Recovered Detectors Indicate Methane Surge: Massey Energy
The company said Monday that readings on two units recovered from the Upper Big Branch Mine indicate a "sudden inundation" of methane and almost immediate explosion occurred.
Massey Energy Company issued a news release Monday about the readings found on two detectors recovered after the explosion in its Upper Big Branch Mine killed 29 miners on April 5. The company said an Associated Press Aug. 27 report prompted the release, adding that the information already was shared Aug. 2 with family members of the miners.
MSHA's investigation of the explosion continues, with about 80 percent of the interviews completed and approximately 90 percent of the mine mapped as of Aug. 25, the latest update on the agency's page about the case.
The release explains how the detectors record methane, carbon monoxide, oxygen, and temperature levels and the levels at which they alarm. Both devices "surged from zero to maximum readings" for methane and carbon monoxide within a three-minute span near 3 p.m. April 5, according to the release, which adds, "Actual levels of methane and carbon monoxide could have been higher, as these detectors do not record levels higher than 5% for methane or 500 ppm for carbon monoxide."
The detectors' "over range" alarms are triggered when those maximum levels are recorded, and testing indicates one detector, found at the longwall face, went from no alarm to an "over range" alarm for methane and carbon monoxide in less than 15 seconds near 3 p.m. The other detector, found about 3,000 feet from the first detector, recorded a "high range" alarm of 1 percent for methane and an "over range" alarm of 500 ppm for carbon monoxide, then an "over range" for methane within 16 to 30 more seconds, also near 3 p.m.
The release says, "Massey believes this information is very important. The data strongly suggest that these detectors were exposed to a sudden inundation of methane and a simultaneous or near simultaneous fire or explosion, as measured by high levels of carbon monoxide."