Le Redoutable class

   The first French SSBN (or more correctly Sous-marin Nucleare Lanceurs d'Engine or SNLE) Le Redoutable was authorized in March 1963, laid down in November 1964 and commissioned in 1971 after being employed for 2,5 years on trials as the prototype for the French naval deterrent known as the Force de Dissuasion in official circles.

   This vessel and its Le Redoutable class sister ship Le Terrible were initially equipped with the 2 400 km range two-stage solid-propellant inertially-guided M1 SLBM that had a single 500 kT nuclear warhead and a CEP of 930 m. In 1974 the third unit, Le Foudroyant, was commissioned with the improved 3 100 km range M2 SLBM with a more powerful second-stage motor but carrying the same warhead and having a similar CEP. The two previous vessels were then retrofitted with the M2 system during their normal overhauls. The fourth boat, L'Indomptable, was commissioned into service in 1977 with the vastly improved M20 missile that had the same range and accuracy as the M2 but carried a new 1.2 MT yield hardened warhead with what is believed to be chaff-dispensing penetration aids to confuse defending radar systems. The last vessel, Le Tonnant, was also completed with the M20 while the three units equipped with the M2 were subsequently brought up to the same standard.

   From 1985 the last four units built underwent yet another modification to carry the M4 SLBM that entered service aboard L'Inflexible. All five boats were also converted to carry the SM39 Exocet anti-ship missile and sonars of the L'Inflexible class. After the paying off of Le Redoutable in December 1991, the remaining submarines of the class were classified as the L'Inflexible class SNLE M4. The better streamlining of the M4 conversion gave the boats a silhouette similar to that of L'Inflexible.