Saphir-class submarine (1928)

The Saphir-class submarines were a class of six submarines built in France between 1926 and 1935 for the French Navy. Most saw action during World War II for the Vichy French Navy or the Free French Naval Forces. Three were captured by Italian forces but not used.

Design
Saphir-class submarines had a surfaced displacement of 761 LT and a submerged displacement of 925 LT. Their dimensions were 66 m long, with a beam of 7.1 m and a draught of 4.3 m. Propulsion while surfaced was provided by two Normand-Vickers diesel motors with a total of 1300 bhp and while submerged by two electric motors providing a total of 1000 hp through two shafts enabling a maximum speed of 12 kn while surfaced and 9 kn while submerged. Their bunkers of 95 LT of oil fuel gave them a surfaced range of 7000 nmi at 7.5 kn, and 4000 nmi at 12 kn and their batteries a submerged range of 80 nmi at 4 kn. They carried a complement of 42 men. Saphir-class submarines could dive up to 250 ft.

The Saphir-class submarines were designed to launch torpedoes and lay mines without surfacing. The moored contact mines they could lay contained 220 kg of TNT and could be laid in up to 200 m of water. They were attached to the submarine's exterior under a hydrodynamic protection and were jettisoned with compressed air.

Service
During the war, five Saphir-class ships operated in the Mediterranean Sea and only Rubis operated with the Home Fleet. Later, she joined the ranks of the Free French Naval Forces. During its service on the side of the Allies, Rubis was a very effective ship. From April 1940 to the end of 1944, it carried out 22 mine laying operations in the waters off Norway. 15 ships sank on its mines, including minesweepers, 4 small warships, and submarines. In addition, it sank one ship with torpedoes. Only one ship in the Mediterranean Sea changed sides to join the Allies, Perle, which on 8 July 1944 was mistakenly sunk in the Atlantic by an Allied plane.

Of the remaining submarines, Diamant was scuttled at Toulon on 27 November 1942; Nautilus, Saphir and Turquoise were demobilized in Bizerte between 1941 and 1942. After the occupation of Tunis by Axis troops, they were taken over by Italians in December 1942. Saphir was renamed "FR 112", and Turquoise, "FR 116". These ships were unusable and disarmed remained in Bizerte until the end of activities in Africa. Shortly before surrendering, the Italians sank them. Only Rubis survived the war and was withdrawn from service on 4 October 1949.