In what may be the next new advancement in mine rescue technology, the Great Escape demonstration was held at the Mine Safety and Health Administration’s Approval and Certification Center on November 8, 2007. The agency unveiled the new concept in post disaster escape and rescue to mining company executives, United Mine Workers members, university leaders, state mining safety agencies, and West Virginia Governor Joe Manchin.
The idea was conceived by MSHA Technical Support director Mark Skiles. Prior to joining MSHA, Skiles managed some of the safest and most productive mines in the United States.
He worked with the A&CC’s Applied Engineering Division (AED) to develop the concept. One of the functions of the AED is to take existing technologies from other industries and apply them to the mining industry to reduce accidents and improve safety and health.
The escape system concept is a potential next step in the evolution of underground mine safety. The system requires minimal ventilation and provides an unimpeded escapeway to a safer location.
The system consists of a series of steel reinforced concrete pipes with various points of accessibility and a positive pressure fan that would be located on the surface and connected by means of a cased borehole. Communications and tracking systems are installed inside the system directly from the surface borehole and inherently protected from fire and explosive forces throughout the entire escape system.
Great Escape also provides a safe conduit for communication and tracking equipment, having the flexibility to accommodate a wide variety of mine configurations using current, commercial/readily available components.
It can be utilized in advancing or retreat mining sections, and could be placed in any of the entries as a longwall section is initially developed. The sections of the pipe could then be removed as the longwall face retreats, thus providing an always present escape system near the miners.
After a fire or explosion, miners have only two choices: escape or barricade. Escape is always the first option.
When escape is impossible, barricading is the only remaining option. Sealing an area from bad air or entering a pre-manufactured refuge chamber can save lives.
The Great Escape is an alternative that can potentially offer both the fresh air that a properly equipped barricading system does and provides an avenue of escape that is protected from fire, explosive forces and bad air.
The system can be supplied with personnel carriers pulled by a battery-powered primary mover, where miners lie face down on the carriers and are transported to a safe area or out of the mine completely.
The Great Escape as demonstrated by MSHA included a tracking and communication system located inside the pipe. The electronic tracking system gave the command center the ability to identify each miner by name as they passed certain locations.
The system also provided a constant means of two-way voice communication, and MSHA has found that installation of communications and tracking systems is relatively easy within the protected confines of the escape piping system.
The escape system also has the potential to reduce time spent on specialized training, as its utilization is very straightforward. Once inside the system, the miner has protection from fire and smoke and a direct escape path is provided.
Imagine the scenario of being trapped in an environment where billowing black smoke is reducing visibility to less than a foot and the roof is only inches above your head. The two combine to create a terrifying, claustrophobic fear that is slowly pressing in on your last nerve.
You are breathing air from a self-contained self-rescuer (SCSR), which requires you to force the air in and out, and the life-sustaining air from the device is much warmer than normal air. Although you know the direction of escape, you do not know if the way is passable.
Every step you take is made by feeling ahead, arms outstretched, to avoid running into a wall of coal or a piece of mining machinery. You finally reach the entry to the right.
You tell yourself that the tunnel is less than 1000 feet ahead. Normally you could walk that distance in about four minutes but with the marginal visibility, you have to feel your way carefully.
Finally, the tunnel end appears out of the smoke; you open the man door and sweet, fresh, clear air flows into your face. The person behind you who has been fearfully holding on to your belt crowds in behind you and several others follow suit.
Initially, their words are rendered unintelligible by the mouthpieces of the breathing devices in their mouths, but the unmistakable tones of relief are clear. Inside the escape pipe, the miners remove their mouthpieces, mount the personnel carriers connected to the primary mover and quickly, and with much less duress, ride through the escape piping system to safety and their loved ones.
The demonstration of the Great Escape showed the reality of such a system may be possible today. This is a complete system that provides a separate, constant, uncontaminated, positively pressured supply of breathable air, independent of whatever else is taking place in the mine.
The system offers miners a potential alternative to refuge chambers, possibly without the periodic required replacement of items due to shelf life expirations. Most importantly, the system potentially provides a safe means of egress through an isolated, uncontaminated and structurally protected escape path.
Additionally, such a system may possibly shorten mine recovery time by providing a protected/isolated path to reach deep into the mine. The relatively easy inspection process of the system creates an additional functionality and time saving benefit.
All mine safety entities within the United States have been working feverishly for almost two years since the 2006 disasters to increase needed protections for our most precious resource, the miner. The MSHA Great Escape system may prove to be a reasonable and cost-effective alternative for miner protection.
MSHA continues to solicit feedback for system improvements from mining industry stakeholders, conduct various tests, address durability questions, and make overall system enhancements. For more information, visit MSHA’s dedicated Great Escape webpage at http://www.msha.gov/FocusOn/GreatEscape/GreatEscape.asp, where the industry public may provide input and suggestions.