France’s fourth Barracuda-class nuclear attack submarine kicks off sea trials

On 24 February 2026, SSN De Grasse, the fourth Barracuda-class nuclear attack submarine, carried out its first sea trials, French shipbuilder Naval Group revealed.

The first sea trial of the SSN De Grasse follows the dock tests carried out since the launch of the submarine in May 2025, as well as the commissioning of its nuclear reactor in December 2025. The operations successively took place in the assembly hall as well as in the dry and water-filled docks to test equipment and systems. 

This new milestone marks an important step in the realization of the Barracuda program, for which the first three SSNs have already been admitted to active duty (SSN Suffren in June 2022, SSN Duguay-Trouin in April 2024 and SSN Tourville in July 2025). 

The submarine will now go through different trials to test its performance before its delivery, which is scheduled later this year to the French Navy.

The last two submarines of the program (SSN Rubis and SSN Casabianca) are currently under construction, at different stages of completion, and their deliveries will be staggered until the end of the decade. 

Led by the French defense procurement agency (DGA) in partnership with the French Atomic Energy and Alternative Energy Commission (CEA) for the nuclear boilers part, the Barracuda program aims to replace the six Ruby-class SSNs put into service in the French Navy from the 1980s. 

Naval Group is in charge of the production of these submarines, from their design to their construction, as well as the manufacture of the main components of the nuclear boilers which are developed and produced with TechnicAtome.

The company is also in charge of providing logistical support and maintaining the submarines in Toulon. 

The Barracuda-class nuclear attack submarines measure 99 meters in length with a hull diameter of 8.8 meters. They have a surface displacement of 4,700 tons and a submerged displacement of 5,200 tons, reflecting a design optimized for both endurance and maneuverability in deep-sea operations.

These submarines use a hybrid propulsion system centered on a pressurized water reactor derived from technology used in France’s strategic submarine and carrier programs. The system includes one propulsion turbine, two turbo-generators, and two electric motors, enabling exceptionally quiet operation and long deployment periods exceeding 270 days per year.

Designed for modern naval warfare, the submarines are equipped with naval cruise missiles for precision deep-strike missions, F21 heavyweight wire-guided torpedoes produced by Naval Group, and modernized SM39 anti-ship missiles developed by MBDA. Their advanced weapons suite provides high versatility across anti-surface, land-attack, and anti-submarine roles.

Among the world’s stealthiest submarines, the Barracuda-class provides the French Navy with a significant combat advantage. Each submarine operates with a crew of 63 personnel and supports discreet underwater deployment of special forces, enhancing France’s power projection and strategic reach at sea.