As I am sure you have all heard on the news, there are 6 coal miners trapped in a central Utah coal mine. Rescuers were drilling several 2" diameter holes down over a thousand feet to find them, and a rescue team had also been tunneling to reach them, when more cave-ins killed three of the ten rescuers. Since it has been about three weeks with no tapping noises, it is assumed that the miners have, sadly, not survived. Today, it appears that rescue operations will be stopped due to danger to the rescuers.
The 2" hole can provide fresh air, a microphone for communications, and even a hose for soup and clean water. The big problem is that they are now on their 6th hole without finding out anything from the cameras they drop down the holes. They don't know exactly where the possible survivors are.
My wife and I have speculated that if a wire had been run down the sides of all the tunnels, with a sensing antenna about every 50 yards or so, then when each miner or piece of equipment passed by, a computer could log each location from a small battery operated signalling device on each miners belt.
Not to be morbid, but, I also believe that it would be useful for the ID signal to log if the miners temp is above or below 85 degrees F. If there are two groups of miners trapped in two separate voids, one void may have bad air, and the other may have viable survivors, so, all resources should be focused on any group that has an actual chance to survive, and minutes may count in the rescue.
Whats the best method of having a location logger for tunnel-miners, and possibly even a tunnel collapse locator? Ron R in SoUtah
