HMS Adventure (M23) - Design

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 (5.8 m).

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 (13 mm) 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.