The Diesel Electric Rail Motor (commonly referred to as a DERM) was a railmotor operated by the Victorian Railways of Australia.
Originally built as a Petrol Electric Rail Motor (PERM) they were the longest-lived railmotor on the Victorian Railways, with the first entering service in 1928 and the last being withdrawn in 1991. The first railmotor was built by the St. Louis Car Company and shipped to Australia where the Victorian Railways built a further 9 copies of it. It was powered by a 220 hp Winton petrol engine which was used until the 1950s when they were converted to twin Diesel Electric engines giving a total of 255 bhp.
By the 1970s the longest regular scheduled journey run by a DERM was the Bendigo to Robinvale run, withdrawn on 3 June 1978. A DERM with a DERM Trailer car ran a regular passenger train on the South Gippsland Line from the 1960s - 1970s