HMAS Perth (D29) - Design and Construction

Design and Construction

The ship was one of three Modified Leander-class light cruisers constructed for the Royal Navy. She had a displacement of 6,830 tons, with a length overall of 562 feet 3.875 inches (171.39603 m), a length between perpendiculars of 530 feet (160 m), a beam of 56 feet 8 inches (17.27 m), and a draught of 19 feet 7 inches (5.97 m). The main difference to the previous five Leanders was that the newer ships had their machinery and propulsion equipment organised in two self-contained units (two Parsons geared turbines and two Admiralty 3-drum boilers in each machinery space), allowing the ship to continue operating if one set was damaged. The two exhaust funnels, one for each machinery space, gave the modified ships a different profile from the early Leanders, which had a single funnel. To cover the separate machinery spaces, the side armour was extended from 84 to 141 feet (26 to 43 m), negating the weight reduction created by the separation. The machinery spaces produced 72,000 shaft horsepower (54,000 kW) for the four propellers, and could drive the ship to a maximum speed of 31.7 knots (58.7 km/h; 36.5 mph). At top speed, the cruiser could travel 1,780 nautical miles (3,300 km; 2,050 mi), while the more economical speed of 22.7 knots (42.0 km/h; 26.1 mph) produced a maximum range of 6,060 nautical miles (11,220 km; 6,970 mi).

The Leanders' main armament was eight BL 6 inch Mk XXIII naval guns, fitted in four twin turrets. During design, it was planned to modify the forward-most and aft-most 6-inch turrets to be fitted with three guns instead of two, but the plan was cancelled when it was determined that the required alterations would cause several negative side effects, including reducing the ship's top speed and causing problems with effective fire control. Secondary armament initially consisted of four 4-inch Mk XVI guns, but these were later upgraded to four twin mounts. For close defence, the ship was fitted with twelve 0.5-inch machine guns in three quadruple mounts, and ten .303-inch machine guns; a mix of Lewis Guns and Vickers machine guns. Eight Mark VII 21-inch torpedo tubes were carried; two quadruple mounts. The ship carried an amphibious aircraft (initially a Supermarine Seagull V, later a Supermarine Walrus) on a catapult. At the time of entry to Australian service, the ship's company stood at 646 (35 officers and 611 sailors), but by the time of her loss, 681 were aboard: 671 naval personnel, 6 RAAF personnel, and 4 civilian canteen staff.

The ship was laid down as HMS Amphion for the Royal Navy at Portsmouth Dockyard on 26 June 1933. She was launched by the Marchioness of Titchfield on 27 July 1934, commissioned into the Royal Navy on 15 June 1936, and completed on 6 July 1936.