Actually, a power failure is not that little for this type of mine. It is hellishly hot down there at 2 km, and most of the power is used for cooling. Still, the miners must undergo 'heat conditioning' in order to work there. Without power, I'm sure the temperatures have gone way up.
These mines are fascinating to a Rock Mechanics dude, such as myself. They are chasing a very narrow, plunging, gold seam, that's only a few inches wide. But in order to get men and machines at the mining face, they have to excavate an opening about 4 feet high. This, of course, was still hell to the miners, but machines are doing a lot of work these days.
At 2 km depth, the rock pressures are intense, so they can't keep the tabular openings, open for long. It wants to squeeze shut as they continue to mine. They used to have horrible rock bursts that killed numerous black miners, but now labour is a bit more expensive :) Now they have specially designed, energy absorbing supports, which allow the rock to squeeze together under controlled conditions. There is a lot of science here.
The continuous excavation is a great model for rock behaviour near earthquake faults, and a lot of studies have been done. This was the inspiration for my master's thesis, and proved to me that there was a natural limit to the induced stress of seismic waves. It was also the basis of my work for underground radioactive waste storage. Alas, none of this science will ever be used in Canada, where these things are dominated by politics.
1 comment:
Fascinating! I heard about "3,000 miners trapped," then that it was an elevator failure, and finally that they were going to move the miners out over the next 20 hours once they got power jury-rigged to the elevator. Hadn't thought about the heat much.
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