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-...
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.
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.
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.
(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.
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.
:(
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)
