The invisible killers

摘要

In October, the announcement of bids to explore for methane underground in areas underlain by Coal Measures across Northern England were greeted locally with some alarm. The anticipated threat was of pollution of water supplies, local explosions, ground collapse, possible asphyxiation. Given the Government's tendency to favour any alternative energy sources, and their absence of any overall national energy policy, it would seem that there must be a reasonable certainty that licences will be issued for exploration. What are the realistic and geological issues involved? At the end of the last war, apart from the increase in open-cast coal mining in efforts of gaining a maximum return from our total coal resources, working thin and close-spaced seams difficult to recover by conventional deep mines, attempts were made to effect the underground gasification of coal. Thermite bombs were planted by boring to seam levels, and fired. Good in theory, it proved difficult to sustain the burning for lack of oxygen, so the plans were put on 'hold' while our immediate needs in fuel were met by normal production by the then National Coal Board. Soon, nuclear power promised to offset the need for the gasification plans.