Clinchfield Coal Company
McClure No. 1 Mine Explosion
McClure, Virginia June 21, 1983 No. Killed - 7
At approximately 10: 15 p.m., June 21, 1983, an explosion occurred in the 2 Left entries of McClure No. 1 Mine of Clinchfield Coal Co., located at McClure, Virginia.
Ten miners were present in the 2 Left entries at the time of the explosion, eight in the face area and two in the track entry. Seven died as a result of the explosion. Three miners at the faces survived the explosion and were rescued.
MSHA investigators concluded that the primary cause of the explosion was the failure of mine management to maintain sufficient volume and velocity of air in the No. 2 and No. 3 entries of 2 Left to dilute, render harmless, and carry away the methane gas being liberated in those entries.
About nine hours before the explosion, the No. 40 crosscut of 2 left was cut through into the longwall setup entries. A failure to install ventilation controls to separate the air split ventilating the setup entries from the air split ventilating the 2 Left entries materially affected the movement of air in No. 2 and No. 3 entries of 2 Left.
The volume and velocity of air became inadequate to dilute and to carry away flammable and explosive gases that were liberated in the area. The failure to maintain the airflow in its proper volume and direction in the setup entries, the 2 Left face area, and outby in the No. 2 and No. 3 entries of 2 Left, allowed an accumulation of an explosive methane-air mixture in the No. 2 and No. 3 entries of 2 Left. These changes in ventilation remained uncorrected for about 9 hours.
The explosive atmosphere was ignited by electrical arcing created by one of six possible sources:
Interruption of the belt control circuit.
A ground fault in the trailing cable for the conveyor belt feeder.
Interruption of the dinner hole light circuit.
Normal operation of the nonpermissible personnel carrier.
Automatic operation of one of the circuit breakers in the section power center.
A fault in the cable plug for the continuous mining machine trailing cable.
Conditions and practices that contributed to the explosion include:
Failure to follow the approved ventilation plan and maintain the separation between the air current ventilating the setup entries and the air current ventilating the 2 Left entries after the two sets of entries were connected at the No. 40 crosscut of 2 Left.
Failure to fully recognize potential consequences of neglecting to maintain separation between the air current ventilating the setup entries and the air current ventilating the 2 Left entries.
Failure to properly evaluate the effects of the open connection at No. 40 crosscut on ventilation of 2 Left entries.
Failure to ensure that procedures for maintaining separation between air currents ventilating two sets of entries were established, fully understood, and followed by persons responsible for carrying them out when the sets of entries were connected.
Failure to ensure that adequate preshift and on-shift examinations were made in the 2 Left entries during the day shift and evening shift on June 21, 1983.
Failure to train certified persons in the proper procedures for conducting preshift examinations of conveyor belt and conveyor belt entries when making belt examinations.
Historical Summary of Mine Disasters in the United States - Volume II