A concept echoed by trains running around the world today, the railmotor was developed as an answer to providing light passenger services to destinations that did not warrant a full train of locomotive and carriages. Railmotors were also among the earliest applications of internal combustion power on rails.

The NSW Railway’s first railmotor was constructed on a road truck frame and sea-freighted up the coast to commence service based out of Lismore; the completion of the North Coast Line through Grafton was still over a decade away.

After further trials, the first 42-foot (12.8-metre) railmotor was assembled at Eveleigh Carriage Works during 1923. A total of 37 of these CPHs were delivered by 1930. Their underframe was constructed of welded steel trusses, while the timber bodywork was largely formed of pine and cedar. This style of construction — adapted from techniques employed in the construction of Sydney tramcars — kept the vehicle’s weight below 15 tons.