The lifeline works by using directional cones attached to the escape rope to reduce the probability of miners becoming confused or getting lost during an emergency by assisting in leading miners to slope, shaft or emergency escape facilities.
The directional cone size and shape was designed to prevent a hand grip from being broken when in use. The rope sections can be quickly and securely locked together with heavy duty sleeves, thimbles and quick links.
For higher visibility and to meet US Mine Safety and Health Administration (MSHA) regulations, the lifeline is marked with reflective tape at 25-foot intervals.
Tests conducted by the US Centers for Disease Control and Prevention’s National Institute for Occupation Safety and Health Lake Lynn Laboratory in 2003, and at mine sites, showed participants identified light vests, lasers and lifelines as the most beneficial devices when working in an underground smoke-filled environment during emergencies.
Miners undertaking emergency response training simulations chose directional lifelines as the most useful tool for negotiating travel through smoke and for leading personnel to safety.
Information on the lifeline is available from MSHA's Approval and Certification Center.
