French Narval-class submarine

Espadon in Saint-Nazaire
Class overview
Operators:	Marine Nationale
In service:	1958–1992
Completed:	6
Retired:	6
Preserved:	1
General characteristics
Displacement:	1635 tons surfaced, 1910 tons submerged
Length:	78.4 m
Beam:	7.8 m
Draft:	5.2 m
Propulsion:	2 shafts, 2 × 7 cylinder diesel engines (4400 hp), 2 electric motors (5000 hp), re-engined with new diesels in 1965–1968
Speed:	16 knots (30 km/h) surfaced 18 knots (33 km/h) submerged
Range:	15,000 nautical miles (28,000 km) at 8 knots (15 km/h)
Test depth:	400 metres
Complement:	63
Armament:	8 × 550 mm torpedo tubes: 6 bow & 2 stern, 14 torpedoes carried

The Narval class (sous-marins d'escadre, "fleet submarines") were patrol submarines built for the French Navy in the 1950s.

Design

The Narval type was an offspring of the E-48 project, inspired by the German Type XXI U-boat of the Second World War, particularly the Roland Morillot brought into French service.

Compared to the Type XXI, the Narval introduced an entirely new schnorchel system and novel detection systems, gained 33% in operational range on electric power (400 nautical miles, compared to the 290 available to the type XXI), and doubled the test depth. The propellers were also particularly studied to minimise noise.

The hulls of the Narvals were assembled from seven 10-metre sections wielded together.

The engine were two-stroke diesels made by the French constructor Schneider, which proved unreliable and noisy to the point where the engine section became difficult to man at full power.

From 1966 to 1970, the Narval underwent extensive modernisation, where their engines were replaced by a diesel-electrical design based on the SEMT-Pielstick 12PA4-185. The sour stern tubes were deleted, electronics were replaced, and the conning tower was replaced by a more modern sail plan from the Daphné class.

Careers

The Narval were used to explore limits of submarines performances in several ways.

In 1958, Dauphin and Requin broke the 30-day world record of the longest underwater cruise held by the nuclear USS Skate and Seawolf, with 32 and 42 days submerged respectively.

In 1964, Espadon and Marsouin sailed up to the 70th parallel north to prepare the first French attempts at navigation under sea ice. These tests were carried out the next year by Dauphin and Narval when they spent a week and a half in the 72nd parallel north.

During her last years, from 1980, Requin was fitted with the sonar system planned for the M4 refit of the SNLE. Similarly, Dauphin was extensively modified from 1986 to be used as a test bed for equipment and sensors to be installed on the Triomphant-class submarines, then under design. When finally decommissioned in 1992, she was the oldest submarine in service. She was later expended as a target ship off Toulon.

In 1985, Espadon became the first French submarine used as a museum ship.

Ships

Name	Builder	Completed	Decommissioned
S631 Narval	Arsenal de Cherbourg	1 December 1957	1986
S632 Marsouin	Arsenal de Cherbourg	1 October 1957	1987
S633 Dauphin	Arsenal de Cherbourg	1 August 1958	1992
S634 Requin	Arsenal de Cherbourg	1 August 1958	1985
S637 Espadon	AC Augustin Normand	2 April 1960	1985 - now a museum ship in Saint Nazaire
S638 Morse	AC de la Seine Maritime	2 May 1960	1986

References

• Conway's All the World's Fighting Ships 1947–1995
• Les sous-marins d'escadre type Narval