CHARLESTON, W.Va. -- Nine years ago last Thursday, a series of explosions rocked the Jim Walter Resources No. 5 Mine in Brookwood, Ala. Thirteen coal miners died.
Federal investigators blamed the disaster in part on Jim Walter Resources' failure to apply enough "rock dust" to control explosive coal dust that can build up underground. The company appealed, and a federal judge ruled that the U.S. Mine Safety and Health Administration's dust samples -- gathered after the explosion -- didn't accurately reflect conditions at the time of the blast.
Now, Massey Energy Co. is raising similar arguments about dust samples. MSHA believes the samples show the coal giant did not do enough to control the buildup of explosive coal dust at its Upper Big Branch Mine, where 29 workers died in a massive blast on April 5.
MSHA might have avoided such legal battles had the agency long ago forced coal-mine operators to install special meters that would allow real-time monitoring of coal-dust conditions in underground mines across the country.
Over the years, experts from the National Institute for Occupational Safety and Health and the now-defunct Bureau of Mines repeatedly urged the mining industry to deploy such equipment.
In one report in 1989, the Bureau of Mines said dust meters were among "the most promising methods" for helping to prevent deadly coal-dust explosions.
"The Bureau of Mines has developed an optical rock-dust meter that can be used underground to give a direct and rapid read-out of the rock-dust content of mine dust samples, thus eliminating the need for laborious and time-consuming laboratory analysis of rock-dust content," said the report, presented to the International Conference of Safety in Mines Research Institutes.
"The in-situ measurement allows for immediate corrective action and has high potential for improving mine explosion safety," the report said. "The Bureau device is in the process of being commercialized."
So far, the United States still does not require rock-dust testing meters. Legislation pending in Congress would force operators to start using them, but block MSHA from basing enforcement actions on the test results for two years or more while the devices undergo further study.
Coal dust is highly explosive, and can turn what might be minor ignitions of methane gas in underground mines into massive blasts that take many more lives.
Federal and state investigators believe that's exactly what happened on April 5, when a huge explosion ripped through the Upper Big Branch Mine, causing the worst U.S. coal-mining disaster in 40 years.
Mine safety experts have known for decades how to prevent coal dust explosions: Apply large amounts of "rock dust," usually powdered limestone, to walls, floors and other surfaces underground. Even if there is an explosion, the rock dust mixes with coal and helps prevent it from fueling a larger blast.
Under the 1969 federal Coal Mine Health and Safety Act, coal companies must apply enough rock dust so that the "incombustible content" of mine dust in clean-air intake tunnels makes up at least 65 percent of all dust measured. In "return air" and other tunnels, rock dusting must be adequate to make the incombustible content 80 percent of all dust measured.
Along with improved mine ventilation practices and explosion-proof electrical equipment, the use of rock dust underground has made massive coal-dust explosions far less frequent, but between 1976 and 2001, inadequate rock-dusting was blamed at least in part on six explosions that killed 46 U.S. coal miners, records show.