Published January 13, 2015
When rescue workers first arrived at Quecreek Mine, they immediately began boring a 6-inch-wide pipe to establish contact with nine miners trapped inside.
It may have saved the miners' lives as well, providing a continuous flow of hot, compressed air to the chamber flooded with chilly water, which raised concerns the miners could succumb to hypothermia. All showed only mild signs of the potentially life-threatening condition after their rescue.
The pipe — stacks of 30-foot-long steel casing attached to a drill bit — served multiple roles during the ordeal, intended at first to establish communication with the miners 240 feet below, said Joseph Sbaffoni of the state Bureau of Deep Mine Safety.
By about 3 a.m. Thursday, the drill worked its way into the chamber.
"We got up there and we hit three times [on the casing] with the hammer. And we heard them hit back a couple times," Sbaffoni said. Several times that day, the rescuers and the miners communicated by tapping on the pipe.
A decision was quickly made to leave the compressor running continuously, since it was pumping oxygen heated to more than 100 degrees to the trapped men.
It was not until a much larger hole used for extracting the miners was completed late Saturday that the air would be shut off.
That's when one of the workers heard a tap on the smaller pipe — a sound not heard since midday Thursday. The workers dropped a cord down with a two-way headset attached to the miners. According to Ron Svonavec, a worker at the scene, a miner told rescuers:
"There's nine men ready to get the hell out of here. We need some chew."
https://www.foxnews.com/story/hot-air-pipe-may-have-been-crucial