INTERVIEW-Utah miner search complicated by retreat method
08 Aug 2007 21:05:14 GMT Source: Reuters
By Timothy Gardner NEW YORK, Aug 8 (Reuters) - The search for six coal workers deep underground in a Utah mine has been complicated by a mining method that left a great load of rock balanced on a few pillars, a federal safety official said. "There's a pretty stiff sandstone formation above the coal mine ... after the pressure builds up to a certain degree, then the pillars start failing," Robert Friend, the deputy assistant secretary of the federal Mine Safety and Health Administration, told Reuters in an interview. Friend said he could not predict when the miners, who have not been heard from since the collapse early on Monday, might be found. Rescue efforts could be set back by a number of things including another "bump," or ground movement, caused by the weight of the stone resting on the pillars carved out by a method known as retreat mining, he said. Ground movement at the mine on Tuesday slowed rescue efforts because workers had to be withdrawn and accounted for. On Monday the miners at the Crandall Canyon Mine were engaged in retreat, or pillar, mining, although it is unclear what the miners were doing at the exact moment mine collapsed, he said. They are trapped 1,500 feet (475 metres) underground and it is not yet known if they survived the cave-in. In retreat mining, coal is extracted until only pillars of coal hold the roof up. Then the pillars are pulled -- or retreated -- causing an intentional collapse. Robert Murray, the president and chief executive of Murray Energy Corp., the co-owner of the mine, has said no retreat mining was going on at the time of the collapse and insists that an earthquake caused the disaster. Scientists have said the collapse itself caused seismic activity. PILLAR DANGERS Retreat mining, used in about 10 percent of underground coal production, is dangerous, according to a 2003 National Institutes of Occupational Safety and Health study. It said miners were more than three times as likely to be killed in a roof collapse than workers in other parts of a mine. Friend said when mine operators follow rules, the method is safe. "Secondary mining has been performed for many many years and it can be performed safely but the operator must follow the approved roof control plan," he said. "In the last 10 years or so, on secondary mining, every case where there was a fatality, the plan was not being followed. If it isn't done safely ... it pays dividends that you don't want." Mines are required to send plans to MSHA before extracting coal by retreat mining. Friend said about 300 mines across the country have retreat plans on file. Tony Oppegard, a former federal mine safety official who is now a Kentucky lawyer specializing in safety litigation, said the method is so dangerous that Kentucky state regulators are now required to investigate mines 48 hours before retreat mining begins. Friend said no federal laws require U.S. inspectors to do that. Federal laws could be strengthened to include more investigations, he said. Oppegard said intentional cave-ins can cover up mistakes because there's no way to inspect work after the roof falls. Friend agreed evidence is lost. "We don't know what goes on or what went on prior to (cave-ins)," he said. "That's just the mining method."
