She was designed as a aircraft depot ship to support real carriers and for submarine and destroyer chasing. For the latter task she was fitted out with a full length flight deck, catapults for launching planes and so on. When used as a support ship were on board workshops operating and carried she with her for instance 36,000 gallons aviation fuel to provide the carriers. The HMS Perseus was a comparable ship. Ordered on 14 April 1939, laid down at the yard of Harland and Wolff at Belfast, North Ireland on 26 June of the same year, launched on 20 November 1941, commissioned on12 March 1943, decommissioned in January three years later, again commissioned in 1949, decommissioned on 17 November 1953 and broken up at Faslane in 1960. With a displacement of 14,750 long tones/14,490 tons (normal)-20,300 long tons/20,600 tons (full load) were her dimensions 200 x 27,51 x 7,0 (full Load) metres or 640’ x 90.25’ x23’. The two Parsons geared turbines and 4 Admiralty 3-drum boilers supplied 40,000 shp allowing a speed of 22 knots. Her crew numbered 1,000 men. The armament consisted of 4x2-100mm guns, 3x4-12pdr (=40mm) anti aircraft guns and 8-20mm guns and she carried with her 35 planes. She was also slightly armoured namely flight deck and magazines were protected by 2” armour.