§ 82. Mr. Corfield
asked the Minister of Power to what extent pneumatic stowing systems are being employed by the National Coal Board for the disposal of waste into the void left by the extraction of coal from the face; and what are the limitations of this method of disposal.
§ Dr. Bray
Pneumatic stowing systems are used as a method of roof control 61W on 2 per cent. of coal faces. I am advised that their use is costly, and that there are technical limitations. Stowing machines cannot match the rate of extraction of modern power loading machines and it would be extremely difficult to transport to the face the large quantities of waste which arise elsewhere underground and from preparation plants on the surface.