Naval Systems

Le Triomphant class

The Le Triomphant class is France's four-boat nuclear-powered ballistic missile submarine class, built by Naval Group and commissioned from 1997 to 2010 to carry the sea-based leg of France's deterrent. NTI says the submarines are based at Ile Longue, Brest, each carries 16 vertically launched M51 ballistic missiles, and can remain submerged for about 60 days.

Various ConflictsUnspecified
Le Triomphant class, Nuclear-powered ballistic missile submarine class, Naval Systems
Image source: SNLE de classe le Triomphant.jpg

Specifications

Length
138 m
Beam
12.5 m
Speed
Over 25 knots submerged
Endurance
About 60 days submerged
Armament
16 vertically launched M51 ballistic missiles plus torpedoes and anti-ship missiles

Service And Conflict Use

Service History

In service
Naval Group says the Le Triomphant generation was commissioned in 1997 and remains in service today as France's sea-based deterrent force.
Used by
French Navy

Conflict Usage

Various Conflicts

No publicly documented use in a named armed conflict found in the sources reviewed. The class is documented as France's nuclear ballistic missile submarine deterrent force rather than a publicly reported conflict-deployment platform.

Timeline

Le Triomphant class Key Events

  1. Le Triomphant generation commissioned

    Naval Group says the Le Triomphant generation was commissioned in 1997 and remains in service today.

    Sources: Four centuries young

  2. Le Terrible enters service

    Naval News says the fourth boat, Le Terrible, was commissioned in 2010 and was fitted with M51 capability from construction.

    Sources: Triomphant-class SSBN

  3. Replacement begins

    NTI says the Le Triomphant-class submarines will be steadily replaced by a third generation of SSBNs beginning in 2035.

    Sources: France Submarine Capabilities

Le Triomphant class Images

Le Triomphant class, Nuclear-powered ballistic missile submarine class, Naval Systems - view 1
Source: SNLE-NG.jpeg
Le Triomphant class, Nuclear-powered ballistic missile submarine class, Naval Systems - view 2
Source: SNLE-NG.jpeg

Related Weapon Systems

Sources

Four centuries youngPublisher: Naval Group | Note: Supports Naval Group responsibility for France's current Le Triomphant-class SSBN fleet. | Accessed: 2026-06-25Triomphant-class SSBNPublisher: Naval News | Note: Supports the class as four French Navy SSBNs built by DCNS, the SNLE-NG designation, the 1997/1999/2004/2010 commissioning sequence, and the class armament context. | Accessed: 2026-06-25France Submarine CapabilitiesPublisher: Nuclear Threat Initiative | Note: Supports the class role, the four-boat force posture, the Ile Longue basing context, the 138-meter length, 12.5-meter beam, over-25-knot submerged speed, around 60-day submerged endurance, and 16 vertically launched M51 missile fit. | Accessed: 2026-06-25SNLE de classe le Triomphant.jpgPublisher: Wikimedia Commons | Note: Supports image provenance and the Licence Ouverte 2.0 licensing context for the primary class image. | Accessed: 2026-06-25SNLE-NG.jpegPublisher: Wikimedia Commons | Note: Supports image provenance and Creative Commons licensing context for a French Navy image of the class. | Accessed: 2026-06-25Snle-snle-ng-svg.svgPublisher: Wikimedia Commons | Note: Supports image provenance and featured-picture status for the class diagram used in the gallery. | Accessed: 2026-06-25