The Porpoise class was the first class of operational submarines built for the Royal Navy after the end of the Second World War, and were designed to take advantage of experience gained by studying German Type XXI U-boats and British wartime experiments with the submarine Seraph, which was modified by streamlining and fitting a bigger battery.[1][2][3]
The Porpoise-class submarines were 290 feet 3 inches (88.47 m) long overall and 241 feet 0 inches (73.46 m) between perpendiculars, with a beam of 26 feet 6 inches (8.08 m) and a draught of 18 feet 3 inches (5.56 m). Displacement was 1,565 long tons (1,590 t) standard and 1,975 long tons (2,007 t) full load surfaced and 2,303 long tons (2,340 t) submerged.[1] Propulsion machinery consisted of two Admiralty Standard Range diesel generators rated at a total of 3,680 brake horsepower (2,740 kW), which could charge the submarine's batteries or directly drive the electric motors. These were rated at 6,000 shaft horsepower (4,500 kW), and drove two shafts, giving a speed of 12 knots (14 mph; 22 km/h) on the surface and 16 knots (18 mph; 30 km/h) submerged.[4][3] Eight 21-inch (533 mm) torpedo tubes were fitted; six in the bow, and two in the stern. Up to 30 torpedoes could be carried, with the initial outfit consisting of the unguided Mark 8 and the homing Mark 20 torpedoes.[1]
Narwhal ran aground at the entrance to Campbeltown Loch, Scotland, on 4 April 1960.[5] She was refloated the next day.[6]
'Narwhal' briefly appears, unnamed, in the 1961 film of The Day Of The Triffids
In 1970 she was present at Portsmouth Navy Days.[7] In October 1976, Narwhal, together with the nuclear attack submarine Sovereign, took part in Operation Brisk, to gain experience in under-ice operations, with Sovereign going on to surface at the North Pole.[8]
Narwhal was decommissioned for the last time on 10 February 1977.[9] On 2 June 1980 Narwhal was sunk off Portland, but was raised in a salvage exercise on 26 June 1980 by the Swedish heavy-lift ship Hebe III.[10] She was scuttled as a target on 3 August 1985 and lies in the English Channel.[11]
United Kingdom
