Seems a lot faster than the UK Trident replacement programme - assuming it sticks to schedule of course....
https://www.defensenews.com/naval/20...-missile-subs/
France to begin building new ballistic missile subs
PARIS — France has launched the program for its Navy’s third-generation nuclear-powered ballistic missile submarines, which will see four vessels eventually delivered to the service.
The Navy is expected to received the first submarine in 2035, with the other three following at a schedule of one every five years.
These four boats, known in France as SNLE (sous-marin nucléaire lanceur d’engin) “will replace the
current [ones] without a break,” Armed Forces Minister Florence Parly announced last week. She said the subs will sail until 2090. “The last sailors to patrol on this SNLE third generation have not yet been born.”
The contracting authorities are the DGA procurement agency and the Alternative Energies and Atomic Energy Commission. The project management will lie with
Naval Group and TechnicAtome, the latter being the prime contractor for the nuclear boiler room.
Thales announced it signed a memorandum of understanding with the DGA for the development of a complete sonar suite for the boats “based on disruptive technologies that represent a significant break from the systems in service today.”
The company will provide new-generation flank arrays and bow-mounted sonars; a towed linear array based on optical technology; as well as intercept arrays, echo sounder technology and underwater telephones. The company said the new sonar suite will be incrementally deployed, with the first versions installed on the current SNLEs.
Parly said the new submarines will be “slightly longer and heavier” than the current Le Triomphant class, which first sailed in 1995 and will continue to do so until 2050. She added that the vessels will “hear better and defend themselves better whilst at the same time being more silent: They will not make more noise than a school of shrimp.”
Parly noted that given the extreme length of this program, France will “maintain a margin for evolutions [in the design], indispensable to take account of technological breakthroughs that we cannot forecast today — I’m thinking notably of cyber defense, improvements in acoustic stealth and the development of better-performing sensors.”......