Redoutable-class submarine (1967)
The "Le Redoutable"-class submarine was a ballistic missile submarine class of the French "Marine Nationale". In French, the type is called "Sous-marin Nucléaire Lanceur d'Engins" (SNLE), literally "Missile-launching nuclear submarine". When commissioned, they constituted the strategic part of the naval component of the French nuclear triad, then called "Force de frappe" (the aircraft carriers and constituting the tactical part). The class entered active service in 1971 with , six submarines were built in total. All have since been decommissioned. The structural changes in "Inflexible" have seen it regarded as a different class from the early  boats. The class has been superseded by the , firing the larger M45 missile (M51 from around 2010). Service history. The first submarine, "Redoutable", was ordered in 1963, built at Cherbourg, launched in 1967 and commissioned in 1971. The first of the class were armed with the M1 MSBS ("Mer-Sol Balistique Stratégique"), the French term for a submarine-launched ballistic missile. 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" 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 The reactor compartment has been replaced by a new section.