Because of separate development by the individual States, the Australian railway network contains links of a number of different gauges.
For this reason bogie exchange facilities have been established at several locations including two in South Australia, at Port Pirie and Peterborough, where the State broad gauge system meets the interstate standard gauge system.
The intention of these exchanges is to allow ready transfer of loaded and unloaded freight wagons from one system to the other. Traffic through the exchange at Port Pirie has increased to the extent that difficulties are being experienced in handling it.
- Study of Port Pirie Bogie Exchange