they
fall under the Construction Products Directive of the EU which requires coordination of
construction regulations so that the regulations do not become a barrier to free trade
within the Union.

The Spanish regulations 20 (Section SI 3, table 4.2) assign evacuation capacity (number of
occupants who may use the stair) of protected stairs as a function of stair width and
number of floors to be traveled. For unprotected stairs they assign different values for
travel upward and downward as a function of width. Stair widths ranging from 1000 mm
(39 in) to 2400 mm (95 in) are covered, implying a minimum width of 1 m (39 in). A
1100 mm (44 in) wide stair corresponding to the US minimum, can accommodate 248
people on two floors, increasing by 36 people for each additional floor.
Occupant loads in the Spanish code are consistent with other countries; e.g., offices are
10 m2 (100 ft2) per person. Stair geometry is regulated in the code section on protection
from falling (Section SU) where stair treads must be at least 280 mm (11 in) and risers
130 mm (5 in) and no more than 185 mm (7 in), with the tread to riser ratio of 4:1 for the
entire length of the stair.
Hong Kong
The Hong Kong building regulations are prescriptive and derive from the British rules.
Following the return of Hong Kong to Chinese sovereignty their designation as a Special
Administrative Region (SAR) permitted them to continue using prior regulations. There
is a separate document for Means of Escape in Case of Fire 21 (MOE). Table 5
(unsprinklered building) and Table 6 (sprinklered building) are similar to the Spanish
table, providing a discharge value (number of occupants who may use the stair) as a
function of width and number of stories. Widths range from 1050 mm (41 in) to 1900
mm (75 in) in 150 mm (6 in) increments, and values for widths exceeding 1900 mm are
permitted by linear extrapolation (without limit). A 1100 mm (44 in) wide stair
corresponding to the US minimum, can accommodate 242 (unsprinklered) or 452
(sprinklered) people on two floors, increasing by 32 people for each additional floor.
Occupant loads in the Hong Kong code are only slightly greater than other countries; e.g.,
offices are 9 m2 (90 ft2) per person. Stair geometry requirements specify treads at least
225 mm (9 in) and risers not more than 175 mm (7 in).
The Hong Kong MOE includes a unique requirement for refuge floors in buildings
exceeding 25 stories in height. Every 25 stories an unoccupied floor (normally a
mechanical floor) must arrange at least 50 % of its area as an area of refuge (2 h fire
separation) for occupants to rest or to cross between stairways. They are required to be
open on at least two sides (with water curtains) above a safe railing height to provide
natural smoke control. They must be served by a fireman’s lift to facilitate rescue
assistance. These requirements have also been adopted in other areas of China and in
some other Asian countries.
Peoples Republic of China
Regulations for building fire safety in China are contained in the Code for Design of
Building Fire Protection 22 (GBJ 16-87) and published as a National Standard that is
locally enforced. Section 5.3 deals with Safety Evacuation of Civil Buildings.

The total width of stairs is specified per 100 people for buildings of specific height (in
stories) and construction class (1 through 4) along with a minimum width of any stair of
1100 mm(44 in). While the definitions of the Chinese construction classes do not align
completely with those specified in US codes, an approximate correlation is presented
below.
Class 1 or 2 buildings (similar to US Type IA and IIIA) require a minimum aggregate
width of 650 mm (26 in) per 100 people for 1 and 2 story buildings, 750 mm (30 in) per
100 people for 3 story and 1000 mm (39 in) per 100 people for 4 story or higher . Class 3
buildings (similar to US Type IIIB) require a minimum aggregate width of 750 mm (30
in) per 100 people for 1 or 2 story, 1000 mm (39 in) for 2 story and 1250 mm (49 in) for
4 story or higher. Class 4 buildings (similar to US Type IV heavy timber) require 1000
mm (39 in) per 100 people for 1 and 2 story buildings. Class 4 buildings are not permitted
taller than 2 stories.
Japan
Japan regulates building safety through a national law that is promulgated by the national
government, through the Ministry of Land, Infrastructure, and Transport (MLIT). The
Building Standard Law of Japan 23 (BSL) is utilized nationally without local amendment
and is enforced by local officials who are empowered to determine compliance or lack
thereof, but not empowered to issue variances or determination of equivalencies. These
can only be determined by the MLIT. Unlike most building regulations the BSL
combines building and zoning regulations.
Beginning in 2000 the Building Standard Law was revised to a performance-based
structure with the prescriptive rules moved into the Building Standard Law Enforcement
Order to facilitate updating and interpretation.
Chapter II, Article 23 deals with stairs which may be through stairs or escape stairs. This
article establishes a minimum stair width of 1200 mm (47 in) with stair treads of 240 mm
(9.5 in) or more and a rise of 200 mm (8 in) or less.
Chapter V of the BSL Enforcement Order deals with Evacuation Facilities. Article 120
addresses through stairs provided for access and egress, and article 121 requires that at
least two through stairs be provided. Article 122 requires that certain through stairs be
designated as escape stairs and be constructed in accordance with article 123. None of
these articles address stair width or geometry. Article 124 requires that the aggregate
width of escape stairs in stores (mercantile) be not less than 600 mm (24 in) per 100 m2
(1000 ft2) of floor area of the largest floor served by the stair.
It does not appear that the Japanese code incorporates the concept of occupant load but
rather specifies required stair capacity in terms of the floor area served, which is the
equivalent of applying a uniform occupant load to all use categories in the group. The
Japanese code typically groups assembly type uses, educational, mercantile, and
residential uses when specifying minimum widths of stairs, doors, and corridors.

Part 2: New Thinking on Egress from Buildings
BUILDINGS ARE TALLER
At the start of the 20th Century the
tallest building in the world (Park Row
Building in Manhattan) stood just 391
feet (119 m). By 1913 the record
height had doubled with the completion
of the Woolworth Building at 792 feet
(241 m). Record heights crossed the
thousand foot mark in 1930 with the
Chrysler Building (1046 feet, 319 m))
and went to 1250 feet (381 m) with
completion of the Empire State
Building the following year (1931).
The World Trade Center (1368 ft, 417
m in 1971), Sears Tower (1450 ft, 442
m in 1974) and Petronas Towers (1486
ft, 448 m in 1998) ended the century
with the tallest building record just
short of 1500 feet (457 m).
The early 21st Century has seen a rapid
surge skyward, first in Asia and then in
the Middle East. The height record (as
of this writing) is Taipei 101 at 1671 ft
(510 m), but several taller buildings are
under construction. The Burj Dubai
Tower is estimated to top out at no less
than 2624 ft (800 m) and there is said
to be a building planned for elsewhere
in the Middle East at 3280 ft (1000 m).
Prior to the World Trade Center
Towers, nearly all the tall buildings
were tapered (or stepped) for a number
of reasons, ranging from reducing
structural loads to not casting shadows on Figure 2 - Timeline of World's Tallest Buildings
neighboring buildings (see Fig 2). This meant Source: Skyscraper Museum (used with permission)
that the occupant load decreased on the higher floors, decreasing the cumulative load on
the stairs, unless there was an assembly use at the top such as an observation deck or
restaurant. Today, most of the taller buildings are uniform with height with no such
decrease in the number of occupants served by the stairs.

In tapered buildings the number or width of the egress stairs can be increased for the
lower floors to accommodate the increased occupant load. However, for tall buildings of
uniform cross section the cumulative occupant load can lead to congestion, and the
number of stairs needed to accommodate simultaneous egress would require so much
space that the building would not be economical. Here, emergency plans rely on phased
evacuation; but this should theoretically include fire endurance for any building elements
that might impact egress at least as long as the required egress times.
Up to and including the Empire State Building these tall buildings were typically Type
1A (4 hr) construction. Thus a reasonable limit on egress times would be 2 h (the 4 h fire
resistance time with a safety factor of 2). From a flow and egress time perspective, using
a conservative 1 min per floor descent rate would limit heights of Type 1A buildings to
100 floors. A rate of 50 floors per hour is used to allow for notification, pre-movement,
and horizontal travel times as well as some rest stops in the stairs.
Beginning with the World Trade Center Towers it became common to permit Type 1B
construction (3 hr). With an occupant load of 390 per floor (110 floors) and three egress
stairs (6 ½ units of total exit width) total (simultaneous) evacuation times were estimated
at about four hours (including congestion, queuing, and transfer corridors), which is
consistent with the egress times observed in the 1993 bombing. Applying the criterion of
a total egress time of half the fire resistance time, one would want the building to
withstand a fire for 8 h or until complete burnout of all combustibles, whichever occurs
first.
PEOPLE ARE BIGGER AND LESS FIT

Percent

In the early 20th Century the 22
Morbid Obesity Rate (BMI>30)
in (1.1 m) unit of exit width
th
35
was sufficient for the 95
30
percentile US adult male. In
Japan
st
Norway
25
the 21 Century this is no
France
20
Sweden
longer the case. The American
th
15
Finland
male is larger with a 95
Spain
10
Canada
percentile shoulder width of 20
5
United Kingdom
in (510 mm), which requires a
Australia
0
United States
28 in unit if exit width and a 56
1980
1985
1990
1995
2000
Year
in (1.4 m) stair (applying
Templer’s 4 in on each side to
account for body sway and Figure 3 - Obesity rates by country
personal space). Templer did Data: International Obesity Task Force, EU Briefing paper, 2005
not allow the 4 in to a handrail
since people were narrower at the waist and hip than at the shoulder, but this is no longer
true.
The physical condition of the average occupant is such that the exertion of descending
many flights of stairs is no longer possible without frequent rest stops and a slower pace.

High percentile (95th) average weights have increased substantially in recent years (Fig 3),
and the number of people reporting that they need assistance due to physical conditions
has also increased.
The WTC Investigation found 6 % of occupants reporting the need for assistance in
traveling down stairs. These increases can be attributed to the widespread adoption of
modern accessibility regulations that have made it easier for people with mobility
limitations to be more active in society, and to the recognition that there are many
conditions not generally considered to be disabilities that can limit the ability of people to
move down many flights of stairs.
NEW TECHNOLOGIES
A number of new technologies are available to address limitations of the past. One of the
most promising is the ability to design and operate elevators safely and reliably during
fires. Here the ability to provide reliable power, sophisticated operational protocols, and
real time monitoring of critical functions, permit the use of protected elevators as a
primary means of egress in fires. Further, fire departments have recognized the need for
protected elevators to provide logistical support to operations in tall buildings.
Modern fire alarm systems combine reliability, flexibility, and advanced functionality
that permits real time monitoring and tactical support for incident management not
previously possible. With the advent of the industry
standard 24 fire service interface in the U.S., it is
possible for the incident command to actively
manage the evacuation process for improved safety
and efficiency. For example, it is possible to
monitor conditions in the stairways in real time and
to advise occupants to change stairs to avoid
congestion, especially where crossover corridors or
refuge floors are provided. Inexpensive cameras
and digital image processing software make it
possible to present images for action to fire service
personnel only when issues arise, permitting a few
personnel to monitor many locations.
Advances in photoluminescent materials now
permit issues of lighting levels and contrast within
stairs to be addressed without the need for complex
emergency power systems(Fig 4). When fully
charged by continuous ambient light these materials
provide more light for longer periods and can be Figure 4 - Photoliminescent materials can be
to illuminate stairways
applied to highlight stair nosing and handrails and used
Source: NRC Canada (used with permission)
as path lighting in transfer hallways.

REFUGE FLOORS
The incorporation of refuge floors in tall
buildings in Asia also represents a new
approach worthy of review.
As
discussed earlier, these are arranged
every 20 to 25 floors (generally on
mechanical floors) to provide a protected
area for occupants to rest temporarily on
their journey down the stairs and to
cross over from one stair to another.
Refuge floors are also intended as
protected space in which people with
disabilities can await rescue by the fire
department (fire service elevators are
generally arranged to be able to stop at
Figure 5 - Refuge floor in a Hong Kong high-rise during a
the refuge floors).
fire drill Source: Arup (used with permission)
Since these requirements are fairly new there have been no emergency evacuations of
buildings so equipped, but there have been evacuation drills that have shed some light on
performance (Fig 5). One issue identified in drills is that many occupants decide to wait
on the refuge floor for the “all clear” which fills the available space, preventing
additional people to enter the floor from the stair. Without wardens or fire service
personnel stationed on the floor to keep people moving, the purpose is defeated. It is not
clear in a real emergency if this will be a problem since occupants may be motivated to
get completely out of the building.
PERFORMANCE METRICS FOR EGRESS SYSTEMS
In the U.S., Australia and Japan, the design of egress systems are based on the population
of the largest, single floor. In U.K., Spain, and China the number of floors served by the
stair impacts the total number of people served by a stair of a given width. Yet in any
performance analysis of an egress system in these or other countries, regulators require a
timed egress analysis to estimate Required Safe Egress Time (RSET) which is compared
against Available Safe Egress Time (ASET). ASET is generally determined by fire
modeling to estimate conditions in the egress path that might lead to injury or death.
Clearly the appropriate performance metric is time, yet there is no regulatory
performance objective nor design criterion for egress systems in terms of time in any of
the codes examined. As early as 1914 the Safety to Life Committee recognized that
designing egress stairs on the basis of flow (of occupants down the stair) required some
“assumed time in which it is safe to exit the building” which is the ASET mentioned
above.
For compliance with the life safety objective of any building regulation, it is reasonable
to determine ASET as the time to reach potentially incapacitating or lethal conditions

anywhere within the means of egress. Considering the fact that the means of egress is
designed to protect people within it from exposure to fire or smoke, it is also reasonable
to assume that a limiting ASET would be the time to fire-induced partial structural
collapse. If burnout occurs before collapse, there is no theoretical limit to the ASET
though a reasonable value may be prescribed instead. Currently, the fire resistance time
of structural components and assemblies rated by a standard fire exposure in units of time
has not been shown to correlate with the time to structural failure of the component,
assembly, or system as a whole for an arbitrary real fire. Clearly, some factor of safety
that is appropriate for the level of uncertainty is needed in order to approximate ASET by
the fire resistance rating in cases where local collapse is estimated to occur before
burnout.
Based on these arguments an appropriate performance objective for egress systems
design may be that the time needed for total evacuation of the building be less than the
required fire resistance time for the primary structural frame (i.e., the columns and other
structural members including girders, beams, trusses, and spandrels having direct
connections to the columns and bracing members designed to carry gravity loads).
Where the fire resistance time is determined by test against a standard fire curve (i.e.,
ASTM E119 or ISO 834) a safety factor could be applied that is large enough to account
for the variability of egress performance and the uncertainty in the fire resistance time
representing the time to failure of at least one element of the primary structural frame.
Where the fire resistance time is determined by engineering analysis following the
Natural Fires or other similar method which accounts for the actual design level fire event,
some lower safety factor could be applied
since the predicted time to structural failure
would be expected to be less uncertain
although the egress variability would be the
same. For the sake of this discussion factors
of safety of 2.0 and 1.5, respectively will be
used; however, the actual values represent
policy decisions that need to be established
through the model code development and
regulatory adoption processes.
Since high-rise buildings in any of the codes
examined for this paper are required to Figure 6 – Interior of skybridge connecting the
have a primary structural frame of not less Petronas Towers at mid-height Source: Bukowski
than 3-h fire resistance as determined by (used with permission)
standard test, the total evacuation time would be required to be no more than 1 ½ h,
reflecting the safety factor of 2.0 discussed above. Recent analyses have shown that
evacuation times of 1 h may be achievable with stairs in buildings up to about 50 stories
and with a combination of protected elevators and stairs for most buildings of any height,
without increasing the number or size of the stairs or elevators above current practice;
this objective is clearly practicable25 .

These same arguments can be applied to the issue of a performance objective for fire
department access. Since U.S. codes require provision of 30 min of local water supply in
high rise buildings, it is reasonable to say that it should be possible for the fire
department to be able to put water on a fire at any height within 30 min. The 30 min
local water supply requirement includes both sprinkler and standpipe flows, and in that
initial 30 min there would be no standpipe flow, so this results in a safety factor. Using
protected elevators fire departments can meet the 30 min objective for buildings of any
height. Using fire department response time and a conservative estimate of 2 min per
floor for ascent with equipment it is straightforward to determine the height threshold for
fire service access elevators.
RETHINKING EGRESS SYSTEMS DESIGN
Some will argue that, other than some specific extreme events like the World Trade
Center attacks, there have been no reported failures to evacuate even the tallest buildings.
Therefore there is no reason to change what has been done for more than 100 years.
There are several things wrong with this argument.
First, there have been some failures in tall building evacuations. A real evacuation of
both Petronas Towers for a bomb scare in 2001 resulted in an evacuation time of several
hours when the skybridge (Fig 6) jammed with occupants crossing to the opposite tower
in accordance with the original evacuation plan. By incorporating elevator egress for
floors above the skybridge the total time for total (simultaneous) evacuation of both
towers was observed in a drill to be 20 min 26 . For Taipei 101 an evacuation drill
conducted prior to opening showed a total
evacuation time of about 2 ½ h. The fire brigade
reported being uncomfortable with this time.
Incorporating protected elevators for egress from
the upper floors reduced that time to just under one
hour 27 .
As discussed previously, buildings have become
much taller and heights continue to increase beyond
the ability of anyone from the upper stories to
egress down stairs. Also, these buildings are much
less tapered with height compared to early Figure 7 –Typical powered wheelchair with
skyscrapers, with larger occupant loads in the upper attached ventilator is used by people with
floors. People today are larger and less fit, and severe disabilities such as Christopher
accessibility regulations have resulted in a growing Reeve. He could only survive away from his
fraction of occupants with mobility limitations chair for a few minutes, and he and the
weighed 300 kg (660 lb) (photo used
requiring egress assistance. Increasingly, there are chair
with permission)
people in buildings who cannot be moved down
stairs under any circumstances (Fig 7). Following the collapse of the WTC buildings,
occupants of tall buildings are reluctant to delay egress and are not comfortable with long
egress times.

STRAWMAN EGRESS SYSTEM PERFORMANCE METRICS
Based on the prior review and discussion the following suggestions are provided to
facilitate the needed rethinking of the philosophy and details of egress system design for
buildings. Thresholds and performance levels are public policy decisions that need to be
made in conformance with the methods in place for making regulatory decisions in an
individual country. These usually require public consultation and a legislative or
administrative process. The suggestions provided in the following sections include
provisions that would be formatted as code requirements (in bold) followed by
explanatory material.
Performance Objectives
Buildings shall be designed and arranged such that the responding fire brigade can
access a fire on any floor and begin suppression operations within 30 minutes of the
transmission of the original alarm, 95 % of the time.
It is expected that this objective will require the provision of a fire service access elevator
in buildings with occupied floors more than 30 m (100 ft) above the level of fire
department access. The 95 % criterion is intended to recognize that conditions may exist
that prevent the objective from being met on occasion, but that most expected conditions
should be considered. The 30 min limit is based on the U.S. requirement for local water
supply for automatic suppression systems.
Buildings shall be designed and arranged such that 98 % of the expected occupants
are able to evacuate the building without outside assistance in a time not exceeding
half of the required fire resistance time of the primary structural frame.
In the U.S. model building codes buildings taller than 4 stories are required to be Type I
construction with either 3-h (Type IA) or 2-h (Type IB) fire resistance as determined in
ASTM E119 for elements comprising the primary structural frame. Thus the maximum
total egress time (applying a safety factor of 2.0) would be either 1.5 h or 1h, respectively.
The 98 % reflects an expectation that there may be some occupants who will require the
assistance of the fire brigade for egress, but that even most occupants with disabilities can
either self-evacuate or require only assistance from other occupants. It is expected that
this requirement would result in occupant egress elevators in Type IA buildings taller
than 80 stories and Type IB buildings taller than 50 stories.
Protected Fire Service Access Elevators
Where required, at least one elevator serving every floor shall be designated for use
by the fire service in emergencies. This elevator shall be powered by normal and
emergency power, with both power and control wiring protected by fire resistant
construction at least equal to the fire resistance requirement applicable to the
primary structural frame. Any alarm transmission to the fire brigade shall result in
the designated fire service elevator being taken out of normal service and recalled to

the designated level. The designated fire service elevator shall open on every floor
into a protected lobby with direct access to a building stair containing a standpipe
and any other required equipment for fire department use. The elevator equipment
shall be protected from compromise by water from sprinklers or firefighting.
Reliable communication with fire service personnel using the elevator and
monitoring of critical functions in the fire command center shall be provided.
Fire service access is not normally considered part of the egress system design except to
the extent operations within the building can have an impact on the evacuating occupants.
The only code found where this is explicitly discussed is in UK Approved Document B
which suggests that in tall buildings one stair may need to be discounted because it will
be blocked by operations on the fire floor and one or two floors below. It should also be
recognized that this “attack stair” may be compromised on any floor(s) above the fire due
to smoke leakage into the stair from the fire floor when the hose is advanced onto the
floor, since the standpipe is located within the stair. Only where a vestibule is provided
(in the U.S. called a smokeproof tower or fire tower) would the stair itself be kept mostly
smoke free. However, the evacuation assistance provided by the fire service, especially
by the fire service elevator, will have a significant impact on the success of the
evacuation.
Protected Occupant Egress Elevators
Where required, all elevators except any designated fire service elevator(s) shall be
designed and arranged to permit their safe use for occupant evacuation. These
occupant elevators shall be powered by normal and emergency power, with both
power and control wiring protected by fire resistant construction at least equal to
the fire resistance requirement applicable to the primary structural frame.
Occupant egress elevators shall operate in a hoistway protected from the adverse
effects of water and opening into a protected lobby on each floor that serves as an
area of refuge while awaiting the elevator. The lobby shall be sized to accommodate
75 % of the occupant load of the floor at 0.5 m2 (5 ft2) per person. Elevator lobbies
shall have direct access to an egress stair and be provided with two-way
communications to the fire command center and approved means to provide real
time information to waiting occupants.
On a fire alarm the elevators shall begin evacuating occupants of the fire floor and
two floors above and below the fire floor, taking them to the level of exit discharge
before returning for another load until all 5 floors are evacuated. On a decision for
a full building evacuation by the official in charge the elevators shall evacuate all
remaining occupants from the highest floors and proceeding downwards, shuttling
occupants to the level of exit discharge before returning for another load.
Information systems on all floors except the level of exit discharge shall
communicate to occupants the status of the system and the estimated wait time.
Information systems on the level of exit discharge shall indicate that the elevators
are out of service and people should not enter.

Occupant egress elevators are by far the fastest means of evacuating a tall building. In
normal service the number, size, and speed of passenger elevators in most buildings are
designed to be able to move approximately 10 % of the total population of the building
from random floors to the level of exit discharge in 5 min. This means that any building
of any height can be totally evacuated by elevator in one hour or less without increasing
the number, size, or speed of the elevators normally provided. Modern elevators utilize
computerized controllers capable of sophisticated operational protocols, and the addition
of real time monitoring and information systems can add the necessary reliability and
guidance to users to permit their use for egress during fires. In addition, occupants use
the building elevators every day for normal ingress and egress. The use of the elevators
for egress in fires is not appreciably different as long as the people are provided with
sufficient information to make decisions.
Considerable effort by NIST, the elevator industry, the American Society of Mechanical
Engineers (ASME), and the building code organizations is being put into the
development of standards and code requirements for protected elevators both for fire
service access and for occupant egress. The language suggested above for both purposes
is consistent with that effort but the activity needs to play out to arrive at a consensus on
requirements for the elevator equipment. Similarly, proposals are being considered by
the model building code organizations for the building code related parts of the systems.
Again, the performance objectives above are consistent with those proposals but the
process should play out to arrive at a consensus of the involved parties.
Stair Width
Where stairs are the primary means of vertical egress in fires and other emergencies
such stairs shall be a minimum width of 1400 mm (56 in). Where protected
elevators are provided as the primary means of vertical egress in fires and other
emergencies stairs shall be a minimum width of 1100 mm (44 in).
Wider stairs are needed to accommodate the increased body size of occupants but this
additional width is not needed where most occupants would be expected to egress by
elevator. Further, any building provided with occupant egress elevators would also have
fire service access elevators, eliminating the issue of counterflow except for the fire floor
and one or two floors below in the attack stair.
Stair Capacity
Where stairs are the primary means of vertical egress in fires and other emergencies
sufficient stair capacity shall be provided to accommodate the maximum number of
building occupants on all floors except any with direct access to the outside, within
the stairways. Where protected elevators are provided as the primary means of
vertical egress in fires and other emergencies sufficient stair capacity shall be
provided to accommodate at least half the maximum number of building occupants
on all floors except any with direct access to the outside, within the stairways. Any
floor containing an assembly space that results in a higher occupant load when

provided with an area of refuge sized to accommodate 100 % of the occupant load
of that floor with direct access to a stair and an occupant egress elevator, shall be
permitted to neglect the additional occupant load for the purpose of determining
stair capacity.
While the philosophy of “storing” stationary occupants in stairs is not intended, the stairs
remain a more protected space within the building. Some occupants may choose to use
stairs (particularly on the lower floors) and the ability to find refuge in stairs is an
important redundancy. Where occupant egress elevators are provided it is expected that
most occupants will use them, but some minimum capacity for refuge is needed.
Likewise, the provision of assembly occupancies (restaurants, bars, conference facilities,
observation decks, …) that result in local concentrations of additional people traditionally
required additional stair capacity that continued through the building to the level of exit
discharge. With occupant egress elevators most of these people will egress by elevator
and it is only necessary to accommodate them temporarily while they await the elevators.
The capacity of an egress stair is defined as the number of occupants who can
descend the stair in a time equal to one half the fire resistance time of the primary
structural frame, at a flow rate of 47 occupants per minute per meter of stair width
(26 occupants per minute per unit of exit width). (The design flow rate is a policy
decision among (81, 47, or 30) occupants per minute per meter with 47 being used in
this example).
The number of occupants that could be served by a stair should be based on the flow or
discharge rate (Flow Method as defined in the 1935 NBS report) over 1h (Type IB) or 1
½ h (Type IA). Table 1 below shows discharge rates per hour, per (22 in) unit and per
meter, and for a 1100 (44 in) and 1400 (56 in) stair, based on assumed flows of 45
occ/min/unit (which has no specific scientific basis but is used in the UK Approved
Document B), 26 occ/min/unit (based on the work of Togawa and Pauls), and 16
occ/min/unit (based on estimates from the NIST WTC report). If one used a flow rate of
26 occ/min/unit, a single 1100 mm (44 in) stair could serve 2160 people (4320 for two
stairs) and a 1400 mm (56 in) stair could serve 2750 people (5500 for two stairs). This
would be the total number of occupants served by the stair(s) on all floors except those
with direct egress to the outside (who would not use the stairs). This would also be
limited to 50 or 80 stories since it would take longer than (1 or 1 ½) hours to descend
from greater heights.
Table 1 – Total Number of Occupants Served by an Egress Stair Based on Flow
Flow
Flow
Dis Rate
Dis Rate
Dis Rate
Dis Rate
occ/min/unit occ/min/meter occ/h/unit* Occ/h/meter* Occ/h/1.1 m* Occ/h/1.4 m*
45
81
2700
4860
5350
5830
26
47
1560
2820
3100
3380
16
30
960
1800
1980
2160
* Multiply by 1.5 for Type IA Construction where ASET is 1 ½ h

In a system designed by the flow method it is important to ensure that the flow through
doors is equal to or greater than the stair flow so that flow restrictions and congestion is
avoided. This raises an interesting issue. There seems to be consensus that flow through
doors is about 60 occupants per minute per door regardless of width. If a design stair
flow rate of 26 occupants per minute per unit is selected, the stair flow in a 2-unit (44 in,
1100 mm) stair is 52 per minute which can be accommodated by a single door. In a 2 ½
unit (56 in, 1400 mm) stair the flow is 65 per minute which will theoretically result in an
accumulation of 5 people per minute at the upstream side of a single door. It needs to be
determined if 56 in stairs need double doors to prevent congestion, as this can be a
significant cost issue in design.
Stair Geometry
Current requirements in the building codes reviewed are consistent with the research
recommendations.
Refuge Floors
Horizontal transfer corridors designed as means of egress components shall be
provided every 25 floors (generally on mechanical floors) to link all egress stairs and
to provide the ability to safely move between stairs.
The initial experience with refuge floors indicates that the provision of a means to
transfer stairways has merit but the provision of a large space to “rest” encourages delays
in evacuation that may be counterproductive to safety. The protected lobby with direct
access to a stair provided as part of the occupant egress elevator system can provide for
rest stops if needed, but most occupants would use the elevators and not need to rest.
Thus, it is recommended to not provide refuge floors but to consider a protected
horizontal transfer corridor linking all stairways on the mechanical floors. The 25 floor
increment is based on the Asian requirement for refuge floors but could be flexible where
only stairway crossovers are provided.
Evacuation Management
Video cameras shall be installed every 5 floors in every egress stairway and in every
egress elevator lobby with the images displayed in the fire command center. Image
analysis software shall be employed to minimize the fire department burden for
monitoring these images.
The potential for changing conditions impacting the safety and efficiency of the
evacuation suggests that full building evacuations need to be actively managed. The
addition of cameras in the stairs and egress elevator lobbies which can be monitored in
the fire command can facilitate such management. Using available software developed
for the security industry the monitoring burden in fire command can be minimized.
Images from cameras in stairs would be kept in background except when no movement is
detected for some time interval, indicating no people or no movement of people. Images

from lobby cameras would be kept in background except when movement is detected,
indicating there are people in the lobby needing pickup. If that floor has not yet been
evacuated this information can be registered with the elevator controller. If the floor has
already been evacuated the presence of stragglers would be noted to the fire department.
Placement every 5 floors is considered reasonable for the purpose. More frequent is
probably not necessary for active management of egress but less frequent might permit
unobserved blockages.
CONCLUDING REMARKS
The increasing height of buildings coupled with changing demographics and public
concerns about the safety of tall buildings have led to a call for a fundamental rethinking
of egress systems. This paper provides a review of the approaches currently found in
building regulations internationally, and attempts to identify the origins of these
specifications including the extent to which they may be based on scientific data or
consensus opinion. The case for moving to a performance metric of time is presented and
a set of criteria for evaluating egress systems against safe egress time is suggested.
Performance criteria based on practical objectives are suggested but these and suggested
regulatory thresholds need to be vetted through the existing consensus process of model
code development and regulatory adoption followed in the adopting jurisdiction. The
result should be a design approach that addresses the needs of occupants and buildings of
all heights with criteria based on sound engineering principles.
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15