To assist the movement of supplies and parts between the railway workshops and loco depots dedicated wagons were provided to transport various components. The wagon group was called HR: the H for railway service only ( See _H__ class ), the R for 'Rolling Stock Branch'.
The wagons were used to transport pantographs, autocouplers, bogies, wheels, traction motors and other components. They were stencilled for the specific traffic which also indicated the workshops involved.
The original vehicles were from scrap "tommy bent"_IA_ wagons as well as underframes from 16t _I__ and IA wagons. In later years, these wagons were replaced by bogie wagons. The HR number group was 1 - 182.
In the late 1980's the HR group was recoded into a new coding sequence.