Redoutable-class submarine (1967)

With the election of Charles de Gaulle as president of France, the French Armed Forces saw a change in direction. Under the new government, French forces were withdrawn from NATO formations due to French unhappiness with American domination of the group. Beginning in the 1960s, French foreign policy would be reshaped to create independence from both of the major opponents of the Cold War, the United States and the Soviet Union. This was later defined in the mantra "to deter – to intervene – to defend". From the foreign policy arose the concept of submarine-based "Force de Dissuassion", with emphasis on the "to deter", which was the focus of new French naval spending.[2]

The new nuclear-powered, nuclear-armed submarine force was planned to be of similar size to the British Royal Navy. However, unlike the British, the French received no support from other nations and the French nuclear program began with a lack of technological expertise to draw from. Furthermore, the Americans refused to provide the French Navy with enriched uranium for the creation of a nuclear reactor.[2] Nevertheless, the project was authorized in 1963.[3] The French Navy resorted to working in conjunction with the civil French Alternative Energies and Atomic Energy Commission (French: Commissariat à l'énergie atomique et aux énergies alternatives), which the US allowed to acquire enriched uranium for experimental land use. A nuclear plant was constructed on land at Cadarache and the reactor was tested to simulate nuclear-powered submarine patrols.[2] Other developments made by the groups working on the project include the development of high-tensile steel by France and the adaption of the submarine hull to nuclear propulsion.[4]

At the same time as the French were developing nuclear propulsion, they were also researching ballistic missiles and nuclear warheads. Caissons were constructed to test fire missiles and by 1967, the submarine Gymnote was fitted with the guidance and navigation systems to be tested. The first ballistic missile launch was at the Landes Trials Centre (French: Centre d'Essais des Landes) at the end of 1968 and nuclear warheads were tested at Moruroa in the Pacific Ocean.[2]

Comparison of different nuclear systems: left, the SNLE (Redoutable type) with the M4 missile; right, the SNLE-NG (Triomphant type) with the present M45 missile and the future M51 missile.

Designated Sous-marin Nucléaire Lanceur d'Engins (SNLE) literally "Missile-launching nuclear submarine", the design initially measured 128 metres (419 ft 11 in) long overall with a beam of 10.6 metres (34 ft 9 in) and a draught of 10 metres (32 ft 10 in). The submarines initially displaced 7,500 tonnes (7,400 long tons) surfaced and 9,000 tonnes (8,900 long tons) submerged.[5] This later increased to 8,000 tonnes (7,900 long tons) surfaced.[6] The submarines were powered by one pressurised water reactor providing steam to two turbines and two alternators and turning one propeller via a turbo reduction drive creating 12,100 kilowatts (16,200 hp). The submarines also sported electric emergency propulsion capable of providing a range of 5,000 nautical miles (9,300 km; 5,800 mi). The vessels could dive more than 200 metres (660 ft) and had a maximum speed of 20 knots (37 km/h; 23 mph). Each boat had two twin crews comprising 15 officers and 120 men.[7]

The first submarine, Redoutable, was ordered in 1963, built at Cherbourg, launched in 1967 and commissioned in 1971. This was replaced by the M2 MSBS beginning in 1974, which was in turn replaced by the M20 MSBS beginning in 1977. All except Redoutable were heavily upgraded from 1985 to fire the second generation MIRV capable M4 missile – Tonnant was recommissioned in 1987; Indomptable in 1989; Terrible in 1990; and Foudroyant in 1993.

Redoutable in Cherbourg

Redoutable has been preserved since 2002 as a museum ship at the Cité de la Mer naval museum in Cherbourg-Octeville, France. The reactor compartment has been replaced by a new section.[10]

• List of submarines of France

• Blackman, Raymond V. B., ed. (1972). Jane's Fighting Ships 1972–73. London: Sampson Low, Marston & Company. OCLC 28197951.
• Couhat, Jean Labayle, ed. (1986). Combat Fleets of the World 1986/87. Annapolis, Maryland: Naval Institute Press. ISBN 0-85368-860-5.
• Gardiner, Robert; Chumbley, Stephen & Budzbon, Przemysław, eds. (1995). Conway's All the World's Fighting Ships 1947–1995. Annapolis, Maryland: Naval Institute Press. ISBN 1-55750-132-7.
• Miller, David (1982). O'Neill, Richard (ed.). An Illustrated Guide to Modern Submarines. Arco. ISBN 0-66805-495-6.