The Diesel Electric Rail Motor (DERM) was a railmotor operated by the Victorian Railways of Australia. History Originally built as a petrol electric rail motor (PERM), they were the longest-lived rail motor on the Victorian Railways, with the first entering service in 1928 and the last being withdrawn in 1991. The rail motor was a standard product of the US Electro-Motive Corporation (a predecessor of Electro-Motive Diesel) and built between 1924 and 1932, albeit to a smaller loading gauge and wider track gauge. The first was imported in 1927, assembled at Newport Workshops, and placed in service in 1928. The bodies of the remaining nine were constructed at Newport Workshops using imported equipment and electrical equipment and placed in service between 1930 and 1931. The rail motors were initially powered by a Winton Motor Carriage Company petrol engine, until these wore out and were replaced in the 1950s by twin GM Detroit Diesel Series 71 engines, with a power output of , derated to match the original generator. A DERM, with a DERM Trailer car attached, ran a regular passenger service on the South Gippsland line in the 1960s and 1970s. By the 1970s, the longest scheduled journey run by a DERM was the Bendigo to Robinvale run, last operated on 3 June 1978. In 1976, RM 56 was fitted with a new seating arrangement, including rotating seats, using components from the Z carriage fleet. Capacity was reduced to 34 passengers, because the new seating arrangement was two either side of the central aisle rather than the previous two and three. The first-class end of the vehicle was moved towards the centre, closer to the engine, but providing a smoother ride by averaging the suspension of both bogies rather than just one. The trial arrangement was used on the Yarrawonga line, but patronage did not increase sufficiently to justify the retention of that service. Following the changes to 56RM, 55RM and 61RM were extensively modified in the late 1970s, with the engines relocated, the body extended, and a new seating arrangement provided. The most obvious external difference was the fitting of aluminium-framed windows on the driver's cabin, and porthole windows for the engine room. These "Super DERMs" were a familiar sight on the adjoining Mornington and Stony Point lines prior to the early 1980s. Details of vehicles Motor units Trailers Preservation All but one of the DERMs have survived into