The following report was compiled from talking to actual workers at Pike River Mine. People who were employed there before the explosion and as part of the attempted recovery operation after the explosion. The information was supplied to me in good faith from people I personally trust. They have no motivation that I know of to report incorrect claims.
A) Preliminary drilling at the site before the mine was established showed the in situ coal to have extremely high levels of gas. The gas levels were so high, experts expressed doubts concerning the practicalities of mining it by underground methods. However as it was a given that open cast mining would not be permitted by the Department of Conservation and also that the economics of removing the overburden were doubtful, the decision was made to proceed with the underground option.
B) During the actual mining of the coal it is normal practice to horizontally drill long holes into the face of the seam to plan drilling and extract gas prior to the coal’s removal. My sources have said that when such holes were drilled, the rate of methane gas exiting from the in seam holes was as high as 100 litres of gas per second.
These two measures ( A and B), the gas in the preliminary drill holes and the gas escaping while drilling the long holes indicated that gas levels in the mine were extremely high. This naturally made the risks of mining it by underground methods also extremely high.
These risks could have been mitigated and perhaps managed by advanced air extraction methods. Keeping the mine well ventilated. However my informants claim that DOC refused to allow (verification needed) the construction of a second large diameter (around 4.15m) ventilation shaft. There was one smaller diameter (660mm) ventilation shaft constructed. So there was only ever one full sized shaft built in a mine known to have extremely high levels of gas. I do not know what factors governed where this one large diameter shaft could be built, however, experts have claimed that it was poorly positioned in terms of the inclines or slopes within the mine. The mine floor actually sloped up and away from the shaft leading to a situation where gas could accumulate quickly if extraction systems ever failed.
Given the high levels of gas, there should have been more than one main ventilation shaft. This raises the question- should experts have allowed the mine to proceed with only one main shaft, and that one shaft placed in a position that was probably not optimal?
My sources tell me that the electrical system providing the power that worked the extraction fans was never reliable. That it was in constant need of attention. In fact, the system had developed a problem and the electrician was on his way to repair it at the time the explosion occurred.
It is known that if methane/oxygen content reaches a certain level in a mine, it can be ignited and will burn.
This then gives us the logic trail that leads to the explosion. High gas content of the coal. Poorly designed and ineffective ventilation. Failure of the ventilation system’s power supply. Gas builds up quickly to explosive levels. An ignition event. Explosion and fire.
Sources also claimed that the more experienced workers were worried by the presence of inexperienced workers who increased the risk of explosion through their unawareness of the need to eliminate sparking through collisions of metal on metal.
So in the mining operation itself we have an extremely high risk operation- high gas content, insufficient ventilation, and inexperienced workers. My sources tell me that the feeling among experienced coal mining locals was that the mine was always a dangerous operation and that an explosion was something they all feared on a daily basis. Risk can be managed. Was it poor risk management at the root of the disaster, or was the risk always going to be too high to manage?
C) Underground mines usually have safe rooms. These are sealed rooms at strategic sites where workers can take refuge in case of fire or other threats. They have supplies of oxygen, food and water and usually a drill hole leading to the surface for air supply. Pike River Mine, in spite of the known risks, had no safe rooms. Miners were issued with breathing kits but these only allowed around a half hour of oxygen.
Why, in an operation that was so high risk, was there not one or more safe rooms? I have been told that the construction of these safe rooms was somehow blocked by DOC, but this is an unclear and unverified allegation that needs to be investigated. All I can suppose is that the destruction of flora and fauna that the drilling of the safe room ventilation shaft entailed made it unacceptable to DOC.
The lack of safe rooms becomes more important when it is suspected that not all miners were instantly killed in the blast. My sources maintain that there were men working some distance from the area of the explosion and it is highly likely they survived as investigation cameras lowered into the mine after the explosion showed no bodies where the men were known to be working.
These same cameras showed no damage from the explosion in these areas. There was no force of impact visible on equipment. For example a pallet of dust sacks at the work face was still encased in the plastic wrapping and the wrapping showed no heat effects. Sources claim that up to 19 men were working in this area. Given that no bodies were visible, this indicates that the men most likely donned their breathing apparatus and attempted to find a route out of the mine. A route that never existed. With only a half hours supply of breathable air, they were doomed. The gas meters lowered into the mine through the drill holes showed a 98% methane level.
Could these men have been rescued if safe rooms had been constructed?
Why did the men agree to work in the mine when the risk was so high? I don’t know the answer to that question. However it is known that PRM had agreed to pay a $9000 bonus if a certain amount of coal had been extracted and made ready for shipment before a certain date. My sources also claim that men who had complained of the high risk of the operation had their employment prematurely ended. This is unverified. Sources also claim that locals aware of the high risk always expected an explosion was going to occur at some stage.
Finally, my sources report that the rescue crews from Australia expressed disbelief at the poor levels of risk management and general safety at the mine, remarking that the New Zealand operation in terms of safety management, was a light year behind similar operations in Australia.
So the questions that arise from these reports are- Where was the government department responsible for coal mine safety management during operations at the mine, and what part did they play in approving a mining operation that, if the reports above are true, should probably never have been undertaken. Why was the risky mining operation, into high gas content coal, approved with only one major ventilation shaft and no safe rooms? Why, when operations at the mine showed a high risk of explosion, were the operations not stopped by safety and risk management regulations? ? Are there regular safety inspections of such operations by government mining inspectors? One would have to assume there are none or the explosion would never have occurred.
If my sources are correct, the information they have supplied brings into question the decision to proceed with the mine. Who was it in the end that made that decision? One would have to assume it would be PRM directors and management, and NZ mining regulators. Clearly the decision was incorrect. Let us hope the upcoming inquiry sheds light on exactly what lead to a decision that in the end resulted in such a terrible tragedy.
TrueblueNZ 
I have zero confidence in the integrity of the enquiry process.
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Well, already, many of the “official” media reports have run counter to what is related above.
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And following on from Keith’s comment [12:21], which I agree wholeheartedly with, I wonder if we will ever receive the answers to the questions you posed above, Red? I have my doubts.
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Good article Red. It appears that there are three spheres that influence decision making in this coal mining caper. The first was of course the commercial/technical aspects of the market around the commodity being extracted and the difficulties of doing the same. The second are the government (and union perhaps), safety and employment issues, which of course developed side by side. Traditionally, mining takes place by finding a balance between these two. Safety and employment matters add to costs because they must be mitigated, which impacts the bottom line economically. This balance has been developed over several centuries, and now operates to some extent (ignoring for now the distortions of government influence). More recently, a third aspect has come to the fore, environmentalism. In just a few short decades this has grown to a power that needs to be reckoned with, and one that operates solely on emotional criteria (i.e. very little factual and logical arguments to support it, but appealing to strong and easily aroused sentiments). Despite its lack of rationalism and common sense, environmentalism has nevertheless managed to get its claws right into government decision making, through subsidiaries and extremists within those already pandering to collectivist ideals. Consequently, the commercial operator, used to dealing with one opposing force, but one that had somewhat converging objectives (unions/safety regulators wanted the mining, but wanted a bigger part for their objective), is now confronted with another force, one that is much more fundamentally opposed to what he is doing. The balancing exercise thus got more complicated, and had the inbuilt tendency to defer to the new party, as it was effectively opposed to the objectives of both the other ones. Hence, safety and labor and economical issues were BOTH traded off against environmental issues.
The end result is a disaster where the real cause and origin of the problem, and those responsible for it, remain hidden, together with their motives .
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Bez, I couldn’t put a lot of the stuff that was being said locally about DOC’s role in this event, but basically they are saying the whole tragedy could have been avoided if DOC had been less ideologically driven.
The rescue crews said that they could see a partial admission of responsibility in DOC’s complete change of attitude (to being so much more co-operative) AFTER the explosion.
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The content of this post should properly be put to the enquiry? Will that be done?
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If the information above is not covered during the inquiry I will follow up on it.
Feel free to post links to it elsewhere. It’s quite important stuff.
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That’s a crapload of methane, more than enough one would have thought to generate some good power loads… This would have killed a few birds with one stone; removed methane from the mine, lowered costs by utilising self electrical generation – therefore increasing profitability, oh and lowered GG emission – if one was inclined to care about that…
Damps have been a problem with mines for hundreds of years now and it seems they weren’t properly accounted for in this case – no wonder the Aussies were suprised…
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Yeah I thought of that myself. Methane is the flavour of the month resource in many places right now. Flows like that are pretty valuable.
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“Flows like that are pretty valuable.”
Too dang right, but using them to generate power (and thus solve some of the electrical problems), or harvesting it (and thus increasing profitability), would have emphasized the quantities escaping. As we all know, methane is considered many times worse than co2 as a “greenhouse gas”. In addition, I understood that access to the shaft, and access to a second shaft site, was a main problem when constructing the mine, i.e. DoC was extremely difficult about this. In short, I surmise that the company was hushed with actual methane levels as they would ave feared that the greenies would have been all over it, having already hogtied the whole exercise. Clearly a wrong decision, but one that certainly fits in the scenario that’s been proposed here.
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I don’t think that methane can self-ignite. You might want to check your facts on that one.
[Thanks Mike. I misunderstood my source. Apparently there is a certain oxygen/methane ratio that needs to be reached before the methane will ignite and explode and burn, but it still requires a source of ignition. Thank you for the correction. ]
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Methane becomes explosive when the amount of methane in the air is in the range of 5 to 15 percent. This would still need an ignition and if the reports are correct that there was an electrical problem or an unawareness of the need to eliminate sparking then the recipes for an explosion are there. I guess we will wait and see when the inquiry returns with its verdict.
This YouTube video gives a good indication of where the workers were said to be working at the time of the explosion and also where the survivors were in comparison.
Now if one was to speculate that the explosion occurred in the middle of the mine (and if this map shown in the video is to scale) then this throws up many questions regarding what would have happened to these men at the back of the mine after the initial explosion.
Another thing i have picked up on in the reporting of this issue which i find unusual is in this article (http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10701944)
In it they state that the video footage from the drill hole was “well away from where the men were working” when in the video above, the CEO of pike river points out that the drill holes and where the workers were to be pretty much in the same position?
Many questions that hopefully will be answered by the inquiry.
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Bez- Found this in company presentation material.
In terms of carbon emissions, coal does contain methane gas as a natural by-product. Pike River estimates there could be approximately 1.4 million tonnes (carbon dioxide equivalent – CO2E) of gas released from the Brunner coal seam over the mine life.
The company will be looking at ways of capturing this gas and using it to generate on-site electricity if viable. If the gas cannot be captured or used, these ‘fugitive’ methane gas emissions would now be taxed under the New Zealand government’s recently enacted Climate Change Response (Emissions Trading Amendment) Act, passed on 16 June 2008.
The potential cost to Pike River will depend on the international price for carbon, but assuming none of the gas is captured and a CO2E price of NZ$24 per tonne3, this would amount to a carbon tax of NZ$1.78 per tonne of coal mined each year.
The Brunner seam contains considerably lower methane gas levels than usually found in an underground mine. This is due to the seam being exposed to the atmosphere along the entire western escarpment resulting in natural methane gas leakage into the atmosphere.
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Just being a dumb arse here . I believe Methane is considered to be a green house gas and are told my cows are evil sacks of shit and just give off Methane 24/7, of course this isn’t good and this will kill the planet. I also note that Jupiter has vast amounts of Methane in its atmosphere. Did Jupiter have to many cows at one stage and if they did were their governments guilty of not taxing the arse out ot their farmers and was in this the reason their planet looks like an image of downtown Wellington.
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I love it how something that leaks naturally from volcanoes, coal seams, peat bogs, etc. is now classified as a pollutant…
And apparently I’m the crazy person…
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Thanks, Red. The plot thickens. According to wikipedia, the global warming potential of methane is 25 times that of co2. If I remember my high school chemics correctly, burning it would result in a co2 volume equivalent to that of methane, hence from the environmental cost perspective an interesting exercise, potentially reducing the co2 levy to 5cts a tonne of coal from 1.78, not taking into account potential savings on electricity costs from harvesting. Question thus remains why harvesting the methane was not viable. The second question, what the actual methane levels were, rather than those expected or promoted, would also be interesting, as this would provide an indication whether the company was mum on the subject.
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Tap a landfill and use the methane run a generator and that is good. http://wellington.scoop.co.nz/?p=23864
Tap a coal measure and that is bad.
Go figure…
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Bez-
From PRM presntation-
“Gas average 4m3/t across lease; up to 10m3/t at depth; no outburst”
I believe this is actually quite a high rate.
Look on net for this PDF-
Gas & Coal Outburst Seminar 20101201 – Blakefield South Ventilation System
A lot of info. Have to fly.
More later.
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A mixture of CH4 and air, with a CH4 level of ~9%, whilst not truly self-combustible, has been known to self-combust. Therefore, if there had been a sudden outburst of CH4 and low ventilation it is entirely conceivable that a volatile fuel/air mix was created, combine this with machinery operating in the area and you have a recipe for an ICBM.
I have long understood that it was suspected that some may have survived the initial explosion, however, based on the fact that they only had 30mins of breathing air available to them, by the time mine control and rescuers even knew about the explosion, these guys would have been dead.
It is clear to me from what I know, and what RB alludes to in this post, that DoC and mine management are going to come out of this with blood on their hands. Unfortunately, the only ones that will do jail time will be mine management, whilst DoC will walk away with their asses cover and their typical air of self-grandeur, despite being ultimately responsible.
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