MSHA will publish the proposed rule, entitled Proximity Detection Systems for Mobile Machines in Underground Mines, on September 2 in the Federal Register.

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.

MSHA is requesting comments as to whether the technology should be required for metal/nonmetal mines. Any input must be received by December 1; the agency will hold public hearings to collect comments as well.

“This proposed proximity detection system rule would better protect miners from being crushed or pinned in the confined underground mine spaces where large equipment is constantly in motion,” said Joseph Main, assistant secretary of labor for mine safety and health. “It is an important component of the department’s ‘Plan, Prevent and Protect’ strategy for safeguarding all workers.”

Kevin Stricklin, MSHA’s administrator for coal mine safety and health, said the agency is confident in the systems’ effectiveness on other mobile equipment since so many operators already have the technology in use.

“We hope to learn from their experiences during the public comment period,” he said.

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. Additionally, the agency said, 42 workers were killed and another 179 were injured in pinning, crushing, and striking accidents between 1984 and 2014.

In the most recent five-year period (2010-2014), accidents killed nine miners in 41 cases — 23 involved coal hauling machines and 18 involved scoops.

The proposed rule is available for viewing at the Federal Register Public Inspection Desk at