French submarine Surcouf 1927-1942

Building started at Cherbourg on 1 July 1927,  1927, launched on 18 October 1929, commissioned in on 16 April 1934, sunk on 18 February 1942 around 80 miles North of Cristobal, Colon when she was destined towards Tahiti when she was hit by the American freighter Thompson Lykes and stricken from the list on 6 December 1943. Until the building of the Japanese 400-class she was the largest submarine ever built. Due to her size she was called in her time a undersea cruiser. Due to the fact that the Washington Naval Treaty didn’t limit the sizes of submarines she could be built, the London Naval Treaty prevented further building of such large submarines.

With a dead displacement of 2,880 tons, 3,250 tons while surfaced and 4,304 tons while submerged were her dimensions 110 x 9 x 7,25 metres or 361 x 29’6” x 23’8”. The test depth was 90 metres. The depth trials where in 1931.

Her two Sulzer diesel engines provided 7,600 hp allowing a surfaced speed of 18,5 knots. The two electric motors supplied 3,400 hp allowing a submerged speed of 10 knots. She was fitted out with two screws. With a surfaced speed of 10 knots was her range 10,000 nautical miles and with 13,5 knots 6,800 nautical miles. With a submerged speed of 4,5 knots her range was 70 nautical miles and with 5 knots 60 nautical miles. Her endurance was 90 days.

Her crew numbered 118 men.

The armament consisted of 2-203,cm guns placed in a twin turret, 2-37mm anti aircraft guns, 4-13,2mm anti aircraft guns, 5-55,ocm torpedo tubes and 4-40cm torpedo tubes. She carried with her 14-55cm and 8-40cm torpedoes. She also carried one Besson MB.411 floatplane and one motorboat.