South Australian Railways 600 class (diesel)

The 600 class is a class of diesel-electric locomotives manufactured by AE Goodwin for the South Australian Railways between 1965 and 1970.

Seven 600 class locomotives were built by American Locomotive Company (Alco)'s Australian licensee AE Goodwin, of Auburn, New South Wales. They were based on the Alco DL-541 model. Goodwin had built 40 similar examples in 1962-64 for the New South Wales Government Railways as the 45 class.

Two were built in April 1965 to be deployed on construction trains for the gauge standardisation project, completed in 1970, that enabled trains to travel from Sydney to Perth without changing gauge. A further five were delivered in 1969–70.^[1][2] They were the only South Australian Railways diesels never to operate on broad-gauge rails. They mainly operated services between Broken Hill and Port Pirie. Latterly they hauled coal trains between Leigh Creek and Adelaide.^[3] In March 1978, the 600s were included in the transfer of South Australian Railways assets to Australian National.

From July 1982 to October 1985, some were hired to the New South Wales State Rail Authority. Based at Goulburn, they operated freight services on the Main South and Illawarra lines.^[3][4]

In 1986, a new computer system required the class leaders of the former South Australian Railways to be renumbered as the last member of the class: hence no. 600 became no. 607.^[5]

In 1994, Morrison Knudsen Australia's factory at Whyalla converted four of the class to operate with Australian National's ALF class locomotives as slug units during shunting, increasing traction at low speed.^[1][6] The cab and engine were removed, retaining four of the six bogie traction motors and filling the engine bay with 30 tonnes of concrete. They were not successful and were placed in store in 1996. Australian Southern Railroad trialled one, designated BU1, in 2000, but it soon returned to store.^[3][7] All four were scrapped in 2009.^[8]

When Australian National Railways Commission assets were sold to Australian Southern Railroad in 1997, the remaining three units were included in the sale. ASR sold them in 2004 to South Spur Rail Services for duties in New South Wales. SSRS sold the business and locomotives to Coote Industrial in 2007.^[9][10] As at October 2014 only two remained in service.^[11] In April 2016, they were sold to Southern Shorthaul Railroad and were stored; 602 was returned to service in 2017.^[12][13]