§ 154.459 — General

(a) Each cargo tank must have a secondary barrier that meets Table 3 and except as allowed in Table 3, the hull must not be the secondary barrier.

(b) If the Commandant (CG-ENG) specially approves an integral tank for a design temperature at atmospheric pressure lower than −10 °C (14 °F), the integral tank must have a complete secondary barrier that meets § 154.460.

(c) If the Commandant (CG-ENG) specially approves a semi-membrane tank under the requirements of an independent tank type B, the semi-membrane tank may have a partial secondary barrier specially approved by the Commandant (CG-ENG).

(d) If Table 3 allows the hull to be a secondary barrier, the vessel's hull must:

(1) Meet §§ 154.605 through 154.630; and

(2) Be designed for the stresses resulting from the design temperature.

Table 3—Secondary Barriers for Tanks