A cement truck has arrived at a Chilean mine as crews enter the final stages of rescuing 33 men who have been trapped deep underground since August.
Workers must pour a cement foundation for a winch that will soon be installed to lift the miners to safety. The winch has been specially designed to gently tug the men to surface; engineers have spared no expense to provide a comfortable ride intended to avoid inducing panic during the ascent.
The men will travel 622 metres in a trip that could take anywhere from 11 minutes to half an hour. They will be tucked into a cramped capsule barely wide enough for a man's shoulders. Planners have gone to considerable lengths to avoid causing them discomfort during the claustrophobic trip, which will see them take a twisting, curving route.
On Monday, crews finished reinforcing an escape shaft and successfully conducted a trial run with a capsule designed to deliver the men.
The first miner could be brought to surface as soon as Wednesday at 12 a.m., Chile's mining minister Laurence Golborne said on Monday afternoon.
Moments earlier, the drillers who completed the escape shaft's reinforcements paraded victoriously down the main gravel thoroughfare of "Camp Hope," the small city of engineers, government officials, Red Cross workers, journalists and waiting families that has sprung up on the rubble-strewn slopes of the San Jose mine.
Every passing day has brought word of new progress, stoking an increasingly festive atmosphere at the camp, where a clown is entertaining children and families are strumming guitars and receiving an ever-increasing numbers of relatives and friends, who continue to arrive at the site during the countdown to what many are calling "D-Day."
The drillers completed their work early Monday, installing 56 metres of a protective sleeve - known as a casing - in the topmost parts of the hole. They had intended to extend the casing to 96 metres, but got stuck before reaching that depth and decided to abandon the effort lest they risk damaging the hole, Mr. Golborne said.
A subsequent test run down the hole with an empty escape capsule, dubbed the Phoenix, went well, he added.
"This test has been very successful. We set some TV cameras inside the Phoenix so we could watch how the hole behaves during the process of movement of the cage. And we could see that there was no stones, neither dust, that was liberated during this process," he said.
"So we are pretty sure that the cage will behave properly as has been designed during the rescue process."
The test capsule was sent to 610 metres, just shy of the 622-metre level where the miners are building a platform to assist their evacuation.
They stayed away from the full depth to avoid the "risk that somebody could jump in," Mr. Golborne joked.
Rescue crews have designed what the Mr. Golborne called "a very precise protocol" for how the rescue will take place. The men will first be taken to a triage area to receive first aid and have their medical condition evaluated. If doctors find any problems with a miner, he will immediately be heli-lifted to Copiapo. If not, he will be sent for an hour or two to a stabilization room for further medical monitoring, before being allowed to meet with two or three family members.
The miners will decide today who they wish to meet, a step that will allow them some ability to handle the inter-personal conflicts that have arisen through their two months of entrapment, including marital disputes and the discovery by wives of several mistresses.
On Tuesday, the men will change to a liquid diet filled with proteins, carbohydrates and potassium that is meant to prevent nausea and vomiting during the ascent.
"Also this will give them a caloric reserve and sufficient energy to endure the physiological stress that they will experience" while they are lifted, Chilean health minister Jaime Manalich said Monday.