Underground Engineering

Over 800 ft underground, surrounded by rough-hewn walls under such tremendous pressure that leaning on them could cause them to violently explode, tests are run on a device that might someday be integral to rescuing miners trapped by cave-ins. The device, under development by a group of Virginia Military Institute (VMI) cadets and professors, relies on seismic waves to transmit distress signals using the earth itself as a conduit. Essentially a modified speaker mounted on a spiderlike frame, the VMIne is affixed to the roof of a mine tunnel and can produce vibrations that travel through the intervening rock, which can be acquired by receivers many hundreds of feet above (Fig. 1).