Hmm. The last I heard, children can have identifying chips implanted, but nothing that will send a locating signal. Cars have locators, but they are hooked to batteries which allow them to transmit their location.
There are a few reasons I can think of why mine companies don't keep locators on their men. 1 being the ability to transmit through that much earth. 2 being the fact that miners are typically supposed to be working in designated areas, a much cheaper way of keeping track of their whereabouts. 3 being that there are health concerns (mainly cancer) with wearing transmitters on a regular basis, especially high strength transmitters.
Now, none of this is to say they shouldn't use them. Perhaps it's something that ought to be raised with WCB. Nobody can work out the health risks, benefits, and costs faster than WCB. lol.
Well, It is done all the time. Seismic workers drill holes all over the North Country and drop a transmitter which sends sound waves that are converted to readings that reflect geological density in the ground. Seems that a Team Leader could carry something that would give location in case of a cave in. Don't know but just seems there has to be something.
4) it's too expensive. Corporations value human lives at just under the cost of a PC