NZR RM class (Sentinel-Cammell)

The NZR RM class Sentinel-Cammell steam railcar was a steam-powered railcar operated by the New Zealand Railways Department (NZR). It was the only one of its type to operate in New Zealand, and one of only two steam railcars trialled in the country; the other was the Clayton steam railcar.

Overview

In the early 20th century, NZR began experiments with railcars as an option to replace unprofitable regional locomotive-hauled carriage expresses and to provide an efficient passenger service on rural branch lines that were served solely by slow mixed trains that carried both goods and passengers. In 1925, a steam railcar was ordered from the England-based Sentinel Waggon Works of Shrewsbury and Metro Cammell of Birmingham, and when it entered revenue service, it was the first railcar to do so in the Auckland Region. It subsequently operated outside this region.

Usage

One task assigned to the railcar was to run a feeder service for the Night Limited express that ran between Wellington and Auckland. This service operated from Thames along the Thames Branch and East Coast Main Trunk Railway to the North Island Main Trunk Railway, where it terminated at Frankton and met the express before returning to Thames. This service was not the sole domain of the Sentinel-Cammell steam railcars, however; it was sometimes a carriage train hauled by steam locomotives such as the U^D class.

Reference is made in more detail in the Ohinemuri Regional History Journal 53, September 2009 to the use of the railcar on the Thames Branch.

Withdrawal

The Sentinel-Cammell steam railcar did not prove popular with passengers or crews and was not expanded into a full fleet. After a few years of service, it was quietly withdrawn and scrapped.