A 200 litre drum of of oil for general lubrication purposes was stored in the steering flat. The oil was taken from the drum using a hand operated semi rotary drum pump. The pump was in need of overhaul, because it only picked up suction after a great deal of effort on the part of the operator.
The fourth engineer, instead of overhauling the pump, decided he knew a better solution. He connected an air line into the top of the drum after sealing the pump suction pipe into the drum. The air was from the 7 bar working air supply. The idea being that the air pushed the oil up the suction pipe, through the pump, when operated, and into his jug.
An oil drum is not a pressure vessel. When it exploded, it made quite a mess. Pieces of the fourth engineer were found all over the steering flat.
Compressed air should only be used for the purposes intended. Take great care before pressurising any piece of equipment. Ensure it been designed and tested to be raised to the intended pressure.