OCR Text |
Show Historical Guide June 2002 16 Feds blame fatal Willow Creek mishap on ventilation The final results of the federal investigation conducted into the fatal accident at Willow Creek placed the blame for the explosion on the mines ventilation system. Two underground workers died and eight miners were injured when the coal production operation at Castle Gate blew up on July 31, 2000. According to the United States Labor Department report, explosive methane gas built up in the mine's labyrinth of tunnels. The ventilators failed to ad equately dilute the gas and into a return air course or to prevent the series of four the surface of the mine, conblasts that occurred at Willow tinued the federal agency's final report. Creek. The bleeder ventilation system at Willow Creek did not adequately control and distribute the air passing through the worked-ou- t area of the 3 panel, according to the federal investigators. The system did not continuously dilute and move methan- Several factors adversely impacted the bleeder ventilation system prior to the accident, according to mine accident investigators. An increase of coal production on the longwall face and an expanding gob resulted in mixtures and other gases, dusts and fumes from area away the worked-ou- t from active production and into the gob. The volatile increase in the amount of methane gas in the mine was accompanied by a D-- e-air greater methane liberation decrease in airflow in the gob. Although vertical degasification boreholes were drilled for the panel at the Willow Creek coal mining operation, the first borehole had not yet been encountered. In addition, the mine ventilation and bleeder system had limited reserve capacity and the availability of ventilation pressure and air quantity was further reduced by the intake air split adjacent to the D seam bleeders. The distribution of airflow in the gob was affected by the 31,2000. An Interruption of ventilathe 3 gob, caused by and an undercast, that were left intact in the worked-oarea, stated the federal agency's ac- gob. Eventually, liquid hydrocarbons became involved in the cident report. The federal investigators indicated that the enforcement actions involving the fatal explosion at Willow Creek should include the issuance of two violations: The bleeder system being used during pillar recovery did not control and distribute air passing through the out area. investigators. Fatal injuries did not occur as a result of the first explosion. After the first explosion, personnel remained on the longwall section to extinguish a fire near the base of the shields on the head gate side of the The mine operator installed framed curtains across four of the six bleeder connectors at the y end of the 3 D-- in-b- longwall pillared area. In addition, an overcast and check curtain were installed in the bleeder connector nearest the head gate side' of the area. gate side of the work-oHowever, the accident investigators from the federal ut D-- the explosion, prevented methane removal from the fire, pointed out the federal longwall face. Conditions worsened in the face area just prior to the second explosion. The fire, .resulting from the first blast occurring inside the Willow Creek coal mine, ignited the subsequent explosions. Fatal injuries likely occurred as a result of the second and third explosions. "I think what we see, if nothing else, is a need for frequent and thorough examinations of the ventilation systems near these longwall ma- agency determined that the chines, explained Allyn Davis, approved plan supplement for the Willow Creek coal production operation did not show the controls at the locations In accident investigation program manager for the U.S. question. The controls inhibited airflow on the head gate side of area where the the worked-ou- t initial explosion and subsequent fire occurred. The initial explosion was sparked by falling rock in one I The highly volatile conditions resulted in an explosion and fire at 11:45 p.m. on July tion of ut 00 Years of Progress fatal underground accident area due to the pocket of methane accumulating in the back of the gob near the longwall setup rooms. lack of fully established internal airflow paths as well as by ventilation controls, such as check curtains 1 gob, between the longwall face and the longwall setup rooms, ignited a small pocket of methane and gaseous hydrocarbons, added the federal investigators. The flame traveled into the methane pocket, stated the accident report. Most likely, a roof fall in the head gate fringe area of the Mine Safety and Health Ad- ministration. Conditions can change rapidly. The ventilation system at Willow Creek did not adequately dilute methane, dust and other gases in the mine. Increased coal production in the local coal production facility meant more methane gas, but the ventilators failed to keep up with the pace, concluded the federal agency's report. . |