Coal mine bump

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A coal mine bump (a bump, a mine bump, a mountain bump, or a rock burst) is a seismic jolt occurring within an underground mine due to the explosive collapse of one or more support pillars. [1]

Contents

In room and pillar mining, tunnels are advanced in a rectangular pattern resembling city streets (tunnels), leaving behind blocks (pillars) of coal. To a miner, a partially completed tunnel resembles a room dug into the coal seam. As mining proceeds, the weight of rock overburden previously supported by coal mined from rooms is redistributed to pillars. If that weight exceeds the strength of a pillar, the pillar can fail by crushing or exploding. An explosive failure is called a “bump.” [2]

In the eastern United States' coalfields, bumps are more likely when the overburden is at least 500 feet (150 m); where a strong, overlying stratum, such as sandstone, occurs near the coalbed; and with a strong, inflexible floor. In the United States, the number of deaths from bumps had dropped off dramatically since the early 1990s, but fatalities are more common in the West where mines often run deeper. Bumps are three times more likely in room-and-pillar mines, and are even more common in mines that do retreat mining, [2] in which the pillars are removed as the miners retreat towards the mine entrance with the intent of allowing an orderly collapse of the mine. [3]

Incidents

The Springhill Mining Disaster was a bump that occurred in Springhill, Nova Scotia, Canada on October 23, 1958.

Debate over the cause of the August 6, 2007, Crandall Canyon Mine disaster, which took place 1,800 feet beneath the surface, raised public awareness about coal mine bumps. [4] Seismologists at the University of Utah and the University of California, Berkeley concluded that an associated 3.9 magnitude temblor was likely caused not by an earthquake, but by the collapse itself. [5] The mine's owner, Robert E. Murray, adamantly disagreed. [6]

Related Research Articles

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<span class="mw-page-title-main">Springhill, Nova Scotia</span> Place in Nova Scotia, Canada

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<span class="mw-page-title-main">Springhill mining disasters</span> Any of three mining disasters in Springhill, Nova Scotia, Canada (1891, 1956, 1958)

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<span class="mw-page-title-main">Springhill Coal Mining National Historic Site</span> Historic site in Springhill, Nova Scotia

Springhill Coal Mining is a National Historic Site of Canada located on the corner of Industrial Park Drive and Memorial Crescent in Springhill, Nova Scotia. The Historic Site, designated in 1998, consists of a museum and the land that once contained the Springhill Coal Mines. Springhill was once one of the most important coalfields in Canada, along with those in Pictou and Cape Breton. Springhill coal was shipped and marketed throughout the Maritimes and Quebec. The surviving mining features in Springhill are among the most complete in Canada. The Springhill Mines were made infamous by a number of disasters that occurred underground, including the 1891 explosion, the 1956 explosion and the 1958 bump.

References

  1. Energy Citations Database (ECD) - - Document #7218222
  2. 1 2 Bornstein, Seth; Talhelm, Jennifer (2007-08-17). "Stress Causes Killer Mine Bumps". USA Today. Associated Press.
  3. Coal Mine Bumps: Five Case Studies in the Eastern United States. National Institute for Occupational Safety and Health. Accessed March 26, 2009.
  4. "Rescue Halted at Mine After 3 Killed and 6 Injured", New York Times, August 9, 2007, Retrieved August 17, 2007
  5. "Seismologists confirm Utah mine collapse probably caused temblor", U.S. Berkeley press release, August 9, 2007, Retrieved August 17, 2007
  6. "Owner of Utah mine is a famously combative figure. Boston Herald . Retrieved on August 10, 2007.