Workplace safety

It has been 12 days since a seismic jolt trapped six coal miners underground in a Crandall Canyon coal mine in Utah. Rescuers still have not been able to reach them.

In a bizarre turn of events, another jolt Thursday night (Aug. 16) caused another cave-in, which killed three rescuers and injured at least six others.

This further tragedy moved Utah Governor Jon Huntsman Jr. to ask officials of the Mine Safety and Health Administration (MSHA) to rethink the search and to consider halting further efforts to save the trapped miners unless the safety of rescuers could be guaranteed. Utah does not want any more injuries, said the governor.

Huntsman also urged federal officials to review the safety of all the nation’s mines, to focus hard on workplace safety, and to let the hard lessons of this disaster improve work conditions of all other miners across the country.

Rescue teams have been obstructed in their efforts by repeated heaves and shudders inside the tunnels. The owner of the mine said there has been relentless seismic activity, so much that the mountain seemed to be alive.

These shudders are seismic jolts, which are called bumps in the mining industry, are the result of compression of the coal pillars. Bumps often happen in the deepest mines, like Crandall, where coal pillars support most of the weight of the mountain. Bumps can cause the roof of the tunnel or pillars to fail; the floor may heave up, and coal can burst from the tunnel walls with the speed of a projectile.

The Crandall Canyon mine was nearing the end of its economic life. Most of the coal had been mined and only coal pillars held the weight of the mountain. And there was a lot of weight. In some places the mountain rises 2,200 feet above the mine, which is a horizontal complex that has been dug 4 miles deep into the mountainside.

In the course of two decades, better technologies have allowed miners in Utah to tunnel deeper than 1,500 feet into the mountain. In older technologies, 1,500 feet was the impassable limit. Experts also think the weight-bearing capacity of coal reaches its limits at this depth.

Former mine safety officials said that the mining techniques used at the Crandall Canyon mine were very dangerous. They have questioned why federal regulators continued to approve work plans for the mine. A former senior adviser said the retreat mining techniques at Crandall carry with them serious risks, and the MSHA’s approval cast doubts on the thoroughness of its review.

These questions about MSHA performance have arisen so soon after the MSHA administrator acknowledged in June this year that there were disturbing issues in MSHA’s regulations enforcement programs prior to the 2006 disasters in three mines where 19 miners were killed.