The CPH (or 42 foot) rail motors were introduced by the New South Wales Government Railways in 1923 to provide feeder service on country branch lines.

[1] Often referred to as "Tin Hares", having evolved at the same time as the mechanical lures used in greyhound racing in Australia, the first vehicle was placed in service on 17 December 1923 and based at Culcairn, in southern New South Wales.

One of the most innovative features was the underframe, taking the form of a modified Warren truss (containing additional vertical struts).

The body for these cars was constructed in a similar manner and dimensions to their powered counterparts, but were mounted on a lighter "C" section steel underframe.

A single driver's cab and multiple unit controls were fitted to the No.2 End of the five trailer cars at this time.

[2] A total of 37 vehicles were built and they operated many branch line services throughout the state, from Kyogle in the north to the Riverina in the south, as well as extensively through the Central West regions, until their widespread withdrawal in November 1983 and replacement by road coaches.

A fleet of 12 CPHs continued to be used extensively in the Wollongong area, working north to Waterfall, west to Moss Vale and south to Port Kembla and Kiama.