Commonwealth Railways GM class

Preserved GM2 at the National Railway Museum in July 2010

Two GM class on the Trans-Australian at Rawlinna in May 1986

GM43 at Mount Gambier while on broad gauge in April 1995

Genesee & Wyoming Australia GM43 and two other GM class locomotives in April 2008

The design was based on the Electro-Motive Diesel EMD F7 locomotive.[1] The first 11 were delivered with EMD 16-567B, 1,119 kW (1,501 hp) engines and four powered axles with the remainder having 16-567C, 1,305 kW (1,750 hp) engines and six powered axles. The final 11 were fitted with dynamic braking.[2]

Delivered to operate on the standard gauge Trans-Australian Railway, the first entered service in September 1951. Further orders saw 47 in service by December 1967. They operated on all of Commonwealth Railways's standard gauge lines including those to Broken Hill, Alice Springs, Marree and Adelaide when converted to standard gauge in 1970, 1980 and 1982 respectively.

In January 1972, three (31, 32 & 34) were loaned to the Victorian Railways for use on the North East line. The latter two were returned in May 1976, the former in November 1976.[3]

In July 1975 all were included in the transfer of Commonwealth Railways to Australian National. In 1979 a few operated to Lithgow, New South Wales on trials, while in October 1983 three (23, 24 & 28) were hired to V/Line returning in October 1985.[3][4]

The GM class were manufactured for standard gauge use, some of the locomotives were converted to operate on 5 ft 3 in (1,600 mm) broad gauge for some of their lives.

Apart from one destroyed in an accident in 1985, withdrawals began in 1988.[2] GM1 was placed on a plinth in Port Augusta, GM2 was donated to the National Railway Museum, Port Adelaide and GM3 to Clyde Engineering, Kelso.[5] By October 1994 only 15 remained in service.[6] A locomotive shortage saw Australian Southern Railroad return GM1 to service in December 1997.[7]

In 1998 Great Northern Rail Services purchased 12 from Australian Southern Railroad.[8] Most were scrapped for parts with only three returning to service seeing use in Melbourne and Sydney. Following Great Northern ceasing operations in 2003, these were sold to Chicago Freight Car Leasing Australia before being resold to Southern Shorthaul Railroad.[2]

In May 2005 Australian Railroad Group forwarded GM30 to Forrestfield workshops to be receive a 2,237 kW (3,000 hp) engine, as fitted to the CLs. The project was never completed and the shell was scrapped.[2][9]

In November 2010 the Department for Infrastructure & Transport placed GM1 in the custody of Rail Heritage WA.[10] In May 2012 Clyde Engineering sold GM3 to Southern Shorthaul Railroad and it was transferred to their Lithgow State Mine Heritage Park & Railway workshop for overhaul.

As at October 2020 all but 2 of the One Rail Australia units are stored unserviceable due to more modern power available for freight services in South Australia while the Southern Shorthaul Railroad units are used on infrastructure and grain trains in New South Wales and Victoria.[11][12][13][14]