fighting ships of the world



GYMNÔTE ballistic missile trials submarine (1966)

Gymnôte 1966

Gymnôte 1980

Name No Yard No Builder Laid down Launched Comp Fate
Gymnôte S655 Q73 Arsenal de Cherbourg 17/3/1963 17/3/1964 17/10/1966 stricken 4/1987


Displacement standard, t


Displacement normal, t

3000 / 3250

Length, m


Breadth, m


Draught, m


No of shafts



4 SEMT-Pielstick diesel-generators, 2 electric motors

Power, h. p.

2600 / 2600

Max speed, kn

11 / 10

Fuel, t

diesel oil

Endurance, nm(kts) 5500(7) /


4 M-1 SLBM (4 M-1)

Sensors Calypso II radar, DUUA-1 sonar
Complement 78
Diving depth operational, m 150

Ship project history: In 1954 studies were made of a torpedo-armed nuclear-powered submarine; the boat was even laid down at Cherbourg in 1956 as hull No Q244. A surface displacement of 4000t on a length of 120m was projected. The inability of the French to produce enriched uranium at this time meant, however, that a heavy-water reactor using unrefined uranium was the only possible propulsion plant. This proved too heavy and construction was halted in 1958. Negotiations with the Americans for the purchase of a reactor failed, and even the purchase of enriched uranium was refused except for land experimental use. The project was abandoned in 1959.

    With the decision to develop an independent sea-based deterrent force, it was decided to complete the hull (now designated Q251) as an experiment submarine for the testing of the new ballistic missiles. A prominent casing abaft the fin housed four vertical launch tubes. Gymnôte was also fitted with the prototype guidance and inertial navigation system intended for Le Redoutable.

Modernizations: 1979: - 4 M-1 SLBM; + 2 M-4 SLBM (2 M-4)

Naval service: No significant events.

Gymnôte 1970

Many thanks to Wolfgang Stöhr for additional information on this page.

Ivan Gogin, 2015