HELP FOR MINERS IN W.VIRGINIA

摘要

When A Mine Col-lapses, it's often silence that kills. After the 2006 Sago explosion,for example, rescuers blindly probed the earth as 13 West Virginia miners hammered a ceiling bolt for help. All but one suffocated. In response, Congress required coal mines to install wireless communication systems. But that has proved to be a tricky mandate: explosions can result when high-voltage electricity-the kind needed to power through thousands of feet of rock-connects with methane, andtraditional routers need line-of-sight contact (rare in a mine).