Students Take Notes
From Underground
in Old Colorado Mine

By Lawrence Biemiller

Idaho Springs, Colo. -- For a guy as big as he is, Dave Mosch runs a mucker with surprising grace. Forward, lift, dump, forward, lift, dump -- watching him work can almost make you forget the dust, the darkness, the inherent danger of being in a narrow, chilly tunnel far inside a mountain. Mr. Mosch crowds onto a foothold on one side of the little machine, turning its battered scoop to one side and at the same time running the mucker forward on the rails, driving the scoop into the rubble of the most recent blast. With control levers that double as handholds, he raises the scoop toward the low ceiling, lifting the rubble over the mucker and dumping it noisily into an ore car attached to the mucker's back end. Forward, lift, dump -- the choreography, picked out by the restless spotlights of helmet lamps, is mesmerizing.

"These have been around since 1905 or 1910," Mr. Mosch says, shouting over the din of the machine and the ventilation fans. "You can move 30 tons in about four hours." The two students working with Mr. Mosch here in the Edgar Mine this summer -- Matt Budin and Joe White -- will learn not only how to use the mucker, but also how to drill into a rock face and fill the holes with explosives that will reduce another five or six feet of Belleview Mountain to rubble. As soon as the ore car is full, Mr. Budin hauls it away with a pint-sized mine locomotive and brings back an empty.

Mr. Mosch is the manager of the Edgar Mine, which has been operated by the Colorado School of Mines as a teaching and research facility for more than 65 years. He's been around mines himself since he was 8 -- he's 40 now -- because he comes from a family in which both men and women have been involved in the mining industry for three generations. As voluble as he is big, Mr. Mosch is eager to talk about mining's history and future, as well as to explain techniques for removing ores from the earth.

"Only three things you use every day are not products of the earth in some form, either from agriculture or mining," he says. "Know what they are?" It takes a minute or two of stalling to come up with all three: oxygen, water, and sunlight. "Right," says Mr. Mosch. Then he runs through a list of common materials obtained through mining and related activities, like rock-quarrying and drilling for oil. Copper, iron, aluminum, silver, zinc, coal, gravel, petroleum -- "You can't live without these things," he says. "The mission is to find them and get them out at a profit."

Getting material out of the earth isn't all that difficult, at least to hear Mr. Mosch tell it. In a small underground mine like this one, a team of two or three miners can drill, blast, and clear five or six feet of new tunnel per eight-hour shift. But making a profit is another matter. Mining is an expensive business: Labor, equipment, and explosives all cost money, as do meeting numerous safety and environmental requirements. Mr. Mosch estimates, for instance, that it costs him $100 to $200 a foot to tunnel here. Miners have to be sure before they start that they'll be able to sell what they extract for more than it cost them to do so. That's the challenge: Besides predicting what minerals they'll find in a mountain -- and where and in what concentrations -- miners have to be able to forecast what the market for those minerals will be like when they finally see daylight. "If you can make money on it, it's an ore," Mr. White explains. "If not, it's just a mineral."

He and Mr. Budin are both juniors majoring in mining engineering, and they've taken courses in surface and underground mining, geology, and mine design. Mr. White says he hopes to find a job developing environmentally safe mining techniques. Mr. Budin is interested in underground mining.

But right now, he says, Colorado has relatively little underground mining -- most ore extraction today is done from large pits that offer mining companies economies of scale. Mr. Mosch, however, predicts that stringent environmental regulations will eventually lead miners back underground: The high price of protecting the environment will make it more feasible to remove ores "surgically," as he puts it.

None of what comes out of the Edgar Mine now is marketable, but once upon a time, ore from the mine carried 80 ounces of silver and a half ounce of gold per ton of rock. The main tunnel is horizontal -- an adit, in mining terminology -- and is believed to have been begun in the 1870's. Known as the Miami Tunnel, it led to drifts, or side tunnels, as well as to stopes, which are cavities excavated above the level of a tunnel to get at mineral veins. The Miami Tunnel is now sealed off at a point about a quarter of a mile in. Beyond are the old workings, far too extensive to be maintained -- airless, pitch-black stopes and raises; the Edgar Shaft, which follows the long-deserted works on the Edgar vein; the mile-and-a-half-long Big Five Tunnel, which bores through the mountain east of the Miami Tunnel and once offered access to other veins in the mountain.

In its current configuration, the mine includes a number of drifts that are usually identified by letters and numbers -- "A Left," "C Right Spur" -- although one is designated the "Galena Drift." Especially in older sections, the ceilings are not much above six feet high, and the drifts are just wide enough that a person can get by on either side of the ore cars, which run on rails set 18 inches apart. The mine has an escape shaft -- a 200-foot climb up a ladder -- but no one is allowed in without a breathing device that, in the event of a fire, could convert lethal carbon monoxide to carbon dioxide for about an hour. Workers and guests alike must sign in, and as they do they pocket numbered brass disks the size of quarters that would identify them in a catastrophe.

Mr. Mosch says the Edgar Mine is one of the safest in Colorado. But later he quietly tells a story about a friend killed in a mine collapse in Alaska. Mine engineers, he says, had recommended the wrong type of rock bolts, which are driven into the disturbed rock of tunnel walls and ceilings to anchor them to competent masses behind. His friend's death, he says, is one reason he's helping to teach students to be mining engineers. Another is that ore prices have fallen so low that it's not profitable to work any of the little mines his family owns.

To avoid emitting unnecessary fumes, the mine's muckers and drills are powered by compressed air, which is piped in from a building just beyond the tunnel's portal. The mine locomotives are diesels equipped with exhaust scrubbers. Mr. Mosch and his students lay the rails themselves, and the diminutive line extends out the portal to a spot where the ore cars' contents can be dumped down a hillside.

Or they can on days when everything is going smoothly. Today, however, the dump mechanism on one of the ore cars has been knocked out of alignment, and the ignition switch on the bigger locomotive, a Plymouth Mine-O-Motive, was left on all night, running down the battery. Mr. Mosch finds a spare battery, but as soon as Mr. Budin gets the engine running, a different ore car derails on the dump track because it had not been swept clear of rocks. Mr. Budin, Mr. White, and a graduate student, Erkan Topal, struggle to jack one car back onto the rails and jack up the hopper of the other. Then it's back into the mine, where Mr. Budin and Mr. White are shoveling up the rubble the mucker couldn't get, clearing a face that Mr. Topal is planning to blast apart for practice.

In addition to mining classes, the school uses the mine for mine-safety courses, scholarly and corporate research, and tours for area schoolchildren. At intervals during the afternoon, pairs of geology students wander out of the darkness of one drift or another, carrying clipboards and measuring tapes that they're using in mapping assignments. Elsewhere in the mine is a cramped, two-level maze used for practice by mine-rescue teams. For those sessions, says Mr. Mosch, the mine can be filled with smoke.

Mr. Mosch says that agriculture is actually more dangerous than mining, although it's hard to imagine farming's being quite as fearsome as, say, a mine fire. "Most people in this business are in it because they like it," says Mr. Mosch. "You're exploring, looking for an ore body that no one's ever seen." He talks of rock faces that are millions of years old, points to faults where the slow movement of rock masses has ground stone to crumbling powder, offers samples flecked with glittering pyrite. His enthusiasm practically glows in the mine's darkness. "Am I getting across the romance of it?" he asks.

Copyright © 2000 by The Chronicle of Higher Education. Published June 30, 2000.