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 Armstrong, 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-Armstrong 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.