CHARLESTON, W.Va. -- Initial testing of the two methane "sniffers" used as part of the monitoring system at Massey Energy's Upper Big Branch Mine turned up no evidence of tampering or malfunctions, the state's top mine safety official confirmed Monday.
"The methane detectors were tested and they didn't find anything wrong with them," said Ron Wooten, director of the state Office of Miners Health, Safety and Training.
But, Wooten said, more tests are needed on other components of the mine's methane monitoring system as investigators try to piece together what caused the April 5 explosion that killed 29 miners.
Federal and state teams are focused on potential problems with the methane monitoring system for a number of reasons, ranging from whether Massey simply didn't make sure the monitors worked properly to allegations that the company routinely disabled such equipment.
Additional testing is planned to examine a "black box" that recorded methane and other mine atmospheric and operational data for six days prior to the explosion.
Wooten said investigators have also acquired a previously used data record that was in place at Upper Big Branch until it was replaced on March 30, and plan to test that equipment as well.
Already, the black box that was in use the day of the explosion has revealed no readings to indicate high levels of methane prior to the blast. It also told investigators that the mine's advanced longwall machine appears to have been shut down about 90 seconds before the explosion.
Among other things, Wooten said, investigators need to test the black box's functionality to ensure that it was able to communicate properly with methane detectors or "sniffers" used in the mine.
So far, investigators have gathered only the two methane detectors that were used in the longwall section of the mine. Other methane monitoring systems used in two continuing mining machine sections have not been acquired because of high water and other dangerous conditions in those areas since the explosion, officials said.
Wooten emphasized that the methane detectors could have been in perfect working order and still have been tampered with. Miners have been known to use plastic bags, jackets or other materials to cover the "sniffers" so they don't detect high levels of methane and automatically shut down mining equipment, Wooten said.
Massey general counsel Shane Harvey responded that there is no indication any such thing occurred at Upper Big Branch.
"All the evidence clearly indicates that the methane monitors were working properly and that no plastic bags or other impediments were put in place to prevent this equipment from functioning in compliance with MSHA mandates," Harvey said in a statement.
Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.