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Cylindrical aquarium housing 1,500 exotic fish bursts in Berlin

theguardian.com

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Re: Cylindrical aquarium housing 1,500 exotic fish bursts in Berlin

#191

Post by iancmceachern »

matheusmoreira wrote: post #154
barbegal wrote: post #117

From an engineering perspective these sorts of acrylic tanks are a nightmare to ensure they are safe. The seams are impossible to inspect rigorously so the only real way of checking that they are safe is to load them with an excess pressure ( https://en.wikipedia.org/wiki/Hydrostatic_test ). This can't be done with a tank of this size so the engineers can only real fall back on giving the tank excessive safety margin…

What's the best material for a tank like this, if not acrylic? Normal glass? Not educated on this subject.

Acrylic is the best material for this application we currently have. If we had a better material, we would use it.

Re: Cylindrical aquarium housing 1,500 exotic fish bursts in Berlin

#192

Post by SergeAx »

I stayed at the hotel this September. My first thought was "oh, my, there is a breakfast area right there on a ground floor, and it is starts buzzing right from 6am!”. Fortunately, the bang happened 20 mins before.

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.

Re: Cylindrical aquarium housing 1,500 exotic fish bursts in Berlin

#193

Post by toast0 »

WhackyIdeas wrote: post #188
toast0 wrote: post #176

Earlier quoted context omitted.

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 i…

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

Re: Cylindrical aquarium housing 1,500 exotic fish bursts in Berlin

#195

Post by mikeyouse »

joezydeco wrote: post #169
fwungy wrote: post #155

The root cause of this was that the hotel was forced to lower their heat due to energy sanctions. Reduced heat caused the aquarium to contract which contorted the structure, eventually causing the failure.

Citation? You're also ignoring the thermal mass and physical pressure of a million liters of water.

They're pulling that "info" from the conspiracy theorist website zero hedge.. that it conveniently aligns with that site's support of Putinist Russia should be noted. The German law limits public space heating to 67º which doesn't seem like it should be nearly enough to cause this kind of failure..

Re: Cylindrical aquarium housing 1,500 exotic fish bursts in Berlin

#196

Post by jacquesm »

bombcar wrote: post #171
mardifoufs wrote: post #152

Earlier quoted context omitted.

From my limited knowledge[0], it does not seem like this would be an easy structure to scan for inspection. Acrylic can even used for the wedges that interface between the phased array (or single element) probe [1] because it's very good at not interfering with ultrasounds. Water is also a very good "coupling" material, which makes it even harder to get a useful scan since there would be no "backwall" reflecting back…

So it sounds like you'd need something on both sides of the "glass" kind of like this aquarium magnet but much larger/complicated: https://www.amazon.com/JRing-Aquarium-Cleaner-Aquariums-Clea... and slowly move it around the whole tank, repeatedly scanning as it goes. So I'm going to put it in the "theoretically possible but nobody will do it" category for now. ;)

It's a much harder problem than that. Even if you did not find the crack just before taking the structure into use a crack could develop at any point in time after that and you're definitely not going to be emptying this tank on a regular basis for inspection.

So you either detect it before commissioning or it will eventually fail if there is a flaw.

Re: Cylindrical aquarium housing 1,500 exotic fish bursts in Berlin

#197

Post by jacquesm »

swader999 wrote: post #168
lqet wrote: post #108

There are now many reports about material fatigue as the primary cause, but I am not so sure. Another article [0] mentioned that the building is currently analyzed by engineers because the firemen found cracks in floors and walls - they are, however, not sure if these cracks were caused by the water, or if they were already there before . In the latter case, something could be wrong with the building's foundations. I…

The hotel was told to lower their temperatures. With cold weather outside the differential between the tank and the lobby is the most likely cause.

That's a good guess, but I'd still like to see the final report if and when it is published and whether or not they manage to find the root cause. Likely the differential made the problem worse to the point that something gave but I suspect that there is a deeper underlying cause that made it sensitive to that difference in temperature to begin with. Either a material flaw, an assembly issue or something else.

Re: Cylindrical aquarium housing 1,500 exotic fish bursts in Berlin

#198

Post by jacquesm »

philodelta wrote: post #123

I know people got hurt (and fish died) but all I can think is, this is a hotel lobby, there most certainly IS security camera footage of the failure and subsequent deluge and man do I want to know what that looked like.

There likely will not be more than a few stills worth of interest, this happened very quickly judging by how far out the street is contaminated.

Re: Cylindrical aquarium housing 1,500 exotic fish bursts in Berlin

#199

Post by DemocracyFTW2 »

pixl97 wrote: post #112
rzzzt wrote: post #79

Earlier quoted context omitted.

Buildings move.

This here. 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 forc…

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.

[1] https://twitter.com/ErdbebenDE/status/1603654695293263873?re...

Re: Cylindrical aquarium housing 1,500 exotic fish bursts in Berlin

#200

Post by swader999 »

jacquesm wrote: post #197
swader999 wrote: post #168

Earlier quoted context omitted.

The hotel was told to lower their temperatures. With cold weather outside the differential between the tank and the lobby is the most likely cause.

That's a good guess, but I'd still like to see the final report if and when it is published and whether or not they manage to find the root cause. Likely the differential made the problem worse to the point that something gave but I suspect that there is a deeper underlying cause that made it sensitive to that difference in temperature to begin with. Either a material flaw, an assembly issue or something else.

I'm basing it off of what this guy is reporting. He seems to have an inside legit view. https://www.zerohedge.com/user/105370
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