(a) Except as allowed in paragraphs (b) and (c) of this section, plates, forgings, forged and rolled fittings, and rolled and forged bars and shapes used in the construction of the contiguous steel hull structure must meet the thickness and steel grade in Table 1 for the temperatures under Sec. Sec. 154.174(b) and 154.176(b).
(b) for a minimum temperature, determined under Sec. Sec. 154,174(b) and 154.176(b), below -25 [deg]C (-13 [deg]F), the contiguous steel hull structure must meet Sec. 54.25-10 for that minimum temperature.
(c) If a steel grade that is not listed in Table 1 has the equivalent chemical properties, mechanical properties, and heat treatment of a steel grade that is listed, the steel grade not listed may be specially approved by the Commandant (CG-ENG), for use in the contiguous hull structure.
Table 1--Minimum Temperature, Thickness, and Steel Grades in Contiguous
Hull Structures------------------------------------------------------------------------
Minimum temperature Steel thickness Steel \1\ grade------------------------------------------------------------------------0 [deg]C (32 [deg]F)............ All............... Standards of the
American Bureau
of Shipping
published in
``Rules for
Building and
Classing Steel
Vessels'', 1981-10 [deg]C (14 [deg]F).......... T<=112.5 mm (\1/2\ B
in.).
12.525.5 mm E
(1 in.).-25 [deg]C (-13 [deg]F)......... t<=112.5 mm (\1/2\ D
in.).
12.5 mm E
(\1/2\ in.).------------------------------------------------------------------------\1\ Steel grade of the American Bureau of Shipping published in ``Rules
for Building and Classing Steel Vessels'', 1981. [CGD 74-289, 44 FR 26009, May 3, 1979, as amended by CGD 82-063b, 48 FR 4782, Feb. 3, 1983; CGD 77-069, 52 FR 31630, Aug. 21, 1987]