British S class, the largest single group of Royal Navy submarines The S-class submarines of the Royal Navy were originally designed and built during the modernization of the submarine fleet in the early 1930’s to meet the need for smaller boats to patrol the restricted waters of the North Sea and the Mediterranean Sea replacing the H-class submarines. Due to major naval construction of the Royal Navy during the Second World War, however, the S-class became the largest single group of submarines ever built for the Royal Navy; a total of 62 were constructed over a period of 15 years, with 50 of the "improved" S-class launched between 1940 and 1945. First Group The first group of S-class submarines consisted of four boats. They were smaller and slower than later classes, and carried less armament, but could be crewed by fewer men. All four were built at Chatham Dockyard, between 1930 and 1932. During the war, they operated in home waters, particularly the English Channel, and off the Scandinavian coast. Second Group The second group of S-class submarines consisted of eight boats. They were larger than the preceding first group and required more men to crew, but carried a similar armament. Construction was divided between Chatham Dockyard, and the yards of Scotts, of Greenock and Cammell Laird & Co Limited, of Birkenhead. All the ships were built between 1934 and 1937. During the war, they, like the submarines of the first group, mostly operated in home waters, ranging as far afield as the Bay of Biscay and the Scandinavian coast. Third Group The third and by far the most numerous group of S-class submarines consisted of 50 boats. They were the largest and most heavily armed of the S-class and required more men to crew. They were one knot faster on the surface, but two knots slower when submerged. Most of the group were built at the yards of either Scotts, of Greenock or Cammell Laird & Co Limited, of Birkenhead, with a handful being built at Chatham, or by Vickers Armstrong Ltd, of Barrow-in-Furness. Construction was carried out throughout the war, particularly between 1941 and 1945. Equipped with a greater fuel capacity than their predecessors, they operated much further afield, in the Mediterranean and in the Pacific Far East.    Specifications, S class, group 3 (improved): Displacement (srf/sub tons): 820/990             Dimensions (L*B*D feet): 219`0*23`9*13`10 Propulsion: diesel-electric 2*950hp 8 cylinder Vickers/Admiralty diesels , 2*650hp Admiralty electric motors, 2 shaft Speed (srf/sub knots): 14.8/9.0 Range (srf/sub n/miles@knots): 6,000@10/65@4 Diving depth (feet): 300 Complement: 5 officers 43 enlisted Torpedo: 6*21" (533mm) internal bow torpedo tubes, 1*21" aft torpedo tube, total of 13 torpedoes  Mines: none Armament: 1*4" main deck gun, 1*20mm’ Oerlikon AA gun, 3*0.303 machine guns Construction A large number of this class were still in service at the end of World War II. Many with long active service were soon sold for breaking up and others expended as targets. Several were transferred, loaned or sold to foreign navies - one to the Netherlands, three to Portugal, four to France and two to Israel. Many still remained as part of the British submarine fleet until well into the 1960s`. Back to History Index           Image Country Year Description Saint Thomas 2008 British Submarine S class