A short note on coal mining
Posted by Heading Out on January 4, 2006 - 12:23am
For those watching the pictures from West Virginia there are a couple of things you might want to know. The mine itself is driven into the side of a hill, and there are a series of tunnels along the side of the coal seam which have been driven into the coal taking out the full seam section. The coal seam is roughly flat, but dips a little as it goes further away from the access. In coal mining jargon the entry to the mine is known as the portal, and it appears there are about five of these and they are just more than man high. The covered tube that leads out of one of the tunnels is a covered conveyor belt, and when the mine is operating the coal is loaded onto the belts near the production face, and carried by the belt out of the mine and up into a silo that contains the coal, until it can be loaded into a truck or rail car that will haul it away from the site.
The mine is developed as a series of parallel tunnels that head into the coal. The coal itself is mined by continuous miners. These are machines that have a large rotating drum at the front of the machine, which has picks inset in a pattern over its surface. As the drum rotates, the picks break out the coal and drop it to the floor where it is picked up by the apron (a metal wedge) beneath the drum, and moved by gathering arms, up onto a small chain conveyor that runs the length of the machine.
The conveyor then dumps the coal either into a shuttle car, or a mobile conveyor belt system that carries the coal then to the main transport belt that carries it out of the mine.
Incidentally the word shaft is being used wrongly by most of the reporters, since it is a vertical access passage, and all these passages are sensibly horizontal.
As the tunnels or drifts are being driven as a set of perhaps five or seven in sequence, the miners drive cross tunnels between them at fixed intervals. This allows a single machine to drive all the headings, and also allows the area to be ventilated, to carry away any gases that might come from the coal.
The pillars that are left between the main drives, and the cross-cuts are designed to be large enough to carry the weight of the overlying ground, and the rock immediately above the tunnels are held in place by bolts that the miners drive into the rock to hold it together, as they drive the tunnels forward.
By using ventilation curtains and building temporary walls (sometimes called stoppings) in the cross passages, a simple path can be made for air to be moved from the portals to the working face. Generally as the mine gets deeper the main fan at the surface can be supplimented by smaller fans inside the mine. In addition, at the face itself the air can be boosted through a large plastic duct to help maintain the condition of the air, where the coal is being broken from the face.
When an explosion occurs the ventilation paths will usually be badly damaged, so that the air cannot circulate through the normal paths. When the rescue teams go in, they must check that the roof is safe to walk under, and also they are (I gather) restoring the ventilation barriers with temporary stoppings so that air can be recirculated making it easier to work. As they go in, they have to stop at invervals to do this, and to get as much gas out of the area as they can.
In regard to the small masks that all miners carry - these are called self-rescuers and are a small box that all miners carry on their belts. When there is a blast the miner opens the box and pulls out the mask that contains a nose clip, and puts the mask into his mouth. By breathing through the mask the miner can walk through dangerous levels of carbon monoxide, since the chemical in the mask will react with the carbon monoxide. It is a one-shot device that gives you enough time to get to a safe haven, or out of the mine. If it is working it gets hot, even hot enough, so I am told, to burn the inside of your mouth. But that tells you that it is possibly saving your life.
There is some ongoing discussion about tags. When a person goes underground (visitor or worker) they are given a small metal tag. ;A record is kept of these, but depending on custom the tag can be kept by the miner in a number of places (I used to keep mine in my shirt pocket, or my pants). It allows the folk at the surface to know how many people are underground and who they are, but it is not easy always to find the tags, depending on local custom as to where you carry it.
Because the mine works an area wider than the total width of the combined tunnels and pillars, after a certain distance the tunnels will turn to work out to the edge of the permitted area. This turn may be what they are talking about as the first break.Then as the total area is worked the main tunnels may turn again. Thus there is a network of tunnels and pillars underground, and it is therefore important that the rescue teams carefully map and plot their way, since directional signs may be destroyed or moved by the accident.
Our thoughts and prayers continue for the families.
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Bob Shaw in Phx,AZ Are Humans Smarter than Yeast?
It should also be born in mind that the agency that provided research to the mining industry was the US Bureau of Mines - it was closed and done away with in the Clinton Presidency.
The greater tragedy is that we still rely on an incredibly dirty fossil fuel to power our lives, when nuclear is both safer and renewable if used properly.
You can find all my reasons for preferring nuclear, as well as commentary about the Chinese coal situation (6500 deaths per year) at Earth Sentinel where you will also find peak oil, renewable energy, and climate change news.
- We think we know what the other person means based on the words chosen by that person, but many times we are wrong in our assumed meaning of those words.
- We want to cling on to good news despite the implausibility of the good news.
- We want to reject bad news despite the high probability that the bad news is the correct version of what has or is happening.
- Leaders think they are doing the right thing by letting the poor bastards continue to hold on to false hopes for just a little bit more time even though the leaders know better.
How does all this translate into the management of information regarding Peak Oil?Are our leaders keeping us poor bastards in the dark even though the leaders know Peak Oil is here? What "secret" did Bush reveal to Congressman Roscoe Bartlett about the administration's understanding of the "non-urgent" situation? Does our innate optimism keep us holding on to hope that technology will save us even though, realisticly, our goose is already cooked? What is the truth? Is Matt Simmons givng us the truth? Is Daniel Yergin giving us the truth? Is Kunstler the last true canary in the coal mine? Is IEA pumping us full of CO or giving us fresh air numbers?
The peak oil situation is analogous in the sense above ie. "false hopes" as you note. There is a well known but controversial result in psychology that happy optimistic people are generally more successful than depressed pessimistic people. However, the depressed people are also more in touch with reality. This is called Depressive Realism. No doubt the observation has been questioned by some psychologists because successful optimists like themselves or as in the peak oil case, Daniel Yergin, would not like to be thought of as delusional. And of course we should never forget in this context that "Jesus Saves".
- words
- use of words
Words are an arbitrary label given to something real in an attempt to exchange information. They are an inevitable abstraction (hence qualifiers, subtype: adjectives etc). A word is lighter than a table.Use of words should be to exchange information in the most clear and honest way. Unfortunately the purpose of words has been corrupted and is used, too often, to manipulate and obfuscate.
Moral: hear the words but seek the meaning. What is meant to be clear should become so, what is not will be suspicious.
The headlines in our local paper (Wilmington, Delaware) read, "They're alive: 12 of 13 miners survive ordeal". I don't understand how on earth could the reporting on this could have gotten so messed up.
'Alive or Dead'? is about as stark a question as is possible to pose, so I am baffled by the whole thing. Unless everybody involved was so overwhelmed by wishful thinking or mass delusion that they only heard what they wanted to.
It's fascinating how we process the data that our sense collect. Last year while visiting a couple over the Christmas holidays, our host was bending over the coffee table wearing his brand new sweater and passing around drinks. There was a lit candle on the table. All of a sudden I see part of his sweater starting to gently burn with a pale blue flame, sort of like a natural gas flame. I didn't do anything because what my eyes told me was something that my brain didn't believe should be happened. Same with the other guests - they all just stared without saying a word. Finally it dawned on our host that yes, his sweater was indeed on fire, and he easily tamped it out without any injury.
But here was a micro example of how the brain doesn't process information it doesn't want to. Perhaps the same sort of thing was at work with the people involved in the mine disaster. There's a lesson in this somewhere.
In the paper the next day, DPS had to help rescue a fall victim transporting them 100ft to a waiting meds helicopter.
In the case of the Mine rescue 3rd hand information from the rescue site was called out to relatives and the press, in their rush to be first ran with it. No waiting for confirmation, just rush it to press.. . . the things that pass for journalism.
joule,
Yes there is, but is the "you" inside of you ready to hear and accept it?
- Realize that your eyes do not "speak".
- But you are agreeing that you have internal conversations within your brain. Different parts talking to each other, debating what to do.
3.Therefore you are indirectly saying, and accepting, that the human brain has multiple information processing parts that often compete, debate with each other before a final outcome / decision is achieved regarding what to do:--Well, maybe that's how Shakespeare might have framed the situation you found yourself in. At least you are being honest with yourself --and sharing the insight with the rest of us.
There are parts of the brain that are highly optimistic and try to frame everything in a positive light. There are parts of the brain that perceive things in a more pessimistic way. The parts debate with each other. Are the 12 miners alive? Are they all dead? Which of the inconsistent possibilities should I accept for the moment? Should I give more weight to the report that CO2 levels are high or should I have faith in Jesus? Should I continue to believe in miracles?
By the same token, Is Peak Oil true? Is it a hoax and a scam? Let me weigh the evidence that comes in from the opposing camps of thought and then come up with my own "reasoned" decision about what might be happening.
Obviously the competing parts of Yergin's brain process information one way and come up with the CERA view of the world. Simmon's brain processes it another way and comes up witht the Twilight view. And Kunstler's cluster-f***d brain goes in yet another direction. They are all probably trying to do the best that they can with the limited resources of their individual brains. Very few a person steps forward and says, "Let me do the worst I can". So witht that insight, perhaps you should "step back" for a moment, ruminate on things, and let the debating parts of your brain think on it for a while. What say your eyes? (Is it all clear now?) What say your ears? (Are we using "sound" logic here?) What says your tongue?
VERY well put!
I just loved your Shakespearean dialogue of what was going on inside my head during the time my eyes saw my host's sweater on fire but the signal of which my brain would not accept.
You raise a good point about social pressure playing a big role. It would have been socially awkward if I started screaming FIRE!, threw my host to the floor, and doused him with a bucket of water if my eyes had indeed been wrong. So, one always has the don't-rock-the-boat syndrome to contend with.