Rapid, Raider and Roebuck, or at the foremast truck in other ships. Racehorse, Raider, Rapid, Redoubt and Relentless had Huff-Duff (High-frequency Direction-finder) added on a lattice mainmast. Ships Q class R class Notes References Destroyers of the Royal Navy, 1893–1981, Maurice Cocker, Ian Allan, Conway's All the World's Fighting Ships 1922–1946, Ed. Robert Gardiner, Naval Institute Press, Warships of Australia, Ross Gillett, Illustrations Colin Graham, Rigby Limited, 1977, Royal Navy Destroyers since 1945, Leo Marriott, Ian Allan, See also Type 15 frigate – most surviving Q and R-class ships were given this conversion post-war. Destroyer classes Ship classes of the Royal Navy