Double-hulled tanker after 6 July 1993 to be fitted with double hulls, or an alternative design approved by IMO". However, in the aftermath of the Erika incident of the coast off France in December 1999, members of IMO adopted a revised schedule for the phase-out of single-hull tankers, which came into effect on 1 September 2003, with further amendments validated on 5 April 2005. After the Exxon Valdez oil spill disaster, when that ship grounded on Bligh Reef outside the port of Valdez, Alaska in 1989, the US Government required all new oil tankers built for use between US ports to be
Oil tanker has a capacity of over , a length overall of and a cargo capacity of . They were the first ULCCs to be double-hulled. To differentiate them from smaller ULCCs, these ships are sometimes given the "V-Plus" size designation. With the exception of the pipeline, the tanker is the most cost-effective way to move oil today. Worldwide, tankers carry some annually, and the cost of transportation by tanker amounts to only US$0.02 per gallon at the pump. In 1954 Shell Oil developed the average freight rate assessment (AFRA) system which classifies tankers of different sizes. To make it an independent