HMS K7

History
United Kingdom
Name	HMS K7
Builder	HM Dockyard Devonport
Laid down	8 November 1915
Launched	31 May 1916
Commissioned	July 1917
Fate	Sold, 9 September 1921
General characteristics
Class & type	K-class submarine
Displacement	1,980 long tons (2,010 t) surfaced; 2,566 long tons (2,607 t) submerged;
Length	339 ft (103 m)
Beam	26 ft 6 in (8.08 m)
Draught	20 ft 11 in (6.38 m)
Propulsion	2 × 10,500 shp (7.8 MW) Brown-Curtis or Parsons geared steam turbines; 2 × Yarrow boilers; 4 × 1,440 hp (1,070 kW) electric motors; 1 × 800 hp (600 kW) Vickers diesel generator for charging batteries on the surface; 2 × 3-blade 7 ft 6 in (2.29 m) diameter screws;
Speed	24 knots (44 km/h; 28 mph) surfaced; 8 knots (15 km/h; 9.2 mph) submerged;
Range	Surfaced :; 800 nmi (1,500 km; 920 mi) at 24 kn (44 km/h; 28 mph); 12,500 nmi (23,200 km; 14,400 mi) at 10 kn (19 km/h; 12 mph); Submerged :; 8 nmi (15 km; 9.2 mi) at 8 kn (15 km/h; 9.2 mph); 40 nmi (46 mi; 74 km) at 4 kn (4.6 mph; 7.4 km/h);
Complement	59 (6 officers and 53 ratings)
Armament	8 × 18 in (460 mm) torpedo tubes, (4 beam, 4 bow); 8 × spare torpedoes; 2 × 18 in torpedo tubes fitted on deck (later removed); 2 × BL 4 in (100 mm) Mk.XI guns; 1 × 3 in (76 mm) gun;

HMS K7 was a K class submarine built by HM Dockyard, Devonport. She was laid down on 8 November 1915 and commissioned in July 1917.

K7 was the only one of the disastrous K class to engage with an enemy; on 16 June 1917 she fired a salvo of torpedoes at the U-boat U-95 and scored a direct hit. However, the torpedo failed to explode with what has been described as typical "K" luck; K-7 escaped retaliation by steaming away at speed.

K7 was involved in an accident with the 4th Light Cruiser Squadron. She was also involved in the catastrophic series of accidents during a night exercise that came to be known sarcastically as the Battle of May Island; K7 was damaged by running over the sinking K4. K7 was sold on 9 September 1921 at Sunderland.