NZR RM Class (Leyland Diesel) - History

History

The New Zealand Railways Department (NZR) had been looking for an economic means of handling regional and rural passenger traffic for over two decades. Branch lines in rural New Zealand were typically operated by mixed trains that carried both passengers and goods, and their schedules were usually slow due to the loading and unloading of freight that occurred during the journey. This slowness made them unpopular with travellers, but insufficient demand existed to justify a dedicated passenger service. Secondary main lines in regional districts often had their own passenger trains, but these were often uneconomic, especially as car ownership and bus competition rose in the 1920s and 1930s. Thus, NZR investigated railcars as an alternate means of providing an attractive passenger service without the expenditure and costs associated with a locomotive-hauled carriage train.

The first experiment with railcars took place in 1912 with a MacEwan-Pratt petrol railcar, and while it was not a success, further research and development was undertaken in the following years. By 1936, no design had proven successful enough to warrant construction of a whole class, though an Edison battery-electric railcar built in 1926 had proved efficient and popular until it was destroyed by fire in 1934, and it might have been replaced with a similar railcar or expanded into a fleet if it were not for the financial constraints imposed at the time by the Great Depression.

In 1936, NZR and a newspaper company were looking into the development of a railcar to provide quick conveyance of both passengers and Christchurch Press newspapers from Christchurch to Westland: although long-term prospects for large railcars existed, a more immediate solution was required. For this experiment, NZR utilised a diesel-engined Leyland bus chassis to create a small railbus. Two were built at Hutt Workshops in Petone and entered revenue service in the South Island.