Every engineer is going to have a bad day, but only an unlucky few will have a day so bad that it registers on a seismometer.
We’ve always had a morbid fascination with engineering mega-failures, few of which escape our attention. But we’d never heard of the Super-Kamiokande neutrino detector implosion until stumbling upon [Alexander the OK]’s video of the 2001 event. The first half of the video below describes neutrinos in some detail and the engineering problems related to detecting and studying a particle so elusive that it can pass through the entire planet without hitting anything. The Super-Kamiokande detector was built to solve that problem, courtesy of an enormous tank of ultrapure water buried 1,000 meters inside a mountain in Japan and lined with over 10,000 supersized photomultiplier tubes to detect the faint pulses of Chernkov radiation emitted on the rare occasion that a neutrino interacts with a water molecule.
Those enormous PM tubes would be the trigger for the sudden demise of the Super-K , which is covered in the second half of the video. During operations to refill the observatory after routine maintenance, technicians noticed a bang followed by a crescendo of noise from the thirteen-story-tall tank. They quickly powered down the system and took a look inside the tank to find almost every PM tube destroyed. The resulting investigation revealed that the tubes had failed in sequence following the sudden implosion of a single tube at the bottom of the tank. That implosion caused a shock wave to propagate through the water to surrounding tubes which exceeded their design limits, causing further implosions and further destruction. The cascading implosion took a full ten seconds to finish its wave of destruction, which destroyed $7 million worth of tubes.
The interesting part about this is the root cause analysis, which boils down to the fact that you shouldn’t stand on 50-cm photomultiplier tubes. Also at fault was the testing regimen for the tubes, which the project engineers anticipated could cause a cascading implosion. They tested this but were unable to cause a cascade failure, leading them to the conclusion it wasn’t likely to happen. But analysis of the destruction revealed a flaw in the testing, which should give pause to anyone who ever had to design a test like this before.
Luckily, nobody was killed or even hurt during the Super-K incident. The observatory was repaired with upgraded tubes and remains in service to this day, with an even bigger Hyper-Kamiokande detector in the works. We’ve covered neutrino observatories before, so check that out if you want more background on the science.
Insert “series of tubes” and “they should’ve used transistors” jokes here.
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On a serious note, high-cost engineering failures like this need to be studied so they don’t happen again.
Someone should write a book perhaps.
https://www.amazon.com/gp/product/B0B3HS4C98/
Looks like they studied it very carefully (and they did testing to discover the exact same phenomenon beforehand, but they unfortunately did it in insufficiently deep water). The new detectors have some kind of acrylic screens inside to dampen implosions, I suspect a bit like the safety devices inside CRTs once they were mature enough.
The new hyper-kamiokande has far more depth and volume, hopefully their precautions were adequate and it works without a hitch
The amount of money we spend on silly curious things is ridiculous. Let save the planet first, then you can piss away all the money you want to find out things like is there water on mars.
Agreed, the printing press should have been shelved until world hunger was solved.
Likewise, nuclear physics has never brought a single bit of good to the world, nor has it ever solved any problems.
We should cut all funding from physics research until we solve all the problems the physics research could help with.
“Let’s save the planet first” is a spectacularly goofy and unbounded goal. There will always be a planet to save. The cost to replace the neutrino detector photomultipliers was around seven million, if I recall. We spend more than that handing out fent to kids on purpose. Discovering new physics is always a priority.
I’m so glad people like you are impotent. When would you be happy, when we fed every single person in Africa and they all 10x in the next fifty years? No, of course not, then you would demand that we feed five billion more Africans, and then fifty
So should africans not be fed..?
You’re being far too charitable to the motives of the “save the planet” people. They want to save the planet from humans by destroying all humans.
Maybe learn to how scientific development works. Understanding elementary particles is pretty helpful to a number of technologies and knock-on effects of related discoveries are complementary to other fields.
The amount of money regularly wasted propping up all kinds of the “too big to fail” unept monopolies truly boggles one’s mind.
TARP sucked out what $375 bils out of our economy – and we could have spent those $375 bils buying each US tax-paying citizen a house of his/her dream, every man, woman, newborn and elderly. We could have reintroduced public transportation nationwide and/or feed and home all the homeless, but, no, we gave them to the banksters who have plenty of their own money (mostly stashed tax-free offshore, of course).
Regardless, our Social Security is not broke, but it will be because all kinds of morons finance their pet peeve projects while nobody is looking.
Aside from that, NASA’s budget is what, 1/100th of the GNP (compare it with 4% GNP spent during the Apollo Program)? For that puny 1/100th GNP NASA regularly invents all kinds of civil technologies (this computer included, btw), whereas those $375 bils just disappeared in the banks’ black holes, nothing new came out, no patents, etc etc.
Funny how it’s never the rivers of gold that are being redirected daily into the pockets of the already ultra-rich that are the target of these “stop wasting money!” cries.
There are entire massive segments of the modern day economy that are less productive/well aimed than science.
I could list so many, and im sure I’d step on someone’s toes for each of them.
I’m sure almost all of us participate in multiple of them.
Here’s a simple one: entertainment. In just a few hundred years, we’ve institutionalized mass entertainment, and we all pump a lot of money (and maybe more importantly time) into it. What could we all do for the world if we spend half the time we spend watching YouTube, TV shows, or browsing social media on something of lasting importance.
It’s easy to point fingers. It’s harder to make one’s self not pointable at.
Unlimately, action is what matters, not ranting online. The later is only good if it actually increases the former (and if I rant hoping that other people fix things…. I’m missing the point)
Funny that it’s scientific inquiry you’re wanting to sacrifice for saving the planet, and not private jets and megayachts.
I’m not seeing how a few million dollars worth of PM tubes is what is preventing us from saving the planet.
Aren’t PM tubes supposed to use cesium? Isn’t cesium supposed to react vigorously with water?
A cascade failure (shockwave in water)
Of cascade sensors (photomultipliers)
IN A CASCADE DETECTOR!? (radiation)
Um, I think the cascade in photomultipliers is the same as the one in a cascade detector. But good try.
yo dawg…