this post was submitted on 28 Dec 2024
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Greentext

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This is a place to share greentexts and witness the confounding life of Anon. If you're new to the Greentext community, think of it as a sort of zoo with Anon as the main attraction.

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If you find yourself getting angry (or god forbid, agreeing) with something Anon has said, you might be doing it wrong.

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[–] BananaTrifleViolin 120 points 6 days ago (1 children)

The biggest problem is he's engineering in Imperial instead of SI units.

[–] [email protected] 6 points 4 days ago

I thought the same way, then became an American engineer. Fuck a horsepower, because it's so goddamned context dependent.

[–] [email protected] 23 points 5 days ago* (last edited 5 days ago) (1 children)

anon's in trouble because they're using psi instead of bar.

Edit: also fuck high pressures are a scary thing.

[–] [email protected] 6 points 4 days ago (3 children)
[–] [email protected] 4 points 4 days ago

He is so dreamy

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[–] [email protected] 10 points 4 days ago

Safety video for anyone with an interest: https://www.youtube.com/watch?v=AEtbFm_CjE0 Delta P is stuff of nightmares.

[–] [email protected] 80 points 6 days ago (3 children)

Am I assuming correctly that we're looking at a big succ-situation, where the diver will big forced through the tube no matter what?

[–] [email protected] 56 points 6 days ago* (last edited 6 days ago) (4 children)

It's a difference of like 7 psi over an area of what looks like maybe 30 square inches, which would be uncomfortable to get caught in, but I don't think you're getting Byford Dolphined

[–] yetiftw 14 points 5 days ago

210 lbs will certainly keep you stuck there though

[–] [email protected] 15 points 6 days ago (2 children)

Ahhh yeah that's where I've heard it before, WTYP had an episode on that!

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[–] BleatingZombie 3 points 4 days ago (1 children)

If you were on your back and had your legs above the hole, is 7 psi strong enough that you wouldn't be able to fight it?

I guess another question would be "how strong would it be compared to gravity?" (if anybody has any idea)

[–] [email protected] 3 points 4 days ago

It very much depends on the size of the hole. 7 psi over 1 square inch is 7 lbs, but the same pressure over 100 square inches is 700 lbs.

For a naive estimate, the hole looks around 6 inches wide, which gives it an area of around 30 square inches, so there's like 200 lbs of water pressure over the area of the hole. An even more naive assumption is that if you were "standing" over the hole in the wall, you would feel 200 lbs of pressure forcing you "down," which I think most people could easily handle. I'm doing more than that right now!

Unfortunately I don't know how to even start to calculate the force of the water on you as it rushes past you, but my gut instinct is that it wouldn't be more than the total pressure in the hole

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[–] [email protected] 19 points 6 days ago

Is 5m enough for that? I feel like no, but i have no idea.

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[–] [email protected] 51 points 6 days ago* (last edited 6 days ago) (3 children)

This unfortunately happened in real life.

Edit: other way around though. The divers were on the air side (habitable quarters) of the chamber.

[–] [email protected] 51 points 6 days ago* (last edited 6 days ago) (1 children)

For more clarification, they were on the high pressure air side. The kind of dives they were doing involved long periods of acclimation to the different pressures involved, so the diving bell was pressurized to 9 atmospheres. Someone fucked up, and the door opened. 9 atmospheres turned into 1 atmosphere very quickly, and the only good thing is that it happened so fast that the deceased wouldn't have even noticed

If you want to see an episode of a podcast about engineering disasters which is itself, ironically, an engineering disaster, well there's your problem

[–] adj16 27 points 5 days ago (1 children)

Just for what it’s worth, it looks like it was actually an equipment malfunction, not someone fucking up, that caused the accident. The company claimed the person fucked it in an attempt to cover their asses, and they were eventually found to be hiding the truth in a court of law.

[–] [email protected] 10 points 5 days ago

Justice should be violent

[–] [email protected] 7 points 5 days ago

The families of the divers eventually received compensation for the damages from the Norwegian government, 26 years after the incident.

Well, it's good that some justice was finally achieved, but that is depressing level of covering up (as usual)

[–] [email protected] 12 points 5 days ago (2 children)

Some parts of that article are straight horror.

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[–] [email protected] 13 points 5 days ago

Top 10 ∆P incidents

[–] [email protected] 41 points 6 days ago

But where's Saddam?

[–] [email protected] 24 points 5 days ago

DELTA P 🗣️🗣️

[–] [email protected] 29 points 5 days ago

This really Byfords my Dolphin

[–] over_clox 41 points 6 days ago* (last edited 6 days ago) (2 children)

I don't see the problem.

I mean, I don't swim, but the dynamics seem to make sense.

What am I missing?

Edit: Ah, don't go near the water passage, right?

[–] spiritsong 24 points 5 days ago (2 children)

Wouldn't this human in theory become a crumpled sausage like what happened to the crab by the leaking underwater pipe?

[–] TwoBeeSan 39 points 5 days ago* (last edited 5 days ago) (3 children)
[–] [email protected] 43 points 5 days ago

They also alleged the accident was due to a lack of proper equipment, including clamping mechanisms equipped with interlocking mechanisms (which would be impossible to open while the chamber system was still under pressure), outboard pressure gauges, and a safe communication system, all of which had been held back because of dispensations by the Norwegian Petroleum Directorate.

Fatigue may also have taken its toll on the crew, who had been working for longer than 12 hours

Builder of the rig Aker ASA's Gross Profit was 7.16B

Norway's oil and gas tax revenue soars to record $89 bln

Imagine forcing your workers into more than 12h shifts, running on 30 year old equipment, the government straight up refusing to upgrade said equipment, while making billions in profits - they don't call it gross profit for no reason....

[–] [email protected] 14 points 5 days ago (2 children)

Fuck all of this

Normally when people say this it is at least a bit of an exageration, but not in this case. That is some straight up nightmare fuel.

Heres a taster for those of you who don't want to read the whole thing.

...bisection of his thoracoabdominal cavity, which resulted in fragmentation of his body, followed by expulsion of all of the internal organs of his chest and abdomen...

[–] Dasus 5 points 4 days ago

You know how often a picture is worth a thousand words?

I feel like those words are worth a thousand pictures. All of them NSFL.

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[–] [email protected] 21 points 5 days ago (7 children)

Not at 15 feet. I don't know enough to say how fast the water would be leaving that hole, but it's maybe a couple hundred pounds of pressure. If he even got caught, it would be super uncomfortable, but he ain't about to get ∆p'd

If you wanna see a real crab-in-a-pipe situation, look up that Byford Dolphin everyone's talking about

[–] [email protected] 7 points 5 days ago* (last edited 5 days ago) (4 children)

Let's convert to metric so we can tell.

15 ft is about 5 m.

Water pressure increases by 10,000 pa per meter (rhogh, rho=1000 kg/m^3, g~10m/s^2), so total pressure is 50 kpa, or 1/2 earth atmospheric pressure.

One side of that hole has ambient pressure of 1 atm. The other side has that plus water pressure totalling 1.5 atm.

A pressure is just an energy density. Multiply by the cross-sectional area of the interface to get the energy gradient across the interface. An energy gradient is a force. We don't have a measure of the cross-sectional area of the hole, but if we expect a person to fit through let's call it 1m^2.

50 kpa = 50 kJ/m^3, so total force felt across this opening is 50kN which is the equivalent weight of five metric tons.

Size of the hole absolutely matters. If it's only the size of a fist (10cm x 10cm) then instead of 5 metric tons it's only 50 kg of equivalent weight, or about the weight of a person and easily survivable.

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[–] Arbiter 30 points 6 days ago

When it’s got ya, it’s got ya.

[–] spiritsong 11 points 5 days ago

Yeah I read about it. Definitely not the nicest way to go.

[–] [email protected] 19 points 6 days ago (13 children)
[–] [email protected] 35 points 6 days ago (2 children)

Muricas version of pressure.

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[–] [email protected] 15 points 5 days ago (1 children)

pounds per square inch. the us version of bar or n/m²

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[–] [email protected] 10 points 5 days ago

It's what you need to power your Protoss army

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[–] [email protected] 21 points 6 days ago (3 children)

I'm unfamiliar with fluid dynamics. How intense would the Delta p problem be in this situation?

[–] [email protected] 12 points 6 days ago (1 children)
[–] baldingpudenda 22 points 6 days ago (1 children)

from the wiki

Investigation by forensic pathologists determined that Hellevik, being exposed to the highest pressure gradient and in the process of moving to secure the inner door, was forced through the crescent-shaped opening measuring 60 centimetres (24 in) long created by the jammed interior trunk door. With the escaping air and pressure, gross dismemberment ensued; it included bisection of his thoracoabdominal cavity, which resulted in fragmentation of his body, followed by expulsion of all of the internal organs of his chest and abdomen, except the trachea and a section of small intestine, and of the thoracic spine. These were projected some distance from the bell, with one section being found 10 metres (30 ft) vertically above the exterior pressure door.

Soup indeed.

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[–] [email protected] 12 points 6 days ago (1 children)

I feel like a delta of less than 10 psi doesn't sound so bad

[–] [email protected] 17 points 5 days ago (3 children)

It depends on the size of the opening. If it's small that's no problem. You could block a 1 inch pipe at 10psi with your bare hand and be largely fine. It's a little less than 10 pounds of force assuming a round opening.

The problem is that the total force scales geometrically with the size of the opening. Make it two feet wide at the same 10psi and now you've got about 4500 pounds of force trying to push you though that opening should you find yourself in the unfortunate situation that it's been completely blocked by your body.

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[–] [email protected] 19 points 6 days ago (4 children)

Do NOT put your dick or butthole there

[–] Iheartcheese 34 points 6 days ago
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[–] [email protected] 5 points 5 days ago

is it just me or does this look like the cover of You Would Rather an Astronaut?

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