BACKGROUND: "Phoenix" to pull Chilean miners out of the dark
Oct 11, 2010, 15:44 GMT
Berlin/Copiapo, Chile - Chilean Navy engineers have built three rescue capsules that could soon be used to extract the 33 miners who have been trapped in the San Jose mine for more than two months.
The capsules have all been nicknamed Phoenix, after the mythical bird that rises from its ashes. They vary in length from about 2.5 to 4 metres.
The capsules feature microphones, loudspeakers and breathing equipment that is meant to last for about 90 minutes.
One 624-metre trip out of the trapped miners' chamber is expected to take 25 minutes. Rescue teams will then need another 25 minutes to prepare the capsule for the next voyage down the shaft - leading to an estimate of one hour per miner to be rescued.
Original plans had called for the two larger Phoenix versions to be deployed because they feature emergency exits, which would allow a passenger to climb back down a rope if the capsule got stuck on its way to the top. But that proposal proved controversial because of the risks involved and so rescuers will only use the smallest capsule.
The plan now is to only use the smallest Phoenix capsule, also because the drilled rescue shaft is not always vertical or perfectly straight. The larger capsule could more easily get jammed in small bends.
The capsules have a diameter of 53 centimetres. The shaft is mostly 66 centimetres wide, except for the first 90 metres, where pipes measuring 61 centimetres have been lowered into the ground.
Phoenix is an enhanced version of the so-called Dahlbusch bomb, a missile-shaped miner rescue device first used in Germany in 1955. It was deployed again in 1956 and 1957, but did not gain international renown until what became known as the Miracle of Lengede - the 1963 rescue of a dozen miners from a flooded German mine.
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