Resolution*, Cairo*, Excellent (gunnery training school)*, Revenge*, Calcutta*, Carlisle*, Curacoa*, Exeter*, Adventure*, Warspite*. Ships marked with * had roll stabilization for layer. HACS III*G as mark III but fitted with GRU and roll stabilization for the layer. HACS IV: Similar to MkIII but with circular screen, magslip transmission and roll stabilization for the layer. Introduced Mk IV table. HMS Birmingham, Sheffield, Glasgow, Aurora, Liverpool, Manchester, Gloucester, Dido, and Fiji classes, Forth, Maidstone, Renown, Valiant, Illustrious, Formidable and Ark Royal. HACS IV G: Mk IV with Gyro rate unit. and es. HACS IV GB: Mk IV and fitted with GRU and complete stabilization in laying and training, Keelavite system of power training. HMS King George V and Prince of Wales, Dido and Fiji classes. HACS V: Improved design, partially enclosed, complete stabilization for elevation and training. Keelavite system of power training, and GRU. Duplex 15 ft HF/RF. Uses Mk IV table. HMS Duke of York, Anson and Howe. HACS V* :As Mk V but single HF/RF and raised HF/RF compared to Mk V. HMS Indomitable, Implacable and Indefatigable. See also Argo clock Ship gun fire-control system References External links Newsreel video of HACS controlled guns in action More Newsreel footage of HACS guns engaging high level bombers HACS: A Debacle or Just-in-Time?) Illustration of the HACS Deflection Screen Appendix one, Classification of Director Instruments HACS III Operating manual Part 1 HACS III Operating manual Part 2 USS Enterprise Action Log The Gunnery Pocket Book, B.R. 224/45, 1945 The true experiences of Mr. Leonard Charles HACS III*G with Type 285 Radar and the MkIII table British Mechanical Gunnery Computers of World War II Progress in Naval Gunnery, 1914–1936 Memoirs of Sub-Lieutenant Robert Hughes, Gunnery Control Officer on HMS Scylla Anti-aircraft artillery Military computers Naval artillery Artillery operation Royal Navy Fire-control computers of World War II Military equipment introduced in the 1930s