Department of Labor
Mine Safety and Health Administration

Accident Info-Gram
June 2003

Continuous Miner Traction Contactor Malfunctions

On June 4, 2003, at an underground mine in District 8, the traction drive contactor of a continuous miner (CM) malfunctioned. The CM operator had completed the first cut of the crosscut to the right. He backed the CM out of the cut to start the cleanup process. After repositioning the CM, the CM operator positioned himself between the cutter head of the CM and the right coal rib. When the traction control was actuated, only the CM's left crawler chain started. This caused the CM to pivot to the right. Fortunately, the CM operator was able to stop the machine just before being crushed between the cutter head and the coal rib.

The traction drive response had been malfunctioning before the accident. Both crawler chains were not always engaging at the same time. Results of the investigation revealed that a retaining clip on the traction contactor was missing. This retaining clip keeps the contactor in proper position.

• When operating continuous miners, continuous miner operators should position themselves in safe locations before moving their machines.
• When continuous miners are being moved or re-positioned, ensure that all persons are beyond the miner's turning radius. (outby the tail or inby the head) Stay out of the Danger Zone!
• Continuous miner controls and their associated contacts can malfunction at any time! Always be prepared for the unexpected.

This information was provided by concerned miners in an effort to eliminate accidents. Accident or "close call" information within District 8 may be shared by contacting the MSHA office at (812) 882-7617.