MUST READ: Second bore hole reaches 33 trapped in Chile mine

COPIAPO, Chile -- Singing the national anthem in a full-throated chorus, 33 miners trapped deep underground thanked their rescuers and settled in for a long wait until a tunnel wide enough to pull them out can be carved through a half-mile of solid rock.

Raising hopes further, a second bore hole punched into the chamber where the miners are entombed, and a third probe was nearing the spot on Tuesday.

After parceling out tiny bits of food and drinking water carved from the mine floor with a backhoe for 18 days, the miners were getting glucose and rehydration tablets to restore their digestive systems.

Capsules carrying oxygen also were sent down through a six-inch bore hole to help the men survive the hot, stuffy, humid conditions in the lower reaches of the gold and copper mine.

The bore holes also will be used to lower communication lines and to provide ventilation, Mining Minister Laurence Golborne said.

Meanwhile, the miners were sending up notes to their families in the same supply capsules on Tuesday, providing solace to people who have held vigil in the chilly Atacama desert since the Aug. 5 collapse.

Their ordeal, however, is far from over.

Above ground, doctors and psychological experts are debating how to keep the miners sane during the estimated four months it will take to dig a tunnel large enough to get them out of the safety chamber 2,200 feet underground, where they have been buried since Aug. 5.

Through a newly installed communication system, the miners told authorities Monday afternoon that they had used a backhoe to dig for trapped water and ate sparingly from their few supplies before rescuers reached their sanctuary with a drill probe on Sunday.

''They had two little spoonfuls of tuna, a sip of milk and a biscuit every 48 hours,'' said Dr. Sergio Aguilar, a physician on the rescue team.

Earlier Monday, each man spoke and reported feeling hungry but well, except for one with a stomach problem, a Chilean official said. The miners asked for toothbrushes.

Officials said they were implementing a plan that includes keeping the miners informed and busy.

''They need to understand what we know up here at the surface, that it will take many weeks for them to reach the light,'' Health Minister Jaime Manalich said.

The shelter is a living room-size chamber off one of the mine's lower passages far from the collapse. It is easily big enough for all 33 men, and the men also can walk around in tunnels below where the rocks fell. The temperature where they are is around 90-93 degrees.

Rescuers also sent down questionnaires Monday to determine each man's condition, along with medicine and small microphones to enable them to speak with their families during their long wait. Rescue leader Andre Sougarret said officials are organizing the families into small groups to keep their talks as orderly as possible.

The men already have been trapped underground longer than all but a few miners rescued in recent history. Last year, three miners survived 25 days trapped in a flooded mine in southern China, and two miners in northeastern China were rescued after 23 days in 1983.