The SNLE-3G ceremony took place in presence of the chief of the French Navy, Admiral Vaujour, the head of the defense procurement agency, Emmanuel Chiva, and the CEOs of Naval Group (shibuilder) and TechnicAtome (in charge of the nuclear reactors).
Pierre Éric Pommellet, CEO of Naval Group, said:
“We are proud to symbolically launch the production of the hull of the first 3rd-generation SSBN today, alongside the DGA, the French Navy, the Atomic Energy Commission and Technicatome, as well as all our state and industrial partners. Through this major program, Naval Group is fully committed to serving French sovereignty and nuclear deterrence, by mobilizing all its skills, talents and industrial resources, and by drawing on a solid defense industrial and technological base, spread across the country.”
Naval Group expects to start assembling the various sections of the first submarine around 2026-2027 ahead of a launch in the early 2030ies and a delivery to the French Navy “after” 2035 (exact year is still confidential at this stage). The four submarines are expected to ensure the French sea-based nuclear deterrent until the 2080ies.
Full scale development of the new submarine, known as SNLE-3G (Sous-marin nucléaire lanceur d’engins – 3rd generation), was launched in February 2021. The new class, which has not yet received a ship name, will replace the current Le Triomphant-class nuclear-powered ballistic missile submarines (SSBN). Like the current boats the new submarines will be built by Naval Group.
At first glance the new submarine is similar in size and form to the current Le Triomphant-class. But it is an entirely new design and is actually almost 10 meters (30 ft) longer (about 150 meters in length, 15,000+ tons displacement submerged, but official figures are still classified). The crew complement (110 sailors), number of SLBM silos (16x) and torpedo tubes (4x) will remain unchanged compared to the Le Triomphant-class.
The main driver for this increased size is stealth. The machinery space will be longer to incorporate an even quieter machinery. This may have some technologies already found on France’s latest nuclear submarine, the Suffren-class attack submarine. Outwardly these include the X-form rudders and pumpjet propulsor.
New sensors
But between the two upper rudders is a difference from the Suffren. A small fin contains a next-generation towed sonar array known as ALRO. This will use optical technology. While this array may in itself be a capability leap, the most important aspect is that it is part of a holistic sensor suite known as ALICIA.
Thales’ ALICIA (Analyse, Localisation, Identification, Classification Intégrées et Alertes) combines a wide range of sensors into the SYCOBS 3.0 data processing system. These include large new flank array sonars and a new bow sonar. The exact technology in the bow sonar has not been reported but Naval News believes that it will have moved beyond traditional cylindrical arrays.
ALICIA will be capable of Ultra-Low Frequency (ULF) detection meaning that even the quietest adversaries may be tracked and identified. “The challenge will be processing the massive amounts of data gathered by the new sensors. The data is expected to be an order of magnitude more than on current boats” the SNLE-3G Program Officer told Naval News in a February 2021 interview. However artificial intelligence will help the crew identify contacts, greatly aiding their work. This will help with both technical and tactical classification. The latter can be based on intelligence which usually leads to a decision from the submarine commander.
According to the DGA program manager, work is ongoing to incorporate a new type of submarines tiles fitted with sensors, but additional details are confidentials.
