You had an explosion (seemingly a methane build-up). Okay, so the methane ignites; so why is there so much carbon monoxide? Is this normal in methane burning reactions?
Secondly, after the explosion, why didn’t the men just try to leave the mine, instead of putting up the plastic sheet and await rescue? Did I miss some part of a report that said they were physically trapped by a cave-in? Presuming there was no cave-in, is it considered safer to await rescue than to try to leave?
Thirdly, why are mine workers equipt with such a small amount of supplemental air? Don’t we have aqualungs that last many hours? And if used sparingly maybe even last a day?
Where are you going to put an aqualung? When I went diving, lugging the airtank on my back was the hardest part and these were tanks designed to last much less than an hour nevermind a number of days. They’re heavy, cumbersome and potentially more dangerous to a miner than the now very small risk of gas buildup.
If your in an environment of little oxygen and much carbon monoxide or even just carbon dioxide, there’s not much chance to use oxygen sparingly. As for the needed quantity, just for those 13 men, that would be a lot of oxygen bottles they’d need to carry around.
They were about two and a half miles into the mine with no way to know conditions between them and the exit. Keep in mind that the mine is described as maze-like, so getting out even in the best of conditions is probably confusing. Miners are trained to stay put and take a defensive position rather than to try and get out, which would probably only result in them getting lost in the maze filled with smoke.
On a happier note, it was released just now that the men essentially died in their sleep and according to notes they left, they didn’t suffer.
Then that’s my ignorance. I always thought that typical aqualungs could hold enough oxygen for multi-hour dives. I wouldn’t expect miners to wear them in day-to-day operations, but thouht maybe something like them would be stored in a common work area. Dangerous? Maybe, but are they anymore dangerous than the one you wore while diving.
So the old TV trick of having a rope leading from where you are to the outside is just that - a fabrication. Hell, without a fool-poof trail leading to the surface you’d never ever get me in a mine (or cave).
The methane (CH4) combines with oxygen (O2) in the air. If there is enough O2 for the reaction to go to completion, it forms CO2 and H2) vapor. If oxygen is insufficient, CO is also formed. The high CO level implies a low oxygen level, both of which are unhealthy. There is always a substantial amount of methane essentially dissolved in the coal, produced by the same decay of vegetation that produced the coal, and ventilating it out of the mine down to safe levels is a constant issue.
Self-rescuers, essentially oxygen generators, are always carried by miners underground, but are only good for an hour or so. If you don’t know you can get out in that time, yes, it’s better to hold still and wait. If you’re trapped, you need a *lot * more than that anyway. It’s a small item, but anything you have to carry around all day (and can get caught and snagged on something) is a problem.
I’m more bothered by the idea of the gas being there in the first place. Was the CO a direct by-product of the explosion, or did the stuff somehow get loosened from the surrounding soil/rocks?
On the aqualung question, miners are required to carry on their belts a portable rescue device type of thing that converts bad mine air into breatheable air. To my recollection, these devices are only good for about an hour or so, depending on how heavy one is breathing. Even this simple device weighs about five pounds, and it is bulky and gets in the way.
Scattered throughout mines as assigned points are larger devices that, to my recollection, are designed to do the same job for about 24 hours. If something bad happens, miners can reach down to their belt to use the emergency pack until they make their way to the safety points, where they can then use the larger devices.
There is no canned air available, as that apparently can pose an explosion risk in some circumstances.
This information is based upon a trip I took to a working coal mine in Pennsylvania several months ago.
Coal beds contain and release methane, and other volatile hydrocarbons, as they are exposed to the air during the mining process (or drilled into from above, such as in coalbed methane recovery). They can also release carbon monoxide naturally too, although this often is in much smaller quantities. It’s possible that some CO resulted from substoichiometric methane combustion, but one would have to know this by checking air monitors before the explosion. In other words, it would be hard to speculate exactly where the CO came from unless one had more data about the case.
FTR, the worst explosions in coal mines are the two-part ones, where a methane gas explosion causes a raising of fine coal dust into the air, where burning embers or some ignition source ignites the coal dust itself. It’s not known at this time if the explosion in this case was a two-part one.
I have learned about the rescue device through my college roommate who is majoring in mining engineering and also has worked a summer internship at a coal mine in West Virginia. In the mining industry, the device is known as a self-contained self-rescuer. Yes, miners are required to wear them. Typical SCSRs are effective for 30 to 60 minutes. Although they can be a life saver, it is not a pleaasant experience to use a SCSR because the chemical reaction that creates ‘breathable air’ is exothermic and heats the mouthpiece to the extent of scalding the lips.
No, the 12 miners had entered and exited the mine on a nearly daily basis. They would not have been confused about finding their way out. They were indeed trapped, however, and that’s why it took rescuers 41 hours to reach the miners.
From what I understand, it would have taken at least several hours after the explosion for CO (carbon monoxide) to build up to toxic levels. The miners formed a makeshift barricade using a mining ventilation curtain to proctect themselves from the rising level of CO gas. It is common for mines to have extra SCSRs in storage but I don’t know if it’s a requirement or if the Sago mine had any extras near the blast site. I was surprised at the initial report of “12 miners alive” after the drill-hole test reveal 400 ppm of CO about 6-7 hours prior to that. Even now, I’m surprised about the critical condition survival of even one miner given the circumstances, but I don’t know all the facts yet. We will know more about the accident later as federal officials investigate.
Minor nitpick of thread title: It’s WV as opposed to ‘WVa.’