Bibliography: p.7.

The HD class of vehicles was one of the most fascinating group of vehicles to operate on the Victorian Railways. The class consisted of hand-me-down stock placed into low mileage traffic for departmental purposes. The HD vehicles claim their heritage in the box vans acquired from the Deniliquin & Moama Railway takeover in 1923. The HR class of vehicles were designed to assist the movement of supplies and parts between railway workshops and locomotive depots. The code was devised as H for railway service only and R for Rolling Stock Branch. Wagons were used to transport pantographs, bogies, couplers, wheels, traction motors and other components and were stencilled for the specific traffic (which also indicated the workshops involved).