The Diesel Electric Rail Motor (DERM) is a type of

railmotor Railmotor is a term used in the United Kingdom, Ireland and the Commonwealth for a railway lightweight railcar, usually consisting of a railway carriage with a steam traction unit, or a diesel or petrol engine, integrated into it. Steam railcars ...

operated by the

Victorian Railways The Victorian Railways (VR), trading from 1974 as VicRail, was the state-owned operator of most rail transport in the Australian state of Victoria from 1859 to 1983. The first railways in Victoria were private companies, but when these companie ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

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were the longest-lived rail motor on the Victorian Railways, with the first entering service in 1928 and the last being withdrawn in 1991.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, also known as the

railcar A railcar (not to be confused with the generic term railroad car or railway car) is a self-propelled railway vehicle designed to transport passengers. The term "railcar" is usually used in reference to a train consisting of a single coa ...

, was a standard product of the US Electro-Motive Corporation (a predecessor of

Electro-Motive Diesel Electro-Motive Diesel (abbreviated EMD) is a brand of diesel-electric locomotives, locomotive products and diesel engines for the rail industry. Formerly a division of General Motors, EMD has been owned by Progress Rail since 2010. Electro-Motive ...

) and built between 1924 and 1932, albeit to a smaller

loading gauge A loading gauge is a diagram or physical structure that defines the maximum height and width dimensions in railway vehicles and their loads. Their purpose is to ensure that rail vehicles can pass safely through tunnels and under bridges, and k ...

and wider

track gauge In rail transport, track gauge is the distance between the two rails of a railway track. All vehicles on a rail network must have Wheelset (rail transport), wheelsets that are compatible with the track gauge. Since many different track gauges ...

. The first was imported in 1927, assembled at

Newport Workshops The Newport Railway Workshops is a facility in the Melbourne suburb of Newport, Victoria, Newport, Australia, that builds, maintains and refurbishes Rolling stock, railway rollingstock. It is located between the Williamstown railway line, Willia ...

, and placed in service in 1928. The bodies of the remaining nine were constructed at Newport Workshops using imported equipment and electrical components, and placed in service between 1930 and 1931. The rail motors were initially powered by a

Winton Motor Carriage Company The Winton Motor Carriage Company was a pioneer United States automobile manufacturer based in Cleveland, Ohio. Winton was one of the first United States, American companies to sell a motor car. In 1912, Winton became one of the first Ameri ...

petrol engine. When those wore out in the early 1950s, they were replaced with twin GM

Detroit Diesel Series 71 The Detroit Diesel Series 71 is a two-stroke diesel engine series, available in both inline and V configurations, manufactured by Detroit Diesel. The number 71 refers to the nominal displacement per cylinder in cubic inches, a rounding off of ...

engines, with a power output of , de-rated 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 Bendigo ( ) is an Australian city in north-central Victoria. The city is located in the Bendigo Valley near the geographical centre of the state and approximately north-west of Melbourne, the state capital. As of 2022, Bendigo has a popula ...

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. Those "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 preservation, with 57RM being the only DERM to have been scrapped. Four are operational, with the remaining five in various conditions, generally as a source of spare parts with long-term restoration in mind. Of the regular DERMs, 58RM, operated by the Diesel Electric Rail Motor Preservation Association of Victoria, regularly runs tours on the Melbourne and Victorian broad gauge system, and 63RM runs trips on the Daylesford line with trailer 26MT when appropriate. 55RM is allocated to the Newport Railway Museum but was sub-allocated to the

South Gippsland Railway The South Gippsland Railway was a Heritage railway, tourist railway located in South Gippsland, Victoria (Australia), Victoria, Australia. It controlled a section of the former South Gippsland railway line between Nyora, Victoria, Nyora and Le ...

. When the latter closed in 2016, it moved to the Yarra Valley Tourist Railway. 61RM operates on the Victorian Goldfields Railway between

Maldon Maldon (, locally ) is a town and civil parish on the Blackwater Estuary in Essex, England. It is the seat of the Maldon District and starting point of the Chelmer and Blackwater Navigation. It is known for Maldon Sea Salt which is prod ...

and Castlemaine.

References