# Dangerous makeshift swimming pool on apartment balcony is a recipe for disaster

I would assume the next photos in that sequence show one of the glass panels breaking, followed by a couple of tons of water blasting that child through a broken-glass-lined hole onto the pavement below.

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I disagree a little. Water is â1â, this we know. There arenât too many liquids that are denser than water, especially in the range of temperatures and materials thatâs youâre likely to be doing large-scale back-of-the-envelope estimations. Like âŚ the weight of water in a swimming pool. I mean, you might want to estimate the weight of a swimming pool of mercury, but itâs frankly pretty unlikely, and if you are trying to figure out the weight of a large pool of mercury (or something even more esoteric like liquid sodium) I thoroughly recommend you use a calculator and some accurate figures for density and volume.

So, â1â is likely the upper end of the scale youâll be using, unless youâre dealing with seawater in which case itâs a bit heavier. Call it 1.1. (itâs actually 1.03, but eh. 1.1 is near enough, and easier to calculate in your head). Oils are lighter, so for large vats of olive oil or crude oil, call them 0.9. Or, for a really quick calculation call them 1 and then take off 10%.

etc.

SI is just flat out better.

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Once upon a time many moons ago before the internet was, I went to a school in SW Ohio. Cincinnati. They had an awful modern tower dorm that they eventually imploded (video on the 'nets). I lived next door in a 4-5 floor old brick dorm called Dabny Hall. Old school. The bathrooms were like a gym and had a big open shower with like maybe 3-4 shower heads on two walls. You entered thru a chest high masonry and tile doorway on a diagonal to those walls.

Some wag thought of bringing a piece of plywood, wrapping it in plastic and then plugging the drain and blasting all the shower heads at max. When I walked in the place was full of people and a half dozen or so were swimming around in the 3-4â deep water. I thought, well, this doesnât look OSHA approvedâŚ but it held! I left as soon as possible in any event.

this guy is asking for troubleâŚbobtatoâs scenario was what I was going to post, so thanks for saving me the trouble mate!

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From looking at the picture carefully:

1. Water level under window casement is not parallel with window.

2. Railing is bowing in the center.

3. Balcony is sagging slightly on the end toward the doorway.

4. Where the balcony joins with the structure, there appears to be a crack
(canât tell if itâs a photo artifact).

Conclusion:
âHey dad, come on in and join me! Cannonball!â

Slosh, slosh, CRA-ACK!

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I loved the sales pitch used by the waterbed companies: that a waterbed has the same square-foot weight loading on the floor as a refrigerator.

Because itâs common to park 9-12 refrigerators in a clump in a room.

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Only way Iâll move back to an apartment.

Black, green, and blue lines are parallel.
Red lines deviate.
This kid is in trouble.

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In this case it wasnât as much help as I would have thought, though. Because designed floor limits are defined in terms of lb/ftÂ˛ or N/mÂ˛. So you have to convert from kilograms of water to Newtons of force that the water exerts in one gravity.

I once got a fortune cookie that stopped me cold; I, like many a boing boing bbs bullshitter, consider myself fairly cleverâŚ

The fortune said âcleverness is suitable for everything but sufficient for nothingâ. I was like wth?? I asked my buddy âwhatâs your fortune say?!â His was âa good friend is someone you have know [sic] for a long timeâ.

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Two questions:

1. Do those lines account for parallax distortion?
2. To what is the red arrow and circle referring/calling attention?
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That balcony would hold forever, but you had to bring it to attention, thanks. Donât you know the Wile E. Coyote effect?

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@M_Dub:

I did compensate for some parallax (of the bottom window, for example). If you measure the angles, all the blue lines are parallel and the water line deviates toward the right.

The photo was taken from an angle above and pointing downward, so the vanishing-point perspective is toward the bottom. It can be seen most obviously by comparing the corners of the upper and middle balcony facing the camera. The balcony stanchions are parallel but offset slightly, while the lip of the middle balcony is not parallel as with the balcony above it (and the lip doesnât have that much overhang to create a huge jump in parallax?).

The angles remain the same, the difference is that parallel lines are closer together toward the bottom of the picture. Itâs basically an isometric view.

The circled area shows a photo artifact or wall defect (compare to the top balcony). This may be because a joist or cantilevered concrete is starting to pull away from the wall and is cracking the masonry at the point of most stress.

(EDIT: Iâve complicated the photo a bit below âŚ click to enlarge)

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Thatâs for the next airbnb renters to worry about!

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metric people are just as dense as the rest of us

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This might help:

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LOL (this is at least nine characters).

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inflate it with heliumâŚiâm confident that will work and is a real thing.

my bet would be on the railings giving way before the reinforced slab and that heâd be swept off the side of the balcony with the exiting water. @MikeKStar, @dan_smooth, and @bobtato beat me to that observation though.

i agree. i wonder what the outcome was? best case the corner of the balcony partly fails, the water drains at a reasonable pace and the kid gets back inside with everone realizing how stupid this was. iâll choose to think this unless we hear otherwise.

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No need to google anything in metric. 1 cubic meter of water = 1 ton. Canât get much simpler than that. Also kinda easy to visualize how big of a volume 1 ton is.

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Doesnât NASA, the military, the standards bodies, etc all operate in metric?

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Huh. I found plenty of statements about the stable max load in Germany, and they were all given as kg per Sqm. Granted, those were not the original documents but interviews with staticians, builders, etc, they all kinda agreed. Also, with being able to calculate the weight so easily, you get fast to the point of âholy crap, thatâs as heavy as may carâ within seconds.

Unless carsâ masses are given in yet another unit, I wouldnât be surprised.

Next trick up: calculate quickly how many sheets of legal paper you need to cover a cube consisting of an imperial ton of water.

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