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This is ALL THINGS CONSIDERED from NPR News. I'm Robert Siegel.
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And I'm Melissa Block.
It could be many weeks, even months, underground for 33 Chilean miners. Rescue workers are lowering supplies and microphones through a bore hole just six inches wide. Psychiatrists are working on plans to help keep the miners sane.
Meantime, a massive, diamond-tipped drilling machine is on the way to drill a hole big enough to pull the miners out one at a time. Here in the U.S., mining experts are considering the immense challenges ahead. We hear that story from NPR's Howard Berkes.
HOWARD BERKES: The 33 gold and copper miners have already spent 18 days trapped nearly a half mile underground. A collapsed tunnel blocks their way out. It took eight tries to reach them with a relatively tiny borehole. The much bigger rescue shaft could take as much as four months to drill, according to Chilean mining officials.
Mine safety experts here are astounded by the task. Davitt McAteer is a former federal mine safety chief.
Mr. DAVITT McATEER (Former Federal Mine Safety Chief): Miners are resilient as a general matter, but that's a long time to be trapped up. It is going to be, no matter what the duration, whether it's weeks or months, it's going to be a difficult time.
BERKES: This is a hard rock mine so there isn't much of a toxic gas threat, including the methane that plagues coal mines, says Felipe Calizaya, a University of Utah mine ventilation expert with experience in neighboring Peru. But breathable air in a confined space is a concern.
Mr. FELIPE CALIZAYA (University of Utah): Thirty-three people, they may run out of oxygen. That's one of the key elements to worry about. And when it comes to waiting for weeks or months, then oxygen depletion is an issue.
BERKES: It's not clear how much air remains underground, whether there's any ongoing airflow or whether sufficient air can be pumped in from the surface. The stability of the space in which the miners found refuge is also a concern. Is it subject to collapse? And reaching them a half-mile down with a big enough hole for rescue is a problematic task.
Bob Ferriter is the senior mine safety specialist at the Colorado School of Mines.
Mr. BOB FERRITER (Senior Mine Safety Specialist, Colorado School of Mines): You know, if you hit a fault zone in there somewhere, it'll take and interfere with that drilling. And drills do, you know, they wander. They dont go a nice straight line. They'll kind of corkscrew around.
There's a possibility of losing that drill or losing that hole. So there's a lot of unknowns drilling that big a hole and then extracting people back up through it.
BERKES: Ferriter recalls two similar rescues in the United States: at the Que Creek mine in Pennsylvania eight years ago and the Sunshine Mine in Idaho in 1972. But both shafts used in those rescues were drilled a fraction of the depth required in Chile. Ferriter says these physical challenges weigh on the minds of trapped miners.
Mr. FERRITER: Your mind will wander around at all the possibilities of things that could go wrong. And then of course you have to have encouragement. You know, hopefully the leader is saying, hey, we're going to get out of here. It's okay. We're going to make it. Look, they found us already, that's half the battle. But these guys are just sitting there waiting. So psychologically it's going to be a challenge.
BERKES: Part of the plan in Chile is to drop microphones into the mine so the miners can speak with their families as they await rescue. They've already sent out written notes. The families have been celebrating the miracle of locating their loved ones alive. Now they're praying for one more miracle.
Howard Berkes, NPR News.
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