Class overview
Name	Dale class
Builders	Kieler Howaldstwerke Hitachi Harland & Wolff
Operators	Royal Fleet Auxiliary
Preceded by	Leaf class
Succeeded by	Rover class
In service	1967–1977
Completed	3
Retired	3
General characteristics
Type	Mobile reserve tanker
Displacement	Derwentdale: 88,555 long tons (89,976 t) Dewdale: 67,000 long tons (68,075 t) Ennerdale: 62,000 long tons (62,995 t)
Length	Derwentdale: 799 ft (244 m) Dewdale: 774 ft (236 m) Ennerdale: 710 ft (220 m)
Beam	Derwentdale: 117 ft 8 in (35.86 m) Dewdale: 107 ft (33 m) Ennerdale: 98 ft (30 m)
Draught	Derwentdale: 42 ft 3 in (12.88 m) Dewdale: 41 ft (12 m) Ennerdale: 40 ft (12 m)
Propulsion	Burmeister and Wain Diesels
Speed	Derwentdale: 15.5 knots (17.8 mph; 28.7 km/h) Dewdale: 15 knots (17 mph; 28 km/h)
Complement	Derwentdale: 56 Dewdale and Ennerdale: 51

The Dale class consisted of three tankers chartered for service with the Royal Fleet Auxiliary (RFA), the naval auxiliary fleet of the United Kingdom. In 1967. They served for a number of years supporting Royal Navy and allied fleet operations, during which one, Ennerdale, was lost. The remaining two were returned to their original owners in the mid-1970s.

Three large modern tankers, built to varying designs in the mid-1960s, were charted by the Royal Fleet Auxiliary to support naval operations east of the Suez Canal, in the waters of the Indian Ocean and the Far East.^[1]

They were given traditional RFA names, reusing three names that had been used for the Second World War-era Dale-class oilers. They were not fitted with equipment to allow them to replenish ships at sea, and were classified instead as 'Mobile Reserve Tankers'.^[1]

The smallest, RFA Ennerdale was also the shortest lived. She hit a coral reef and sank off Port Victoria on 1 June 1970.^[1] The wreck was subsequently destroyed with explosives fired from Wessex helicopters to prevent an oil spillage from threatening the Seychelles.^[1]

RFA Derwentdale was returned to her original owners in 1974, but RFA Dewdale remained in service until 1977.^[2] During this time Dewdale saw service with the Aden task force during the British withdrawal in 1967, and was then active then on the Beira Patrols.^[2] She was the last to leave service with the RFA, being returned in 1977 and commencing service under her old name of Edenfield.^[2]

In July 1967, the MOD announced that it had bareboat chartered, for a period of seven years, three large tankers for the Royal Fleet Auxiliary.^[3] These vessels were the largest in the RFA fleet at the time.^[4]

Derwentdale was launched as Halcyon Breeze by Hitachi Zosen Corporation at its Innoshima, Hiroshima shipyard on 18 January 1964, for Caribbean Tankers Ltd, managed by Court Line(Ship Management) Ltd, London.^[5] She began her RFA charter on 17 June 1967.^[3]

Dewdale was launched as Edenfield for Hunting (Eden) Tankers Ltd, managed by Hunting & Son Ltd, by Harland & Wolff on 5 March 1965^[5] and began her charter on 14 August 1967.^[6]

Ennerdale was launched on 31 August 1963 as Naess Scotsman for the Anglo-Norness Shipping Co Ltd^[5] and began her charter in July 1967.^[7]

• List of replenishment ships of the Royal Fleet Auxiliary

• Colledge, J.J. Ships of the Royal Navy: An Historical Index Volume 2: Navy-built Trawlers, Drifters, Tugs and Requisitioned Ships. Newton Abbot: David & Charles.
• Puddefoot, Geoff (2009). The Fourth Force The Untold Story of the Royal Fleet Auxiliary since 1945. Barnsley, South Yorkshire, UK: Seaforth Publishing. ISBN 978-1-84832-046-8.