After World War II, the Victorian Railways undertook a major rebuilding program known as Operation Phoenix.

One of the first tasks was the upgrading of passenger services on country branch lines, through the replacement of 23 wooden-bodied railmotors built in the 1920s, and the withdrawal of steam locomotive hauled mixed trains.

The van bodies were constructed with composite wood and steel framework, and aluminium sheeting screwed to the frames.

Each was also capable of holding a single ton of luggage, the train crew only were permitted to walk through the centre motor unit engine room.

The railcars soon saw use on the Bendigo-Deniliquin and Ararat-Portland services, and by the time the 91RM was delivered, Mansfield, Wonthaggi, Woomelang and Wangaratta were also being served by the units.

The long Glenrowan – Wangaratta section often saw the railcars exceed the 60 miles per hour (97 km/h) speed limit.

[6] Each passenger unit was equipped with adjustable seating, internal heating, non-draught windows, water tanks for drinking or washing, along with ample luggage storage in overhead wire racks.

The lighting system was powered by the then-standard Victorian Railways' 24vDC supply, which utilised a belt-driven axle generator to charge batteries and 20-watt globes.

[4] As a result, when running in multiple each unit needed to have its own driver, the two communicating through the standard whistle codes used on locomotives.

[6] The last 280 hp (209 kW) Walker railmotor ran on 17 September 1980, with 82RM operating the 08:00 service from Melbourne to Woodend and return.

[6] Each unit was originally painted in all-over royal blue, with silver roofs, striping and highlighting.

Scrapping then continued at a fairly easy pace until 1977, when VicRail decreed that branch lines in general were to be closed, rendering the units without a purpose.

On Saturdays the unit pair would run on the Werribee shuttles, and occasionally to either Bacchus Marsh or Seymour as railmotor shortages dictated.

In 1981, two railmotors and a trailer – 32RM, 91RM and 56MT – were scheduled to be transferred to the SteamRanger Heritage Railway at Victor Harbor, South Australia.

22RM was static in the Newport Railway Museum, with 85RM held for future addition, and 59MT was similarly allocated, but was badly vandalised, potentially to be replaced by 64MT.