T-class submarine

The T class, also called the Triton class, was a group of fifty-three British diesel-electric patrol submarines built just before and during the Second World War to replace the earlier O, P and R classes. The design began in 1934 and stressed a powerful bow torpedo armament, long range for the Pacific and easier maintenance than its predecessors. The lead boat, Triton, was commissioned on 9 November 1938. Most boats came from Vickers at Barrow-in-Furness, but the Royal Dockyard at Chatham on the River Medway built several of them, among them Torbay, Tradewind, Trenchant, Turpin and Thermopylae. Four boats served in the Royal Netherlands Navy as the Zwaardvisch class, and survivors were rebuilt after the war in the Super-T conversion, some of it also done at Chatham. The Royal Navy retired its last operational boat in 1969.