West VA Mine Blast Likely Caused by Frictional Ignition

Likely Cause of West VA Mine Explosion: Frictional Ignition from Continuous Mining Machine

I couldn't believe my ears when I heard the claim being promoted unquestioningly by the media, that the methane explosion in the Sago mine was caused by LIGHTNING. In short, the media, and no doubt the corporate mining "safety officials" are hoping to convince the public that the disaster was an act of God! The lightning idea was mentioned as a rather remote possibility by J. Davitt McAteer a mining safety expert at Wheeling Jesuit University. However, the media conveniently ignored the rest of McAteer's observations. McAteer reported to Joseyln King and Betheny Holstein of the Wheeling Intelligencer http://www.wju.edu/about/adm_news_story.asp?iNewsID=1855&strBack=%2Fabout%2Fadm_news.asp that "he is more bothered that the Sago Mine in Tallmansville, W.Va., was idle over the holidays, and that workers there were restarting equipment Monday. This action in itself could have ignited a fire if methane gas or coal dust were present: "You would need some combustible (for a fire to spark), and you would get this with methane gas or coal dust...Methane gas accumulates during idle periods, particularly when there is a change in barometric pressure...What I am most concerned about is that methane causes a smaller explosion....But it can suspend fine particles of coal dust in the air which also can explode, and coal makes a more powerful explosion than does methane."

Although lower barometric pressure caused by a passing storm can, possibly contribute to methane accumulation, the exotic explanation of lightning need not be invoked. The most common cause of methane ignition is frictional ignition. A 1998 UK study reports, "Frictional ignitions have been reporrted for hundreds of years and over time, the risk of frictional ignition occurring has significantly increased. Due to the changing trends in mining methods and equipment development, frictional ignitions have become the most dominant cause of methane gas ignitions in underground coalmines throughout the world. ...

"Ignitions have been caused by frictional contact between metal and rock, rock and rock, and metal on metal. Ignitions typically occur due to heat energy raditating from a surface that has been heated by frictional contact. However, ignitions can also occur due to the exothermic oxidation of pyurite that has been struck by cutter picks.

"Methods have been identified to reduce the probability of ignitions as well as to prevent them. However, the mining community in general has been slow to react to the developments being found through research. The prime example being water spray, whose ptoential to reduce ignitions was discovered in the mid-1970s. It has taken over 20 years (it, into the 1990s) for efficient, commercial spray systes to become available, and even now, they are difficult to source. The techology transfer from researchs findings to the mine site seems very slow.

"The risk of frictional ignitions is increasing with the current trends in the mining industry and the level of funding given to research in this area has reflected this."

http://www.mining.unsw.edu.au/Publications/abstracts/WhiteD_1998.pdf.

A 2000 UK Health and Safety report observes that the increased use of continuous mining machinery increases the risk of frictional ignition. The report observes that continuous miners were responsible for half of the fricitional ignition events occuring between 1994-1999 in UK coal mines.

http://www.hse.gov.uk/research/journals/mrn14.htm

The International Coal Group, Inc. reports "The Sago mine which was
originally opened in 1999 as a contract mine, closed in 2002, and then reopened
as a captive operation in the first quarter of 2004. Sago is expected to reach
full production by the fourth quarter of 2005." The Sago operaztion uses "the room-and-pillar mining method with continuous miners and shuttle cars for coal removal from the face." http://sec.edgar-online.com/2005/06/15/0000950123-05-007352/Section7.asp

Continuous mining machines are the coal mining counterparts of the logging industry's skidder - a machine that can continuously rip "product" out of the mine(woods), reducing the manpower required. They operate on electricity and thus there is always a risk of sparking from pinched wires (for example). But the continuous forceful drilling is an intense source of friction. Ignition risk aside, these machines are hazardous.

Coal News reports "Remote control continuous mining machines without an onboard operator’s compartment are now the norm in the industry and in early 2004 there were about 699 continuous mining machine units operating in the United States. Of these about 91% functioned with radio-remote control extended cuts in excess of 30 feet of common place.

"Unfortunately, machine operator positioning has become an often unrecognized safety concern, particularly when remote control continuous mining machines excavate a turn (turn a crosscut). From January 2001 through July 2004, remote control CM operators or helpers have been involved in ten roof fall fatalities and eight machinery crushing fatalities. These 18 fatalities represent 41% of the 44 total underground coal mining fatalities over the time period." http://www.coalnews.net/view.php?id=8

13 miners were killed in 2001 at Blue Creek mine No. 5 in Alabama in 2001. Workers had warned officials for weeks that they feared methane pockets had been building up. But, as coal miner Mike Ely reported, "The company says a rock fall landed on a large battery charger and ignited the gas. But there is no reason to believe any details the company offers about such events. And there are many reasons for them to lie. This much is known: a spark went off underground in air filled with methane." http://www.wsws.org/articles/2001/sep2001/mine-s27.shtml