These wagons were built to transport superphosphate between the main superphosphate supplier in Geelong and its own distribution centre in Wodonga, about 200 mile away.
The hopper wagons were built in 1978, coded JPF and numbered 601 - 610.
In the 1979 recoding they became VHFY. At the time the combination "PY" was used to indicate passenger train use, hence the swap from P to F in the coding to indicate Phosphate/Fertiliser.