The South Australian Railways 500 class is a class of 4-8-2 steam locomotives introduced by the former South Australian Railways (SAR) in 1925. The locomotives were upgraded in 1929 by the installation of booster engines to increase the tractive effort to . The resulting 500B class, with a 4-8-4 wheel arrangement, was briefly the most powerful steam locomotive class to operate in Australia until supplanted by the slightly more powerful NSWGR D57 class 4-8-2. During the late 1930s, the SAR followed the image-building trends being pursued by overseas railroads, covering all but two of the locomotives' piping and plumbing with a smooth casing and adding valances under the running boards. The last of the class was withdrawn from service in 1963.
History
The 500 class were part of larger order for 30 steam locomotives placed with Armstrong Whitworth, England, in 1924, as part of the rehabilitation of the state's rail system being overseen by Railways Commissioner William Webb. They replaced the Rx and S class locomotives, many dating back to 1894, that were still performing mainline duties, meaning that double and even triple heading was common. All ten 500-class locomotives arrived in Adelaide in 1926, and entered service on the Adelaide to Wolseley line as far as Tailem Bend. All were named after notable South Australians.
Rebuilding In May 1928, 506 was experimentally fitted with a booster in a newly built four-wheel trailing truck, replacing the original unpowered two-wheel truck. The modification, popular in the United States, proved highly successful, increasing the locomotive's tractive effort from to . Boosters were subsequently fitted to the nine remaining locomotives, resulting in the class changing to 500B – although their popular name, among railway employees and the public alike, remained "Mountain class" rather than their new "Northern" configuration. With their upgraded tractive effort, the 500B class briefly became the most powerful non-articulated steam locomotives to operate in Australia until supplanted the following year by the New South Wales D57 class.
Throughout the mid-1930s, all but two of the locomotives in the class were semi-streamlined and had valances fitted. The first two locomotives were withdrawn from service in 1955 and the last was withdrawn in 1963.
504 is preserved as a static exhibit at the National Railway Museum, Port Adelaide.
Class list Number Date in service Date condemned Name 500 4 June 1926 May 1963 James McGuire 501 2 July 1926 September 1958 Sir Henry Barwell 502 22 May 1926 July 1961 John Gunn 503 23 July 1926 July 1962 RL Butler 504 18 October 1926 July 1962 (Preserved) Tom Barr Smith 505 28 October 1926 July 1962 Sir Tom Bridges 506 25 October 1926 July 1962 Sir George Murray 507 12 October 1926 March 1958 Margaret Murray 508 14 September 1926 July 1962 Sir Lancelot Stirling 509 24 August 1926 July 1961 WA Webb
References
Further reading