Source: U.S. Department of Labor's Mine Safety and Health Administration, Arlington, Va.
A 42-in.-diameter concrete pipe anchors a new concept to assist underground miners in quick, safe evacuation during an emergency. Last week, MSHA debuted its "Great Escape" rescue system at the agency's Approval and Certification Center in Triadelphia, W.Va. The system uses reinforced concrete pipe with 4-in. wall thickness to form a tunnel of any length required. MSHA engineers note that data shows the tunnel structure could withstand a 50-ton collapse or methane explosion, and could be made watertight if flooding were a concern.

Conceived and developed by MSHA's Office of Technical Support, the rescue approach prototype consists of a tunnel with doors and vents at various access points and end caps. Standard pipe and components for the prototype were supplied by a Rinker Materials pipe plant outside of Pittsburgh.

Actual escape system installations may be able to use smaller-diameter (probably 30-in.) pipe and be installed between the mine's working sections and an escape shaft or, depending on the mine layout, run completely to the surface. The escape system would be fitted with a communication and tracking infrastructure and battery-powered personnel carriers to transport miners to the surface. A fan situated at the surface would pump breathable air through a borehole connected to the escape pipe.

According to MSHA, the system went from concept to working prototype in 28 days. The agency will evaluate feedback from industry stakeholders and continue to test the prototype to make overall system improvements.