The Grampus-class submarines were a group of minelaying submarines built for the Royal Navy in the late 1930s. These boats are sometimes referred to as the Porpoise class from the single prototype, HMS Porpoise built in 1932. Five boats to a modified design were built between 1936 and 1938. The ships were all named after marine mammals.
|Preceded by:||River class|
|Succeeded by:||T class|
|Length:||289 ft (88 m) (Porpoise), 293 ft (89 m) (others)|
|Beam:||29 ft 10 in (9.09 m) (Porpoise), 25 ft 6 in (7.77 m) (others)|
|Draught:||15 ft 10 in (4.83 m) (Porpoise), 16 ft 10 in (5.13 m) (others)|
|Propulsion:||2 shaft, Diesel (3300 hp) plus electric (1630 hp)|
Only one, HMS Rorqual, survived the war.
Boats in class
|HMS Porpoise (N14)||Vickers, Barrow||30 August 1932||Sunk by Japanese aircraft in the Malacca straits, 16 January 1945.|
|HMS Grampus (N56)||Chatham Dockyard||25 February 1936||Sunk by Italian torpedo boats Circe and Clio off Sicily 16 June 1940.|
|HMS Narwhal (N45)||Vickers, Barrow||29 August 1935||Sunk 30 July 1940 by German aircraft near Norway.|
|HMS Rorqual (N74)||Vickers, Barrow||21 July 1936||Arrived Newport to be broken up 17 March 1946.|
|HMS Cachalot (N83)||Scotts||2 December 1937||Sunk by Italian torpedo boat Generale Achille Papa off Cyrenaica 30 July 1941.|
|HMS Seal (N37)||Chatham Dockyard||27 September 1938||Captured by the Germans in the Kattegat 4 May 1940 after sustaining mine damage, commissioned as the UB, scuttled 3 May 1945, but later raised and scrapped.|
|Wikimedia Commons has media related to Grampus class submarine.|