HMS K7
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 involved in the accident with the 4th Light Cruiser Squadron. She was also involved in the Battle of May Island exercise. K7 was damaged in the exercise by running over the sinking K4. K7 was sold on 9 September 1921 at Sunderland.
Design
K7 displaced 1,800 long tons (1,800 t) when at the surface and 2,600 long tons (2,600 t) while submerged. It had a total length of 338 feet (103 m), a beam of 26 feet 6 inches (8.08 m), and a draught of 20 ft 11 in (6.38 m). The submarine was powered by two oil-fired Yarrow Shipbuilders boilers supplying one geared Brown-Curtis or Parsons steam turbine; this developed 10,500 ship horsepower (7,800 kW) to drive two 7 ft 6 in (2.29 m) screws. Submerged power came from four electric motors each producing 350 to 360 horsepower (260 to 270 kW). It was also had an 800 hp (600 kW) diesel engine to be used when steam was being raised, or instead of raising steam.