Terms of Service and Privacy PolicyAt first glance, the Soviet submarine S-49 looks like a design mistake. The Project 633 submarines were diesel-electric attack submarines developed for the Soviet Navy in the 1950s and built in Gorky (modern-day Nizhny Novgorod). In 1969, S-49 returned permanently to the Black Sea Fleet and continued in service as a normal Soviet attack submarine. Essentially a giant underwater weapons laboratory, the Project 633RV allowed engineers to test the entire firing process before the weapons entered service on operational submarines. Analogous to the U.S.-made Tomahawk, this was the first missile of its class fielded on Soviet submarines.