1625-0101 Stat/Authority

46 CFR 32.59-1 (up to date as of 3/25/2025)
Minimum section modulus and plating thickness requirements—TB/ALL.

46 CFR 32.59-1 (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 32 —Special Equipment, Machinery, and Hull Requirements
Subpart 32.59 —Minimum Longitudinal Strength and Plating Thickness Requirements for
Unclassed Tank Vessels That Carry Certain Oil Cargoes—TB/ALL
Authority: 46 U.S.C. 2103, 3306, 3703, 3719; E.O. 12234, 45 FR 58801, 3 CFR, 1980 Comp., p. 277; DHS Delegation No. 00170.1,
Revision No. 01.4; Subpart 32.59 also issued under the authority of Sec. 4109, Pub. L. 101-380, 104 Stat. 515.
Source: CGFR 65-50, 30 FR 16671, Dec. 30, 1965, unless otherwise noted.

§ 32.59-1 Minimum section modulus and plating thickness requirements—TB/ALL.
(a) As used in this section, Rule means the current Rules of the American Bureau of Shipping or other
recognized classification society, as appropriate for the vessel's present service and regardless of the
year the vessel was constructed.
(b) The requirements of this section apply to all in-service, unclassed tank vessels certificated to carry a
pollution category I oil cargo listed in 46 CFR Table 30.25-1.
(c) For all vessels except those limited on their Certificate of Inspection to river routes only, the minimum
midship section modulus must be—
(1) At least 90 percent of that required by Rule; or
(2) Where there is no specific Rule requirement, at least 100 percent of that which is necessary to meet
the bending moment developed under a full load condition in still water, using a permissible bending
stress of 12.74 kN/cm2 (1.30 t/cm2, 8.25 Ltf/in2).
(d) Within the 40-percent midship length, the average flange and web thicknesses of each longitudinal
stiffener must be as follows:
(1) For deck and bottom stiffeners: at least 85 percent of Rule thickness, unless a buckling analysis
demonstrates that lesser thicknesses can be safely tolerated. However, the average thickness must
never be less than 80 percent of Rule thickness; and
(2) For side stiffeners: at least 75 percent of Rule thickness.
(e) Within the 40-percent midship length, the average thickness for longitudinal strength plating must be at
least as follows:
(1) Weather deck: 75 percent of Rule thickness;
(2) Hatch: 70 percent of Rule thickness;
(3) Trunk: 75 percent of Rule thickness;
(4) Sheer strake: 75 percent of Rule thickness;
(5) Outer sideshell: 75 percent of Rule thickness;
(6) Inner sideshell: 75 percent of Rule thickness;
46 CFR 32.59-1(e)(6) (enhanced display)

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46 CFR 32.59-1 (up to date as of 3/25/2025)
Minimum section modulus and plating thickness requirements—TB/ALL.

46 CFR 32.59-1(e)(7)

(7) Outer bottom; 75 percent of Rule thickness;
(8) Inner bottom: 70 percent of Rule thickness;
(9) Keel: 75 percent of Rule thickness;
(10) Bulkheads: 75 percent of Rule thickness.
[CGD 91-209, 58 FR 52602, Oct. 8, 1993]

46 CFR 32.59-1(e)(10) (enhanced display)

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