On crude oil tankers>20000dwt and product carriers >30000dwt, the aggregate capacity of all ballast shall not be less than the SBT capacity required under regulation 13 to meet the IMO draft and trim requirements.
Suction wells of cargo tanks may protrude into the DB tank below provided that the well is made as small as possible and the height of the suction well from the bottom is not less than 0.5h from the bottom shell plating.
Ballast, Vent pipes and Sounding pipes shall not pass through cargo tanks and vice versa; except for short lengths of pipes which has to be of complete welded construction or equivalent.
