The day is edging closer where 33 miners trapped in a Chile mine are rescued and brought to the surface. Channel 4 News illustrates how the rescue attempt is supposed to work.
Mining officials in Chile conducted a rehearsal of the evacuation procedure yesterday in anticipation of the day the 33 miners will begin to return to the surface.
The miners will be assessed and evaluated for up to an hour once brought to the surface and will then be extracted by helicopter to a “stabilisation area” where they can be reacclimatised to life back on the surface, according to Chilean Health Minister Jaime Manalich.
Rescue workers also demonstrated the type of sunglasses the miners will need to wear once above ground. They have not seen daylight for over two months.
The sunglasses will prevent their eyes from suffering damage, as they will be unused to bright light.
Channel 4 News Foreign Affairs Correspondent Jonathan Miller says it can take anything up to 40 minutes for the small rescue capsule to reach the men.
The 33 miners are trapped 701m below ground level.
The rescue team has been drilling three separate shafts in case one fails. Locally the pumps are nicknamed "The Tortoise", "The Hare" and the "The Elephant". It's "Plan B" - "The Hare" - that is leading the way.
Using the 12cm borehole which reached the miners in August and has been delivering supplies, "The Hare" has been widening this hole to 71cm, just wide enough to fit the escape pod.
Three rescue cages have been designed by navy engineers. Each capsule weighs just under 500kg, with communication links and three air tanks to allow the men to breathe for up to 90 minutes. The internal dimensions are tiny: just 1.9m by 53cm.
The journey to the surface can take anything from 20-40 minutes for each man.
Chile’s Mining Minister Laurence Golborne said he hoped the escape shaft would reach the men by Saturday.
He claimed once the drill breaks through, it could take anywhere from three to 10 more days to pull all the miners to safety.
The officials still need to decide whether or not to install a steel sleeve down the shaft. That would reduce the risk of something going wrong during the rescue attempt, but lowering a steel pipe down the shaft will take more time and also may cause its own problems.
Mr Goldborne insists that the decision will be based entirely on technical factors once a vide camera can examine the walls of the shaft.
Among family and friends of the miners, expectations have been high that a rescue is only a matter of days away. This comes after the country’s President Sebastian Pinera said that his government was close to pulling the men to safety.
Mr Pinera said this week that he hoped to be there in person to see the rescue before leaving on a trip to Europe on 17 October.