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. Introduction 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. Construction They were lightweight vehicles and considerable care was taken in the original selection of materials used in their construction. One of the most innovative features was the underframe, taking the form of a modified Warren truss (containing additional vertical struts). No bolts or rivets were used in its construction and it was fabricated entirely by electric arc welding. It is believed to be the first application of such technique on a railway vehicle in Australia. The body was of timber construction, using mainly Queensland yellow wood, pines and cedars. The cars were finished externally with tongue and grooved timber below the window line. In addition, five similar non-powered trailer cars were constructed between 1926 and 1927. 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. Seating arrangements were similar, however, they featured a larger centre Guard's compartment. They were numbered 51 to 55 and carried the coding CTC. Seating As built, the normal seating capacity was 45, 21 in 1st class and 24 in 2nd class. A further seven could be accommodated on the flap seats provided in the guard's compartment. An additional feature of these cars were the prized seats either side of the driver (the drivers cab being centrally located in the middle of the carriage, there was one passenger seat located either side of the driver's cab, looking directly ahead). During their lifetime, seating arrangements were modified to suit the working being undertaken and included the removal of a varying number of seats for increased luggage capacity. From the mid-1970s the so-called "Big Cab" conversions were applied to a number of units. This involved the construction of a wall between the first and second rows of seats to create an isolated driver's cab. The back of the original driver's cab was removed and a loose seat provided. This conversion was applied to one end only and could be fitted