Atmospheric Conditions and Explosions in Coal Mines

Abstract

URING the long history of coal mining a belief has developed among miners that mine explosions are often associated with stormy weather. This widespread theory is so strongly held that men have sometimes refused to work in mines on stormy days. Coal companies also acknowledge the possibility of such a relationship; and because they do, extra precautions are taken in some mines during stormy weather. This paper presents some results obtained from an investigation into the effect of daily and seasonal changes in atmospheric conditions on the explosive compounds present in coal mines. Attention is focused on the possibility that such changes produce conditions in mines conducive to disastrous explosions. It is not surprising that there is a high accident rate in coal mines. Operating heavy machinery underground in cramped space and cutting and moving thousands of tons of coal each mining day are bound to make mining hazardous. Although explosions occur less often than other accidents, they usually result in a high death toll, and miners have grown to fear them more than any other type of accident. Several compounds present in coal mines are ignitible. Two, methane gas (CH4) and coal dust, may occur in such abundance that their ignition results in disastrous explosions. That explosions in coal mines result from combustion of gas has been recognized from the early days of coal mining; that coal dust alone can be an explosive element is a more recent realization. Coal dust as an explosion hazard, though early recognized by many mining experts, was not accepted by the majority of coal-mining interests in the United States until convincing tests had been carried out at the Pittsburgh testing station in 1908 and 1909.