Naval Group handed over the fourth Barracuda type nuclear-powered attack submarine (SSN) De Grasse (S636) to the French defense procurement agency (DGA) and to the French Navy (Marine Nationale) on 24 June 2026.
According to Naval Group, the delivery of the SSN De Grasse comes exactly four months after the submarine’s first sea trials. This very quick pace is because the shipbuilder benefited from feedback and experience gained from the first three submarines of the program, Since being rolled out of its construction hall in May 2025, the De Grasse has successively completed its dockside trials, the divergence of its nuclear reactor in December 2025, and a four-month sea trials campaign that began on February 24, 2026.
The submarine is named after Lieutenant général des armées navales François Joseph Paul, Comte de Grasse, Marquis of Grasse-Tilly, a French naval officer. The Comte de Grasse is best known for his crucial victory over the Royal Navy at the Battle of the Chesapeake in 1781 during the American Revolutionary War.
In an interview with Naval News, Admiral Xavier Petit, Commander, French submarine forces (ALFOST) explained that De Grasse features some improvements compared to the first three boats in the class: Among them are a new version of the submarine’s combat management system (known as SYCOBS – this new SYCOBS version brings new features to the CMS) and a new generation electronic warfare system.
The delivery of the fourth boat-in-class marks an important milestone in the Barracuda program for which the first three SSNs have already entered active service (Suffren in June 2022, Duguay-Trouin in April 2024, and Tourville in July 2025). The final two submarines of the program (Rubis and Casabianca) are currently under construction at various stages of completion, with deliveries scheduled through the end of the decade.
Naval Group, in cooperation with its partners, is responsible for the production of this series of submarines, from design to shipbuilding, for manufacturing the main components of the nuclear reactors which are developed and produced with TechnicAtome. Naval Group is also in charge of providing logistical support and maintaining the submarines in Toulon.
Technical characteristics
missiles
SSBN and Charles-de-Gaulle aircraft carrier, one propulsion turbine, two turbo generators and two
electric motors