Double Hull Tankers

Minimum Required Ballast

The MEPC agreed an interpretation of MARPOL Regulation 13F for determining which tanks and void spaces may be credited in determining compliance with the minimum ballast capacity required to facilitate safe operation during ballast voyages without introducing ballast to the cargo tanks. Engine room ballast tanks or the portion of ballast tanks located within the cargo block extending inboard or above the theoretical double hull boundary are to be excluded from the aggregate ballast capacity. However, void spaces existing within the double hull boundary may be included in the aggregate ballast capacity.

Application of the Double Hull Requirements

The existing interpretation under MARPOL 73/78, which allows a vessel delivered after the date specified in the regulations to be treated as an “existing” vessel (rather than a “new” vessel provided the delayed delivery was unforeseen) was extended to cover vessels under the double hull provisions of regulation 13F.

Accordingly, vessels which were contracted prior to 6 July 1993 or, in the absence of a contract, began construction prior to 6 January 1994 may be treated as an existing vessel and thereby excluded from the double hull provisions of regulation 13F if the vessel did not complete its construction by 6 July 1996 due to an unforeseen circumstances beyond the control of the builder and the owner in the vessel’s delivery. The U.S. reserved its position on this unified interpretation.