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 Warren truss. 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 , pines and cedars. The cars were finished externally with tongue and grooved timber below the window line.
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. 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 to either the No.1 or No.2 End.
Engines
As built, they were fitted with petrol engines, the first four receiving a 6-cylinder 75 hp Thornycroft Z6 and the others a 6-cylinder 95 hp Leyland type with a four-speed mechanical transmission controlled by a lever in the cab. Some units were later fitted with a 6-cylinder 150 hp Leyland petrol engine and a Lysholm-Smith hydraulic transmission. Experiments were also made with AEC and Winton engines in some vehicles. A 6-cylinder 120 hp Leyland diesel engine was also trialled in one unit. During World War 2, to conserve fuel, gas producer units were fitted to six vehicles. Five of these six were destroyed when fire spread to the vehicle. Beginning in 1945, a programme began to replace the petrol engines with 6-cylinder GMDetroit Diesel 71 Series engines and Twin Disc 3-position hydraulic transmissions. It was also at this time that multiple unit controls were fitted. A single driver's cab and multiple unit controls were fitted to the No.2 End of the five trailer cars at this time.
