Chile mine rescuers work on 'Plan B'

media captionThe BBC's James Reynolds takes a tour around Camp Hope in Chile

Engineers in Chile are working on a plan that they hope will dramatically speed up the rescue of 33 miners trapped in a collapsed shaft.

Workers are due on Monday to start drilling an escape shaft going about 700m (2,300ft) underground, which is likely to take four months to complete.

But engineers say widening an existing tunnel may reach the men in two months.

Officials are looking at several plans to rescue the men, who have been stuck below ground since 5 August.

Engineer Walter Herrera told reporters: "We can broaden the hole that is already there with the latest generation machines and using a wider diameter bore."

Mr Herrera said government experts were studying his proposal.

Health Minister Jaime Manalich announced on Saturday that "Plan B has already been designed", promising more details later.

However, Mining Minister Laurence Golborne had earlier dismissed speculation that the miners could be rescued in as little as 30 or 60 days.

"The information is extremely clear, the time frame is... between three and four months," Mr Golborne told local media, according to AFP news agency.

As part of the original plan, Chile has imported a special hydraulic bore to drill the escape shaft down to the miners.

The Strata 950 will drill a shaft down to the men, and a capsule can be lowered to rescue the men one by one.

Legal moves

On Friday, Mr Manalich said five of the trapped miners were showing signs of depression, and that psychologists would try to help them through an intercom system.

media captionThe BBC's Gideon Long describes the footage of the miners as they sent greetings from underground

The miners at the San Jose gold and copper mine near the city of Copiapo, some 725km (450 miles) north of Santiago, were discovered last Sunday after the mine collapsed several weeks earlier.

Rescuers have managed to drill a small tunnel to the men from the surface to allow supplies to be sent down.

On Thursday the men made a video for their families showing their living conditions in the shaft, which was broadcast on Chilean TV.

The men appeared to be in good spirits, despite their ordeal.

Many family members have camped out at the surface of the mine.

Some relatives have launched legal cases against government officials and the owners of the mine, which was reopened in 2008 after being closed because of an accident.

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