A radio that can send a clear voice signal at least 11,600 feet into an underground coal mine may never get beyond the prototype stage because its developers say the market for it is too small.
Pittsburgh Tribune-Review: June 23, 2006-- A radio that can send a clear voice signal at least 11,600 feet into an underground coal mine may never get beyond the prototype stage because its developers say the market for it is too small.
Coal production has increased steadily since World War II, but modern technology and a shift to surface mining allows companies to mine more coal with fewer employees at fewer mines. The decline in miners and underground mines has shrunk the market for mine safety devices.
Patrick Murphy, spokesman for Kutta Consulting of Phoenix, said the relatively small market makes it hard for companies to recoup the cost of developing equipment that meets federal standards for use in underground mines. "The road is littered with attempts at doing that within the industry," he said.
Kutta has an Army contract for a radio to help troops maintain contact with their command centers as they move through basements, subways and other underground urban structures. When the federal government began looking for better mine communications devices after the Jan. 2 Sago Mine disaster in Upshur County, W.Va., Kutta offered its prototype for evaluation. The radio's broadcast reached at least twice as far as any other system tested, but Kutta can't afford to spend any more money that doesn't focus on its commitment to the Army, he said.
"We've kind of run out of budget to do any more field tests," Murphy said. One of the Sago miners was killed by a methane explosion. Eleven slowly asphyxiated while awaiting rescue. One man survived. The explosion disabled the mine's wire-based phone system, leaving miners with no contact with rescuers.
The National Institute for Occupational Safety and Health tested the Kutta system and four others from March 28 to April 27 at Consol Energy's McElroy Mine near Moundsville, W.Va. The other systems reached 500 to 2,000 feet inside the mine; the Kutta system broadcast the entire length of the 5,000-foot test area, said Jeff Welsh, deputy director for the institute's Pittsburgh laboratory.
"We were still getting good voice communications at 5,000 feet," he said.
In a May 31 test at Consol's Enlow Fork Mine in Greene County, the Kutta signal again traveled the entire length of the test area -- this time, 11,600 feet. The agency also tested one system by Transtek Inc. of Plum that is designed to transmit directly from the surface through the earth. Transtek's system delivered a good voice signal through 270 feet of earth.
"There are some mines that are in that range, but there are mines that are up to 2,000 feet (deep)," Welsh said.
Transtek spokesman Bob Nigrini said the company is modifying the equipment and plans to run tests at 500 and 1,200 feet. The technology theoretically can transmit through at least 2,000 feet of earth, but the company has to find the right configuration. "We've got to change the frequency we're operating at, in addition to changing the size of the cables," he said.
Article by: Brian Bowling
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