Whitehaven Colliery

Miscellaneous Notes and Incidents

A compressor attendant at Ladysmith Colliery, Cumberland was burned by an ignition of vapourised oil in the crank chamber of an electrically driven vertical two stage compressor, situated at the side of a main intake haulage road. The capacity of the compressor was 3,000 cub. ft. of free air per minute and it compressed to 80 lb. per square inch. There is an inter-cooler between the stages. The cylinders and inter-cooler are water jacketed, through which the water flows by gravitation. The water is turned off when the compressor is not working. About 20 minutes after the attendant started up the compressor, he observed smoke issuing from the oil door at the bottom of the crank chamber and just as he switched off the current the fumes exploded. He stated that he turned on the water before starting up, but this is doubtful. Subsequent examination showed that a very high temperature had been attained due, no doubt, to running the compressor for a considerable time unloaded, with the jacket water supply curtailed or entirely shut off, that oil had been fed too freely to the cylinder, and that the oil, being of too thick a nature, mixed with the dust particles drawn in with the air and so clogged up the valve seats. The institution of a system of recording the temperature of the air at the point of discharge might have prevented this accident. Temperature gauges can be fitted and so arranged that the pointer makes an electrical contact, which can be adapted to trip a switch or ring a bell before the temperature reaches the danger zone.

Source: 1925 Mines Inspectors Report