Chilean rescuers are growing increasingly optimistic about pulling the 33 trapped miners out far sooner than originally estimated, and with drilling quickly advancing on three narrow escape chutes, they raced Tuesday to decide on a design for the capsule that will lift the men to safety.
President Sebastian Pinera has staked his presidency on being able to show the world that his government has safely rescued the miners ahead of schedule. He promised the men after they were found to be alive Aug. 22 that they would be home by Christmas — a timeframe mining experts called far too conservative — and then put hundreds of rescuers to work on three simultaneous drilling operations to reach them more quickly.
The engineer in charge of the rescue effort, Andre Sougarret, said Tuesday that "it's still premature to talk about shorter timeframes. We're sticking with the first days of November as the final date of the rescue."
|Romina Gomez, daughter of trapped miner Mario Gomez, writes him a letter in the eating area outside the collapsed San Jose mine in Copiapo, Chile, Tuesday Sept. 21, 2010.|
But the rescue team's own numbers suggest faster progress. The biggest drill, labeled "Plan C," is capable of much faster speed, and the deeper it gets, the faster engineers plan to drill.
Barring unforeseen complications, it could break through to the miners at a point nearly 2,000 feet (597 meters) underground in the second week of October. Sougarret has said it would then take 8 days to insert an iron sleeve in the 28-inch-wide (71-centimeter-wide) chute to prevent rock falls while miners are being pulled out.
There's also the matter of an Oct. 15-22 European trip scheduled by Pinera, who promised the miners in a video chat Sunday that he would be there to hug them as they emerged.
While his ministers have struggled to manage expectations, Pinera could hardly contain himself when asked by reporters at the mine to commit to a date, saying with his usual broad smile that "it will be sooner than what you expect."
In another indication of the rescue effort's progress, Sougarret said the rescue capsule — named Phoenix for the mythical bird that burns to ashes, only to rise again and live for hundreds of years — has to be ready within 10 to 12 days after they decide on a final design this week.
With that in mind, engineers were viewing prototypes of the capsules Tuesday at ASMAR, the Chilean navy's shipbuilding operation in Talcahuano, where three of the capsules will be built to provide backups in case anything goes wrong.
The specifications are elaborate: The capsules must come equipped with tanks to provide three hours of oxygen, wheels mounted on shock absorbers to maintain contact with the pipe's walls, an internal harness to prevent injury to the miners, and a wireless communication system so the men can remain in touch with people inside and outside the mine during the 15- to 20-minute journey to the surface.
It also must fit through a chute just 23 inches (58.4 centimeters) in diameter, while also providing just enough room to squeeze inside for the largest man trapped below, a miner whose shoulders measure 19 inches (48 centimeters) across.
"That's the critical dimension for the cage's design," Sougarret said in a briefing Tuesday at the San Jose mine.
ASMAR plans a cylinder with walls of steel 0.16 inch (4 millimeters) thick, with an escape hatch and interior harness system designed to enable the occupant to lower himself back down into the mine should the capsule get stuck.
"Everything is advancing OK, the technical team ... is already at ASMAR evaluating the rescue capsule design. It has been baptized Phoenix. This week we will decide" its final characteristics, Mining Minister Laurence Golborne said by Twitter on Tuesday.
The capsule designers have received some guidance from U.S. engineers involved in Pennsylvania's 2002 Quecreek coal mine disaster, said Tom Foy, one of nine men who were pulled to safety in an operation that has many similarities to the effort in Chile.
Foy, now 61, was stuck for three days about 270 feet underground, in a coal seam just four feet high, with groundwater rising and oxygen disappearing. By the time rescuers broke through with an air pipe and heard them bang nine times to signal their survival, Foy figures they had just an hour of air left.
The Quecreek rescuers didn't bother installing a metal sleeve inside their escape chute. Groundwater gushed through walls of the hole and drenched the rescue cage as they were pulled up.
"Who cares about the water — just get us the heck out of there! It was pouring like buckets, but who cares?" Foy recalled. "They could have pulled me up on a rope for all I cared."