COPIAPO, Chile (AP) — 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 (15 centimeter) 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 (670 meters) 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.”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.Aguilar did not say how long those meager supplies lasted after the landslide that caused a tunnel to collapse inside the San Jose gold and copper mine about 530 miles (850 kilometers) north of Chile’s capital, Santiago.Officials released a portion of the recording of the dialogue, in which miners are heard singing Chile’s national anthem.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.Engineers worked to reinforce the first bore hole by using a long hose to coat its walls with a metallic gel to decrease the risk of rocks blocking the hard-won passage through the unstable mine.The lubricant makes it easier to pass supplies through capsules nicknamed “palomas,” Spanish for dove. The first of the packages, which are about 5 feet (1.5 meters) long and take about an hour to descend from the surface, held rehydration tablets and a high-energy glucose gel to help the miners begin to repair their digestive systems.Actual food will be sent down in several days, after the men’s stomachs have had time to adjust, said Paola Neuman of the medical rescue service.Rescue teams also sent oxygen. Miners had complained there was not enough air in the stretches of the mine below where the main shaft collapsed.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 (32-34 degrees Celsius).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.Meanwhile, an enormous machine with diamond-tipped drills capable of carving a 26-inch (66-centimeter) -wide tunnel through solid rock and boring at about 65 feet (20 meters) a day was on its way from central Chile to the mine, outside Copiapo in north-central Chile.The machine was donated by the state-owned Codelco copper company and carried on a truck festooned with Chilean flags. Just setting it up will take at least three more days.Besides dealing with the miners’ immediate physical needs, rescuers were preparing psychiatric counseling. The miners reported that a shift foreman named Luis Urzua, 54, had assumed leadership of the trapped men.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. Few other rescues have taken more than two weeks.Chile is the world’s top copper producer and a leading gold producer, and has some of the world’s most advanced mining operations. But both the company that owns the mine, San Esteban, and the National Mining and Geology Service have been criticized for allegedly failing to comply with regulations. In 2007, an explosion at the San Jose mine killed three workers.Chilean President Sebastian Pinera said Monday that “there is not going to be any impunity” and said investigations were under way.Shortly after the accident, Pinera fired two top executives of Sernageomin, Chile’s mine safety regulator, after reports that the mine had reopened too soon and without real security improvements after a fatal accident three years ago.The miners’ relatives are suing and claim their loved ones were put at risk working in a mine known for unstable shafts and rock falls. Company executives have denied the accusations and say the lawsuits could force them into bankruptcy.

• Federico Quilodoran