Upper Big Branch Mine Explosion

Upper Big Branch Mine Explosion. . , Following the footprint. Every mine explosion leaves behind a footprint that offers clues to investigators as to where the blast originated and how the force traveled from the ignition point. The footprint left behind in the Upper Big Branch mine tells the story of an explosion that started with the ignition of a small amount of methane gas and then was fueled by coal dust that had been allowed to build up for miles through the mine. , The Explosion. As the shearer operator cut into the sandstone top of the longwall, the friction created sparks. Typically, when machinery cuts into coal, there is little sparking because the coal is soft. When shearer bits hit rock surrounding coal, sparks fly. On April 5, 2010, the sparks ignited a pocket of methane or natural gas that likely had risen from the floor or migrated from the gob , a previously mined area located behind the longwall. , Although the shearer was equipped with water sprays designed to douse the flame at the point of ignition, later testing found that the sprays on the shearer had been removed or were clogged, rendering them ineffective. The crew could do nothing to halt the propagation of the fireball as it ignited coal dust that had built up in the Tailgate 1 North area. As the flame propagated, it formed the shape of a wedge that grew to a massive slug that sped through the mine, up to the roof, and down to the floor. A series of explosions was created as the compressed air on the leading edge of the force caused the coal dust to become airborne. Thus, the explosion generated its own fuel with the air/dust mixture behaving like a line of gunpowder, carrying the blast forward in multiple directions, eventually reaching its strongest level at Headgate 22. , (sidebar) , When a mine explodes suddenly and with great force, as happened at Upper Big Branch, methane is immediately suspected as a primary source. Odorless, colorless, and highly combustible, methane is the most common (naturally occurring) hazardous gas found in underground coal mines. , Methane explosions occur when a buildup of methane gas comes into contact with an ignition source, such as a flame or spark. Because sparking is common in the mining process, history is replete with Methane explosions. , Small methane ignitions do not have to turn into major explosions if mine operators adhere to basic safety measures, such as maintaining adequate ventilation systems, removing explosive coal dust from mining operations, spreading required amounts of rock dust, and ensuring that water sprays on mining equipment are kept in good repair and function properly. Because these basic safety systems failed at Upper Big Branch Mine, a minor flare-up of methane led to the nation’s worst coal mining disaster in 40 years.