Abdiel-class minelayer

The Royal Navy ordered the first four ships in 1938, with a further two acquired as part of the War Emergency Programme. They were specifically designed for the rapid laying of 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 load of up to 150 mines was required to be carried under cover, therefore a long, flushdecked hull with high freeboard was required. The mines were laid through doors in the sterns; the ships carried their own cranes for loading.[1]

In size these ships were almost as long as a cruiser but laid out much like a large destroyer but the three straight funnels were an instant identifying feature. Top speed was specified as 40 knots (74 km/h). To achieve this they were given a full cruiser set of machinery and with an installed output of 72,000 shaft horsepower (54,000 kW) on two shafts, they made 39.75 knots (73.62 km/h; 45.74 mph) light and 38 knots (70 km/h; 44 mph) deep load. To put this into perspective, the contemporary Town-class cruisers had 80,000 shp (60,000 kW) and a full load displacement of 12,980 tons, just short of four times that of the Abdiels.

The ships were initially to be armed much as destroyers, with three twin HA/LA Mark XIX mounts for QF 4-inch (100 mm) L/45 Mark XIV guns, with an elevation of 70°, in 'A', 'B' and 'X' positions, a quadruple "multiple pom-pom" mounting Mark VIII for the QF 2-pounder Mark VIII and a pair of quadruple 0.5-inch Vickers machine guns.[1]

Wartime modifications involved adding a Type 279 radar at the masthead, a primitive metric wavelength air warning set, later replaced by a Type 286 then a Type 291, as they became available. A Type 285 radar was fitted to the rangefinder-director on the bridge, this was a metric set and could provide target ranging and bearing information. The centimetric Type 272, a target indication radar 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 to remedy the shortcomings in anti-aircraft defence. Six single Oerlikon 20 mm cannons were initially added on P Mark III pedestal mountings, although these were later replaced by powered twin Mark V mountings. Ariadne and Apollo had two twin Mark IV "Hazemeyer" mountings for Bofors 40 mm guns sited amidships, replacing the pom-pom in 'Q' position, and these mounts carried their own Type 282 Radar for target ranging; Ariadne had an additional "Hazemeyer" mounting in 'B' position, replacing the 4-inch guns. In July 1945, Ariadne was refitted in the United States 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 Type 282 Radar and the Oerlikon mounts regunned with Bofors guns (this combination was known as the "Boffin").

Although they were effective ships in their intended role, the combination of high internal capacity and exceptionally high speed meant that they were equally valuable as fast transports.[2] 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 destroyers) Tigre.[3] 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. Manxman received a similar disguise to pass for the Vichy contre torpilleur Léopard so she could pass Corsica and mine the approaches to Livorno.

On 25 October 1941, Latona was hit by a 250-pound (110 kg) bomb in the engine room, causing a serious fire that spread to the munitions she was carrying and resulting in her loss. Welshman was torpedoed and sunk by U-617 in 1943. Manxman took a torpedo in her engine room but survived, although repairs took two years.

Apollo, Ariadne and Manxman survived the war and saw post-war service, with their pennant numbers changed from "M" to "N". Apollo served as a despatch vessel and Manxman as a mine warfare support ship. In 1953, Manxman was used to depict a German raider in the re-made film of C. S. Forester's novel Brown on Resolution; for this her funnels were enlarged to alter her outline, dummy 6-inch barrels were fitted over her 4-inch guns, and her bow was painted to indicate 'torpedo damage'.

• List of ship classes of the Second World War

• Caruana, Joseph (2012). "Emergency Victualling of Malta During WWII". Warship International. LXIX (4): 357–364. ISSN 0043-0374.
• Cocker, M.P. (1993). Mine Warfare Vessels of the Royal Navy: 1908 to Date. Shrewsbury, England: Airlife Publishing. ISBN 1-85310-328-4.
• Gardiner, Robert. Conway's All the World's Fighting Ships 1922-1946. Naval Institute Press, ISBN 0-87021-913-8.
• Lenton, H.T. British and Empire Warships of the Second World War.Greenhill Books, ISBN 1-85367-277-7.
• Nicholson, Arthur (2015). Very Special Ships: Abdiel-Class Fast Minelayers of World War Two. Barnsley: Seaforth. ISBN 978-1-84832-235-6.