Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/370990
TIONS ILLUSTRATED OUR EXPERTS Going Underground — Roof Control Septermber 2014 Joseph Flick is director of the Miner Training Program in the Department of Energy and Mineral Engineering at The Pennsylvania State University. He develops safety curriculum and conducts mine safety training programs for miners and supervisors in the Pennsylvania coal, and metal/ non-metal mining industries. He has more than 30 years of mine safety training experience, holds a master's degree is safety sciences and is a CMSP. With 42 years of total min- ing experience in both coal and limestone surface and underground, owner of J.W. Granville Consulting Bill Gran- ville credits his years of safe mining to the mentoring he received early in his career, and he now enjoys mentoring others. Specializing in safety, leadership, troubleshooting, and problem solving, Gran- ville now primarily works with mine startups from planning to completion. A major commandment in underground stone mining is that no miner should ever advance beyond a scaled area. Scaling in a mine is a continuous process. As they work, scalers move from good, known scaled conditions to lesser-known, unscaled condi- tions. Scaled roof sections can be identifi ed by the scale tracks, which are lighter-colored scratch marks in the stone. Even after a section has been scaled, the scaler must follow up and provide maintenance scaling. Mechanical scaling is an effective method for knocking larger loose stone off of the mine's roof and walls, but it is ideal to fol- low up mechanical scaling with manual scaling to better ensure management of all loose stone. Additionally, manual scalers can help inspect the roof from a vantage point of height, looking and listening, as well as searching for cracks, bulges, and dropped ledges. Manual scalers also can mark sections for roof bolting in mines that use mechanical bolts. In some underground stone mines where the rock layers in the roof are thinner, the roof must be shored up with me- chanical bolts. Much like thin layers of wood are compressed and glued together to create strong plywood, roof bolting compresses and fastens layers of rock to create a strong, rigid, beamed roof. New technology in roof mapping allows the miners to know locations of voids and solid rock, along with hardness, to ensure correct drilling control, bolt length, and resin amounts. Conditions in a mine can change in a blink of an eye, and it is diffi cult to impart information in a classroom or through reading about the inherent hazards, yet how a miner reacts to a hazard can make all of the difference in controlling it. While MSHA mandates the hours underground miners must be trained, the best training is on the job, working with an experienced miner who can teach a new miner about the sights and sounds he or she must know. Never-ending process 2 3 The manual advantage 5 Shore it up 6 On-the-job training Craig Collins is the electrical engineering manager at J.H. Fletcher and Co. Collins earned his bachelor's degree in electrical engineering at the West Virginia Institute of Technology and his master's degree in engineering at Marshall University. He began at Fletcher in 1994, and his experience in underground mining has led to improve- ments in ergonomic machine controls and advancements in safety systems for mobile mining machinery.