Proposals have been forward to get the miners out quicker than than estimate four month period [AFP]

Rescue workers in Chile will begin the long task of drilling a shaft to rescue 33 miners trapped underground for the last 24 days.

Officials are now pushing for an accelerated rescue plan, and Sebastian Piners, the president, said he wants to get the miners out before September 18, the bicentennial anniversary of Chile's independence from Spanish colonial rule.

Under current plans, an Australian-made hydraulic bore will begin drilling a hole 66cm wide on Monday, aimed at pulling the miners out one at a time from the hot and damp shelter where they are huddled underground.

"The shaft we're drilling to the shelter will go down 702m in a straight line [to the trapped miners]," Andre Sougarret, the engineer in charge of the rescue operation, told AFP news agency on Saturday.

He also said the drilling operation was expected to last three to four months, in line with previous estimates.

The hydraulic bore drills at a maximum rate of 20m per day.

The initial narrow shaft it will dig will have to be doubled in diameter to allow a man to pass through, according to Sougarret.

Officials are also considering drilling where the main entrance ramp to the San Jose gold and silver mine collapsed on August 5, though some engineers fear the site remains unstable.

A third option being tabled suggests broadening an already existing shaft some 12cm in diameter, about 300m from the emergency shelter where the miners are confined.

Talking to loved ones

According to Geotec, the company owning the drilling equipment, expanding that shaft could free the men in about 60 days, two months ahead of early estimates.

However, mining minister Laurence Golborne denied reports of a possible rescue within the next month.

"We have reviewed 10 different options," he told Radio Cooperativa.

"Up to now there is no alternative... that would allow us to get them out in 30 days."

Golborne said that while the Australian-made bore went to work, engineers would also be widening a third existing access shaft to the miners' shelter from 10.2cm to 30.5cm so bigger objects can be sent to them.

On Thursday, most of the miners were shown in good spirits in a video they sent to their families at the surface, but a handful of them appeared to be struggling psychologically.

The trapped miners spoke for the first time with their loved ones Sunday, reassuring each other in brief conversations by radio-telephone.

"To hear his voice was a balm to my heart," Jessica Chille said after speaking to her husband, Dario Segovia.

Limited to one minute per miner, the wives, mothers and fathers lined up for their first person-to-person conversations since a cave-in on August 5 that blocked the miners' exit from the San Jose gold and copper mine.

Jaime Manalich, the health minister, said five depressed miners were in a better state of mind after receiving food, vitamins and communicating with friends and relatives, who sent them a video recording earlier on Saturday.

Chilean authorities have already taken steps to improve the men's mental resilience for the wait that lays ahead, especially by reaching out to organisations and individuals with experience in long isolation.

Four officials from the US space agency Nasa were due to arrive in Chille on Monday to provide expertise, while submarine commanders in Chile's navy have already given advice.

Source: Agencies