French Start Next-Generation Ballistic Nuclear Missile Submarine Program

Naval Group Image

French Military Minister Florence Parly last week announced the start of the full development phase of the SNLE 3G program, which will see the construction of France’s third generation nuclear missile submarines (SSBN) of the third generation.

The event on February 19 took place in the hydrodynamics test center of the French General Armaments Directorate (DGA) in Val-de-Reuil, Normandy.

The Military Planning Act 2019-2025, France’s military planning law, calls for the replacement of the four SSBNs of the Le Triomphant class with four SSBNs of the third generation (SNLE 3G) from 2035. This is intended to ensure the continuity of French seafaring and deterrent with at least one SSBN on patrol See anytime.

The French armed forces and the DGA (Direction Générale de l’Armement or the French government’s defense procurement and technology agency), which is responsible for all project management, run the SNLE 3G program. It is the subject of a framework agreement with industry on the development, industrialization, logistics and production of the four SSBNs. The Naval Group is the prime contractor for all submarine manufacturing in a joint venture with TechnicAtome, which is responsible for building core boilers.

The first order, which will be awarded in 2021, includes the development studies by the end of 2025, the realization of the first elements of the hull and boiler room of the first SNLE 3G, as well as the adaptation of the Naval Group’s industrial manufacturing equipment for this program.

During her speech, Parly said, “The third generation SSBN will be slightly longer and heavier compared to the Le Triomphant class SSBN. It’ll hear better and defend itself better. It will be quieter: it won’t be louder than a school of shrimp, which is absolutely extraordinary. It will blend in perfectly with the ambient sounds of the sea, which is a guarantee of operational superiority. “

More than 200 companies from the French industrial and technology base of defense will work with the Naval Group to provide design or construction services for devices and systems.

Ultimately, this program will include up to 100 million man hours over the next 30 years, including 15 million hours of design and more than 80 million hours of construction.

More than 300 people work in design and construction activities at the Naval Group’s submarine yard in Cherbourg, more than 2,000 employees. The teams in Cherbourg will build the platform – hull, structure and part of the internal modules – integrate the equipment and systems into the platform and carry out commissioning and testing of the submarine facilities.

As part of the SNLE 3G program, the DGA has signed a Memorandum of Understanding with Thales for the development of a complete sonar suite that includes a wide range of sonar arrays and associated processing systems.

Thales will provide new generation flank arrays and arch-mounted sonars, an optical technology (ALRO) -based linear tow array and all other devices in the sonar suite (intercept arrays, echo sounders, underwater telephones).

Naval Group Image

The ALICIA sensor data processing system (Analyze, Locate, Identify, Classify by Intégrées et Alertes) with a user interface designed for the variety and volume of data available, optimizes the operator’s workload and provides decision support.

The new Sonarsuite will be made available gradually, with the first technological components and system versions to be installed on second generation SSBNs (SNLE 2G) from 2025 and on third generation submarines (SNLE 3G) from 2035.

TechnicAtome is responsible for the planning, construction and commissioning of the nuclear propulsion reactor in collaboration with the Naval Group, which has overall responsibility for the ships.

According to the company, the design of the reactor for the third generation SSBN benefits from more than 50 years of expertise in compact reactors with the permanent integration of innovations to increase the military performance of the reactor, its availability and the energy capacity of its core and nuclear safety guarantees. In this regard, the SNLE 3G program’s nuclear propulsion reactor is a link between the lower-powered reactor of the Barracuda-class submarine and the reactor of the future PANG aircraft carrier. This reactor, known as the K22, delivers a significantly higher output. Your design studies have just started to follow suit Decision of the French President Emmanuel Macron on December 8, 2020.

The overall design of SNLE 3G seems to be an evolution of the SNLE 2G (Le Triomphant class SSBNs) rather than a revolution. Like its predecessor, it has a sail tip: a one-piece composite fairing that is attached to the submarine sail and hull. It improves hydrodynamic performance by allowing an even laminar flow of water over its surface. It also features a pump jet. The stern arrangement is reminiscent of the Suffren-class SSN (X-rudder configuration), but includes a centerline fin for a towed array. According to the artist’s impression, the hull of SNLE 3G is completely covered with anechoic tiles. The current class of French SSBNs also has tiles, but only in some key areas of the hull. Echo-free tiles are tiles made of rubber or synthetic polymer that help absorb the sound waves from active sonar, as well as the lower noise emitted by the submarine itself.

According to submarine expert HI Sutton, the bow arrangement, in which the entire nose is dedicated to a sonar dome, implies a very large spherical sonar arrangement. This is similar to the Le Triomphant class. The design shows only four torpedo tubes mounted behind the sonar dome. These have to be angled outwards in order to bypass them. This can limit the speed at which torpedoes can be fired.

Speaking to Naval News during the event, the French Navy’s SNLE 3G program officer (Marine Nationale) told Naval News that future SSBNs will be prepared for threats from 2035 and beyond, particularly in the area of ​​sonar detection.

SNLE 3G by the numbers

Naval Group Image

Length: About 150 meters
Shift: 15,000 tons (submerged)
Crew addition: Over 100 sailors


  • 16x modernized M51 SLBM (probably known as M51.4)
  • 4x torpedo tubes for F21 heavyweight torpedo and probably the FCASW (Future Cruise and Anti-Ship Weapon)

First steel cut: 2023
Delivery of first class SSBN to the French Navy: 2035
Year out of service (for the class): 2090

Comments are closed.