Surcouf

The Surcouf (N N 3) was a cruiser submarine in service with the French Navy. Launched in 1929, it was commissioned on April 16, 1934. It was designed by the French engineer Robert Surcouf. It was the largest submarine in the world until the emergence of the Imperial Japanese Navy I-400 submarine launched in 1944.

After the German invasion of France in May 1940, it served with the French free forces from June 1940. However, it would be sunk long before the war ended, not by the Germans but by an American ship. It was accidentally sunk by the US steamer Thompson Lykes in the Gulf of Mexico on February 18, 1942. The American ship had rammed the Surcouf, opening a gaping crack through which tons of water rushed in until it went down to the bottom of the ocean.

Technical Features

The Surcouf (N N 3) had a double hull, heavy gun armament as it was fitted with two 203mm naval guns, which was quite unusual for a submarine. It was also equipped with fire control system, a motor boat, and cargo compartment. Its power plant allowed it to sail for long distances without mooring at port, more than 18,000 km.

Specifications

Length: 110 m (361 ft)

Beam: 9 m (29 ft, 6 in)

Displacement: 4,304 tons (submerged)

Draft: 7.25 m (23 ft, 9 in)

Power Plant: 4 Sulzer Diesel engines; 2 electric motor; 2 shafts, generating 7,600 HP.

Armament: eight 550mm and four 400mm torpedo tubes, four in bow, the other external; two 203mm guns, and two 37mm AA guns.

Compliment: 118 sailors and officers

The French submarine Surcouf in 1937