Summary: The French Marine Nationale has officially welcomed the Duguay-Trouin, the second Suffren-class nuclear-powered attack submarine, into active service. This vessel, part of the Barracuda program, enhances France's naval capabilities with features like advanced optronic masts, pump-jet propulsion, and deep strike capacity with naval cruise missiles. Initially delayed by the Covid-19 pandemic, the Duguay-Trouin underwent rigorous testing, including a shakedown cruise in various water conditions and a visit to Martinique. This class of submarines, slated to replace the older Rubis and Amethyste classes, is set to be the backbone of France's submarine force through the 2060s, emphasizing France's commitment to maintaining a cutting-edge and versatile naval presence.

French Navy Activates Second Suffren-Class Submarine, Enhancing Naval Warfare Capabilities

The second Suffren-class nuclear-powered attack submarine (SSN) Duguay-Trouin (S636) entered “active duty” with the French Marine Nationale earlier this month. Developed as part of the Barracuda program, the vessel underwent sea acceptance trials just over a year ago.

Chief of staff of the French Navy, Admiral Nicolas Vaujour, announced via X, the social media platform formerly known as Twitter, on April 4, 2024, “Today I declared the admission to active service of the Duguay-Trouin, the second submarine of the Suffren class. Faster, more durable, more versatile, more discreet. In the hands of our crews, it will become an outstanding fighter for future operations.”

The keel for Duguay-Trouin was laid down in June 2009 but construction was delayed due to the Covid-19 pandemic. The boat was finally rolled out of the submarine construction hall at the Naval Group shipyard in Cherbourg in November 2022 and delivered to the French Navy in July 2023 after her initial sea trials. 

According to Shephard Media, the tests were led by the Direction Générale de l’Armement (DGA), in conjunction with the French Alternative Energies and Atomic Energy Commission and in close partnership with the French Navy, Naval Group, and TechnicAtome. These included a static dive, or immersion without propelled movement, to check the stability of the submarine; surface and diving tests; safety and operation of the installations, including its nuclear boiler room; and diving tests to verify the operation of its combat system, including its ability to implement its weapons and communicate.

Completed Her Shakedown Cruise

In March, the submarine completed the sea trail phase of Verification of Military Characteristics—known as shakedown cruises in the U.S. Navy—which allowed the crew to test the vessel’s performance and endurance as well as the equipment’s conformity to the requested specifications.

During those tests last month, the Duguay-Trouin sailed in cold and warm waters, with a brief port-of-call visit in Fort-de-France, the capital of the Caribbean island and French overseas territory of Martinique. It was marked the first for a Suffren-class SSN.

S636 is the eleventh French Navy vessel and the first submarine to be named for the French privateer/corsair and admiral René Duguay-Trouin (1673-1736). He is best known for his service with the French Navy during the War of the Spanish Succession in the early eighteenth century.

The Suffren-class

The Suffren-class submarines were developed to replace the existing Rubis-class and Amethyste-class boats and provide France with an enhanced sub-surface attack capability. The new class of attack submarines will serve as the backbone of France’s submarine force until the 2060s, while delivery of the four other submarines is expected to take place over the next decade.

The nuclear-powered Suffren-class submarines have a surface displacement of 4,600 tons, an underwater displacement of 5,200 tons, and an immersion depth of 300 meters. The boats can be employed in anti-surface warfare (ASuW), anti-submarine warfare (ASW), land attack, intelligence gathering, crisis management, and special operations.

Among the innovative enhancements on the boat is its “optronic” mast, which replaces the telescopic mast. According to Naval Group, the submarines’ builder, the mast will ensure a better collection of visual information and better sharing of this information among the crew. This new feature, combined with advanced detection capabilities, guarantees the attack submarines’ superiority in their intelligence missions.

The boats also incorporated technology from the Triomphant-class of French Navy ballistic missile submarines, notably its pump-jet propulsion. The Suffren-class was developed to provide the French Navy with a real combat superiority and for the first time enable a deep strike capability via MBDA naval cruise missiles, which can engage land-based targets located hundreds of kilometers away. The vessel can be equipped with F21 heavyweight wire-guided torpedoes and modernized Exocet SM39 anti-ship missiles.

Each submarine can accommodate a crew of sixty sailors—including twelve officers and forty-eight petty officers. The boats were further designed to accommodate up to fifteen Commandos Marine or other Special Forces operators and can integrate with a removable dry deck shelter aft of the sail able to embark the commandos’ new generation PSM3G Swimmer Delivery Vehicle (ECA Special Warfare Underwater Vehicle).

Author Experience and Expertise: Peter Suciu

Peter Suciu is a Michigan-based writer. He has contributed to more than four dozen magazines, newspapers, and websites with over 3,200 published pieces over a twenty-year career in journalism. He regularly writes about military hardware, firearms history, cybersecurity, politics, and international affairs. Peter is also a Contributing Writer for Forbes and Clearance Jobs. You can follow him on Twitter: @PeterSuciu.

You can email the author: [email protected]