The effort to save 33 Chilean men trapped deep in a mine is an unprecedented challenge, mining safety experts said Tuesday. It means months of drilling, then a harrowing three-hour trip in a cage up a narrow hole carved through solid rock.
If all of that is successful, the freed men will emerge from the earth and "feel born again," said an American miner who was part of a group dramatically rescued in 2002 with similar techniques. But that rescue pulled men from a spot only one-tenth as deep.
"They're facing the most unusual rescue that has ever been dealt with," said Dave Feickert, director of KiaOra, a mine safety consulting firm in New Zealand that has worked to improve China's dangerous mines. "Every one of these rescues presents challenging issues. But this one is unique."
First, engineers must use a 31-ton drill to create a "pilot" hole from the floor of the Atacama Desert down 2,200 feet to the area in the San Jose mine where the men wait.
Then, the drill must be fitted with a larger bit to carve out a rescue chimney that will be about 26 inches wide - a task that means guiding the drill through solid rock while keeping the drill rod from snapping or getting bogged down as it nears its target.
Finally, the men must be brought up one at a time inside a specially built cage - a trip that will take three hours each. Just hauling the men up will itself - if there are no problems - take more than four days.
"Nothing of this magnitude has happened before; it's absolutely unheard of," said Alex Gryska, a mine rescue manager with the Canadian government.
Gryska said he is confident that Chile's state-run Codelco mining company, with its vast expertise in the world's top copper-producing nation, would successfully drill the hole out. But he said he is worried about the three to four months officials say it will take to do so - and the key role the miners themselves will play in their own rescue.
Chilean officials said that the miners will have to remove upward of 3,000 tons of rock as it falls into the area where they are trapped. There is little danger to the men - the area includes a shelter and about 500 meters of a shaft outside that. But as the rock starts to fall a month from now, the men will work in nonstop shifts to remove it with wheelbarrows and industrial sweepers.
"The thing that concerns me is welfare of workers, their mental state. That will be real tough," said Gryska. "From a health perspective, it's hot down there. They're talking about working 24/7 in 85 degrees for two months. Their mental state for that work will be critical."
Early on, Chile's Health Minister Jaime Manalich said at least five of the men showed signs of depression. But spirits have improved with a supply of water, food, special clothes to keep them dry in damp conditions and the first verbal communication with loved ones this week.
Chilean officials are meeting with "life sciences" specialists from NASA on Tuesday. The team will give advice based on the U.S. space agency's experience in helping astronauts through the ordeals of living for as long as a year in cramped quarters and with limited contact with friends and family.
If the drilling goes as planned, the miners will then face the ordeal of being stuffed into a tubular, metal cage for three hours as they are slowly pulled up.
Experts say one of the few times such a technique was used was when nine U.S. miners were hauled out of the flooded Quecreek Mine near Somerset, Pennsylvania, in 2002. But those men were trapped for just three days 73 meters underground.
Quecreek survivor Mark Popernack noted that the Chilean miners "already went through more than what we went through," but the Somerset, Pennsylvania, resident said no matter the method, "to come up is the best thing in the world."
"If they make it, if they get that hole drilled, when they come out of there, they'll feel like they're being born again," said Popernack.
"Enjoy the ride, that's my advice to them," he said. "It'll be a long ride, but they'll enjoy it. Because when they see the light of day, they're going to feel pretty good."
This program aired on August 31, 2010. The audio for this program is not available.