 When the class was designated as "K", names beginning with that letter were allocated to the ships but never used.The class saw extensive wartime service and seven were lost, including four at the Battle of Jutland.The "Acasta"s were larger and heavier armed than the preceding H and I classes ( and , respectively), displacing about 25% more and with the mixed calibre armament replaced with a uniform fit of QF 4-inch guns, which the "Acasta"s introduced.