With the completion of a narrow rescue shaft deep into a collapsed Chilean mine Saturday, experts plotted the next steps to fish out the 33 miners trapped inside.

"There is still a long road ahead, and precautions to take," said Chilean Mines Minister Laurence Goldborne.

Chilean officials said it could take three to eight more days before the men start coming out, one by one, in a slender capsule lowered some 624 meters (2,047 feet) from the surface.

But engineers first must decide whether to line all or part of the tunnel with steel tubes to reinforce it. They will lower a camera into the shaft later in the day to examine it closely.

And the miners must detonate explosive charges to enlarge a passageway to accommodate the four meter (12 foot) long rescue capsule.

Once the shaft has been prepared, an expert in mine rescues and a navy nurse will then descend into the mine in the capsule to prepare the workers for their exit.

The strongest will leave first, followed by the weakest. Last will be those considered tough enough to be left behind for a few extra hours.

They will be fitted with bio-harnesses used by astronauts to monitor their heartbeat, breathing, oxygen intake and temperature. The escape capsule will be equipped with oxygen and communications gear.

If a problem arises, they should be able to go back down.

Estimates suggest the operation will take up to two hours per miner, and could be completed over a total of two days.

Medical staff will immediately attend to each miner as they rediscover daylight for the first time in more than two months.

Then will come their first, private reunions with close relatives before traveling by helicopter to the nearby city of Copiapo for two days of intensive medical exams.

Around one thousand journalists are expected at the San Jose mine for the exit of the miners, some of whom have already received media training.