The "Attacker" Class were the second batch of escort carriers built in the USA for the Royal Navy, the lead ship - Attacker - having originally been intended to be one of the "Avenger" Class. They were also the first escort carriers to be ordered after the USA entered the war; the USN kept the other 10 vessels ordered at the same time, as these became the "Bogue" Class.
Like their predecessors they were converted from mercantile hulls; unlike their predecessors they were powered by steam turbines instead of diesels. Speed was increased to18 knots, although overall size and displacement were much the same as the earlier classes.
Although the first of the class arrived in the UK in January 1943, none actually commenced active service until August of that year. This attracted a great deal of American criticism, but was largely caused by unavoidable delays in getting the ships to England, and by what the RN considered to be essential alterations to the aviation fuel systems, lengthening of the flight deck, the addition of permanent ballast, and so on.
Once the ships were ready for action they soon proved themselves, both as convoy escorts and fighter support ships for amphibious landings. The proved to be useful and efficient conversions and had, among other things, introduced the Royal Navy to the American style of cafeteria messing.