SAN JOSE MINE, Chile -- The 33 trapped Chilean miners who have astonished the world with their discipline a half mile underground will have to aid their own escape -- clearing thousands of tons of rock that will fall as the rescue hole is drilled, the engineer in charge of drilling said Sunday.

After drilling three small bore holes in recent weeks to create lines of communication with the miners and deliver basic food and medicine, Chile's state-owned Codelco mining company will begin boring a rescue hole this afternoon that will be wide enough to pull the men up through 2,300 feet of earth.

The first step will be to drill a "pilot hole" similar in size to the other three. Then much larger machine cutters will grind through that hole, forcing rock to fall down into the shaft area near the trapped men.

Failure to keep the bottom clear of debris could quickly plug the hole, delaying a rescue that officials say could take three to four months.

"The miners are going to have to take out all that material as it falls," Andres Sougarret, Codelco's head engineer on the operation, said in a phone interview.

In all, the trapped miners will have to clear between 3,000 and 4,000 tons of rock, work that will require crews of about a half-dozen men working in shifts 24 hours a day.

Sougarret declined to estimate how long the work would take, saying it would depend on how each step went.

On Sunday, Mining Minister Laurence Golborne, reiterated the government's estimate of three to four months to rescue the men, rejecting local reports citing engineers who said it could be done in much less time.

Steps are being taken to keep the men as strong as possible -- physically and mentally.

Telephone wire was being snaked down one of the bore holes on Sunday, and Golborne said that within a few hours one representative from each family would be allowed to talk to one of the miners -- the first verbal communication they would have. Until now, handwritten notes have been passed through tubes sent up and down the bore holes.

A new video released Sunday showed the miners sending greetings to their families and talking about how they are doing better since receiving food.

Most were upbeat, expressing gratitude to their families and the rescuers for the support they are receiving via handwritten notes. But when speaking about their wives and children, many broke down.