(a) The purpose of this subpart is to establish mandatory safety and operational requirements to reduce environmental damage resulting from the discharge of other non-petroleum oil.
(b) This subpart applies to each tank vessel specified in Sec. 157.01 of this part that--
(1) Is 5,000 gross tons or more;
(2) Carries other non-petroleum oil in bulk as cargo or cargo residue; and
(3) Is not equipped with a double hull meeting Sec. 157.10d of this part, or an equivalent to the requirements of Sec. 157.10d, but required to be equipped with a double hull at a date set forth in 46 U.S.C. 3703a (b)(3) and (c)(3).