The General Engine and Boiler Company, Hatcham Ironworks, London, produced two types of air compressor for use in torpedo warfare. These were: a single cylinder compressor operating at 400 revolutions per minute capable of producing air at a pressure of 1,500 pounds per square inch, and suitable for use in torpedo boats and launches; and a double cylinder compressor operating at 350 revolutions per minute, suitable for use in corvettes. A number of these compressors had been sold to the British, Russian and Greek Governments.