Construction Begins on France’s First 3G Nuclear-Powered Ballistic Missile Submarine

France's inaugural third-generation nuclear-powered ballistic missile submarine (SNLE 3G) saw its steel cutting ceremony held at Naval Group's shipyard in Cherbourg on March 20, marking the commencement of the project.

Launched in February 2021, the SNLE 3G (Sous-marin nucléaire lanceur d’engins – 3rd generation) program for the French Navy integrates various entities, including the armed forces, the French defense procurement agency DGA, which oversees project management, the French Atomic Energy Commission (CEA) responsible for nuclear boilers, and Naval Group, managing overall project responsibilities for the submarines, in collaboration with TechnicAtome for nuclear boilers.

The program's inaugural follow-on contract, awarded in February 2021, encompasses development studies until the end of 2025, as well as long lead time procurement, production of the first hull, boiler room components for the first 3G SSBN, and adaptation of Naval Group's manufacturing resources to meet the specific requirements of the 3G SSBNs.

Production of the primary components of the nuclear boiler room and propulsion system, notably the tank for the 1st SNLE 3G, has already commenced at Naval Group's Nantes-Indret site.

The 3G SSBNs will possess extended detection capabilities with latest sensors, enhanced stealth attributes including improved hydrodynamics and heightened maneuverability, equipped with new weaponry and combat systems.

The upcoming class appears similar in size and shape to the existing Le Triomphant-class. However, it represents a completely fresh design, boasting nearly 10 meters of additional length, approximately 150 meters in total length, with a submerged displacement exceeding 15,000 tons, although official specifications remain classified.

The crew size, 110 sailors, the number of SLBM silos, 16, and torpedo tubes, 4, will remain consistent with the Le Triomphant-class. The primary rationale behind this increase in size is enhanced stealth capability. The elongated machinery space will accommodate even quieter machinery, possibly incorporating technologies already featured in France's latest nuclear submarine, the Suffren-class attack submarine. Notable external features include the X-form rudders and pumpjet propulsor.

Furthermore, the current French SSBNs (SNLE 2G) will benefit from some of these innovations, preceding the arrival of the four 3G SSBNs, to ensure optimal performance throughout their operational lifespan until the 2050s.