Britain’s Military Afloat Reach and Sustainability (MARS) program was begun in 2002, and aimed to buy up to 11 supply ships for the Royal Navy’s Royal Fleet Auxiliary. Unfortunately, all the project could produce was studies, MoD planning delays, and slow progress. In 2007, MARS was broken up into a series of smaller buys, with an initial focus on the critical state of the RFA’s fuel carriers. Even that effort ran into delays, but the last 3 years have seen Britain’s Royal Fleet Auxiliary retire 3 of its 4 Leaf Class replenishment oilers. Another 3 of its remaining 5 oilers were commissioned in 1984 or earlier, and their single-hull design no longer complies with MARPOL regulations for fuel-carrying ships.
Replacements are urgently needed, in order to keep the Royal Navy supplied around the world. In February 2012, Britain finally placed a MARS order for 4 oilers, which will measure over 200m long and around 37,000t apiece. It has been expected for some time that these ships would be built outside of Britain, and that has held true.