The U.S. Mine Safety and Health Administration (MSHA) has announced its final federal rule outlining the use of proximity detection systems at all underground operations. The rule, which takes effect March 16, will be phased in over eight to 36 months to provide operators an opportunity to obtain MSHA approvals, modify continuous miners to be compliant and complete required miner training.

The phase-in periods are based on the availability of the four currently MSHA-approved proximity detection systems, the estimated number of continuous mining machines that must be rebuilt or replaced by new machines during these periods, and manufacturers’ capacity to produce and install these systems. To meet the standards set in the rule, a proximity system must:

• Cause moving or repositioning continuous mining machines to stop before contacting a miner;

• Provide audible and visual warnings on the miner-wearable component and a visual warning on the machine before it stops;

• Provide a visual signal on the machine that shows the machine-mounted components are functioning properly;

• Prevent movement of the machine if any machine-mounted component is not functioning properly (except limited movement for repairs);

• Prevent electrical interference that adversely affects the performance of other electrical systems in the mine; and

• Be installed and maintained in proper operating condition by a trained person.

A list of approved systems is available on the agency’s website: According to historical federal data, there have been 35 deaths where U.S. coal miners have been pinned, crushed or struck by continuous mining machines in underground coal mines since 1984. Based on manufacturer information, nearly half of the continuous mining machines in operation—425 of approximately 863—are already equipped with proximity detection systems. Most will meet the provisions of the final rule with only minor system changes, such as adding warning signals.