A New Holland tractor with hydraulic couplings was being used by Blue Circle to shunt their wagons around.
The full wagons were on the down (Mildura) end of the siding..
Dragged up to the discharge hopper.
Then shunted to the up side
Back in the days, it was quite common for private siding holders to shunt wagons using adapted tractors.Going further back, horses were used to move small wagons and even rakes of wagons around Victorian yards.