Re: Mine Exploration
Posted by RiverRat on June 19, 2003 at 11:39:39:
In Reply to: Re: Mine Exploration posted by Ed on June 19, 2003 at 09:55:22:
What do you mean by "Here we go again"? Are safety questions not important? Or am I (again) missing something? If you don't ask you won't learn.
There are small battery powered O2-percent detectors around. They are used for entry into confined spaces. Cavers also use them, some caves are known for bad air. They only measure percentage of oxygen, they don't detect poison gas such as carbon monoxide. If you want the Full Monte of detectors, be prepared to lay out big bucks.
I would also be concerned on mine structural quality. Mines are usually constructed by blasting (read: fractured rock). Some of the worst mines are the Depression era mines, where they reworked old mines with no money and less safety, removing pillars, scraping out low grade remaining in the mines, and so on. "Wet" mines have rotten timbers. I know, desert mines usually aren't wet, but they were at the end of a very long trail, and safety was heavy. Most of the precious metal mines you see were reworked during the depression. "Gopher" or "Coyote" holes are notorious for caving, even when they were being worked.
War stories, #1: Two men were killed in Tuolumne County, CA. One entered a mine, and went down. His friend entered to try to pull him out: he also went down. Both died from apparent carbon monoxide poisoning. Both bodies pulled out by Sherriffs Search and Rescue Team using self-contained-breathing-apparatus, a major effort.
#2: I entered a mine (with lots of air flow) by myself and was crawling through a narrow spot and looked up. I was in a stope, they had bridged the stope with timbers and dropped mine waste on top of it, the timbers had completely rotted away, the mine waste had glued itself together except where it had caved and that was what I was crawling over, you could see the wood grain of the vanished timbers impressed on the bottom of the mine waste. I carefully backed out. I may be dumb but I ain't stupid. Haven't been back.
#3: Exploring a mine area, my 7 yo found me: "I found the entrance". It was a little 6" opening where the portal had caved, leaving a little crawl space (I am probably fatter than the opening). I spent quite some time explaining (yelling) about mine safety and why you never go in some mines. Would he have gone in? Probably not, but the alternatives make me sick in the pit of my stomach.
As the carpenters say, "Measure twice, cut once".