As proposed, coal mine operators will be required to use proximity systems that cause a coal-hauling machine or scoop to stop before contacting a miner; provide audible and visual warning signals when a miner gets too close to the machine (within the machine’s warning zone); provide a visual signal on the machine that indicates the system is functioning properly; prevent movement of the machine if the system is not functioning properly; prevent interference with or from other electrical systems; and be installed and maintained by a person trained in the system’s installation and maintenance.

The rule, if placed into effect, would be effective in phases. According to MSHA’s proposal, mines will have eight months after the rule goes into effect to be in compliance for coal-hauling machines and scoops manufactured after the effective date of the rule (also for coal-hauling machines and scoops equipped with an existing proximity detection system).

Coal hauling machines and scoops equipped with an existing proximity detection system—which cannot be modified underground or needs to be replaced with a new proximity detection system—or those units manufactured on or before the effective date of the rule and not equipped with a proximity detection system must be in compliance within three years after the rule’s effective date.

According to federal data, as of this June, just 155 of approximately 2,116 hauling machines and scoops working underground were equipped with such systems.