HMS Adventure (M23)

HMS Adventure, pennant number M23, was a minelaying cruiser of the Royal Navy built in the 1920s that saw service during the Second World War. Her commander between 1928 and 1929 was the future First Sea Lord John H. D. Cunningham.

Laid down at Devonport in November 1922 and launched in June 1924, Adventure was the first vessel built for service as a minelayer, she was also the first warship to use diesel engines, being used for cruising.

On entering the service she joined the Atlantic Fleet. From 1931-1932, she underwent a refit. During this refit she received a rounded stern in place of the original square one.

In the early months of the Second World War, she was damaged in the Thames Estuary and was repaired at Sheerness.

In 1940, she laid minefields in the Orkney Islands and St. George's Channel and in 1941 was damaged by a mine while off Liverpool.

In 1944, she was converted to a landing craft repair and accommodation ship; in 1945 was reduced to reserve; and in 1947 was sold to T W Ward Ltd. and broken up at Briton Ferry.

Adventure was adopted by the City of Plymouth.

Design
Adventure was built to replace the converted First World War veteran Princess Margaret, and her design was dictated by a requirement for a large mine capacity and a good cruising range. The mineload was to be carried completely internally, dictating a long, tall hull, and there were four sets of rails running the length of the hull to chutes at the stern. She was built with a transom, or flat, stern, to improve cruising efficiency, but the dead water caused by such a form meant that mines tended to be sucked back into the hull when they were launched; an obviously dangerous situation for a minelayer. As a result she was rebuilt with a traditional cruiser, or rounded, stern, increasing the length by 19 ft.

Propulsion was by plant as installed in the C-class cruisers, but to increase cruising efficiency a novel diesel-electric plant was trialled, the propellers being driven by either set of machinery through gearboxes. The diesel-electric plant was removed by 1941, along with the small diesel exhaust that had been trunked up the second funnel. Adventure's high topweight resulting from the mineload carried high up in her hull meant that typical cruiser type armament could not be fitted. Instead, four QF 4.7 in (120 mm) guns on high-angle mounts were carried in 'A', 'Q', 'X' and 'Y' positions, in hindsight a more useful arrangement. The anti-aircraft armament was completed by a single octuple multiple pom-pom in 'B' position (not fitted until the late 1930s) and a pair of quadruple .5 in Vickers machine guns.

By 1941, she had been fitted with Radar Type 291 air warning at the masthead, Radar Type 285 on the high-angle HACS Director Control Tower on the foremast spotting top and Radar Type 272 centimetric target indication on the foremast, below the spotting top. By 1944, nine 20 mm Oerlikon guns had been added, two of which had replaced the useless Vickers machine guns. Adventure was converted to a repair ship for landing craft for the Normandy landings.

Mining on 13 November 1939
Adventure was badly damaged, most probably by a German magnetic mine in the Thames estuary at 05:26 on the morning of 13 November 1939. Twenty-three men were killed in this incident. She was sailing in company with HMS Blanche (H47) and HMS Basilisk (H11). Blanche was also mined at 08:20 and sank at 09:50. One man was killed on Blanche.

Normandy Landings
During the Normandy landings in 1944 Adventure was deployed off Mulberry B as a support and repair vessel; she landed repair parties on 19 June for extensive salvage work on damaged landing craft.