With commendable foresight, considering the quantity of tonnage then being ordered, the 1938 Naval Estimates allowed for the construction of one of a new type of ship, to be employed on the maintenance of the aircraft of a Fleet Air Arm that was obviously due for expansion. She was to be the aviation equivalent of a submarine or destroyer depot ship in providing major forward repair facilities for jobs beyond the capabilities of the average carrier. Though described as an 'aircraft maintenance carrier', it would appear that acting as a carrier was part of her specification, an option taken up due to the wartime shortage offlightdecks. Like the Ark Royal, HMS Unicorn was given two hangars and a flightdeck increased in length by an ungainly overhang aft. She possessed great freeboard with only moderate length, giving an oddly foreshortened aspect.
The Unicorn was laid down in 1939, launched in 1941 and completed in 1943, in time to join the CVEs of Force V, tasked to provide the fighter cover for both fleet and forces ashore in the first 24 hours following the landings at Salerno. In the event, it was nearly four days before the capture of an airfield ashore could relieve the force of the responsibility, during which time the combination of the CVEs' low speed and small decks while operating in near windless conditions, wrote off over 40 fragile Supermarine Seafire fighters in deck accidents alone. The Unicorn's 6-kt speed advantage and larger deck prevented even more losses.
By early 1944 the Unicorn was in the Far East, still doubling as operational carrier pending the delayed arrival of the Victorious. Laid up for several years after the war, she was reactivated for the Korean War, finding at last her true vocation at a time when shore air support was almost all carrier-based. The Unicorn shuttled with replacement aircraft to and from Singapore, her space frequently being used as short-term trooping accommodation. She was scrapped in 1959.
Designed as an 'aircraft maintenance carrier', wartime shortage of carriers led to HMS Unicorn being pressed into frontline service. Aspart of Force V, Unicorn helped provide figh ter support for the Salerno landings in 1943 and saw action off Okinawa the next year.
Equipped with a double hangar like Ark Royal, Unicorn had a shortened hull, giving her a rather cumbersome appearance. In reserve from 1946 to 1949, she was recommissioned as a transport carrier for the Korean war, ferrying aircraft and serving as a troopship.
Specification HMS Unicorn Type: maintenance carrier and secondary light fleet aircraft-carrier Displacement: 14,750 tons standard Dimensions: length 195. l m (640 ft); beam 27,4 m (90 ft); draught 5.8 m (19 ft) Propulsion: 2-shaft geared steam tur bines delivering 40,000 shp (29828 kW) Speed: 24 kts Armour: none Armament: four twin 114-mm (4,5-in) DP, three quadruple 2-pdr AA, and 12 20-mm AA guns Aircraft: 35 when used as a light fleet carrier Complement: 1,050