The Dupuy de Lôme class consisted of two submarines built for the French Navy during World War I. Commissioned in 1916, they did not enter service until 1918. Both boats were re-engined with diesels taken from ex-German U-boats during the mid-1920s. They were sold for scrap in 1938.

Design and description The Dupuy de Lôme class were built as part of the French Navy's 1913 building program.Smigielski, p. 211 The double-hulled boats were designed by naval constructor Julien Hutter to satisfy a requirement for steam-powered, high-speed submarines. They displaced surfaced and submerged. The boats had an overall length of , a beam of , and a draft of . Their crew numbered 41 officers and crewmen.Roberts, p. 452

For surface running, the Dupuy de Lôme-class boats were powered by a pair of three-cylinder vertical triple-expansion steam engines, each driving one propeller shaft using steam provided by two oil-fired du Temple boilers that operated at a pressure of . The engines were designed to produce a total of to give a speed of , but during 's sea trials on 20 April 1916, she only reached from . When submerged each shaft was driven by a electric motor. The designed speed underwater was , but the boats only reached during their sea trials. Sané demonstrated a surface endurance of at and a submerged endurance of at during her trials.

The Dupuy de Lôme class was armed with a total of eight torpedoes. Two internal torpedo tubes in the bow angled outwards three degrees. Four more were located in four external rotating launchers amidships, two on each broadside; one pair each fore and aft of the conning tower that could traverse 143 degrees to the side of the boats. The last pair were in external tubes in the stern aimed outboard at an angle of seven and a half degrees. While the boats were under construction, a anti-aircraft (AA) gun was ordered to be installed in August 1915, but this was ordered to be replaced by a light gun later that year. Another 75 mm gun was added to the boats in an order dated April 1916. Sané had her forward 75 mm gun replaced by a gun in 1917.Garier 2000, pp. 106–107

Ships Name BuilderLaid downLaunchedCompleted Fate Dupuy de Lôme (Q105)Arsenal de Toulon1 September 1913 9 September 191522 July 1916 Stricken, 29 July 1935 Sané (Q106) 29 December 1913 27 January 1916 September 1916Stricken, 24 July 1935

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