The first group of six ships were under construction at a variety of yards when they were bought. Swan Hunter and Wigham Richardson Ltd and Harland and Wolff built two each, while Cammell Laird and Co. and Lithgows each produced one. The ships saw active service during the war, in the Arctic, Atlantic and the Far East. was bombed and sunk while sailing as part of Convoy PQ 17 in 1942, while was wrecked during the operations off Narvik in 1940. was torpedoed in the Mediterranean and broke in half, but was later repaired, was nearly destroyed by a kamikaze attack in the Pacific, and was accidentally torpedoed by at Trincomalee in 1944. Those ships that survived the war remained in service with the Royal Fleet Auxiliary, with most being disposed of in the early 1960s. The longest-lived was "Bishopdale", which despite being decommissioned in 1959, was not scrapped until 1970.