Rubis Rolled Out: France’s Fifth Suffren-Class Nuclear Attack Submarine Heads for Trials

France rolled out Rubis, the fifth of its six Suffren-class nuclear-powered attack submarines, at Naval Group’s Cherbourg yard on 16 October 2026. The boat left its construction hall for the floating launch platform in the Cachin basin, in a ceremony led by Armed Forces Minister Catherine Vautrin. Rubis still has to be floated out, then complete quayside and sea trials before delivery to the French Navy, which Naval News expects by the end of 2027.

Last updated: 17 October 2026

Key facts

Boat: Rubis (S639), fifth Suffren-class (Barracuda program) SSN
Milestone: transfer from the build hall to the launch platform, 16 October 2026
Next: float-out, quayside trials, sea trials; alpha sea trials expected by summer 2027 (Naval News)
Class status: Suffren, Duguay-Trouin and Tourville in active service; De Grasse delivered June 2026
Last boat: Casabianca, under construction, delivery due by 2030
Program lead: DGA, with CEA for the reactors; builder Naval Group

French Armed Forces Minister Catherine Vautrin speaking in front of the submarine Rubis in Cherbourg — Armed Forces Minister Catherine Vautrin speaks at the transfer ceremony of the nuclear attack submarine Rubis, Cherbourg, 16 October 2026. Photo: French Ministry of the Armed Forces (DGA).

What happened in Cherbourg?

According to the French defence procurement agency (DGA), Rubis began its move from Naval Group’s construction hall to the launch device in the Cachin basin on 16 October. Vautrin presided over the ceremony, with DGA chief Patrick Pailloux present. “Rubis is a French success,” she said, crediting the workforce of the Cotentin peninsula and the wider industry. Completion work will continue up to the first float-out, followed by trials alongside the quay and then at sea, run jointly by state and industry teams.

Naval Group chief executive Pierre Éric Pommellet said the milestone came 17 months after the same step for De Grasse, the fourth boat, according to the company’s statement published by Naval News. Regional and trade press, including Le Marin and Tendance Ouest, covered the ceremony on site.

Where the Barracuda program stands

The six Suffren-class boats replace the Rubis-class SSNs that entered service from the 1980s. Here is the count as the DGA gives it, keeping delivered and in-service status apart:

Boat	Status (DGA, 16 Oct 2026)
Suffren	Admitted to active service, 2022
Duguay-Trouin	Admitted to active service, 2024
Tourville	Admitted to active service, 2025
De Grasse	Delivered June 2026; admission to active service pending
Rubis	Rolled out 16 Oct 2026; trials ahead
Casabianca	Under construction; delivery expected by 2030 under the 2024–2030 military programming law

The DGA says more than 10,000 people and 800 companies have worked on the program, with 3,000 direct jobs mobilised every day, 800 of them at subcontractors.

What is a Suffren-class submarine?

The Suffren class is France’s second-generation nuclear attack submarine, designed and built by Naval Group. Compared with the small Rubis class it replaces, it is larger and quieter, and it brings two capabilities the French Navy did not have under water: land attack with the MBDA MdCN naval cruise missile and covert deployment of special forces through a divers’ hatch and an optional dry deck shelter. Its job, in the French MoD’s words, is to control sea areas and to support the ballistic missile submarine force and the carrier group around the Charles de Gaulle.

Key specifications

Item	Suffren class (Naval Group / French MoD)
Builder	Naval Group, Cherbourg (reactor components with TechnicAtome)
Length	99 m
Diameter	8.8 m
Displacement	4,700 t surfaced, 5,200 t submerged
Speed	About 25 knots submerged (French MoD)
Propulsion	Pressurised water reactor, two propulsion turbines, two turbo-generators, two electric motors
Weapons	MdCN naval cruise missiles, F21 heavyweight torpedoes, Exocet SM39 anti-ship missiles
Crew	65 plus commandos
Availability	More than 270 days a year (Naval Group)

The propulsion plant is a hybrid: a pressurised water reactor derived from those in the Triomphant-class ballistic missile submarines and the Charles de Gaulle drives turbines, with electric motors for quiet running. Our explainer on naval nuclear propulsion covers how these plants differ between countries. The anti-ship weapon is the submarine-launched version of the Exocet.

How it compares

Its closest peers are Britain’s Astute class and the US Virginia class; both are bigger boats. We compare the British and French designs in detail in Astute vs Suffren, and rank the class against others in our top 10 attack submarines.

Why the name Rubis?

The French Navy reuses names of units decorated in combat. The original Rubis was a Free French minelaying submarine in the Second World War. The DGA credits it with 28 combat missions and 683 mines laid; it received the Cross of Liberation from General de Gaulle and the Croix de Guerre 1939–1945. The last boat of the class, Casabianca, also honours a wartime submarine.

What comes next

Naval News reports that Rubis is set to begin alpha sea trials by summer 2027 and be delivered by the end of 2027. It also reports that the DGA and Naval Group are working on an upgrade roadmap for the class and on early studies for a third-generation SSN, which is not yet a formal program.

FAQ

What is the Rubis submarine?

Rubis (S639) is the fifth Suffren-class nuclear-powered attack submarine built by Naval Group for the French Navy. It was rolled out in Cherbourg on 16 October 2026.

How many Suffren-class submarines does France have?

Six are on order. Three are in active service (Suffren, Duguay-Trouin, Tourville), De Grasse was delivered in June 2026, Rubis is preparing for trials and Casabianca is under construction.

When will Rubis enter service?

Naval News expects delivery to the French Navy by the end of 2027, after alpha sea trials planned by summer 2027. Admission to active service usually follows delivery.