Whiskey-class submarines (known in the Soviet Union as Projects 613, 640, 644, and 665) are a class of diesel-electric attack submarines that the Soviet Union built in the early Cold War period. Design The initial design was developed in the early 1940s as a sea-going follow on to the S-class submarine. As a result of war experience and the capture of German technology at the end of the war, the Soviets issued a new design requirement in 1946. The revised design was developed by the Lazurit Design Bureau based in Gorkiy. Like most conventional submarines designed 1946–1960, the design was heavily influenced by the Type XXI U-boat. Patrol variants Between 1949 and 1958 a total of 236 of an envisaged 340<ref>Kuzin, V.P.; Nikolskiy V.I. Voyenno-morskoy Flot SSSR 1945-1991. Istoricheskoye Morskoye Obshchestvo, Sankt Peterburg, 1996</ref> submarines of this type were commissioned into the Soviet Navy. The vessels were initially designed as coastal patrol submarines. These patrol variants are known in the west as Whiskey I, II, III, IV, and V and were called Project 613 in the Soviet Union. Whiskey I − twin guns in conning tower Whiskey II − twin guns and twin 25 mm guns Whiskey III − guns removed Whiskey IV − 25 mm guns Whiskey V − no guns - streamlined conning tower and snorkel Missile variants In the 1950s and 1960s some Whiskey submarines were converted to guided missile submarines, with the capability to fire one to four SS-N-3 Shaddock cruise missiles. In 1956, the first prototype was ready. It was a regular Whiskey class modified with a launch tube aft of the sail containing a single SS-N-3c. This vessel was known in the West as Whiskey Single Cylinder. Between 1958 and 1960, six additional Whiskey-class submarines were converted to carry guided missiles. These boats had two missile tubes behind the sail, and were known in the west as the Whiskey Twin Cylinder, and Project 644 boats by the Soviets. Between 1960 and 1963, six boats received an extended sail that could contain four Shaddock missiles. These were called Whiskey Long Bin in the West and Project 665 in the Soviet Union. All guided missile variants of the Whiskey class carried the P-5/ NATO SS-N-3c Shaddock land-attack missile, and had to surface in order to fire their missiles. The boats of the single and twin cylinder class also had to raise their missile tubes, which were