Abdiel class minelayer

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Abdiel class RN Ensign
General Characteristics
Displacement: 2,650 tons standard
3,415 tons full (1938 group) / 3,475 tons (WEP group)
Length: 400½ feet (p/p), 418 feet (o/a)
Beam: 40 feet
Draught: 11¼ feet (14¾ feet full)
Propulsion: 4 Admiralty 3-drum water-tube boilers, Parsons geared steam turbines, 2 shafts, 72,000 shp
Speed: 39¾ knots (38 kts full)
Range: 1,000 nm at 38 kts
Complement: 242
Armament: (1938 group) 6 x QF 4.7 in L/45 Mark XII on twin mountings CP Mark XIX, (later 6 x QF 4 in L/45 Mark XVI on twin mounts HA/LA Mk.XIX)
4 x QF 2 pdr L/39 Mk.VIII on quadruple mount Mk.VII
8 x 0.5 in Vickers machine guns on quadruple mount Mk.I (later up to 12 x 20 mm Oerlikons on single mounts P Mk.III or twin mounts Mk.V)
156 mines
Armament: (WEP group) 4 x QF 4 in L/45 Mark XVI on twin mounts HA/LA Mk.XIX
4 (Apollo) / 6 (Ariadne) x 40 mm Bofors on twin mounts "Hazemeyer" Mk.IV
up to 12 x 20 mm Oerlikons on single mounts P Mk.III or twin mounts Mk.V (later up to 6 x 40 mm Bofors on single mounts Mark V "Boffin"
156 mines

{tocleft} The Abdiel class were a class of six fast minelayers commissioned into the Royal Navy and active during World War II. They were also known as the Manxman class and as "mine-laying cruisers".

Contents

[edit] Design

The Royal Navy ordered the first four ships in 1938, with a further 2 acquired as part of the War Emergency Programme. They were specifically designed for rapidly laying minefields in enemy waters, close to harbours or sea lanes. As such they were required to be very fast and to possess sufficient anti-aircraft weaponry to defend themselves if discovered by enemy aircraft.

A large mineload of up to 150 mines was required to be carried under cover, therefore a long, flushdecked hull with high freeboard was required. The resulting ship was almost as long as a cruiser, but was laid out much like a large destroyer. However, the three straight funnels were an instant identifying feature. Top speed was specified as 40 knots. To achieve this they were given a full cruiser set of machinery and with an installed output of 72,000 shp on four shafts they made 39¾ knots light and 38 knots deep load. To put this into perspective, the contemporary Southampton class cruiser had 80,000 shp and a full load displacement of 12,980 tons, just short of 4 times that of the Abdiels.

The ships were initially to be armed much as destroyers, with three twin CP Mark XIX mounts for the QF 4.7 inch Mark XII gun (which had a maximum elevation of only 40°) in 'A', 'B' and 'X' positions, a quadruple "multiple pom-pom" mounting Mark VIII for the QF 2-pdr Mark VIII and a pair of quadruple 0.5 inch Vickers machine guns.

Wartime modifications involved adding Radar Type 279 at the masthead, a primitive metric wavelength air warning set, later replaced by Type 286 then Type 291 as they became available. Radar Type 285 was fitted to the rangefinder-director on the bridge, this was a metric set and could provide target ranging and bearing information. The centimetric Radar Type 272, a target indication set with plan position indicator (PPI), was fitted to the front leg of the foremast. Following the loss of Latona to air attack, the surviving ships were re-armed with three twin HA/LA Mark XIX mounts for the QF 4 inch L/45 Mark XIV gun with an elevation of 70° to remedy the shortcomings in anti-aircraft defence. Those on the stocks were armed with these mountings from new, but 'B' mount was suppressed and replaced (in Ariadne only) by a twin "Hazemeyer" mounting Mark IV for the 40 mm Bofors. Both Ariadne and Apollo had two such mountings sided amidships, replacing the pom-pom in 'Q' position, and these mounts carried their own Radar Type 282 for target ranging. Six single 20 mm Oerlikon guns were initially added on pedestal mountings P Mark III, although these were later replaced by powered twin mountings Mark V. In 1945 Ariadne was refitted in the United States in July 1945 for far eastern service, when the Bofors mounts were replaced by American pattern models (Mark I) with off-mounting "simple tachymetric directors" (STD) fitted with Radar Type 282 and the Oerlikon mounts regunned with Bofors guns (this combination was known as the "Boffin").

[edit] Service

Although they were effective ships in their intended role, the combination of high internal capacity and exceptionally high speed meant that they were extremely valuable fast transports. As such for much of their service they were used for running supplies; particularly men and matériel to isolated garrisons such as during the siege of Tobruk and Malta in Operation Harpoon. With three funnels and the outline of a destroyer, Welshman was camouflaged to appear like the Vichy French "contre torpilleurs" (large destroyer) Le Tigre[1]. For this, a false bow was fitted, funnel caps were added, the mine chutes were plated over and a false deckline was painted on to camouflage the high flush-deck.

Latona was hit by a 250 pound bomb in the engine room that caused a serious fire, which spread to the munitions she was carrying and caused her loss on October 25, 1941. Welshman was torpedoed and sunk by U617 in 1943. Manxman took a torpedo in her engine room but survived, although repairs took 2 years.

Apollo, Ariadne and Manxman survived the war and saw post-war service, with pennant number flag superior changed from "M" to "N". Apollo served as a despatch vessel and Manxman as a mine warfare support ship.

[edit] Ships

[edit] 1938 group

[edit] War Emergency Programme (WEP) group

[edit] References

  1. ^ http://www.bbc.co.uk/ww2peopleswar/stories/88/a1985088.shtml BBC World War II; People's War, retrieved August 30, 2006
  • British and Empire Warships of the Second World War, H T Lenton, Greenhill Books, ISBN 1-85367-277-7
  • Conway's All the World's Fighting Ships, 1922-1946, Ed. Robert Gardiner, Naval Institute Press, ISBN 0-87021-913-8
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