CHARLESTON, W.Va. -- Federal and state officials investigating the Upper Big Branch Mine disaster say they are examining a variety of potential problems with the mine's methane monitoring system -- ranging from whether Massey simply didn't make sure the monitors worked properly to allegations that the company routinely disabled such equipment.
Government teams hope to get some answers next week, when they run more detailed tests on a "black box" that recorded data from the mine's longwall section for the six days prior to the April 5 explosion that killed 29 Massey Energy miners.
Investigators are looking closely at the methane monitoring practices at the mine, in part because miners have told them automatic shut-off systems for mining machines were routinely bypassed at the mine, but also because Upper Big Branch had a history of not properly maintaining its monitors.
During the two years prior to the explosion, U.S. Mine Safety and Health Administration inspectors cited Massey's Performance Coal at least 16 times for not meeting deadlines to recalibrate methane monitors so they would measure the explosive gas correctly.
"To me that's just unconscionable on the operators' part," said Kevin Stricklin, MSHA's coal administrator. "They are not respecting methane gas."
Mine safety experts believe the Upper Big Branch blast involved an ignition of methane that was then made far worse by a buildup of highly explosive coal dust. The explosion was the worst U.S. coal-mining disaster in 40 years.
Widespread media accounts, including reporting by National Public Radio, have cited an incident in February in which a miner said a Massey electrician was ordered to "bridge out" the device that would shut off a continuing mining machine if methane levels increased toward the explosive range of between 5 and 15 percent.
Ron Wooten, director of the state Office of Miners Health, Safety and Training, said his agency has gathered evidence that convinces investigators such allegations should be closely examined as the probe continues. Wooten declined to elaborate.
Early this week, Massey CEO Don Blankenship and other company officials held a closed-door meeting in which they told families of the Upper Big Branch miners that evidence has shown that methane monitors in the mine's longwall section were not disabled at the time of the explosion.
Massey believes the blast occurred near the longwall machine because of a large crack in the floor that could have allowed methane to seep into the mine. Upper Big Branch experienced such "methane outbursts" from the mine floor in 2003 and 2004 without any injuries. Neither Massey nor government investigators have said what steps were taken to prevent such an incident from recurring.
After Massey's family meeting, Wooten and state special investigator Davitt McAteer told the Gazette that Massey was premature in drawing conclusions about the methane monitors and that much more work needed to be done on that part of the probe.
Wooten later explained that, despite Massey's statements, the "black box" data had yet to be examined in any detail and that his investigators had not reached a conclusion one way or the other about possible tampering with methane monitors. Wooten also said that a preliminary review of the data revealed no sudden rush of methane gas prior to the explosion, as had been hinted at by Massey officials.
The review also indicated that someone hit the shut-off button on the longwall machine about 90 seconds prior to the explosion, Wooten said.
It's not clear why the machine was shut off. Investigators are considering the possibility that some condition in the mine prompted workers to hit the button. Or, Wooten said, workers may have simply shut down the longwall machine for the scheduled shift change. Workers who could have answered that question were killed in the explosion, Wooten noted.