Compressors

A bank of compressors sits in the compressor house at Kandos Cement Works, several large machines lined up on concrete pads with their drive motors at one end and their air receivers running along the wall behind. Each compressor is a horizontal reciprocating unit with a heavy flywheel at the drive end, the type that was standard plant in Australian heavy industry for most of the twentieth century. The paintwork is chipped at the edges where decades of maintenance access have worn it back. Pressure gauges are mounted on the air receivers behind. Cabling runs from the motor terminal boxes up to the overhead trays. The compressor house is lit through high windows along the upper wall. The room is silent.

A cement works runs almost everything on compressed air at some point in its circuit: pneumatic conveying of cement and dust, instrumentation lines, the actuators that operate dampers and valves, and the air blast that fluidises material in the silos. The compressor house was where that air supply was generated. The bank at Kandos ran continuously while the plant was operating, with units rotating through service and standby for maintenance. The plant closed in September 2011 after 95 years of cement production. The compressors stopped at the same time. Most of the larger compressed-air consumers have since been removed from the plant; the compressors themselves have stayed in place.