Mine fires | AspenTimes.com

Mine fires

Tim Willoughby
Aspen Times Weekly
Willoughby CollectionA metal door attached by a rope at the Midnight Mine Tunnel entrance could protect miners from life-threatening fires.

The methane gas/coal dust explosion at Massey Energy Company’s Upper Big Branch mine that recently killed 29 coal miners in West Virginia reminds us of the risks underground workers face each day. Just as news coverage of airplane crashes greatly exceeds that of car collisions, large-scale mining fatalities make the news while daily deaths from black-lung disease and avoidable accidents receive scant coverage.

Although my father spent three decades underground, mostly in Aspen’s Midnight Mine, he would not set foot in a coal mine. His miner’s braggadocio accompanied him as he faced daily underground dangers; but he deemed entering into coal seams to be an unreasonable risk. Bad air from dynamite blasting and occasional “dead air” pockets with insufficient oxygen that could cause a miner to black out were risky enough. Local miners did not contend with combustible coal dust and methane gas. Catastrophic explosions many times more powerful than miners’ daily detonations of dynamite were not possible in Aspen’s mines.

Aspen sometimes suffered underground fires. The 1897 Smuggler fire was the most serious. A layer of carboniferous shale spontaneously caught fire when tunneling miners exposed it to oxygen. It did not erupt into a flaming, combustive blaze, but a slow smoldering fire hampered work in the lower levels of the mine. Higher temperatures and unpleasant air challenged miners for years.

The Smuggler’s engineers tried to solve the problem by sealing off sections of the mine with bulkheads that denied oxygen. That approach was not sufficient. Only unintended consequences squelched the fire. An outside fire burned the Free Silver shaft house. That fire shut off the water pumps that pulled thousands of gallons from the bottom levels of the mine to the surface. The lower workings flooded, ending the fire, but also ending mining at the lower levels. A decade passed before the Smuggler dewatered the lower workings.

The Midnight Mine did not encounter smoldering fires like the one in the Smuggler, but when mine safety standards were created in the 1930s and ’40s, a low-tech safety device was installed for a different kind of fire problem. During that period a mine disaster sparked safety concerns: A fire outside a mine had killed miners deep inside. Fires near a tunnel or shaft entrance send smoke into a mine while sucking out life-sustaining oxygen from within the mine. A fire that was not immediately extinguished would kill anyone inside.

The Midnight experienced outside fires from dropped candles, a mule that ran through a building knocking over a candle, and a blacksmith fire that got out of control. Fortunately, each time workers outside quickly extinguished these fires before they spread.

A simple safety device was installed to address the problem. A large sheet of half-inch cast iron was suspended by a hemp rope above the tunnel entrance. The rope, strung through a pulley above the entrance, was anchored about 30 feet away. The sheet of metal was set into a snug frame a few feet from the entrance so that it could fall quickly and form a tight seal if the rope was severed. If flames from a fire burned anywhere close to the tunnel, the hemp rope would burn through, causing the metal door to fall, preventing smoke from billowing into the tunnel and oxygen from being sucked out.

The device was never tested in a real fire, but the miners thousands of feet away worked without worrying about what was happening outside.


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