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.