Cylindrical aquarium housing 1,500 exotic fish bursts in Berlin(theguardian.com) |
Cylindrical aquarium housing 1,500 exotic fish bursts in Berlin(theguardian.com) |
:(
edit: title has been edited since this comment
You're also ignoring the thermal mass and physical pressure of a million liters of water.
Or maybe that should be "Fish go Wandering"?!
— This Aquarium, probably
At 6 AM you're not going to have many people standing around with cell phone cams for it (and anyone around when the giant tank starts making horrible noises would be hopefully smart enough to run for higher ground).
> Off-Topic: Most stories about politics, or crime, or sports, unless they're evidence of some interesting new phenomenon. Videos of pratfalls or disasters, or cute animal pictures. If they'd cover it on TV news, it's probably off-topic.
HN really needs a European mod to maintain the quality of this board.
> Please don't complain that a submission is inappropriate. If a story is spam or off-topic, flag it. Don't feed egregious comments by replying; flag them instead. If you flag, please don't also comment that you did.
(someone flag me, I can't flag myself)
If anything, the water tank was heating the room instead of vice versa.
I don't mind it being posted here, but to be fair that is just repeating what one politician is saying: "'Of course, the investigation into the cause has not yet been completed, but the first signs point to material fatigue,' said Berlin Interior Senator Iris Spranger (SPD) of the German Press Agency."
Now if someone were to point at some image and explain why that makes them think it was fatigue that would be great.
This is more interesting than the "look what I cloned in Rust" posts at the least.
A lot. It depends on your personal preferences.
If you, as me, are interested in building aquariums and, as me, has watched with disbelief a couple of thick glass panes becoming arches by just 50cm of water, the system built and the planning put on it should be awesome enough. This tank worked for 20 years than is more than most hardware.
If you (as many people here) are interested in space and Mars colonization, you need seriously consider learning the art of keeping fishes in huge tanks. Aquaculture skills will be vital to keep a colony out of the earth.
To start, is one of the better methods known to produce quality food fast to keep your people feed. Some fishes are particularly well suited for space travel, and can even travel safely dehydrated in a paper envelope.
Even more important, tanks with aquatic organisms will be basic to recycle the residues in your small city. Water will be precious stuff and higher tanks allow a much better evaporation control.
You don't want one million litters flood happening in your spatial base so there is a big lesson here for us to learn
All it takes is one incorrect application of a seam bond and a small crack will form. The crack may take decades to propagate with no way of detecting it. When the seam opens up a bit the crack will then propagate the entire length of the seam extremely rapidly and the whole tank will fail. Ideally failures would be slow and predictable but this is impossible with acrylic.
These sorts of failures have occurred before https://www.plasticstoday.com/materials/when-acrylic-aquariu... and will keep occurring as long as this type of construction is used.
- 15 segments of acrylic glass
- 12 segments for the outer cylinder, 3 for the inner
- all segments worth 4 million EUR
- 200 wall thickness
- shipped in a steel construction
They did not say it, but from the video it looks like the segments were assembled in at the destination but not in their final location.
EDIT: I misunderstood, looks like the outer cylinder was assembled in-place, the inner one on-site and then lifted inside.
For completeness, here is the video, but it is in German:
Interesting bit:
> It got a little tricky when taping off the glass envelope with foil to prevent possible cracks. Acrylic glass is a sensitive material that absorbs water over time. If it then dries out too quickly, cracks can appear even in the glass walls, which are up to 20 centimeters thick.
I know that metal fatigue is a known thing that airlines check for and when they went to carbon fiber they had to develop tools to detect fatigue/cracks.
There are other ways to scan for defects, but I'm mostly familiar with ultrasound phased arrays. Other NDT methods are also hard to use in the field after manufacturing.
[0] I work in NDT (non destructive testing), but I'm not a physics engineer and (work further up the stack from the actual probes/scanners). So this is an approximation, and I might be wrong.
[1] This random link is pretty useful to get an idea I think, but I'll also ask around our inhouse scientists if I get the occasion today!
https://www.olympus-ims.com/en/ndt-tutorials/transducers/pha...
It forms the basis of some magic tricks involving walking on or supporting things in water. (I say some, the rest are totally magic and you should enjoy them.)
They could have steel bands providing reinforcement which would be just slightly obtrusive at some angles, but boy, now it would have bands and well, it's not an uninterrupted glass [acrylic] cylinder.
I don't think any installation of this size can be truly safe. It has to be constructed in-situ being too large to transport so you would have to come up with some way of pressure testing the tank in-situ.
Plastics are weird, and examining the wreckage will give a lot of information about the failure mode.
In the latter case, something could be wrong with the building's foundations. I am no expert, but if such a massive aquarium is only slightly tilted to one side, I would expect the forces acting on the glass to be ill-distributed. Material fatigue would then only be a secondary cause.
[0] https://www.faz.net/aktuell/gesellschaft/ungluecke/aquarium-...
Also, there's a sentiment of "how could this happen, it was only upgraded two years ago?!" in all the articles I have read so far - maybe it happened precisely because of that? But let's see what the investigation will reveal...
It probably helped that it happened at 6AM ...
preliminary cause - material fatigue
Reminds me of the Champlain Towers accident - there were surveillance cameras everywhere, as well as a fire alarm control panel (that was critical to the incident as it would’ve been the one triggering an alarm to prompt everyone to evacuate) but no efforts were made to recover either despite the fire alarm panel checking in with the control centre several times (on battery power, over a mobile phone connection) after the collapse, proving that it was still alive and recoverable.
I guess they worked out that it was better to play dumb and let this evidence go away than recover it and potentially get into more trouble. I suspect it’s the same situation with the aquarium.
https://news.ycombinator.com/item?id=34012469
Before: https://www.sueddeutsche.de/image/sz.1.5716681/1280x720
After: https://www.sueddeutsche.de/image/sz.1.5716703/860x1290
It seems like the inner glass (for the elevator shaft) is still intact.
https://www.theguardian.com/world/2022/dec/16/huge-cylindric...
> A freestanding cylindrical aquarium housing about 1,500 exotic fish has burst in Berlin, causing a wave of devastation in and around the Sea Life tourist attraction, police have said.
> Glass and other debris were swept out of the DomAquarée complex, which houses a Radisson hotel, a museum, shops and restaurants, as 1m litres of water poured out of the 14-metre-high tank shortly before 6am.
> Operators say the aquarium has the biggest cylindrical tank in the world that contained 1,500 tropical fish of 80 different species before the incident.
> The aquarium, which was last upgraded in 2020, is a big tourist attraction in Berlin. A 10-minute elevator ride through the tank was one of the highlights of the attraction.
> 10-minute elevator ride through the tank
That's 1.4 meters per minute, or ~2.3 centimeters per second. The aquarium and the fish in it must have been marvelous to watch, because otherwise even imagining being stuck in an elevator moving at this pace feels terrifyingly boring to think about.
This poster on Zerohedge provides more details:
I am directly involved in the legal cleanup of this and can provide a little more detail as to what actually happened (Tyler, reach out to me you have my email if you'd like to verify my identity here).
The city of Berlin required the hotel reduce the ambient temperature of the hotel lobby to save on energy due to sanctions. Its been abnormally cold in Berlin the past few nights dipping down to -11°C last night and -12°C the night before that. The water is heated to a constant temperature above 30°C for many of the fish species that lived in the tank.
As the nights got colder and colder, the lower ambient temperature of the air surrounding the tank likely started causing deformations and hairline cracks in the bottom of the tank where the pressure is the greatest. Last night at -11° caused the ambient temperature to drop too low given the reduced heating in the lobby and is what it looks like caused the "sudden unintentional disassembly"/catastrophic failure of the tank.
Everyone is already lawyering up including the city, the HVAC manufacturer, tank manufacturer, HVAC installer, building engineer, hotel - the litigation is going to be fun to watch and work on.
What isn't covered in the news is damage. The tank in 2003 cost €13 million. Today its orders of magnitude more expensive to replace, some of the fish were quite exotic and are expensive losses in and of themselves. Then you have the damage to the hotel lobby and façade, electrical components of the building in the three-story basement are also effected and large amounts of water went into the parking garage where many vehicles are parked not only from the hotel and offices but from an attached apartment complex to the hotel.
Losses are tens of millions. All because the city made the hotel turn down the heat.
[1] https://www.rbb24.de/panorama/beitrag/2022/12/berlin-karl-li...
Unless they were subjecting the tank to draining and filling cycles often, it seems more like a design/build fault that was a ticking time bomb from the start.
huh?
I know of the aquariums with tubes under/through the water, but this seems to be something different.
Looks like it was a remarkable elevator ride.
Too sad it’s destroyed - hope insurance will cover all the damage. I wouldn’t want to switch places with the owner currently…
We're rational enough to mostly chalk it up to coincidence or selection bias, but not calculating enough to take advantage of gullible people
(Edited to mention selection bias)
- Pisces: A difficult day despite the expansion of your living space
- Scorpio: ...
Interestingly, looking at the tank from my room, I never thought about the scenario when it breaks. I thought "engineers must put a lot of extra margin when constructing this". Turned out I was wrong.
[1] agrees with you at 19.9psi
[1] https://www.engineeringtoolbox.com/hydrostatic-pressure-wate...
Sadly I never availed of the elevator ride through the aquarium.
After the strange coup try in Germany the last week, I wouldn't discard still that is not another destabilization attempt by some hypothetical agent. Weren't cameras set around the Hotel hall?
How would that work? Is this site important enough to destabilize the country?
But I'm probably just hypothesizing too much [again] while trying to analyze the case. It just feels strange coupled with the last long chain of strange events happening right now. To be fair, twenty years are a lot of time for an acrylic tank.
It looked pretty cool and was a good place to bring people who didn't know Berlin after a visit to the beautiful Pergamonmuseum, which is 5 minutes walk away.
But I went on the elevator only the first time, it was clear that that wasn't a good idea at all.
The seams between the panels are likely also not designed to be loaded that way.
Just the asymmetrical load on the structure could do the trick at a relatively small angle because it might cause the structure to get compressed against something bordering it. This is not a trivial engineering project.
(side note: what a weird name for an aquarium manufacturing and design company)
ICM has already removed AquaDom from their portfolio page https://icm-corp.com/portfolio/ , but a cached version (for now at least) exists at https://webcache.googleusercontent.com/search?q=cache:XGSNC7... .
Structural engineers take their work very seriously, much more seriously than your typical software person and you can bet that any and all lessons learned from this incident will be incorporated into future designs. They don't just slap stuff together for the laughs and call it a day.
By the way, here's a big cool 3D printer that prints opaque acrylic: https://m.youtube.com/watch?v=b3CY3P28qyQ
I was able to get the owner of the house to see the wisdom of replacing the third toilet water tank.
This is what I assume they mean.
You could dream about a fire for any reason, and fires are unfortunately common enough to at least make local news so unconsciously scanning a headline during the day may plant a "dream worm".
But this happens quite often, even for personal things, like details of the birth of our first kid a couple of weeks before the due date, down to the amount and color of hair, the precise time for a natural birth, and the mino complications right after.
It always gives me split second pause because I want to believe ("quantum entanglement" is weird or witchery is real - she's East European after all). But there's almost always a good explanation for the percieved prescience.
They may be blameless by any reasonable standard, but knowing how/when something will reach end of life is an important part of design. We learned a similar lesson with airplanes.
I mean, you could probably do chemical vapor deposition, but it wouldn't be a single crystal so what's the point?
So I'm going to put it in the "theoretically possible but nobody will do it" category for now. ;)
So you either detect it before commissioning or it will eventually fail if there is a flaw.
[0] https://www.atlasobscura.com/articles/stephen-hawking-time-t...
That's a little bit early to start aiming at the city, isn't it? The call to reduce energy consumption is, if anything, coming on as a case of too little, too late if anything given the ongoing crisis over here; it is altogether a reasonable thing to do. As is always the case in Germany with such things, there will be maddening array of if/then/otherwise escape hatches that is part of those rules, and, frankly, if the management of the hotel and the people responsible for the aquarium had been in the know that keeping a constant temperature in the lobby was essential to the structural integrity of the aquarium and they still lowered it, they're mad. If they weren't told they can't be held responsible. If the manufacturer did know or should have known, they'll be in (sorry) hot water.
All of this is conjecture at his point so phrases like "all because the city told them to turn down the heat" have to be understood in the conjunctive or, better, be explicitly written in that voice.
>For want of a nail the shoe was lost.
>For want of a shoe the horse was lost.
>For want of a horse the rider was lost.
>For want of a rider the message was lost.
>For want of a message the battle was lost.
>For want of a battle the kingdom was lost.
>And all for the want of a horseshoe nail.
The moral of the proverb is: it is important to ensure that critical systems have redundancy built in.
The writer pretty clearly has an axe to grind with the city, the sanctions, the war, and a lot more (read some of his other comments). His conclusions might turn out to be true, but I don't think he cares if they are or not.
The earth you live on is not solid, more like a squishy orange. When you build a heavy building on it, the building can sink further.
Buildings themselves are subject to the dynamic loads of temperature, wind, their occupants square dancing, and more.
Sometimes unexpected loads are added. A new highway or building built into a rock layer near it can subject the previous building to vibration and other forces and cause damages.
Given that amateur seismic stations located 8 and 14 km away from the location were able to pick up a signal from the event[1] of a 1000 tons of water falling to the ground from a height of ~ 2 to 15m, one should image the building itself should have had some sort of influence to its immediate surroundings.
[1] https://twitter.com/ErdbebenDE/status/1603654695293263873?re...
I'm curious if there is something about acrylics which makes it impossible to make very large single pieces.
A fish tank a relatively constant by comparison.
If your friend had 30 tanks and thousands of fish, they should have had a more involved backup plan that involved a dedicated generator in addition to a UPS. A small generator would have been a tiny fraction of the materials and livestock costs of running a setup like that.
Agreed though that it was a ticking time bomb. As for better backup plans: even autostart generators for data centers can fail when you need them most. Backup plans end up with more and more layers until you think you've got it all and then some little oversight will get you. In his case he probably could have done more but that's only because we're looking at it after the failure, for decades it worked.
Though the moment the UPSs hit 50% you might try to run to Home Depot and grab a generator, but by that time they'd all be sold out.
Massive tractor tires can be 50+ psi and when they pop it is devastating.
To be excruciatingly specific.
The event does not seemed truly random to me. If it was, the probability of breaking in the 90% of the time when there was people around would be much higher than breaking in the 10% small time interval without people. Extreme luck is rare. Looking for an external trigger seems appropriate
But the only surface really accessible to people was the escalator, and now we know that it didn't broke. The outer surface is mounted over the escalator door, can't be scratched purposely without taking a lot of troubles. Can't be shoot without leaving evident marks of a crime
If we assume that the thermostat didn't broke and that material fatigue is not an optimum explanation (it was checked and maintained in 2020), then temperature differences seem a good candidate. It broke in winter, in the hour where day/night differences should be maximum. The outer temperatures that night were -10C if I'm not wrong.
In the lab I've chemically tested acrylics that were bullet-resistant at low-cm window thickness. No bullets were used in my phase of the operation, but I was clipping off chips from the exact coupons which had been physically measured beyond the fracture point.
You can tell there's a difference in ductility and brittleness with temperature. Pretty tough stuff regardless.
In the aquarium these are supposed to be very thick-walled acrylic curved panels bonded together.
If the water was maintained warm enough for the reef fish while the ambient air dropped below freezing I don't like that idea. The entire temperature differential being borne by the thickness of the acrylic could mean there are different plastic properties diverging among the inner and outer surfaces of the "glass" panel. This could give rise to stress being concentrated deep within the panel if the transition is not too smooth.
Conditions like this could be recreated if so.
Might have been OK if they had penguins and cold-water fish this time of year.
"[S]tatic fatigue occurs during prolonged and constant application of stress" (my emphasis) - much like the glass/acrylic at the bottom of a 14m high, 1M litre water column, say.
In the Panama City there is an overhead swimming pool many meters above the restaurant floor. I've dined there a couple of times and never feel quite comfortable with that much water hanging over me supported by a sheet of acrylic.
After this that feeling is likely not going to be any less :)
On the other hand, this feels especially sad for some reason.
Warehouse cats can be nice warehouse companions too (depending on what happens in the unit).
I've had to do some mouse removal work in my forest adjacent home, and it's not pleasant, but neither is having mice around.
To be fair, you have to catch and release most fish in the UK which, whilst annoying for the fish, doesn't seem to do them much harm since there's e.g. a whole bunch of 30y+ old carp that keep getting caught.
You're allowed to keep a certain set of game and sea fish if they're big enough and from the appropriate place.
People use "glass" to mean the clear part of a window, not the actual material, in this context.
A trade name.
I'm no expert, but I know that a hot tub on slightly uneven ground has a good possibility of bursting and ruining the tub due to how much stress the water will unevenly put against a side. I don't see why the same underlying reasons wouldn't apply here too.
https://www.youtube.com/watch?v=B3U3ClFRjrQ
Compared to the side of the truck...
In Costco they sell this cat food called ‘Maintenance cat’. Maybe we need one of those cats.
Of course, cats can cause a different sort of trouble than mice. :D