III machine gun. Low-angle fire for the main guns was controlled by the director-control tower (DCT) on the bridge roof that fed data acquired by it and the rangefinder on the Mk II Rangefinder/Director directly aft of the DCT to an analogue mechanical computer, the Mk I Admiralty Fire Control Clock. Anti-aircraft fire for the main guns was controlled by the Rangefinder/Director which sent data to the mechanical Fuze Keeping Clock. The ships were fitted with a single above-water quadruple mount for torpedoes. The Tribals were not intended as anti-submarine ships, but they were provided with ASDIC, one depth charge rack and two throwers for self-defence, although the throwers were not mounted in all ships. Twenty depth charges was the peacetime allotment, but this increased to 30 during wartime. Wartime modifications Heavy losses to German air attack during the Norwegian Campaign demonstrated the ineffectiveness of the Tribals' anti-aircraft suite and the RN decided in May 1940 to replace 'X' mount with two QF Mark XVI dual-purpose guns in a twin-gun mount. To better control the guns, the existing rangefinder/director was modified to accept a Type 285 gunnery radar as they became available. The number of depth charges was increased to 46 early in the war, and still more were added later. To increase the firing arcs of the AA guns, the rear funnel was shortened and the mainmast was reduced to a short pole mast. Construction and career Authorized as one of seven Tribal-class destroyers under the 1935 Naval Estimates, Mohawk was the eleventh ship of her name to serve in the Royal Navy. The ship was ordered on 10 March 1936 from John I. Thornycroft & Company and was laid down on 16 July at the company's Woolston, Southampton, shipyard. Launched on 5 October 1937, Mohawk was completed on 7 September 1938 and commissioned two days later at a cost of £339,585 which excluded weapons and communications outfits furnished by the Admiralty. Under the command of Commander Richard Frank Jolly, the ship was initially assigned to the 1st Tribal Destroyer Flotilla with the Mediterranean Fleet and arrived at Malta on 13 October. The following month she patrolled the Malta-Egypt leg of the Royal Air Force (RAF)'s Long-Range Development Flight of three Vickers Wellesley bombers that were preparing to break the world flight distance record by flying from Egypt to Australia non-stop. At the end of the month, Mohawk ferried