British Royal Navy`s U-class   The first three U-class submarines were ordered in 1936 to serve as unarmed targets for anti-submarine vessels. But in a change of policy, and perhaps foreseeing the coming war, Undine, Unity, Ursula laid down at Vickers in February 1937, were modified during construction to accommodate six bow torpedo tubes, 4 internal and 2 external, so that they could undertake short offensive missions. To allow the construction of a deck gun the hull in front of the conning tower was reinforced. From their first sea trails the three boats preformed excellently, and together with low coast and ease of production made the design very successful.   In 1939, a realization of the inevitability of war, the Admiralty ordered the first quantity production, the boat were found very suitable for operation in the North Sea and the Mediterranean.   Under the 1940-41 war programs a second batch of submarine was ordered. This second group did not differ much from the first, the tow external torpedo tubes were removed, an approximately increase of 5 feet in the stern gave them a more streamlined shape aft and improved the flow of water over the propellers Specifications, U-class, first group: A simple saddle-tank hull design Displacement (srf/sub tons): 630/730             Dimensions (L*B*D feet): 190`7*15`9*15`9 Propulsion: 2*615hp dieselengines, 2*825hp electric motors driving two shafts Speed (srf/sub knots): 11.5/9 Range (srf/sub n/miles@knots): 4,050@10/170@2.5 or 23@8 Diving depth (feet): 200 Complement: 5 officers 26 enlisted Torpedo: 4*21" (533 mm) internal bow torpedo tubes, 2*21" external bow torpedo tubs, total of 10 torpedoes Mines: none Armament: 1*3" main deck gun, 3*0.303 machine guns Construction First group of fifteen boats, three + twelve, were built in 1937-40. The second group of thirty-four submarines were built in 1940-43. A production of 22 similar V-class submarines, based on the U-class, were built during the war time-differ in welded hull giving them 300 feet diving depth.  Back to History Index   Image Country Year Description United Kingdom 2001 Unity class 1939, SSK