SAN JOSE MINE, Chile – Drillers on Friday neared the lower reaches of a gold and copper mine where 33 men have been trapped for more than two months, preparing for a breakthrough that would unleash a national outpouring of joy.

Engineers had just the last 128 feet of rock to carve through, and were working carefully to keep the T130 drill from jamming or punching through with too much force, Mining Minister Laurence Golborne said.

“We are very close,” he said. “It would be very complicated if after all the work we have done … you lose the hole. We have to be very careful and do it in a controlled way.”

The “Plan B” drill was poised to win a three-way race to reach the miners with a hole wide enough to accommodate their escape capsule. Two other drills, “Plan A” and “Plan C,” had to slow down after repeatedly veering off course.

The breakthrough — to be heralded with a siren — was sure to be an emotional milestone in the tent city known as “Camp Hope.”

“There’s just a little bit left to go, a very little bit,” said Cristina Nunez, anxious to see her husband, Claudio Yanez, and shivering in the bitter cold of the desert morning.

Anxiety was surging among some of the families who have held a vigil since the day the mine collapsed. With their men trapped inside, wives, parents, siblings and children have been forced to improvise and deal with all manner of relationship issues. And each miner has had to choose which two or three close relatives can see them first in the mine’s field hospital after they surface, creating hard feelings among those left out.

“Their nerves and tension are about to explode,” said Chile’s first lady, Cecilia Morel, who has more than 30 years’ experience as a family counselor. She said she encouraged them to be patient and even use breathing exercises to stay calm, and she plans to stay nearby so she can keep counseling them in the next few days.

“My interest is to try to contribute and create an atmosphere that allows them to be more calm, to be more relaxed, to learn some things,” she said.

If the shaft’s rock walls are found to be strong, the miners could be pulled out beginning Tuesday. If not, rescuers will line the shaft at least partially with steel pipe, delaying the rescue for three to eight more days.

President Sebastian Pinera announced that Bolivian President Evo Morales would join him for the rescue. One of the trapped miners is Bolivian.

The actual rescue is expected to take 48 hours as the miners are pulled out one by one, a made-for-TV spectacle that has drawn nearly 800 journalists to this isolated spot in the desert.