Wednesday, August 21, 2013

Temperature In Relation To Coal Mining Accidents

Coal Mining History
Coal mining used to be a dirty, dangerous, soul-destroying job. It has since morphed into a dirty and dangerous but rather well-paid job whose toll on the environment has increased even as its toll on the health and well-being of miners has decreased.  

The American coal-mining industry began in the latter half of the 18th century, in Pennsylvania, which was even as late as 1995 the fourth largest coal-producing state in the United States. Miners were typically immigrants, though commonly from countries which also had mining operations, like Wales or Germany. Men who did not know how the mines worked were not welcome because their lack of experience usually ended up killing others in addition to themselves. The only certainty in a coal miner’s life was the ubiquitous presence of coal dust and “gob”; that is, high-potency methane gas. Both, though mitigated by various modern ventilation and filtering methods, remain a constant.

In their homes, which were generally owned by the mining company and boasted four walls if no running water or toilet, miners’ wives struggled constantly to keep coal dust to a minimum while husbands struggled to make enough “scrip” to buy food from the company store. It should not be assumed that all coal mining company owners were exploitative, however. Manipulative, misleading overseers were more common, and provided a buffer between what might have otherwise been benevolent owners and happily employed workers.
Coal, mined as either “hard” (anthracite) or “soft” (bituminous), had many uses in the U.S. during the Industrial Revolution. It was used to make steel and burned to create electricity. In fact, its use producing electricity was so popular that, by 1830, Pittsburgh used more than 400 tons per day to light the homes of the growing middle class and to power light industrial applications like the manufacture of steel parts, machine tools, light bulbs, telephones, typewriters, sewing machines, batteries and miner’s headlamps.

Types of Coal Removal
Mining, both then and now, was often conducted using the room and pillar method. In Pennsylvania, it was (and is) the exclusive method used in underground bituminous mining, including longwall mining operations.  This involved cutting and carrying out the coal in a “room-sized” area, and leaving untouched the “walls” that held up the ceiling in this room; walls comprised of the same coal as was being hauled to the surface. Miners would then move on to another “room”, leaving horses or donkeys to carry the coal the rest of the way.  
Longwall mining, now mechanized, takes a swath of coal about 1200 feet deep and between 2 and three miles long in a single sweep. This method destroys good farmland by turning a field into a series of hills and swales up to six feet deep. Along the way, longwall mining also destroys building foundations, wells, and septic systems.

Mine Management, Excessive Heat Hazards
Thanks to American miners’ hardiness and integrity, modern mines in the coal-laden Appalachian region are carefully managed. Longwall operations mandate braced and vented spaces to keep methane gas to a minimum. Deep mines (i.e., more than 3900 feet (1200 meters) are the most dangerous because they have a higher-than-average ambient air temperature which can lead to spontaneous coal combustion even in the absence of methane concentrations.
A depth of 2900 feet (900 meters) is considered the average depth for deep-level mining operations, yet even at this depth air temperatures in the ventilation shaft can rise so high that they block the release of trapped gases to the surface, in imitation of a thermal inversion layer. In fact, at this depth, rock itself is expected to be more than 116 degrees F (47 degrees Celsius).  
This heat, in the presence of the almost inevitable spontaneous combustion of coal dust and carbon monoxide, can cause such a tremendous conflagration that, to those above ground, it sounds and acts like a bomb. It can result in collapsed caverns, trapped miners and highly contaminated air, not to mention those who get terribly burned from the initial gaseous explosion or get trapped under falling “room” walls.  
Where mining companies have insisted on more-than-adequate ventilation, temperatures at a half-mile underground can still rise so high that miners who are older, permanently affected by lifelong ailments like silicosis (Miner’s lung) or twisted limbs from slip-and-fall accidents, or inadequately hydrated,  can faint and even die from heatstroke.

The United Mine Workers of America
If death in the mines was not uncommon, crippling accidents were even less rare, leaving miners to the generosity of their employers and – where that was absent – the benevolence of their fellow miners. It was this ever-present danger and constant uncertainty that led miners in the late 18th and early 19th centuries to try to unionize. They succeeded, and by 1903, the United Mine Workers of America, or UMWA, boasted 250,000 members.  
These miners, many of whom have watched relatives die of lung diseases or mining injuries, have earned and deserve wages that basically double all industries across the U.S. For example, in Alaska, where the average worker makes about $48,000, the coal miner makes $75,000 and earns every penny of that. 


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