French submarine Inflexible (S615)

The Inflexible (S 615) is the sixth and final of the Redoutable class SNLE ("Sous-marin Nucléaire Lanceur d'Engins", "Nuclear Missile-Launching Submarine") of the Force océanique stratégique (FOST), the submarine nuclear deterrent component of the French Navy.

Construction began on 27 March 1980. She was launched on 23 June 1982, commissioned on 1 April 1985 and decommissioned on 14 January 2008.

Inflexible uses basically the same design as the other Redoutable-class vessels, but has benefited from technological advances over its predecessors:

• She uses the M4 missile, which carries 6 independent 150 kilotonne of TNT equivalent nuclear warheads. Range is reported to be over 4500 km.
• Miscellaneous improvements were made in electrical systems, nuclear systems (improving safety and stealth), rudder and engines (improving reliability and stealth).
• TIT (Traitement de l'Information Tactique, "Tactical Information Processor"), a cluster of French-designed computers and serial digital bus links for intersystem communication.
• DMUX21 sonar.
• Capability of launching the SM 39 Exocet anti-ship missile
• Improved inertial navigation system.
• Improved internal communication system—SNTI, Système Numérisé de Transmissions Intérieures (Digital Internal Communication System)
• Miscellaneous acoustical stealth improvements
• Improved hull profile

The other Redoutable-class submarines have been modified to meet the standards of the Inflexible ("Refonte M4"). The Inflexible was officially decommissioned on 14 January 2008.

In entertainment

Inflexible has inspired Le Soleil ne se lève pas pour nous ("No sunrise for us") by Robert Merle, a 1987 semi-fictitious book in form of a romanced documentary.