Federal mine safety regulators 31/2 years ago dropped a plan that could have required underground coal mines to use improved flame-resistant materials on conveyor belts, government records show.In July 2002, the U.S. Mine Safety and Health Administration withdrew the proposal to tighten testing for belt materials. The proposal had been meant to “significantly reduce or eliminate” belt fires like the one that trapped two miners Thursday night in a Massey Energy mine in Logan County.MSHA had proposed the rule change in December 1992, in the final weeks of President George H.W. Bush’s administration.At the time, the agency said it wanted to address growing concerns about a string of belt fires in underground coal mines, according to rulemaking documents. The rule was never finalized during the Clinton administration, and was then withdrawn by MSHA by President George W. Bush’s administration on July 15, 2002, according to a Federal Register notice.When it withdrew the proposed rule, MSHA cited a decline in conveyor belt fires.Between 1993 and 2002, MSHA said, the industry reported 10 conveyor belt fires. That was a decrease from 34 reported fires during the previous 10 years, from 1983 to 1992.MSHA attributed this decline to improved monitoring and maintenance of conveyor belts and “technological advances” in belt systems themselves.With improved monitoring of belt systems, MSHA said, miners discover hazardous conditions sooner and can avoid or stop fires. Better rollers, bearings and other equipment help stop belts from slipping and sparking, causing fires, the agency said.Bob Friend, acting deputy administrator of MSHA, said in a briefing Friday afternoon the fire in the Aracoma Alma No. 1 mine in Melville, Logan County, showed that the agency’s action was justified.
“The decision was made that the hazards of belt fires would be addressed through carbon monoxide monitoring systems, and information on this incident indicates that the system at Aracoma did provide the warning that was expected, and that’s why the miners were withdrawn,” Friend said of the group of miners that escaped the mine.Conveyor belt systems are used extensively in underground coal mines to transport coal.In 1992, MSHA estimated that there were about 3,000 feet of conveyor belts in a small underground mine and 28,000 feet — about five miles — of such belts in larger mines.Conveyor belts are a potential cause of mine fires, in part because belts can slip and cause sparks.
Between 1970 and 1990, 307 underground coal mine fires were reported and investigated by federal mine safety officials, records show.Conveyor belts were involved in 42 of those fires, or about 14 percent.
In its 1992 rule proposal, MSHA said, “belt fires as a percentage of total fires have shown increases over the last twelve years with half of the belt fires occurring in the last eight years.”MSHA data shows that, in nearly a third of the belt fires, flames traveled for “hundreds of feet” — creating “a severe hazard to the health and safety of miners.”“When belt fires reach the propagation stage, they produce more fire gases and spread faster than the fires of surrounding coal surfaces,” MSHA has said. “The belt fires that have occurred since 1970 have burned as much as 2,000 feet of belt before the fire was extinguished.”In its proposed rule, MSHA said its existing test for evaluating flammability of conveyor belts “is not optimal.” For example, MSHA said, some belts that passed the agency’s test could actually burn easily and become quickly consumed by fire.MSHA said the United Kingdom had developed conveyor belt tests that forced companies to use materials that were more resistant to fires.“Germany and the U.K. are currently involved with the other European nations to negotiate a common standard,” MSHA said.
MSHA held public meetings on the conveyor belt fire problem in 1989, and formed a special industry committee to recommend solutions. The idea to write new testing rules was among the committee’s recommendations.In its rule, MSHA said it had worked with the Bureau of Mines to develop a “large-scale flammability test” that would more accurately judge conveyor belts. The test would use a large tunnel, or “fire gallery,” to more accurately judge whether belt materials would burn inside a coal mine.But, MSHA said, this test required an expensive fire gallery facility and large amounts of belt, making it expensive. MSHA said it would not be feasible for government agencies or belt manufacturers to build and operate such a testing facility.So, MSHA and the Bureau of Mines developed a smaller, laboratory-scale flammability test that would provide similar results. MSHA said it compared the laboratory tests with results from a large-scale test, and found them comparable. Of 16 samples tested, only one passed the lab test but failed the large-scale test, MSHA said.“The development of flammability tests is not an exact science,” MSHA said. “Because of the difficulty in designing a laboratory-scale test that is in complete agreement with a large-scale test, the comparison of test results obtained between these two procedures is considered to be very good.”