849 at Mile End Loco Depot, Adelaide, South Australia in December 1985.
45 Co-Co 830 Class ALCO DL 531 (725kW / 970HP) were built between 1959-1966 by AE Goodwin, Granville, NSW.
In 1959 the South Australian Railways placed an order for 10 Alco DL531 locomotives for use their narrow gauge network. Further orders saw the fleet built up to 44 by February 1970 with 15 narrow gauge, 12 standard gauge and 17 broad gauge examples. In February 1970 an additional unit was purchased second hand from Silverton Tramway.
In March 1978, 43 were included in the transfer of the South Australian Railways to Australian National with the other two going to the State Transport Authority before also moving to Australian National. From July 1974 until December 1980 847-849, were loaned to the Public Transport Commission where they were pooled with the 48 class.
Following the conversion of the Adelaide to Alice Springs in the early 1980s and the release of some Commonwealth Railways NJ class locomotives, beginning in April 1980 some 830s were transferred to Australian National's TasRail operation with 20 transferred by August 1986 Withdrawals of the TasRail fleet commenced in late 1987 with only three in service by April 1989. Australian National repatriated five to the mainland while two were sold to Silverton Rail and shipped to Broken Hill. One was preserved by the Don River Railway, Devonport The remainder were scrapped.
In 1991, six were rebuilt as the DA class with new cabs to allow them to be used as shunters. In December 1994 two 48 class locomotives were purchased from the State Rail Authority. One was rebuilt as DA7 and the other scrapped.
Australian National's remaining 830 class were all included with the sale of the South Australian freight operations to Australian Southern Railroad in August 1997.
In June 2000 three were sold to ATN Access for use on grain services. All were included in the sale of the business to Pacific National in February 2004 but are now stored.
The sale of Australian Railroad Group to QR National included 852. It was sold to Junee Railway Workshop in 2008 and after being overhauled returned to service in 2012.