NAVYPEDIA

Photo

Dauphin 1979

Ships

Name	No	Yard No	Builder	Laid down	Launched	Comp	Fate
Narval	S631	Q61	Arsenal de Cherbourg	10/1951	11.12.1954	1.12.1957	stricken 6.1983
Marsouin	S632	Q62	Arsenal de Cherbourg	11/1951	21.5.1955	1.10.1957	stricken 11.1982
Dauphin	S633		Arsenal de Cherbourg	1/1952	17.9.1955	1.8.1958	stricken 12.1992
Requin	S634		Arsenal de Cherbourg	2/1952	3.12.1955	1.8.1958	stricken 11.1985
Espadon	S637		A C Augustin-Normand, Le Havre	12/1955	15.9.1958	1.4.1960	stricken 9.1985
Morse	S638	132	A C de la Seine-Maritime, La Seine	2/1956	10.12.1958	1.5.1960	stricken 12.1986

Technical data

Displacement standard, t	1320
Displacement normal, t	1635 / 1910
Length, m	78.4
Breadth, m	7.80
Draught, m	5.20
No of shafts	2
Machinery	2 Schneider diesels / 2 electric motors
Power, h. p.	4400 / 5000
Max speed, kts	16 / 18
Fuel, t	diesel oil
Endurance, nm(kts)	15000(8) /
Armament	8 - 550 TT (6 bow, 2 stern, 14)
Electronic equipment	Calypso radar, DUUA-1 sonar
Complement	63
Diving depth operational, m	200

Standard scale images

Graphics

Project history

In 1947 the STCAN was asked to produce plans for a new class of submarine of 1200 tonnes standard. Requirements included a speed of over 16kts submerged and a range of 15.000nm with snorkel. Long range was the overriding consideration because the continued existence of a French empire demanded the ability to make a lengthy transit and still be able to undertake a patrol of 7-14 days.

In drawing up the plans the constructors leaned heavily on experience with the ex-German Type XXI boat Roland Morillot and the two reconstructed 1500t boats of French origin (L'Andromède and L'Artémis).

In addition Dinechin, who was responsible for the basic design, visited the USA in order to make a detailed study of current US Navy thinking.

The result was an improved Type XXI, almost identical in dimensions and displacement but with superior performance. Two boats were ordered in 1949, two in 1950, and the final pair in 1954.

Problems were experienced in developing a high-tensile steel capable of resisting pressures at the 200m maximum diving depth, and the increased pressures also necessitated many changes in other areas, notably more powerful emergency blowing systems. An exceptionally strong all-welded double hull was adopted. Hull-form, propellers, rudder and driving planes were all the subject of intensive studies. The Cherbourg-built boats were assembled in pre-fabricated sections each 7x10m - the first French submarines constructed by this method.

The action information and fire control centre was based on that developed in L'Artémis, as was the fin with its raised section aft. The latest detection equipment was fitted. In addition to the six bow tubes, two tubes were fitted aft outside the pressure hull.

Problems were experienced in finding a suitable diesel, as few French engineering firms were willing to undertake a series of only twelve engines. Schneider 2-stroke diesels were chosen in preference to 2.4-stroke Sultzer and 4-stroke MAN diesels. When fast diesels later became available it was decided to replace the machinery by a diesel-electric installation. Three SEMT-Pielstick PA 4 12cyl diesels, each rated at 750bhp, replaced the Schneider units. New electric motors each of 2400hp were installed, and to these were added a pair of electric cruise motors each of 40hp. All six boats were taken in hand from 1965 onwards, and besides the replacement of the propulsion system major improvements were made to the weapons and detection equipment.

Modernizations

1965-1970, all: machinery was replaced by 3 Pielstick diesel-generators (2250hp) and 2 electric motors (4800hp), fin was rebuilt; - 2 - 550 TT (stern) (20 torpedoes were carried at all), DUUA-1 sonar; + DUUA-2 (active), DUUA-2 (passive), DUUX-2 sonars

1970s, Narval: + swimmer delivery vehicle

1980, Requin: + SM39 Exocet SSM (instead of part of torpedoes)

1986, Dauphin: was fitted with the prototype bow section for the Amethyste class SSN, length oa became 81.4m.

Naval service

Marsouin had a serious fire 4.8.1978, later repaired.