The Bathurst-class corvettes were a class of general purpose vessels designed and built in Australia during World War II. Originally classified as minesweepers, but widely referred to as corvettes, the Bathurst-class vessels fulfilled a broad anti-submarine, anti-mine, and convoy escort role.

A total of 60 Bathurst-class corvettes were built, at eight Australian shipyards: 36 were paid for by the Australian government and 24 were built on British Admiralty orders. Of these UK-owned vessels, 20 were officially commissioned into the Royal Australian Navy (RAN), and manned by RAN personnel, while four served in the Royal Indian Navy; none of the UK-owned vessels was commissioned into the Royal Navy. An order for three more Bathursts, to be constructed in India, was cancelled before they were laid down.

Although the Bathursts were designed for the anti-submarine and anti-mine roles, they also served as troop and supply transports, provided air defence for convoys and disabled ships, participated in shore bombardments, and undertook hydrographic surveys. Three ships were lost during the war: one to an air attack and two to collisions with friendly merchant ships. (Following the war, a fourth vessel sank after hitting a mine while sweeping the Great Barrier Reef.)

After the war, the Admiralty ships were sold to the Turkish Navy, Royal Netherlands Navy, and civilian operators, while several RAN-owned vessels were transferred to the Royal New Zealand Navy, temporarily reactivated to facilitate National Service Training, or sold to civilians. Four of the Dutch Bathursts were transferred to the Indonesian Navy; one of these was destroyed in 1956 by anti-government rebels. The rest of the RAN and Admiralty ships were sold for scrap to help fund other projects. Two vessels are preserved as museum ships.

Background In 1937, in an initially unrelated development, the Australian Commonwealth Naval Board (ACNB) approved the procurement of three net-laying boom defence vessels. However, in February 1938, the ACNB also identified a need for a class of general purpose, 'local defence vessels' that were easy to construct and operate. (This need emerged from plans for a training tender attached to the RAN anti-submarine warfare training school.)The Australian Corvettes, p. 1Stevens, A Critical Vulnerability, p. 103 The ships had to be capable of both anti-submarine and minesweeping duties. Consequently, the number of boom defence vessels ordered was reduced to two, and resources for the third were re-allocated to a prototype local defence vessel.

During July 1938, the RAN Director of Engineering, Rear Admiral Percival McNeil, was instructed to develop plans for a local defence vessel, with a displacement of approximately 500 tons, a speed of at least , and a range of .Stevens, A Critical Vulnerability, pp. 103–104 McNeil completed his drawings in February 1939; his proposal called for a 680-ton vessel, with a speed of , and a range of . McNeil's unbuilt prototype – sometimes known as HMAS Kangaroo – more closely resembled a sloop than the original concept of a local defence vessel; the increase in size and speed also meant the vessel would have been more versatile than originally envisioned. It would have been equipped with a 4-inch gun, ASDIC and either depth charge launchers or minesweeping equipment, depending on operational requirements. In the meantime, however, the order for three net-laying vessels was re-instated before construction of McNeil's prototype could begin.Stevens, A Critical Vulnerability, p. 104 (The second of these Bar-class boom vessels to be commissioned was instead named .)

Although McNeil's "Kangaroo class" was never built, his general concept attracted interest in Australian naval circles, as it offered advantages over existing minesweeper and anti-submarine classes and could be built in Australia with local resources, with the exception of weapons and some specialised instrumentation.Stevens, A Critical Vulnerability, p. 105 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.Donohue, From Empire Defence to the Long Haul, p. 29Stevens, A Critical Vulnerability, p. 148

In September 1939, following the outbreak of war, there was a new procurement process for seven ships of a design based on McNeil's concept. Additional orders were soon placed by both the ACNB and the British Admiralty, and a total of 60 Bathurst-class ships were built, including 36 ordered by the RAN for home duties and 24 paid for by the Admiralty. Of these British-ordered vessels, 20 vessels were commissioned into the RAN and crewed by Australian personnel, on the understanding that they would be attached to Royal Navy fleets; a further four vessels were commissioned into the Royal Indian Navy.

The Bathurst class were officially classified as "Australian Minesweepers" (AMS) to hide their intended primary role in anti-submarine duties, although the Bathursts were popularly referred to as corvettes.Stevens et al., The Royal Australian Navy, p. 108

Design

Each ship's company varied in size: the standard complement was 85, including 6 commissioned and 12 to 13 non-commissioned officers.Frame & Baker, Mutiny!, p. 165 Over 20,000 personnel served on a Bathurst during the war: the early ships were primarily manned by reservists, while the majority of the 'Hostilities Only' personnel recruited during the war served on a Bathurst-class vessel sometime during their career.Stevens et al., The Royal Australian Navy, p 115 Sailors were accommodated in ten-man messdecks, which were small, poorly lit rooms that were perpetually damp from seawater and sweat. In anything but calm weather, hatches and portholes would have to be closed: sunlight and fresh air was a rarity inside the hull. Because of the conditions, high rates of sickness (particularly pneumonia and tuberculosis) were experienced. Officers slept in cabins with bunks (as opposed to hammocks), and ate and relaxed in each ship's wardroom, complete with bar and steward service. The difference in conditions between officers and sailors prompted tensions between these two groups.

Six large escort vessels based on a scaled-up version of the Bathurst design were considered for construction in mid-1941, but the design was determined to be inferior to the .Stevens, A Critical Vulnerability, .p 166

Armament and equipment The most common armament for Bathurst-class corvettes was a 12-pounder gun or a 4-inch Mark XIX high-angle gun, three Oerlikon 20 mm cannons, two Lewis .303 machine guns, and two .303 Vickers machine guns.Lind, The Royal Australian Navy – Historical Naval Events Year by Year, p. 173 The corvettes carried up to 40 depth charges, which were deployed by 4 throwers and 2 chutes.HMAS Goulburn – HMA Ship HistoriesHMAS Glenelg – HMA Ship Histories Many of the 12-pounder carrying corvettes were refitted with the 4-inch during their service life, while one of the Oerlikons was often replaced with a Bofors 40 mm gun.HMAS Gympie – HMA Ship Histories Bathursts equipped with the 4-inch main gun were primarily allocated to northern waters, because of the increased air threat and the greater anti-aircraft capabilities of the 4-inch compared to the 12-pounder gun mounted on other corvettes.Stevens, A Critical Vulnerability, p. 228

Due to the variety of shipyards constructing the corvettes, as well as the varying roles the Bathursts were pressed into, there was no true standardisation of armament. Some ships varied significantly from the common armament profile, while an individual ship's weapons outfit could vary significantly for different periods of her career. At one stage, carried six Oerlikon cannons, a number later reduced to four.HMAS Geraldton (I) – HMA Ship Histories By comparison, the outfit of consisted of a single 4-inch gun and a single 40 mm gun.HMAS Junee – HMA Ship Histories

The Bathursts were equipped with modified Type 128 asdic equipment, redesigned to be used without a gyroscopic stabiliser.Stevens, A Critical Vulnerability, pp 154–155 Minesweeping equipment also varied across the class: ships equipped with the newer 'LL' minesweeping gear were distributed as evenly as possible throughout major Australian ports.

Each was fitted with a triple expansion steam engine (usually fabricated by railway workshops) to drive two propellers at a theoretical maximum speed of , although this required ideal conditions and was rarely achieved.Frame & Baker, Mutiny!, p. 164

Construction

Construction of the ships required a significant expansion of the Australian shipbuilding industry. This was achieved by bringing disused dockyards back into production and establishing new facilities.Mellor, The Role of Science and Industry, p. 455 The lead shipyard was Cockatoo Docks & Engineering Company in Sydney, which laid down the first ship, , in February 1940, and produced a further seven vessels.Stevens, A Critical Vulnerability, p. 152Mellor, The Role of Science and Industry, p. 457 The other seven shipyards involved were Walkers Limited in Maryborough, Queensland (7 ships), Evans Deakin & Company in Brisbane (11 ships), Mort's Dock & Engineering Company in Sydney (14 ships), Poole & Steel in Sydney (7 ships), State Dockyard at Newcastle, New South Wales (1 ship), HMA Naval Dockyard at Williamstown, Victoria (8 ships), and BHP at Whyalla, South Australia (4 ships).Gill, Royal Australian Navy, 1942–1945, p. 104 Each ship cost approximately A£250,000 to build.

The initial rate of construction was slow, due to a variety of factors: delays in equipment delivery from overseas, industrial problems, a lack of qualified labour, and the difficulty of naval overseers in supporting all eight shipyards at once primary among them. The initial prediction was that two vessels per month would enter service through 1941, but by June 1940, only five of the seventeen ordered so far had been laid down, and the RAN was advised at the end of 1940 that only seven would be completed December 1940. The prioritisation of Admiralty orders by the Australian government meant that RAN-ordered ships were further delayed, although the Admiralty later allowed the first four of their ships to remain in local waters until replacements entered service. Rate of construction increased by late 1941, although the increasing need of shipbuilding resources for repairs as the war progressed slowed the rate of construction back down.Stevens et al., The Royal Australian Navy, pgs. 121, 132 The corvette's build time was comparable to that of an ; the fourteen-month construction time for was equal to or faster than the individual build time of half the corvettes.Colebatch, The enemy within that killed Curtin

Three additional Bathursts were to be built for the Royal Indian Navy by Garden Reach of Calcutta.Lenton,British and Empire Warships of the Second World War, p. 258 All three were laid down on 3 May 1943, but were cancelled and broken up on the slipways in March 1945. Instead, three Flower-class corvettes were transferred from the Royal Navy to India.

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