Armstrong on Pike River

Written By: - Date published: 11:27 am, November 27th, 2010 - 71 comments
Categories: Mining - Tags:

As the public and private mourning for the Pike River 29 continues, focus will begin to shift to how this event occurred with no less than five inquires soon to begin. John Armstrong has a very good article on the issues that will be in the spotlight. This is not a question of politics, it’s about preventing future tragedies and I ask you to keep your comments in that vein.

Now, Armstrong makes some comments on the political ramifications but I’m not going to quote those because I don’t want this post to be about party politics. You can check out his article here.

“there is still an awful lot of the necessary ritual of death yet to be played out across the six o’clock news before it is time to ask some hard questions.

Those questions are not going to provide reassuring answers.

As a British mining expert told the BBC, methane levels in the mine must have built up to levels between 5 and 15 per cent of the atmosphere, at which point the gas becomes explosive.

Either the warning systems were inadequate or were not working properly. Or if they were working, they were not being monitored properly. There are no other explanations.”

Methane is 0.0002% of the general atmosphere so getting to a combustible level of over 5% is a huge increase. Its not unusual for coal seams to contain pockets of ‘fire damp’, which is mostly methane, that can be released by mining. Ignition of released methane has been responsible for numerous mining disasters including the previous big one in New Zealand, just down the road from Pike River at the Strongman mine.

But, precisely because methane pockets are known to occur and are dangerous, there are well-developed monitoring and safety procedures that would prevent an explosion. News reports have said that Pike River had asked the government for more information about safely handling methane releases. So, either those measures weren’t in place at Pike River, they weren’t being used properly, or something unusual like a very large and sudden release of methane occurred.

In terms of the effectiveness of the regulations and their enforcement, questions will be asked of “Labour Minister Kate Wilkinson and what she or her department knew or did not know about what was going on at Pike River Coal.

So far, Wilkinson has been kept very much in the background. It is Key’s show. And understandably so, given the magnitude.

It will probably remain Key’s show. What will worry him is that Wilkinson’s hands-off, laissez-faire approach to regulation and monitoring might have left National badly exposed.

Little appears to have emerged in concrete form from a public consultation exercise begun under Labour to improve “hazard management” in the underground mining industry.

Instead, Wilkinson ruled out re-instituting “check inspectors” who would be elected by fellow workers to keep an eye on safety standards.”

It’s perhaps worth explaining what a check inspector is. They are workers, elected by their comrades, who are tasked to be basically full-time health and safety officers. They check the safety of the site before shifts begin and continuously throughout the day. Compare this to the current regime where there are just one or two mine government inspectors for the whole country who make inspections every few months. Check inspectors know their mine, their personal safety and that of their mates and co-workers is on the line, and they deal with issues with the workers behind them, rather than coming in as an outsider.

Australia has check inspectors and New Zealand used to have them until the law was changed in the late 1990s. The miner’s union (the EPMU) consistently called for them to be re-instated but it wasn’t until after two deaths in 2006 that the government began to pay attention. A report was commissioned. In submissions, the EPMU repeated its stance and mining companies were generally opposed. The Herald reports that Pike River didn’t want them at all, although I’ve heard they wanted publicly funded check inspectors (the cost would otherwise be on them).

At any rate, before any decisions could be taken, the 2008 election occurred and the new minister, Wilkinson, dropped the issue.

Armstrong draws attention to “two speeches by Jim Anderton in Parliament this week. The left’s old war horse was not in the mood to join the chorus of praise for the West Coast’s resilience at what fate might have in store for it.

That kind of sentiment has produced a miserable mythology which decrees the Coast must always suffer.

That is not good enough in Anderton’s book. So he effectively served notice that he will putting his not inconsiderable weight behind efforts to find out why things went so dreadfully wrong at a mine which, as it has been open barely a year, should have had all the right equipment and safety practices.

Anderton seems to have made it his personal mission to end the life-and-death lottery that working in underground mines has entailed.

Doing so, moreover, would be the best possible tribute to those who died in the explosion.

Anderton cannot be accused of exploiting the catastrophe for selfish political motives.

For starters, his credentials as the voice of blue-collar workers such as miners are unquestioned. His statements in such circumstances carry huge moral suasion.

He also has nothing to gain politically. He is leaving Parliament at the next election, now no less than 12 months away.”

If Jim can leave Parliament having provided the leadership to raise the standard for health and safety for miners and other workers, then he will have achieved a great thing. The chance to learn and improve from this disaster must not have been lost. The West Coast might be all-too-familiar with dealing with disasters but that doesn’t mean we have to accept them as inevitable.

A little side note on the future of the mine. Pike River has only just started production. The first of two hydro-mining systems have just been installed and there have been only two export shipments of a few tens of thousands of tonnes. Nearly all of the 50 million tonne reserve is still in the ground. To put it bluntly: Pike River has cost $300 million so far and produced just $10 million worth of coal with $15 billion worth still left. The company is understandably keen to get digging again. But I don’t think that will be appropriate until the causes of this disaster are understood and safety measures have been improved.

Even then, restarting the mine will not be a simple exercise. The series of explosions means there’s obviously coal burning, which is providing the ignition when the methane/oxygen balance reaches the right point to explode. Coal seam fires are notoriously hard to extinguish and mining obviously can’t take place while burning is churning out toxic gases. The Australian system that pumps nitrogen in to displace the combustible gases is not guaranteed to work. One only need to look to Centralia, the most famous example of a coal seam fire, to see how long these things can burn.

71 comments on “Armstrong on Pike River ”

  1. IrishBill 1

    I was really angered by Armstrong’s grotesque assumption that unions would seek to exploit pike river for political payback on the Hobbit. He seems to think that any push from the unions to seek justice for these miners will be some sort of political game-playing.

    Perhaps he’s spent so long focused on horse-race politics that he’s lost sight of the real world that unions operate in and in which empathy, sorrow and anger are real emotions. He may also wish to consider the revelation than an investigation and any law changes flowing from it will be about saving workers’ lives rather than being an exercise in scoring trite political points.

    Frankly his comments show him in a poor light.

    • Eddie 1.1

      yeah. I left that stuff out and the reference to Mana because I thought it was very unbecoming.

      I thought it was good basic analysis of the issues and that’s what I’ve used but then there was this superstructure of ‘how’s that going to affect the polls’, which was just unneeded.

      likewise, O’Sullivan talks about the issues and then starts turning it into a case against ‘green mining’, presumably in favour of open cast mining. That kind of political point socring was totally uncalled for.

    • lprent 1.2

      Agreed. Armstrong kind of misses the point.

      I want to find out what in the hell happened in that mine. There are basically two scenarios that I can see.

      Slow buildup in a location away from the miners, with a failure in remote monitoring not turning off ignition sources.

      Or a sudden release probably gassing the miners here they stood.

      Both are usually preventable.

    • Swampy 1.3

      Armstrong knows you don’t have to look very far to find people associate with a union who have similar beliefs.

      • Marty G 1.3.1

        it seems to me that Armstrong hasn’t spoken to anyone in the unions about this issue, or even understands how any of them think, to assert that anyone would be seeing this as a political opportunity.

        and your assertion to the contrary, swampy, that comes with no evidence, is disgraceful.

    • Doug 1.4

      Labour’s Damien O’Conner, has suggested that no one as to blame and that the disaster is ‘just one of these things that the West Coast unfortunately has had to get used to over the years’.

      Engineering, Printing and Manufacturing Union (EPMU), which represents some eighty PRC employees, has gone into bat for the company’s owners.

      National secretary Andrew Little told the New Zealand Herald yesterday there was ‘nothing unusual about Pike River or this mine that we’ve been particularly concerned about’.

      • Swampy 1.4.1

        There must have been an enquiry into Strongman. what was the outcome?

        DOL must have investigated some of the more recent incidents (Mt Davy, Spring Creek, [somewhere in 2006])

  2. ghostwhowalksnz 2

    Armstrong should be reflecting on the information that is just now coming out about possible causes of the explosion which are only being raised by international media like the BBC.

    These sources seem to be based on informed opinion about what happened in the mine of the day of the first explosion yet have to travel to the other side of the world to become public knowledge.

    Does Armstrong have any concerns about the lack of vital information from NZ sources being reported by his own papers journalists? It seems that the BBC has better sources in the West Coast than the NZ Herald.

    • lprent 2.1

      The BBC probably do. The limiting factor on journalism is their ability to understand the information that they’re being told.

      I haven’t been that impressed with many of our general journos abilities at assimilation of technical information. Some of the idiocies that I’ve seen in the media on tech stuff are pretty appalling. And we’re too small a country to have enough tech level journos on tap.

      But the BBC, NYT, etc probably do. Which is why they’re on the news folder in my pad. I find the articles easier to understand because there is a better understanding of the topics.

      • ghostwhowalksnz 2.1.1

        “As a British mining expert told the BBC…. ”

        Silly me for thinking that journalists asked questions ?

        • KJT 2.1.1.1

          My experience of journalists is much like that I have of RWNJ’s and denialists. Form an opinion and then ignore any thing which shows they are wrong. The most factual part of newspapers, these days, are the letters to the Editor.

          • ghostwhowalksnz 2.1.1.1.1

            I think the term is ‘horizontal journalism’ – many different topics covered very superficially.

            The opposite is ‘vertical’ .

            Then there is the pre Xmas advertising boost, the more readers the more money they can charge for the big ads.
            Its any editors dream to have a massive human interest story this time of the year

    • BLiP 3.1

      Self-indulgent, weepy-eyed, touchy-feely, purple prose masquerading as journalism, complete with subtle digs at environmentalists and others so as to frame blame – and don’t fool yourself, the blame game is in full swing and the PR spinners are working flat out:

      The money from the mine filters down through to Greymouth and the other little towns and all the way to the supermarket and shops. It pays mortgages. None of this would have happened if they’d allowed it to be an open cast mine, he’d said. Darn greenies . . . (snip) . . . It’s miners who go up there and if the mine had been open cast these combustible gases would have simply dispersed into the atmosphere . . . (snip) . . . They had terrific safety standards, he had heard. The men weren’t even allowed to wear a watch in the mine in case friction led to a spark . . . (snip) . . . That’s Milton Osborne, 54, a miner and local councillor who helped fight a hard but futile fight to keep little Ngahere School in Greymouth open when Labour was in government.

    • Foolsgold 3.2

      I read that article. Interesting to see the ‘blame the greenies’ line being tottered out once again. I was on the West Coast not too long ago in Hokitika. There was a lot of anger about a proposal to build a tourist tree top village being blocked, blamed on ‘greenies’ not sure what the issue was but I think with the coast being deprived of jobs people are a bit tetchy when it comes to environmental protection being used to block development. Will be interesting to see if this idea gains traction.

  3. Swampy 4

    The question I would like to ask the Australians most is what happened to the robotic mine reconnaisance vehicles they were developing a decade ago. Said to be capable of travelling 10 km underground.

    http://www.google.com/search?hl=en&site=webhp&&sa=X&ei=I1bwTMDAOoXEsAO2-7W7Cw&sqi=2&ved=0CBIQvwUoAQ&q=numbat+mine+reconnaissance+vehicle&spell=1

    Sunk without a trace it would appear.

    • Colonial Viper 4.1

      Long been known that you cannot replace boots on the ground.

      • pollywog 4.1.1

        how about paws ?

        surely you could train a dog with a camera and monitoring gear to walk down a mine.

        if we can get ’em to force sheep through a gate on a steep hill then WTF ?

        • KJT 4.1.1.1

          Just give a tv camera and a radio control set to a 6th form tech class. I am sure they will come up with something that could have a look in a few days.

        • Colonial Viper 4.1.1.2

          Yeah I actually think you might have a point with this. However there may be some…shall we say…animal rights objections raised.

      • Swampy 4.1.2

        The CSIRO are world leaders in robotic technology and they are working on many projects, robotic technology is already used in parts of mining.

        • Colonial Viper 4.1.2.1

          Yep that is true esp for routine tasks, but still a big fail in emergency rescues and also recon of previously uncharted (changed) terrain.

          • Swampy 4.1.2.1.1

            However a robot specifically designed for mines would be a big step up from the rest of what was on offer. The fact that they had worked on one specifically designed, and tested, in underground mine conditions makes it all the more strange for our authorities to be left scrambling when it came to the crunch.

  4. andy (the other one) 5

    Listened to John Key on Willy & JT show, Radio live on friday. Key talked about how the All Blacks wanted to wear west coast socks in game with Wales but they are red and clash with welsh colours.

    Key quipped ‘we actually turned the west coast blue but that’s another matter’, thought that was quite nasty and in bad taste.

    also, the geography of the area does no suit open cast mining, too steep, so too difficult, too expensive = no business case, how deep was the bore hole drilled? That is an amazing amount of rock to move to get to $200 a tonne coal.. The mine was like all businesses a RISK, parameters set by NZ as a country, subject to the whims of markets and the environment. Suddenly all these people think that we can suspend the the rule of law so we can sell coal cheaper than Australia.

    The trees don’t magically grow back, I am no greeny mining hater just like reality based decision making not talk back inspired economic lunacy.

    Check out how they do it in the US, mountain top removal, would go down well here, Not!

    • Colonial Viper 5.1

      Key quipped ‘we actually turned the west coast blue but that’s another matter’, thought that was quite nasty and in bad taste.

      Now can someone with the wherewithal get this on to youtube…

      • andy (the other one) 5.1.1

        Here, someone may want to grab it.about 2.450ish, my paraphrasing not totally accurate. Socks red we turned it blue part is true.

        http://www.radiolive.co.nz/PM-John-Key-visits-Willie–JT-talks-Pike-River/tabid/506/articleID/17589/Default.aspx

        • Bill 5.1.1.1

          Followed by reference to “the rescue campaign“…draw your own conclusions from that turn of phrase.

          Jee-zus! “and fathers and sons and brothers and all that sort of stuff making comments…”

          • aj 5.1.1.1.1

            A lack of repsect for position to if I recall – ‘she’s lending us the jet engine to clear the fire’
            should have been Prime Minister Gillard…

          • Marty G 5.1.1.1.2

            it is the verbal diarrh0ea of someone saying what they’re meant to say in a situation, rather than speaking from the heart and head

            • Tigger 5.1.1.1.2.1

              The ‘even though we turned it blue, they’re red’ comment is superb because that’s where his head is at. He doesn’t give a flying fig about the tragedy, ultimately it’s just about blue vs red. Truly we’re all in this as New Zealanders, but don’t forget it’s us vs them. And the righties are ‘us’ by the way. Utter tosser.

              • Jim Nald

                Well, my poor lounge echoed with a very loud “WTF PM???”

                • pollywog

                  Sooner we see the arse end of this chumpkey the better, and if we do, then we get the equally eloquent and monotonously smug Goffinator with his silly walk championing things for team red…

                  Yay…we’re truly spoilt for choice…no really we are, truly blessed !!!

    • richard 5.2

      Exactly right Andy. Open cast mining there is not an option for two reasons. The first, as you mention, is that it is too deep underground. You would have to move a mountain to get at it. The mine manager said as much on Closeup last night. Secondly, part of the mine is in Paparoa National Park. The only reason consent would have been given for mining this land is if effects were minimal.

    • Swampy 5.3

      Mountain top was removed at Stockton (Mt Frederick) so it does happen here

  5. vto 6

    I like the sound of check inspectors and their sanctity.

    Fools we are to have let them go.

    .

  6. maui 7

    I can’t help wondering if the Hawera fault traversed by the mine, and seismic activity around Christchurch are somehow linked.

    • Swampy 7.1

      A geologist has suggested exactly that, but his theory is contentious.

      • Colonial Viper 7.1.1

        The commentator on the Guardian website said that a sudden roof (‘gob’) collapse releasing large stores of methane originally emanating from the coal face but not adequately ventilated away as the cutters proceed is the most likely cause of this style of explosion.

        As per Sanctuary:
        http://thestandard.org.nz/open-mike-28112010/#comment-275147

        • Swampy 7.1.1.1

          There was another blast this afternoon. Makes you wonder if there will be any mine left to reopen (and other thoughts best left unmentioned)

        • Swampy 7.1.1.2

          More armchair experts at work?

          The commenter is referring to longwall mining. This system is not used at Pike River. They use continuous miners and hydraulic monitors.

          Subsidence is a feature of longwall mining – ground subsidence is specifically banned at Pike River due to the national park above.

          • Colonial Viper 7.1.1.2.1

            Good research there Swampy. Its good to know that a non-miner can understand what happens and why.

            • Swampy 7.1.1.2.1.1

              All my information about Pike River comes from the documents on their website. For example:
              http://www.pikeriver.co.nz/files/investor_centre/IPO-new-zealand-prospectus.pdf
              On page 46, Fig 8 is a perspective view of the country over the mine site.
              On page 53. Section 3.5 details the mining methods.
              On page 55. Fig 12 shows a map of the underground mine. This is a typical plan of a “room and pillar” mine. Pillars of coal are left in place to support the roof against collapse.
              On page 57 is an aerial plan of the location of the mine and support facilities and access road.
              Here is a map of the area on Google Maps:
              http://bit.ly/ew1D6G

  7. Treetop 8

    Armstrong’s above article is spot on regarding the most likely cause of the human tragedy at the Pike River Mine. Armstrong says, “Either the warning systems were inadequate or were not working properly. Or if they were working, they were not being monitored properly. There are no other explanations.”

    It is 31 years today since flight TE901 crashed killing 257 passengers and crew on Mt Erebus. I consider the most important piece of information which would have given the families closure would have been the missing pages in Captain Collin’s black note book. Then Constable Leighton found it, and then Sgt Gilpin sent it to the lock up at Mc Murdo Sound. Gilpin was not aware of the missing pages being missing until the inquiry, (not sure if it was Chippendale’s one or Mc Mahon’s inquiry, think the latter one).

    What assurance do the families of the very brave 29 who were killed at Pike River have that the methane readings will not go astray or be altered? I do not want to see interference or concealment by another National Prime Minister. Muldoon had a terrible track record with three Royal/Commissions of inquiry, Crewe Murders, Moyle inquiry and the Erebus inquiry.

    • Treetop 8.1

      Mahon is the correct name, not Mc Mahon, sorry.

    • Jim Nald 8.2

      After John Key’s handling of Worth, his ‘blind’ trust, and Wong, he will have to work immensely hard to be persuasive or convincing about full, transparent and open inquiries.

    • Treetop 8.3

      Msytery over Erebus diary: 25 October 2009

      Gilpin became aware of the missing pages in Collin’s black note book when he saw video footage in a television documentary. Gilpin did inform Mahon, but the inquiry was over.

      http://www.nzalpa.org.nz/Portals/4/New%20Articles/mystery-over-erebus-diary-30930.pdf

    • insider 8.4

      Shouldn’t it really have read “There are no other explanations that I as a journalist in Wellington/Auckland with no experience in mining have been able to think of.”

      Just because he hasn’t thought of it doesn’t mean it is unthinkable or impossible. Whole teams of NASA scientists never thought a chunk of ice or a frozen O ring could destroy a space shuttle, but it happened.

      • Treetop 8.4.1

        The main cause is not in doubt that a build up of methane caused the first explosion on 19 November 2010. On Q & A yesterday Matt Mc Carten remarked that miners leaving the shift said to those starting the shift that there was a smell of gas. The ventilation used to extract the methane is also an issue as it does appear to not have been adequate in removing the level of methane required.

        I think that all documents (in particular methane readings and safety checks) need to be put into a safe lock up to prevent another possible situation as occurred with Collin’s diary flight plan co-ordinates/chartered route going missing.

        Good point about the cause of the 1986 space shuttle explosion.

        • Pascal's bookie 8.4.1.1

          “Good point about the cause of the 1986 space shuttle explosion.”

          ya reckon? Way I see it the o rings failed. I reckon NASA types could quite accurately predict what would happen next. What they had was a lack of real time knoweldge about the state of the system. ie the warning systems were inadequate.

          Perhaps insider can think of a better example, but I think that:

          1)warning systems inadequate
          2)warning systems adequate but malfunctioning
          3)warning sytem adequate and functioning, but not monitored properly

          pretty much covers the possibilities.

          • Treetop 8.4.1.1.1

            The O ring was fine, it was the ice which compromised the O ring. As for the warning systems there is no point in having them unless they can avert the danger and they need to be monitored.

          • insider 8.4.1.1.2

            4) warning systems adequate and functioning, but speed of methane leak and explosion faster than ability of systems (and people) to respond.

            • Pascal's bookie 8.4.1.1.2.1

              Nope. Again, that’s ‘warning systems inadequate’.

              It’s about finding ‘what’ is to blame. Not ‘who’. (The ‘what’ may turn out to be a ‘who’, but that’s beside the point.)

              The task is to prevent deaths in these events.

              If the warning systems didn’t pick up the problem, or were too slow to respond to it, they were inadequate to the task.

              It may be that no system could possibly be up to the task, and that the system in place at Pike River was the best available, and that therefore no person was at fault.

              But if that was true, it would still be the case that the warning and response system was inadequate to the task of preventing these events.

              • insider

                I think it is quite evident the systems were inadequate, in that they didn’t prevent the deaths. But was the event foreseeable or extreme, or the result of cascade failure? And we need to distinguish between the immediate response to inflated levels and the longer term safety systems.

                Everything I’ve heard and seen say PR had similar monitoring equipment, standards and processes as other mines. Seems odd all would fail at once, especially when they were all configured to detect that key risk, but it’s not unheard of in similar disasters where you get multiple minor issues accumulating to become a single major one.

                But if it was a sudden, high concentration methane escape that exploded immediately, then no warning system is going to respond adequately; instead it is the processes that are designed to prevent that gas becoming an issue that you need to concentrate on, such as predictive tools and ongoing sampling and analysis and risk assessment.

                There does appear genuine surprise at the level of gas build up and the failure of detection systems. Sadly we probably won’t know why for a year or two.

                • lprent

                  The problem with a having a high concentration methane release causing the explosion is that it will require time to mix down to a exploding concentration. It is almost impossible to make methane combustible in concentrations greater than 15%, most methane outbursts in mines contain significant CO2, you have to have fairly good levels of O2 to sustain the explosion otherwise it squelches, and all human ignition sources are meant to automatically turn off everywhere when concentrations reach above 1%. It takes time for a methane outburst to get to the right concentrations. The automatics should have reacted within that time frame.

                  I’d expect that we’re going to find a systematic gotcha in the mix somewhere, like the automatic shutdown systems were rebooting or a set of cables with both the primary and backup in it had been cut and not repaired.

                  • Colonial Viper

                    The most explosive mix of methane to air is 9%. At 5% (too lean) and at 15% (too rich) methane in the atmosphere will ignite but not with the very explosive power of a 9% mix.

                    So yeah, it takes time to mix down to a properly explosive concentration.

                    • KJT

                      I would not be too quick to say that.
                      An explosion displaces a lot of gas. The inward rush of air after the explosion can easily bring it quickly back to explosive levels.

                      It has happened in other situations.

                      Best to wait for the inquiry.

        • Swampy 8.4.1.2

          Methane is odourless – it was some other kind of gas they smelt.

      • Colonial Viper 8.4.2

        Whole teams of NASA scientists never thought a chunk of ice or a frozen O ring could destroy a space shuttle, but it happened.

        !

        Dude you clearly never read the full investigation report.

        Frontline NASA scientists and engineers were fully aware of the risks and tried to get the Challenger launch scrubbed. The weather overnight had been the coldest ever recorded prior to any prior shuttle launch and there were numerous concerns. The people in the know were however over-ruled by senior management who wanted to have a teacher in space in time for a Presidential speech and photo-op.

        Yeah that turned out well, didn’t it.

        FFS the disinformation on the intatubes is horrendous.

  8. Treetop 9

    I know it is hard to give some people the benefit of the doubt when they have a track record.

  9. Adrian 10

    I have read this “should have been open cast” meme on a few blogs now. I just wanted to add my to cents – being that I am a geophysicist who has worked on mineral exploration projects and stuff and because its starting piss me off.

    Any one who suggests Pike River should have been pitted is either an idiot or they are lying.

    This is 7 m thick coal seam under at least 160m (the borehole depth) of cover rock. The cost of moving this cover would be 1000’s of times the value of the contained coal. The only places in the world where coal is pit-mined are those where the coal is at the surface.

    Its a pathetic emotive beat up that will, of course, pass unchallenged into the canon of good-keen-man kiwi folklore.

    • pollywog 10.1

      Adrian…can we quote you on that and arrange an interview to counter the inevitable bullshit push to blame the greenies ?

      • Adrian 10.1.1

        You can quote me – sure. Given that I am currently trying (desperately) to finish my PhD I am not sure I am the most credible source to the outside eye. Not that the usual FUD spreaders give a jot for the facts when delivered by experts, reality having that left wing bias and all.

        FYI I worked overseas in gold and copper exploration and returned to better (read impoverish) myself. I have no dislike for mining, oil etc etc. I have a particular distaste for the hypocrisy of almost everyone involved – left right, green, blue, whatever. I am entirely driven by rational pragmatism.

    • Bored 10.2

      Adrian, forgive my ignorance. By “pitted ” do you mean open cast or mined in a tunnel?

      I did palaeontology many years back along with a large chunk of geomorphologhy. It is my understanding correct that any area with fractured rock from active faulting massively increases the risk of gas intrusion into shafts? With regard to the West Coast any comments on this?

  10. Adrian 11

    By pitted I mean open pit or open cast. The suggestion that they could remove a mountain range to access a 7m thick coal seam is ludicrous. If we get to the point where such an endeavours were economically viable, then we will have much bigger problems than gas in coal mines.

    re Fracturing in mines. I imagine this may increase the possible ingress of gases into a mine, but I highly doubt that is the situation here. The portal crosses a fault ~1 km from the mining area – the amount of ‘extra’ gas that could enter through a 7m diameter hole is trivial.

    The gas is in the coal – the same cooking process that produces coal produces gas. When you hack into the coal you liberate the gas. The coal at Pike River was prized for being high grade = more cook = more gas. Simple. You mention fractured rock – well New Zealand is fractured rock. Coal mines blow up often than in the past – but it still happens.

    The basic problem as I see it is that Pike River is an uphill mine, and the main ventilation shaft is lower the top end of the mine. Ventilation was maintained by using barriers to force air around the top end before being pulled back towards the ventilation shaft. Basically a closed loop like a ?.

    The moment ventilation stopped, volatile gasses would have begun to accumulate near the top of the mine because methane is less dense than O2. So the top end would have been accumulating methane seeping from the entire mine not just its local area. I could see the methane concentrations rising very rapidly in such a situation.

    The initial explosion would have destroyed the ventilation ‘channeling’ system so now air goes in the portal and straight up the ventilation shaft, without ever going to the backend of the mine. The top end of the mine is now basically a CH4-CO gas tank.

    • Bored 11.1

      Thank you Adrian, very illuminating. Much appreciated.

    • Colonial Viper 11.2

      The initial explosion would have destroyed the ventilation ‘channeling’ system so now air goes in the portal and straight up the ventilation shaft, without ever going to the backend of the mine. The top end of the mine is now basically a CH4-CO gas tank.

      Thanks for some real info here. What starts out as a safety system turns out to be very fragile without redundancies and produces a death trap. Neat.

  11. Swampy 12

    The Listener has made this there feature article this week. One part of the article seems to question exactly how much monitoring equipment there actually was in this mine.

    To the uninformed layperson like me I presume technology as such would allow detectors to be placed at a distance, connected by electric wires which run back to a control room to monitor all different parts of the mine.

    However it appears from what is written that the standard practice in mines overseas is to have tubes which draw a flow of air from various locations and the sensors are actually outside the mine. This system is called a “tube bundle”. The Pike River mine didn’t actually have one of these systems installed.

    In the article the chairman Dow is quoted as saying “we monitor the quality of air going in, we monitor the quality of air going out… we have monitors on all the equipment near the coalface and all the senior supervisors carry personal monitors”. And he also says “Pike didn’t need a tube bundle system”.

    The other important and relevant points raised in the article are the levels of gas in the mine, whether they were high or not, and whether Pike River used a gas drainage system.

    What do mining regulations say in NZ, is it possible they are not up to scratch so our mines safety systems may not be up to say Australian standards.

    • Colonial Viper 12.1

      I think there was a gas drainage system; I read that one of the points deterring rescuers from going in was that the gas drainage system had been damaged and was venting 500L of methane per second straight into the mine.

  12. Swampy 13

    Yesterday another Australian journalist criticised the police being in charge of the operation

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