(a) The structure of an integral tank must meet the deep tank scantling standards of the American Bureau of Shipping published in ``Rules for Building and Classing Steel Vessels'', 1981.
(b) The structure of an integral tank must be designed and shown by calculation to withstand the internal pressure determined under Sec. 154.407. [CGD 74-289, 44 FR 26009, May 3, 1979, as amended by CGD 77-069, 52 FR 31630, Aug. 21, 1987]