An off-the-shelf 42-in.-diameter concrete pipe and components from Rinker Materials anchor a new concept to assist underground miners in quick, safe evacuation
An off-the-shelf 42-in.-diameter concrete pipe and components from Rinker Materials anchor a new concept to assist underground miners in quick, safe evacuation during an emergency. In early November, the U.S. Department of Labor’s Mine Safety and Health Administration debuted The Great Escape rescue system at the agency’s Approval and Certification Center in Triadelphia, W.Va.
Taking its name from the 1963 Steve McQueen film in which a group of American POWs dig an escape tunnel out of a Nazi prison, The Great Escape system uses reinforced concrete pipe (from a Rinker facility outside of Pittsburgh) 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 200-ft.-long rescue approach prototype consists of a tunnel with doors and vents at various access points and end caps. With recent high-profile mining disasters in West Virginia and Utah putting pressure on the mining industry to emphasize safety and evacuation, the atmosphere for this type of simple, easily replicated escape system was right. We’re looking at anything that looks like it might save lives, says John Faini, center chief, MSHA Approval and Certification Center. We’ve had a tough couple of years, and this system could have saved some lives if it had been in place.
Actual escape system installations may be able to use smaller-diameter (probably 36-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. If this system takes off, we’d want to get a custom design for different types of mines and probably more reinforcement, Faini adds. We also hope that if the industry adopts this that the economies of scale will make it more affordable for companies. For the prototype, the 42-in. pipe was about $76 per foot. That’s not cheap, but we’re hearing from industry insiders that the price could decrease by a third.
The escape system would be fitted with a communication and tracking infrastructure and battery-powered personnel carriers to transport miners to the surface. The strength of the pipe will protect the vulnerable communications and tracking equipment from fire and explosion damage. A fan situated at the surface would pump breathable air through a borehole connected to the escape pipe. The positive pressure inside the tunnel will allow the miners to leave a dangerous atmosphere and escape in clear air.
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. Faini is encouraged by the initial response to the prototype. Usually any new idea is shot down when it’s first introduced, and the system will have no better than a coin’s flip chance of becoming standard, he says. But a local paper in West Virginia did a survey about this system, and 75 percent were in favor of it. That’s significant. It is important for the mining and concrete industries to be flexible and work together. Every mine is different and may require new specifications or components for each escape system.