Bathurst Class Corvette - Background

Background

In February 1938, the Australian Commonwealth Naval Board (ACNB) identified the need for a general purpose 'local defence vessel' (which itself evolved from plans for a training tender attached to the anti-submarine warfare training school at HMAS Rushcutter) that was easy to construct and operate. The ships had to be capable of both anti-submarine and mine-warfare duties. The RAN's Director of Engineering, Rear Admiral P. E. McNeil, was instructed in July 1938 to prepare plans for such a ship, with a displacement of approximately 500 tons, a speed of at least 10 knots (19 km/h; 12 mph), and a range of 2,000 nautical miles (3,700 km; 2,300 mi).

In an initially unrelated development, three Bar class boom defence vessels were ordered by the RAN in 1937, but when the requirement was lowered to two ships in early 1938, the third, HMAS Kangaroo, was earmarked for construction as a prototype of the 'local defence vessel'. McNeil completed his drawings in February 1939; his design was for a 680 ton vessel, with a speed of 15.5 knots (28.7 km/h; 17.8 mph), and a range of 2,850 nautical miles (5,280 km; 3,280 mi). The prototype would have been armed with a 4-inch gun, equipped with asdic, and able to fitted with either depth charges or minesweeping equipment depending on the planned operations. Although closer to a small sloop than a local defence vessel, the increase in size and speed meant the design was more versatile than originally envisioned. Before construction could begin, the number of boom vessels was increased back to three, and Kangaroo was laid down as a boom defence vessel.

Although the Kangaroo prototype was never built, the design was retained as it had advantages over dedicated British minesweeper and anti-submarine vessels, and with the exception of weapons and specialised instruments, could be built using local resources. Although not perfectly suited for any specific role, the all-round general capability for minesweeping, anti-submarine warfare, patrol, and escort duties was seen as a good short-term solution until better vessels could be requisitioned or constructed. The design underwent the normal procurement process, and in September 1939, the ACNB approved seven ships of a slightly modified design. Additional orders were quickly placed by the RAN, the British Admiralty and the Royal Indian Navy, with 60 ships constructed over the course of World War II; 36 were commissioned into the RAN, 20 were manned by RAN personnel but were paid for by the Admiralty, and 4 were built for the Royal Indian Navy. The ships were officially designated "Australian Minesweepers" (AMS) to hide their intended anti-submarine role, although the Bathursts were popularly referred to as corvettes.