France Rolls Out Fifth Suffren-Class Nuclear Attack Submarine for Final Fitting and Testing

France has moved its fifth next-generation nuclear-powered attack submarine, the Rubis, out of its construction hall in Cherbourg as the vessel enters the next stage of completion and testing, Christopher McFadden reported for Interesting Engineering.

France's fifth Suffren-class nuclear attack submarine, Rubis, leaves its construction hall in Cherbourg for final fitting and testing. [Photo: Marine natonale Facebook]

The submarine, designated S639, is the fifth vessel in France's Suffren-class program, also known as the Barracuda program. It is intended to replace the French Navy's older Rubis-class nuclear attack submarines, which entered service beginning in the 1980s.

Naval Group, the French shipbuilder responsible for the program, has already moved the new Rubis from its construction hall.

The submarine was transferred toward the shipyard's launch and transfer system in Cherbourg, marking a major construction milestone.

The move means the submarine's principal structure has been completed, but it does not mean the vessel is ready for operational service.

Further work remains, including the installation, integration and testing of onboard systems.

The submarine will undergo checks at the quay before proceeding to sea trials, after which it must meet the requirements for delivery and acceptance by the French Navy.

Sea trials could take place in 2027, although the schedule remains subject to the completion of fitting-out work and testing. No confirmed date for the start of trials was identified in the reporting reviewed.

The Suffren class is designed for a range of missions, including anti-submarine warfare, intelligence gathering, special-forces support and land-attack missions.

Its design includes an X-shaped stern control arrangement and pump-jet propulsion, features intended to support maneuverability and reduce underwater noise.

France plans to field six Suffren-class submarines to replace its six older Rubis-class boats.

The program is intended to strengthen the French Navy's undersea capabilities, with the remaining vessels scheduled to enter service over the coming years.

The sixth and final submarine in the new class is named Casabianca. Completion of the fleet is planned by the end of the decade, although individual delivery dates may change as construction and testing progress.