English: A model of the Colossus Class Light Feet Carrier HMS Ocean at the Glasgow Transport Museum, 2 March 2007.

By 1941 it was clear there was an urgent need for a fleet carrier that could be built in numbers much more quickly than the large, armoured Fleet Carriers then being built. Moreover, the Naval dockyards were fully occupied for the foreseeable future. The answer was to use merchant ship builders to build a cheap, simple, unarmoured carrier using mercantile scantlings, not warship ones (although using modified Naval machinery from cancelled cruisers) with a life just long enough for the duration of the war. Sixteen Colossus Class carriers were ordered but in the event six were redesigned as Majestic Class carriers to operate larger and faster aircraft. The ten Colossus carriers were launched in 1943-44 and completed in 1944-46, two being completed as Aircraft Maintenance Carriers. They had 42,000 shp geared turbines, 2 screws and a maximum speed of 25 kts. The ships measured 695 ft x 80 ft x 18.6 ft and had a displacement of 13,200 tons. As designed their armament was 24x2 pdr AA pom poms (6x4) and 16x20mm AA guns but as each ship was completed, the AA armament was strengthened and eventually only 40mm AA guns were carried (usually 17). 48-52 aircraft were usually carried. Before the war ended, six Colossus carriers were completed of which four fleet carriers plus a maintenance carrier were posted to the Pacific Fleet but arrived too late to see combat.

HMS Ocean was built by Alexander Stephen, Glasgow being launched in 1944 and completed in 1945. Although she was completed before the end of the war and intended for the Pacific Fleet, in the event she was sent to Cammell Laird, Birkenhead for conversion to a specialised night fighter carrier with the latest radar and these works weren’t completed until November 1945. Apart from operating Fairey Firefly night fighters, she was the last carrier to operate Fairey Swordfish biplanes and the first to operate the twin-engined de Havilland Hornet. She was also used for the first pure-jet landing on a carrier, a de Havilland Sea Vampire flown by the incomparable Eric ‘Winkle’ Brown in December 1945. She also operated Supermarine Seafires and did two tours in the Korean War in 1952 and 1953 when one of her Hawker Sea Furies shot down a MiG-15. In the 1956 Suez Crisis she was used as a helicopter assault carrier with Bristol Sycamores and Westland Whirlwinds. After that she became a training carrier, was placed in reserve in 1958 and broken up in 1962.