Weird. Earlier today I awoke from a nap after strange dreams and attempted to produce images in midjourney of a giant aquarium breaking. I must psychic or something.
You do realise that becoming a 10x dev will mean you're getting underpaid? It's better to become a 0.1x developer so you're sure you're getting the better end of the deal ;).
Speaking as a 10x dev, this is truth. I have felt underpaid most of my career. After 30 years, I don’t give as much at work anymore. I bought a farm and most of my energy goes there instead. I suggest wishing for a healthy balanced life. No happiness comes from being undervalued and underutilized.
Case in point - yesterday morning she told me about a vivid dream of a major apartment fire she had. Look what just happened in Lyon [0].
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.
It's Midjourney. It has me wandering the uncanny valley for hours every day, there is so much undiscovered country. My sleep is disrupted. I'm in an altered state and I'm more tuned to recognizing coincidences and generally making associations between images that may or may not be floating around in the latent space.
In my reading I have read of several such occurrences, and experienced one myself. On 2 Feb 1990 I fell asleep in front of the TV and dreamed I was a journalist in Cape Town, South Africa. There was buzz about a possible speech by F.W. de Klerk in front of Parliament. I was concerned that I needed a snack on the way, and hoped that the gov't would provide donuts. Then I woke up and CNN was nagging me that de Klerk was about to address Parliament. The subject was South Africa transitioning out of apartheid.
It looks to me as if they're actually a lot of smaller pieces put together, but maybe I see it incorrectly. Maybe one day, architects will stop designing things that are structural liabilities, or engineers actually get to say no to it before construction starts.
Incredibly unlikely for any part of the structure to have been designed by an architect, most likely a highly specialist subcontractor design item. Our insurance would not cover it and it is illegal for architects to practice without insurance in many EU countries. The closest any architect would get to this is to go to a big fish tank company and say I want a big fish tank with diameter x and height y, can you do it and how much will it be...
I don't understand your comment. Architects did not design this fishtank, engineers did, ones that specialize in such constructions. Whether or not the design was at fault or there were construction or maintenance issues or the tank was modified out-of-spec, whether there was damage due to the recent renovations are all open questions.
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.
Modern sapphire glass (Al₂O₃) is basically transparent aluminium, and it is very strong. Probably way too expensive to make an aquarium out of it, though!
This is an amusing line of inquiry. Sapphire is growing in popularity for microchips. I found a source for single-crystal sapphire ingots... they only go up to 8 inches (~20cm) in diameter, about 60mm long. This tank was about 11 meters in diameter, 25m long. Scaling that up would be quite the project.
I mean, you could probably do chemical vapor deposition, but it wouldn't be a single crystal so what's the point?
Not sure about Germany but in the UK the designers would be unlikely to still be liable anymore under the original contract to design this, liability under the contract would be up to 12 years from when the work under the contract was completed. They might be liable in tort for professional negligence but it's much harder to prove that this has occurred especially after 20 years. More likely the company that was under contract to inspect/maintain this will get hammered.
Where do you have the year from? The aquarium was opened 2003 after several years of building. And seeing it now, two weeks ago it even had its 19th "birthday". Speak about bad timing.
You mean, they put the fish behind glass in a artificial habitat, which apparently was not built well enough to not break. And you still think humans were just well-meaning? How would you feel if someone took you and your family, and put ya all behind glass, for others to watch? Oh, and there will be an elevator going through your new habitat? Still just fine? I told ya, humans are horrible creatures, they dont even see the errors of their own way.
> 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.
I think we're richer for having this type of content, not least because someone has posted elsethread that the early signs point to material fatigue. The system works as far as I can see, and I think we're some way off the front page of HN being flooded by TikToks.
I don’t know about TikTok, I just know this post was submitted by someone with 50 karma originally pointing to a German radio station news site, in German. It was only changed to the Guardian later, perhaps by a mod.
> not least because someone has posted elsethread that the early signs point to material fatigue
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.
> What exactly have we learned that’s valuable from this news?
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
I mean as long as we're quoting (and breaking) the guidelines:
> 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.
> 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.
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.
Any fish that got flushed out will be lost, they need things to be 'just so'. I once helped clean up at a friends place who had 30 aquariums with thousands of fish after the power went out longer than his UPS could provide it. The mess was sickening. He never had another tank after that and it was his life's passion.
Interesting to think about. On the one hand, it's no different than any of the random stuff that happens to fish in the wild, or wildlife in general. Being killed for no reason at all is the default in nature; humans build societies and civilizations and develop technologies in large part to avoid it.
On the other hand, this feels especially sad for some reason.
We have an industrial unit which has a mice problem. Every time I go to B&Q (home hardware store for non-UK folk) with the intention of buying mice traps, I just can’t push the button. These mice are destroying our stock, but I just cannot do it. I would be a terrible fisherman.
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.
Have you considered outsourcing? To a cat (or cats) or a pest control company. The pest control company will probably check and close off opportunities for mice to enter the unit, which cats won't do, so you might want to consider retaining both options.
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.
We took our cat in, but she absolutely hated it. Then we thought she escaped for a few hours until we found her expertly hiding underneath some machinery.
In Costco they sell this cat food called ‘Maintenance cat’. Maybe we need one of those cats.
Yeah... around here shelters separate out 'barn cats' from 'pet cats', barn cats are tolerant of people but not really socialized to appreciate people. Rather than taking an existing pet cat and putting him or her to work, I'd try adopting a barn cat and putting them to work. Often, barn cats do retire and become pet cats towards the end of their life, if circumstances allow.
Of course, cats can cause a different sort of trouble than mice. :D
I'm sorry for your friend's loss and for the lost livestock, but it seem like it was simply a ticking time-bomb.
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.
Most people in cities in the US have never experienced a power failure that lasts longer than an hour or so (and many places have NEVER had one). It's understandable that people don't think much about it.
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.
It was the work of a lifetime. Power here has been so reliable that people forget that it can fail, and even though he was somewhat prepared it turned out not to be enough.
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.
I can only imagine the smell. I remember once having a small aquarium as a kid and it had that 'fishy' smell to it. The whole place must smell like that now.
If you're curious about the design considerations and construction techniques for large aquaria, the standard reference is Stachiw's Handbook of Acrylics for Submersibles, Hyperbaric Chambers, and Aquaria: https://www.bestpub.com/books/product/cid-151.html
Plastics are weird, and examining the wreckage will give a lot of information about the failure mode.
Road bike tires go up to 150 or so... but that doesn't really matter, what matters is that the surface here is massive and you need to withstand all of the force evenly or it will go. Even one crack would do it, it's not going to just seep out water but explode along the fracture, much like a popped balloon isn't going to gracefully deflate.
Side note: tractor tire inner tubes make great trampolines. My aunt and uncle run a small farm (one farm over from the farmhouse where my mom was born) and gave us a tractor tire inner tube when I was young, and we jumped on it enough to require several patches throughout the years.
In contrast, my bicycle tires at are 130psi, and while loud, the explosion is minor. I think the amount of air/water/matter escaping is part of the equation, but someone more physics-inclined could probably ascertain to a better degree how this affects the outcome.
Take a large sheet of acrylic, warm it, bend it by warming it and applying pressure. If the circumference is large take multiple ones. Glue ends together, glue in base plug.
If the engineers didn't know it would fail in 20 years from material fatigue, that's something that should be learned.
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.
20 years is a very long time for a structure under such extreme stress. You can bet that this accident will influence all such designs and cause a structural review of every other large tank made of acrylic in the world, as well as various under water tunnels in large aquaria.
Fatigue from what? It's a stationary object housed indoors, not a car or plane that goes through several climatical, temperature and environmental changes to cause fatigue.
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.
I'm no engineer but this would be static fatigue[1], no?
"[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.
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.
This, and it's in particular true for this very part of Berlin, a city that is well known for literally having been "built on sand", see https://de.wikipedia.org/wiki/Palast_der_Republik#Abriss_zwi... which is about the demolition of the comparatively big building of the Palast der Republik which was just across the street on the other side of the river. That building had to be carefully and slowly dismantled to avoid sudden changes in the hydrogeological (?) equilibrium of the load-bearing layers.
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.
Sand is - strangely enough - quite stable. Clay, peat and lots of other substrates are a lot less stable than sand and when building on them you need to take all kinds of precautions to ensure your foundation doesn't one day go for a walk.
Settlement of the building it's housed in, temperature variations (things contract and expand as temperature changes), random impacts and vibrations (e.g., road traffic, heavy construction nearby), and so on. All of these contribute to fatigue.
A tropical aquarium is keep at the same temperature. Unless somebody would disconnect it to save energy or the termostat[s] would fall, shouldn't have experienced a lot of changes in their volume by this.
The aquarium was likely very constant (otherwise the fish would die, they tend to be extremely sensitive to variations, especially rate of change), but the surrounding air likely was not.
Those fishes can stand an interval of temperature if changed slowly. A main question to check would be if the thermostat was deliberately lowered by the owner in the previous weeks to save energy
Maybe the insurance companies could sue the government if this was indeed the case. I would really like to see the bad policy makers go to jail or get hit with huge fines.
Not so much. A big mass of water act as a temperature buffer and air pumps and filters are mixing the water column all the time. It takes several hours to cool.
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.
Yes, that is widely reported now as a very preliminary cause. Also that it has been completely modernized in 2020. Here is a promotional video of the renovation activities:
https://vimeo.com/530397162
That's a real shame only a few fish survived. It's fortunate only two people hurt. That looks nasty from the picture. Maybe next time less brittle acrylic. Off the top of my head a 14 m high tower of water - there would have been approx 20 psi at the bottom of the tank.
Considering there was a hotel lobby under the aquarium, it's actually a miracle that only 2 people were hurt. Too bad for the fish though.
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...
Yes, it could have been much worse if it had happened at, say, 6PM. Although some hotel lobbies can start to get busy even at that hour (airport hotels, etc).
as someone who has an aquarium, i'm amazed it didn't happen in the middle of the night. Any time I've had an overflow issue or something, it's always in the middle of the night and my water sensor is blaring
I’m renting a house with three bathrooms. Two of the three toilets, on separate occasions, spontaneously cracked and leaked water. Both happened between 5am and 6am-ish. I was awake for one and heard it, and woke up shortly after the other one happened and found my kitchen flooded. The cracks in the two toilet water tanks were identical. Given the comments about the water temp and lobby temps, I’m guessing that hour and temperature changes could be linked.
I was able to get the owner of the house to see the wisdom of replacing the third toilet water tank.
And you do have first hand information, that this was the reason, as you speak with such authority of that matter?
Like, you do know that the temperature in that hotel was significantly lower than last year?
I mean, it seems possible, that it was the reason, (even though the water temperature itself hopefully did not change as the fishs do not like that) and the last nights were quite cold in germany, so stress from temperature difference is possible, but before I claim to know something, I wait until I know.
That is one eventual first quick assumption by some (mostly nontechnical journalists), but nothing official and confirmed, or you have sources? Otherwise please don't sell this as fact. Knowing the place, it still had heating, so I personally find this also unreasonable.. would only make sense to me if it got to freezing temperatures or below 4°C, but that for sure wasn't the case.. I doubt that place was much colder than at other times, like maybe 2-4 degrees.. but if you have any real details on that this would be welcome.
Most fishtanks have to stay in a pretty narrow range of temperatures or the fish die. A big professional installation like this I expect will have both water heating and water cooling (aircon, but for water).
And in a glass fishtank, the glass is in good thermal contact with the water, but bad thermal contact with the room air - so the glass will end up being at fishtank temperature.
So, unless they had extracted all the fish and turned the tank heating off, I don't think what you say is true.
It's possible that the installation assumed a particular temperature range in the surrounding area. The water was still heated to the proper temperature but because the surrounding air was lower than design parameters allowed, was leaking more heat than designed for, requiring the water heating to work harder. Zero idea if any of that is correct but it shouldn't be ignored as a possibility and is one possibility that could be eliminated very quickly if not true.
It's filled with tropical fish, so surely the water would have been at a decent temperature - definitely nowhere near freezing. The thing was in a fancy hotel lobby too (I was there once for an Apple event), I doubt they'd let the place go down to such low temperatures.
I've stayed there as well for two nights a few years ago, it was a great attraction. Really, really large too - a million liters of water, five stories tall or higher, I don't even remember.
I've been there so many times, every time I went to Berlin, sad news.
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.
Water pressure is very high over 60cm tall for a standard glass panel. This is the reason to not have really big home aquariums for hobbyists in the market, unless you build it directly. They grow in surface instead to be taller
I can confirm it was a great place to visit. I went there 2018 even as a Berlin native. The highlight of the tour was taking the elevator into that water dome. Impressive stuff.
Too sad it’s destroyed - hope insurance will cover all the damage. I wouldn’t want to switch places with the owner currently…
I think it could take a little while to come out, but I'm sure they had cameras in the lobby. It did just happen this morning after all. The building's structural integrity is being checked.
Exactly - the security cam footage takes a few days to be released if the company wants it, or a few weeks to leak quietly if they don't.
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).
264 comments
[ 10.2 ms ] story [ 622 ms ] threadWe'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)
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.
[0]https://www.bbc.com/news/world-europe-63997158
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.
I mean, you could probably do chemical vapor deposition, but it wouldn't be a single crystal so what's the point?
(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... .
edit: title has been edited since this comment
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.
— This Aquarium, probably
> 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.
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
> 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)
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.
On the other hand, this feels especially sad for some reason.
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.
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.
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
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.
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.
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.
Plastics are weird, and examining the wreckage will give a lot of information about the failure mode.
Massive tractor tires can be 50+ psi and when they pop it is devastating.
https://www.youtube.com/watch?v=B3U3ClFRjrQ
Compared to the side of the truck...
[1] https://www.rbb24.de/panorama/beitrag/2022/12/berlin-karl-li...
huh?
This is what I assume they mean.
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.
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.
A fish tank a relatively constant by comparison.
"[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.
[1] https://en.wikipedia.org/wiki/Static_fatigue
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...
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.
[0] https://m.youtube.com/watch?v=90eg_erObDo
[1] agrees with you at 19.9psi
[1] https://www.engineeringtoolbox.com/hydrostatic-pressure-wate...
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
I was able to get the owner of the house to see the wisdom of replacing the third toilet water tank.
Like, you do know that the temperature in that hotel was significantly lower than last year?
I mean, it seems possible, that it was the reason, (even though the water temperature itself hopefully did not change as the fishs do not like that) and the last nights were quite cold in germany, so stress from temperature difference is possible, but before I claim to know something, I wait until I know.
And in a glass fishtank, the glass is in good thermal contact with the water, but bad thermal contact with the room air - so the glass will end up being at fishtank temperature.
So, unless they had extracted all the fish and turned the tank heating off, I don't think what you say is true.
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.
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.
https://youtu.be/aM6niCCtOII
Too sad it’s destroyed - hope insurance will cover all the damage. I wouldn’t want to switch places with the owner currently…
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).