Post-war Developments

 

After the war, the Allies were quick to adopt modern German submarine technology. The British built two experimental submarines using peroxide turbine propulsion, but the unstable nature of hydrogen peroxide and the success of American nuclear propulsion caused the concept to fall out of favor. The Soviets began building improved versions of their Type XXI submarines. Some 265 of these submarines, designated Whiskey and Zulu classes by NATO observers, were completed between 1950 and 1958, more than all other navies built between 1945 and 1970 combined. (Soviet shipyards produced a total of 560 new submarines during this period.) The U.S. Navy studied German technology and converted 52 war-built submarines to the Guppy configuration (the "y" being the acronym for "Greater Underwater Propulsion"). It was added for pronunciation reasons. These submarines removed their deck guns and installed streamlined conning towers; larger batteries and snorkels were installed; four torpedoes were fired, and some boats had one of their four diesel engines removed. As a result, they had a submerged speed of 15 knots and better underwater endurance.

After World War II, the major powers switched to nuclear power, but most of the world's navies continued to buy, and in some cases build, submarines that were direct descendants of the fast diesel-electric submarines of the war. (Indeed, many of them were designed and built in West Germany.) Postwar diesel-electric submarines continue to be equipped with snorkels, but fighter aircraft have adopted improved radars that can detect even the small heads of snorkels, and aircraft are similarly equipped with more snorkels. Primitive radars from World War II could detect submarines that had surfaced during World War II.