Doug's Darkworld

War, Science, and Philosophy in a Fractured World.

The lessons of the King’s Cross Fire, or why building the LHC may be a bad idea

with 14 comments

The King’s Cross Fire was a fire on an escalator in a subway in London in 1987. 31 people died, more than 60 were injured. It made the news of course, and I’m sure many of my older readers remember it. And if they were like me, they recall that the fire was on a wooden escalator. And if they thought much about it, they thought, well, what did they expect with a wooden escalator? Well, turns out they expected the fire to behave like hundreds of previous fires on these escalators, a bit of smoke for awhile, then the fire crew arrives and puts out the fire. So not only could the subway operators not have predicted this catastrophic occurrence, as it turns out, there was no way they could have predicted it. We’ll get to that in a moment.

OK, so we have two underground subway platforms connected by a tunnel with a WWII era largely wooden escalator in it. At some point a fire started under the escalator, almost certainly from a dropped match. Like so many other small fires before it, the staff simply closed off the escalator and called the fire department. The platforms above and below the escalator ramp remained open and were crowded with travellers, it was about 7:30 in the evening. Then, before the fire department arrived, and with no warning … the entire escalator above the fire burst into flame. Imagine over ten tons of bone dry wood and varnish igniting at once, survivors report that it was as if a giant blowtorch suddenly turned on. Everything flammable within about 40 feet of the tunnel top immediately burst into flame from the intense heat, including people. I will leave the horror and chaos to the gentle reader’s imagination.

So what the hell happened? How come this fire was different than the hundreds of others that preceded it? Investigators first thought it was possibly a bomb, the IRA was still active then. That was quickly ruled out by fire investigators examining the wreckage and debris. A train had arrived in the lower platform just before the flashover, and no doubt air being forced up the tunnel by the piston effect helped fan the flames, but it couldn’t account for the extreme intensity of the fire. So investigators made a sophisticated computer program to simulate the fire. And turned it on. The fire burned normally for a few minutes, then the smoke and flames from the fire lay down and hugged the floor instead of rising to the ceiling, heating the upper part of the escalator until a  few minutes later it burst into flame at once, neatly replicating the fire. Smoke isn’t supposed to do this, it’s supposed to rise, not follow the floor. Investigators figured there must be something wrong with their program, and built scaled replicas.

And it did the same thing. To their surprise, investigators had discovered a hitherto unknown effect, now called the trench effect. In the right shaped tunnel with the right grade, smoke and flames from a fire in the right location will travel along the floor instead of rising to the ceiling. So while the fire was small and seemingly not dangerous, it was slowly but surely heating up the more than ten tons of wood and varnish above the fire. And when it got hot enough, it all caught fire at once. Highly flammable paint in the tunnel also burst into flame, contributing to the fire. And thus at the cost of 31 lives, science learnt something new about fires in tunnels. The remaining wooden escalators were of course removed, and highly flammable paint was no longer used on tunnels, as well as other changes to prevent a recurrence.

The lesson here? The map is not the territory. No one could have predicted this fire, because no one knew about the trench effect. And this is a point that I think a lot of people who believe in science forget. No matter how will understood something is, no matter how great our understanding of it, no matter how mundane and commonplace it is … reality bats last. There is always the possibility that humans are missing part of the picture. And this is especially true when humans do something that has never been done before. This is one of the reasons I am uncomfortable with the LHC (the world’s largest atom-smasher.) It’s also one of the reasons that building nuclear power plants all over the place may not have been such a grand idea, as Fukushima is now showing us.

In other words, no matter how smart the experts are that assure us that something is safe, that doesn’t mean it actually is safe. And when one factors the inevitable human error into the equation, it seems to me that “how bad could it get?” should be a far more important factor in safety calculations. Worst case scenarios sometimes do happen, including worst case scenarios like the King’s Cross Fire that even the experts couldn’t have predicted. Maybe the LHC is safe, I certainly hope so. I still would sleep better if we waited till we had the means to build it in orbit or on another planet though, building an experimental device that some people think could destroy the Earth strikes me as a bit foolhardy. Especially since the only real reason governments are spending piles of money on the LHC is because it may help build ever more fearsome nuclear weapons.

So we’re kinda screwed by the LHC no matter what happens. Sleep tight.

(The above image of the King’s Cross Fire aftermath is claimed as Fair Use under US copyright law. It’s not being used for profit,  is central to illustrating the post, and its use here in no way interferes with the copyright holder’s commercial use of the image. Coming next, four epic fails of modern capitalism.)

 

Written by unitedcats

April 13, 2011 at 2:05 pm

Posted in History, Science

Tagged with ,

14 Responses

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  1. Most of the supposed danger scenarios with the LHC are universe-ending, not just planet-ending. And in this case, they’re pretty darn sure that it won’t do anything that’s not replicated every day by cosmic rays hitting the upper atmosphere, just in an environment more amenable to close observation.

    Tom Dickson-Hunt

    April 13, 2011 at 3:36 pm

  2. Your comparison has one major flaw. Energy.

    We don’t know what discoveries we can make with the LHC. But one thing is certain: The amount of energy in the system is finite.
    Earth survived a bombardment, far more energetic than the LHC will ever achieve, over billions of years. Why would a man made machine with less energy be the end of us?

    jm

    April 13, 2011 at 3:59 pm

  3. Because there might be something different about particles hitting the upper atmosphere and slamming particles together in an accelerator that we don’t yet appreciate? I’m not claiming it isn’t safe, I’m pointing out that no one can guarantee that with 100% certainty. Reality conforms to its rules, not ours.
    —Doug

    unitedcats

    April 13, 2011 at 4:12 pm

  4. It seems odd to me how people make out the nuclear accident to be the worst aspect of the disaster in Japan.

    Don’t get me wrong- it’s definitely a bad deal. Will some people die, or have long term health effects, because of the Fukushima reactors blowing? Definitely.

    Will as many people die or be hurt from that as from the earthquake or tsunami? Not a chance. Not even close.

    If we really cared about saving lives, we’d put some of that focus people have on stopping nuclear power into making sure people know what to do when a tsunami happens, and improving evacuation routes and procedures.

    But of course that’s not nearly as sexy. Saving lives is not what we care about, what we care about is whatever is most easy to scare us- whether we’re being scared to sell more pageviews and commercials, or to march to an unnecessary war, or bail out some rich folks, or what have you.

    You say “reality bats last”- I disagree. Reality bats second to last. What bats last is our biases and our skewed perceptions of what that reality is.

    Chris

    April 13, 2011 at 6:56 pm

  5. Prof. Chris Busby says that there could eventually be over 400,000 deaths from Fukushima: http://llrc.org/fukushima/fukushimariskcalc.pdf

    I guess 400,000 counts as ‘some’ eh? Not to mention the huge amount of land that will become permanently abandoned. Or the radioactive fish.

    The consequences of nuclear power accidents are simply too big to ever be acceptable.

    ET

    April 14, 2011 at 3:13 pm

    • If there are 400,000 deaths from Fukushima I’ll eat my hat. Hell, if there are 40,000 I’ll eat my hat.

      If there are less than 4,000 will this professor eat his hat? Will you eat yours?

      Chris

      April 15, 2011 at 8:10 pm

    • >The consequences of nuclear power accidents are simply too big to ever be acceptable.

      This is a value judgement, and it’s not responsible to make it based on an immediate emotional reaction to the Fukushima deaths (whatever they may be). In this instance, the choice is, more or less, between nuclear power and coal–or between that choice and blackouts. Coal ash is, apparently, more radioactive than the normal output of a nuclear plant–make of that what you will–but that number is essentially negligible. It’s true that nuclear accidents have much worse worst-case scenarios than coal plant accidents, but as far as I can tell it’s a fairly impressive statement as to the safety of the nuclear plants that it takes a truly epoch-making disaster such as the Japanese earthquake and tsunami to make one melt down in a big way. Realistically, people are not going to choose an energy policy that leaves them with regular blackouts, so in the choice between nuclear power and coal, which would you pick?

      Tom Dickson-Hunt

      April 16, 2011 at 5:57 pm

  6. I will not eat the lies.. the constant industry shills who try to compare different kinds of radiation to confuse people, like telling the public this is ‘no more radiation than flying in an airplane’.

    Go to Fukushima yourself. Eat the vegetables that grow there.. stay for a few months while your at it. Be sure to eat the seaweed and fish from the local markets too. Then you will be literally eating the lies yourself. Put your mouth where your mouth is.. its only like getting a chest xray! “honest”

    ET

    April 16, 2011 at 5:30 am

    • In my experience, no one who talks about “radiation” in any general public forum knows anything about what the word means. I’m not as clear on it myself as I should be, but at least I don’t constantly refer to radioactive fallout as “radiation”. To note: The actual radiation dose anyone receives due to Fukushima, who’s not actually entering the plant or living within a mile, is going to be negligible. The issue is the radioactive fallout, and I’ve heard conflicting reports on how much of that there is and how much problem it’s going to be.

      Tom Dickson-Hunt

      April 16, 2011 at 6:00 pm

    • I’m not going to go to Fukushima… because of course it’s dangerous there. I’m not going to go to the exclusion zone, and I’m not going to eat vegetables that have been shown to found dangerous amount of radiation.

      However I do live in Tokyo. There’s a huge difference in being 300 km from the reactors vs. being 30 km away. And a big difference eating veggies grown in Chiba vs. veggies grown in Ibaraki.

      Chris

      April 16, 2011 at 8:29 pm

  7. OK, that last comment did it. My next post will be on Fukushima and will address the comments above and other issues. Thanks everyone. —Doug

    unitedcats

    April 16, 2011 at 7:51 pm

  8. “and I’ve heard conflicting reports on how much of that there is”

    yes. forces, very large interests, are busy not informing the public. however it will eventually be realized for the epic disaster it is. the economic impacts will be far reaching and deflationary.

    if someone were to write a movie plot that included what is actually happening it would jump the shark. but here it is.

    “The problems we face will not be solved by the minds that created them.”- Albert Einstein

    ET

    April 17, 2011 at 10:32 pm

  9. actually the socalled trench effect was not responsible for the disaster.
    there was a much more complex set of events and situations in play in the fire but the chief culprit was excess amounts of grease on the roller tracks.
    as usual the management got off scotfree instead of being charged with manslaughter for allowing crap to build up for years.

    have a read of the Ram-Lam-Firetube-Blast Effect

    fleur

    September 20, 2011 at 8:02 am

    • I didn’t say it was responsible for the fire, I said the Trench Effect as a previously unknown phenomena that was a major factor in making this fire the disaster it was. I agree that poor maintenance and complacency on the part of management appears to have been the proximate cause of the disaster, but that wasn’t the topic of this post. Sadly there’s a lot of disasters where the contributory negligence or worse of government agencies was never investigated, let alone prosecuted. Possibly the topic of a future post, the tendency of bureaucrats to cover up their incompetence, and how often they succeed. Thanks. —Doug

      unitedcats

      September 21, 2011 at 6:16 pm


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