Three simple steps could protect workers when it comes to dealing with electrical equipment, according to the Mine Safety and Health Administration (MSHA).
1) Lock out the energy source.
2) Tag out the disconnecting device.
3) Try out and test to ensure that power is off.
Failure to take the time to perform these three steps is one of the top five causes of all mining fatalities, MSHA reports. In fact, reportable numbers in this area are grim. In the metal/non-metal sector, there have been 30 fatalities, six permanent disabilities, 257 lost-time injuries, and 45 restricted day injuries during a 10-year window.
“A solid lock out-tag out procedure is the only sure way to prevent injury or fatality from an unexpected start-up of machinery during the process of repairs or general maintenance,” says Anne Kelhart, CMSP, director, safety and human resources, for Bechtelsville, Pa.-based Martin Stone Quarries, Inc. “This is particularly important because statistics are not in favor of the victim when an unexpected start up is initiated. Injuries are often gruesome.”
Most electrical accidents happen, MSHA reports, while work is being performed on energized circuits during maintenance or troubleshooting. Rather than emphasize quick repairs, it’s important for managers and miners to consider the risks to miners by prioritizing speed over safety.
“Make sure people are given the time to do it right,” Kelhart advises. “If people are pushed to perform a task in less time than is appropriate, it can cause people to cut corners.”
She notes that a culture of safety begins at the top of a company and flows down through the ranks. “I think we’ve made huge strides in embracing a culture of safety at all levels,” Kelhart says. “It’s the result of making miners professionals so they take pride in their work and in doing it correctly, as opposed to giving “attaboys” for doing it too quickly. That should never be the culture in today’s mines.”
Martin Stone Quarries has had a solid, safety-based culture for a number of years, Kelhart says, but that can be attributed — at least in part — to assigning consequences to miners who chose to act in an unsafe manner. “A number of years ago, we suspended a supervisor for a week because of a lock out violation,” she says. “That sent a serious message to the staff.”
As part of a safe lock out-tag out process, consider the following additional steps:
• Before beginning lock out and tag out procedures, make sure all workers are aware of planned maintenance, and coordinate activities with other operators and contractors.
• Set up barricades around affected equipment and post warning signs.
• If there are multiple switches for shutdown, use the one closest to the equipment.
• Do not use the disconnect switch to stop equipment. It could lead to arcing and could cause injury.
• When disconnecting energy, stand to the side of the device and look away from it.
• Consider additional protections such as a platform for wet conditions and insulated gloves.
• Once electrically powered equipment is de-energized, power switches should be locked out.
• A lock should be affixed to the disconnect switch rather than the start/stop switch.
• Workers should never lock out on top of another’s lock.
• Once the lock is in place, remove the key.
• Personal keys should be carried by miners, while keys to system locks should be stored in a lock box.
• Post a tag that identifies the worker performing the task.
During major work periods, such as during annual preventive maintenance or throughout the installation of an equipment upgrade, it’s common for lock outs to extend beyond a single shift or day. Even so, remember that a lock should be installed and removed only by the person to whom it is issued. If in doubt about a lock and remaining maintenance tasks, contact the off-site worker identified in the tag out at home, check their time card to see if they have punched out, or examine the parking lot to see if their vehicle is still on site. Supervisor locks are particularly important for these scenarios.
“There are several steps and best practices involved in a proper lock out-tag out procedure,” Kelhart says. “If I had to choose one step to name as the most important, it would be the final step — always attempt a re-start before you begin work.”
This final step, also known as try out, involves pushing the “start” switch to see if equipment starts (it should not). If the equipment starts, shut down again and verify that the proper equipment is locked out. If it starts, and the correct equipment is locked out, MSHA recommends warning co-workers, posting a guard, and notifying management immediately.
“If the machine re-starts, there is a problem with the lock out,” Kelhart notes. “This step gives workers the opportunity to go back to step one in the lock out process before tragedy strikes. Because to err is human, attempting a re-start before beginning work may be the only thing that stands between a worker and serious injury or death.”