Dolfijn-class submarine

300px Dutch submarine HNLMS Dolfijn (1960)
Class overview
Name:	Dolfijn class
Operators:	Royal Netherlands Navy
Succeeded by:	Zwaardvis class
Subclasses:	Potvis class
Built:	1954-1966
In service:	1960-1992
Completed:	4
Retired:	4
Preserved:	1
General characteristics
Type:	Submarine
Displacement:	1,530 tons (surfaced) 1,826 tons (submerged)
Length:	79.5 m (261 ft)
Beam:	7.8 m (26 ft)
Draught:	5.0 m (16.4 ft)
Propulsion:	2 shafts, diesel electric. 2 MAN type diesels (2800 hp) and two electric motors 4000 hp
Speed:	14.5 kn (26.9 km/h; 16.7 mph) (surfaced) 17 kn (31 km/h; 20 mph) (submerged)
Complement:	67
Sensors and processing systems:	Radar type 1001, Sonar: passive and active
Armament:	8 x 533mm (21 inch torpedo tubes) 4 bow, 4 stern, 16-22 torpedoes, fitted for minelaying via torpedo tubes

The Dolfijn-class submarines of the Royal Netherlands Navy are a class of four submarines; Dolfijn, Zeehond, Potvis and Tonijn. They were built in the late 1950s and the early 1960s. They were the first indigenous submarines built for the Royal Netherlands Navy after World War II.

Design

The Dolfijn class was a special Dutch design and had three separate pressure hulls arranged in a triangle and enclosed in external steel casing. The upper hull for the living/working part of the crew and the lower two hulls were for the engines, batteries and storage rooms. This allowed the submarine to dive much deeper than other submarines from the late 1950s, with a test depth of 200 metres (660 ft). The designer was F Gunning.

The order for a second group of boats, also known as the Potvis class, was postponed in the late 1950s while the possibility of building a nuclear powered submarine was considered and rejected. The order for two boats was re-instated in 1962. These boats had their diesels replaced and electronics updated in 1978-79.

Zeehond was converted into a trials ship by RDM shipyard in Rotterdam in 1990 and used as a technology demonstrator for a closed cycle diesel air-independent propulsion system until 1994.

Ships in class

Ship	Builder	Laid down	Launched	Commissioned	Fate
Dolfijn	Rotterdamse Droogdok Mij	30 December 1954	20 May 1959	16 December 1960	Broken up 1985
Zeehond	Rotterdamse Droogdok Mij	30 December 1954	20 February 1960	16 March 1961	Test ship 1990, Scrapped 1997
Potvis class
Potvis	Wilton-Fijenoord, Schiedam	17 September 1962	12 January 1965	2 November 1965	Decommissioned 1992, Broken up 1994
Tonijn	Wilton-Fijenoord, Schiedam	26 October 1962	14 June 1965 1965	24 February 1966	Decommissioned 1991, preserved in the Dutch Navy Museum in Den Helder.

References and external links

• Conway's All the World's Fighting Ships 1947-1995
• Specifications and histories [1]
• Illustrated information on Tonijn [2]