L'Inflexible (S 615) was 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.

The submarine uses the M4 missile, which carries 6 independent 150 kilotonnes of TNT equivalent nuclear warheads.

L'Inflexible received TIT (Traitement de l'Information Tactique, "Tactical Information Processor"), a cluster of French-designed computers and serial digital bus links for intersystem communication and DMUX21 sonar.

L'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.

You can help Wikipedia by expanding it.This article about a specific military ship or boat of France is a stub.