The Dark class, or Admiralty "Type A", were a class of eighteen fast patrol boats that served with the United Kingdom's Royal Navy starting in 1954. All were named with a prefix of 'Dark'. The class could be fitted as either motor gun boats or motor torpedo boats, depending on the type of armament carried. They were the only diesel engined fast patrol boats in the Royal Navy. The class was fitted (along with the Nasty class) with the Napier Deltic two-stroke diesel engine. This was of unique layout, an opposed-piston engine with a triangular layout of three banks, 18 cylinders in total.
Construction The boats were constructed with alloy framing and wooden decks and skin. The exception was Dark Scout which had all aluminium decks, skins and frames. Originally 27 units were ordered by the admiralty from seven builders. Nine were eventually cancelled in 1955, including Dark Horseman which at the time was partially completed and on the stocks in the builders yard.
The all-aluminium version was exported to Burma (five units), Finland (two units), and Japan (one unit) by builders Saunders-Roe.
Design With no previous experience of using diesel engines in vessels of this size, it was not fully understood how dirty they would get from the exhaust fumes. Originally launched in the normal Royal Navy grey, they eventually had their hulls painted completely black to disguise the staining from exhaust emissions . For a short while, a compromise half grey/half black combination was used.
Fate An Admiralty decision in 1957 took nearly all fast patrol boats out of commission, with nine of the new Dark-class to be laid up. On 20 December 1960, the Admiralty stated that the Coastal Forces would not be completely abandoned in case it needed to be expanded in the future. A special boat squadron was nominated, but it did not include any of the Dark-class.
Several of the ships were sold to Wessex Power Units for sale onto the Italian Customs Service (8 hulls) in February 1966. Two were used for target practice, with Dark Gladiator sunk by HMS Amazon and HMS Naiad off Portland in December 1975. At least two, Dark Clipper and Dark Fighter, managed to survive up to as recently as June 2001 when they were broken up in Malta.
Legacy The Dark class would be the final commission of this quantity for patrol boats of this size and speed. The following classes had greatly reduced numbers with the numbering only two vessels and numbering only three.
A similar hull design was used by Saunders-Roe in a prototype, R-103, which led to the development of the experimental hydrofoil, , for the Royal Canadian Navy.
Ships OperatorNamePennantBuilderLaunchedFateP1101Saunders-Roe28 October 1954Sold January 1970P1102Saunders-Roe9 December 1954Sold on 3 October 1961P1103Saunders-Roe11 December 1954Sold February 1966P1105Saunders-Roe6 September 1955Sold February 1966P1104Saunders-Roe23 June 1955Sold February 1966P1108Vosper & Company30 September 1954Sold February 1966P1109Vosper & Company9 February 1955Sold on 16 March 1967Broken up June 2001P1113Taylor (Chertsey)4 October 1955Sold on 16 March 1967Broken up June 2001P1114Taylor (Chertsey)5 December 1956Used as target and sunk December 1975P1115McGruer (Clynder)16 March 1957Used as target 1977Sold 1985P1110Vosper & Company29 March 1955Sold on 16 March 1967P1116Miller (St. Monance)18 March 1954 Sold on 13 April 1962P1112Thornycroft16 May 1957Sold February 1966P1118Morgan Giles (Teignmouth)6 July 1955Sold February 1966P1119Morgan Giles (Teignmouth)6 September 1955Sold February 1966P1111Thornycroft26 September 1956Sold February 1966P1107Vosper & Company30 August 1954Sold February 1966P1116Saunders-Roe20 March 1958Sold on 2 July 1961T201Saunders-Roe24 March 1956Blackman 1971, p. 38.Stricken 1975Gardiner and Chumbley 1995, p. 268.T202Saunders-RoeStricken 1975T203Saunders-RoeStricken 1975T204Saunders-RoeStricken 1975T205Saunders-RoeStricken 1975Vasama ISaunders-RoeStricken 1977Gardiner and Chumbley 1995, p. 93.Vasama IISaunders-RoeStricken 1979PT9Saunders-RoeStricken 1972Gardiner and Chumbley 1995, p. 238.
Cancelled ships OperatorNameBuilderSaunders-RoeSaunders-RoeSaunders-RoeVosper & CompanyVosper & CompanyVosper & CompanyThornycroftThornycroftMcGruer (Clynder)
See also PTF boat
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