HMS P311

	Practice torpedo is loaded onto P311 at the Holy Loch, Scotland, 1942
History
United Kingdom
Name	HMS P311
Ordered	11 June 1931
Builder	Vickers-Armstrongs, Barrow
Laid down	25 April 1941
Launched	5 March 1942
Commissioned	7 August 1942
Fate	Sunk 8 January 1943
Badge
General characteristics
Displacement	1,290 tons surfaced; 1,560 tons submerged;
Length	276 ft 6 in (84.28 m)
Beam	25 ft 6 in (7.77 m)
Draught	12 ft 9 in (3.89 m) forward; 14 ft 7 in (4.45 m) aft;
Propulsion	Two shafts; Twin diesel engines 2,500 hp (1.86 MW) each; Twin electric motors 1,450 hp (1.08 MW) each;
Speed	15.5 knots (28.7 km/h) surfaced; 9 knots (20 km/h) submerged;
Range	4,500 nautical miles at 11 knots (8,330 km at 20 km/h) surfaced
Test depth	300 ft (91 m)
Complement	61
Armament	6 internal forward-facing 21-inch (533 mm) torpedo tubes; 2 external forward-facing torpedo tubes; 2 external amidships rear-facing torpedo tubes; 1 external rear-facing torpedo tubes; 6 reload torpedoes; 1 x 4-inch (102 mm) deck gun;

HMS P311 was a T-class submarine of the Royal Navy, the only boat of her class never to be given a name. She was to have received the name Tutankhamen but was lost before this was formally done. P311 was a Group 3 T-class boat built by Vickers-Armstrongs at Barrow-in-Furness and commissioned on 5 March 1942 under the command of Lieutenant R.D. Cayley. She was one of only two T-class submarines completed without an Oerlikon 20 mm anti-aircraft gun, the other being HMS Trespasser.