COPIAPO, Chile — Engineers reinforced a lifeline Monday to 33 miners entombed deep inside a Chilean gold and copper mine, preparing to keep them supplied with food, water, medicine and communications during the four months it may take to carve a tunnel wide enough to pull them out.A team of doctors and psychiatric experts also arrived Monday at the remote mine, implementing a plan to maintain the miners' sanity as well."We need to urgently establish what psychological situation they are in. 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 explained.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.The miners' survival after 17 days is very unusual, but since they've made it this far, they should emerge physically fine, said Davitt McAteer, who was assistant secretary for mine safety and health at the US Labor Department under President Bill Clinton."The health risks in a copper and gold mine are pretty small if you have air, food and water," McAteer said.Still, he said the stress of being trapped underground for a long period of time can be significant.The miners seemed to be aware that their rescue may take a long time, according to one of them, Mario Gomez, perhaps the eldest of the trapped men at 63, who wrote a note to his wife."Even if we have to wait months to communicate. ... I want to tell everyone that I'm good and we'll surely come out OK," Gomez wrote, scrawling the words on a sheet of notebook paper the miners tied to the probe. "Patience and faith. God is great and the help of my God is going to make it possible to leave this mine alive."Mine officials and relatives of the workers had hoped the men reached a shelter below where the tunnel collapsed Aug. 5 at the San Jose gold and copper mine about 530 miles (850 kilometers) north of the capital, Santiago. But they had said the shelter's emergency air and food supplies would last only 48 hours.