To change secondary lines in New South Wales from steam to diesel, AE Goodwin built the DL531 under ALCO license. With six axles, this had a weight of only 74 tons and a six-cylinder with 1,050 hp. Until 1970, the NSWGR received a total of 165 locomotives in standard gauge, which it designated as class 48. Otherwise it was also known as RSD8.
The South Australian Railways also bought 45 DL531 in three different gauges and designated them as class 830. The Silverton Tramway bought three, and customers were also found in Brazil, Peru and Pakistan. In Australia, many were retired from the state railways in the nineties and sold to private railways, many of which are still in use today. 