GW50A May 1955
The Sea Lords on 28 January 1955 directed DNC to prepare a 5in armed cruiser based on GW36. The resulting GW39 inspired Staff Requirement TSD 2295/55 for a cruiser with two twin 5in, 48 missiles and 31kts deep and dirty. This became GW41. Further developments included the 6in Mk26 and a notional single 6in mount (GW42-46). These provided the Sea Lords with useful guidance but all were poor designs with inefficient use of magazine space. In April 1955 the Controller asked for another series of designs, by now Armstrong Whitworth had supplied more concrete data on the Sea Slug weight and dimensions and a decision was taken to abandon the 5in gun. However, the 5in still crops up, including the 4.5in Mk.6. GW48 was the smallest, GW49 had twin 5in guns, GW50 was a revised GW47 with three YEAD units to provide adequate speed, displacing 13,000 tons and dimensions of 570 x 76 x 19ft 6in.
When Mountbatten visited Bath on 17 May he was shown the sketch design of GW50A, basically GW50 with a displacement margin added. The design grew too. Displacement 13,500 tons (deep). Dimensions were 600ft (oa) (590 ft wl) x 76ft x 19ft 3in. Speed was 31.5kts deep and clean with three 35,000shp YEAD sets, endurance 4,500nm at 20kts. Armament was two twin 5in, four twin 40mm L/70 and 48 Sea Slug missiles. The radar fit was one Type 901 director, six MRD-3, Type 984, Type 992 and Type 974. A self-defence Type 176 sonar was likely too. Armour protection was 1.5in side and deck except for the machinery areas which had 1in deck.
Drawing Note: This drawing based on official sketch drawings of GW50A
GW51A May 1955
GW51 was the 6in armed version of GW50 with a raised bridge. Displacement was 13,900 tons; dimensions 590 x 77 x 19ft 6in and 31.75kts speed. When Mountbatten visited Bath on 17 May he was shown the sketch design of GW51A, basically GW51 with a displacement margin added. Displacement 14,500 tons (deep). Dimensions were 625ft (oa) (615 ft wl) x 77ft x 19ft 6in. Speed was 31.5kts deep and clean with three 35,000shp YEAD sets, endurance 4,500nm at 20kts. Armament was two twin 6in, four twin 40mm L/70 and 48 Sea Slug missiles. The radar fit was one Type 901 director, six MRD-3, Type 984, Type 992 and Type 974. A self-defence Type 176 sonar was likely too. Armour protection was 1.5in side and deck except for the machinery areas which had 1in deck. Complement was 78 officers and 970 ratings.
Drawing Note: This drawing based on official sketch drawings of GW51A
GW52A May 1955
GW52 was a version of GW51 with two twin 3in L/70 mounts aft, adding 160 tons of weight and 10ft to the length. Displacement was 14,500tons; dimensions 600 x 78 x 19ft 9in and 31.75kts speed. When Mountbatten visited Bath on 17 May he was shown the sketch design of GW52A, basically GW52 with a displacement margin added. Displacement 15,100tons (deep). Dimensions were 635ft (oa) (626ft wl) x 78ft x 19ft 9in. Speed was 31.5kts deep and clean with three 35,000shp YEAD sets, endurance 4,500nm at 20kts. Armament was two twin 6in, two twin 3in L/70, two twin 40mm L/70 and 48 Sea Slug missiles. The radar fit was one Type 901 director, six MRD-3, Type 984, Type 992 and Type 974. A self-defence Type 176 sonar was likely too. Armour protection was 1.5in side and deck except for the machinery areas which had 1in deck. Complement was 76 officers and 970 ratings.
Drawing Note: This drawing based on official sketch drawings of GW51A