1625-0101 Stat/Authority

46 CFR 31.10-21a (up to date as of 3/25/2025)
Periodic gauging of tank vessel midbodies more than 30 years old that...

46 CFR 31.10-21a (Mar. 25, 2025)

This content is from the eCFR and is authoritative but unofficial.

Title 46 —Shipping
Chapter I —Coast Guard, Department of Homeland Security
Subchapter D —Tank Vessels
Part 31 —Inspection and Certification
Subpart 31.10 —Inspections
Authority: 33 U.S.C. 1321(j); 46 U.S.C. 2103, 3205, 3306, 3307, 3703; 46 U.S.C. Chapter 701; E.O. 12234, 45 FR 58801, 3 CFR,
1980 Comp., p. 277; E.O. 12777, 56 FR 54757, 3 CFR, 1991 Comp., p. 351; DHS Delegation No. 00170.1, Revision No. 01.4.
Section 31.10-21 also issued under the authority of Sect. 4109, Pub. L. 101-380, 104 Stat. 515.
Source: CGFR 65-50, 30 FR 16662, Dec. 30, 1965, unless otherwise noted.

Editorial Note: Nomenclature changes to part 31 appear by USCG-2025-0186, at 90 FR 12238, Mar. 17, 2025.
§ 31.10-21a Periodic gauging of tank vessel midbodies more than 30 years old that carry certain
oil cargoes—TB/ALL.
(a) As used in this section, the term “midbody” means the 40-percent midship length (0.40L) of the tank
vessel. The age of the midbody is determined from its year of original construction.
(b) Midbodies of all tank vessels certificated to carry a pollution category I oil cargo listed in 46 CFR table
30.25-1 must undergo an initial gauging survey and periodic regauging surveys as follows:
(1) An initial midbody gauging survey must be accomplished no later than the next drydocking
inspection after the midbody becomes 30 years old.
(2) Regaugings:
(i)

Midbodies of double hull tank vessels, or single hull tank vessels with independent tanks, that
operated in fresh water at least 6 months in every 12-month period since the last drydock
examination must be regauged at intervals not exceeding 10 years;

(ii) Midbodies of all other tank vessels must be regauged at intervals not exceeding 5 years.
(c) The midbody gauging survey must be comprised of at least three transverse (girth) belts of deck, bottom,
side, inner hull, trunk, and longitudinal bulkhead plating and attached longitudinal members. The number
and specific locations of the gauging points shall be to the satisfaction of the Officer in Charge of Marine
Inspection (OCMI).
(d) Except as provided in paragraph (f) of this section, within 60 days of the vessel's required compliance date
the owner or operator shall submit the following to the OCMI that issued the vessel's current Certificate of
Inspection:
(1) The gauging survey results.
(2) An engineering analysis signed by a registered Professional Engineer licensed by any state of the
United States or the District of Columbia, or signed by a Coast Guard-approved organization, that—
(i)

Certifies the vessel's compliance with the minimum section modulus and plating thickness
requirements of subpart 32.59 of this chapter; or

46 CFR 31.10-21a(d)(2)(i) (enhanced display)

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46 CFR 31.10-21a (up to date as of 3/25/2025)
Periodic gauging of tank vessel midbodies more than 30 years old that...

46 CFR 31.10-21a(d)(2)(ii)

(ii) Proposes structural repairs and/or modifications that will bring the vessel up to the required
strength standards.
(e) The vessel owner or operator shall keep a permanent copy of the Coast Guard-approved gauging report
available for inspection by the OCMI.
(f) Instead of the submittals required by paragraphs (c) and (d) of this section, current classification with the
American Bureau of Shipping or another recognized classification society, or a load line certificate issued
in accordance with the International Convention on Load Lines or the International Voyage Load Line Act,
may be submitted as evidence of compliance with the requirements of this section.
[CGD 91-209, 58 FR 52602, Oct. 8, 1993]

46 CFR 31.10-21a(f) (enhanced display)

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