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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

#131

Post by lqet »

abduhl wrote: post #122
a4a4a4a4 wrote: post #118

Earlier quoted context omitted.

The normal force of the tank wall to the floor will shear across the acrylic if it's not perfectly flat. Pressure outwards is normal to the tank wall relative to the water, but if this force goes diagonally through the floor, that's bad.

If the tank burst due to it shearing off of its base then it is not the glass that has the problem; it’s the connection to the base. This might sound pedantic but the OP said the forces on the GLASS were ill-distributed. The most important part of after the fact disaster analysis from an engineering context is being excruciatingly specific about the performance of structural elements.

But isn't the overwhelming majority of the glass material connected to the base by the glass itself (namely the glass below it)?

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

#132

Post by zimpenfish »

WhackyIdeas wrote: post #74
TeMPOraL wrote: post #41

Earlier quoted context omitted.

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.

> 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.

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

#133

Post by zimpenfish »

wyuenho wrote: post #67
nottorp wrote: post #61

Earlier quoted context omitted.

They'll start on the report after they finish mopping 1000 m^3 of water i guess. This is more interesting than the "look what I cloned in Rust" posts at the least.

What exactly have we learned that’s valuable from this news?

At least one person learnt of the existence of "static fatigue". Which I'd count as a win, personally.

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

#134

Post by ceejayoz »

TeMPOraL wrote: post #37
defrost wrote: post #15

Link to English article: 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 o…

> 14-metre-high tank > 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.

You've never sat on a bench for 10 minutes to look at something neat? They move even slower.

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

#135

Post by kayodelycaon »

abduhl wrote: post #130
upsidesinclude wrote: post #128

Earlier quoted context omitted.

If you wanted to be pedantic you would correct the statement because there is no glass. To be excruciatingly specific.

The article refers to the aquarium as glass throughout it.

The material used is plexiglass, aka acrylic, a type of clear plastic. Actual glass is probably too brittle or expensive.

People use "glass" to mean the clear part of a window, not the actual material, in this context.

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

#136

Post by Traubenfuchs »

zython wrote: post #21
Fricken wrote: post #2

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.

Please dream of me winning the lottery and or becoming 10x dev.

Why would you ever want to become a 10x dev instead of winning the lottery?

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

#137

Post by bombcar »

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…

Is there no way to detect cracks or is it just prohibitively expensive to do so?

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.

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

#138

Post by bombcar »

abduhl wrote: post #115
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…

Why would you expect the forces acting on the glass to be ill-distributed if the enclosure were tilted slightly? Water pressure acts hydrostatically. The enclosure appears to have a circular cross section. As long as the tilt is not severe there is no reason to believe anything other than tensile hoop stresses due to equal circumferential loading will develop.

I would expect it's not the tilted slightly that would matter but simply settling after installation - a settling foundation can crack concrete and glass so stresses could change if the foundation of the tank was moving.

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

#139

Post by voakbasda »

koonsolo wrote: post #113
zython wrote: post #21

Earlier quoted context omitted.

Please dream of me winning the lottery and or becoming 10x dev.

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.

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

#140

Post by bombcar »

boppo1 wrote: post #120
MengerSponge wrote: post #104

Earlier quoted context omitted.

170.65 kPa, or 24.75 psi. I imagine even Flex Tape can't hold that!

Doesn't seem crazy, my tires hold 38 psi.

PSI is a measurement that can be hard to translate between various items like tires and tanks and foundations: https://www.engineeringtoolbox.com/building-foundations-load...

Massive tractor tires can be 50+ psi and when they pop it is devastating.

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