Anon's in trouble

The biggest problem is he's engineering in Imperial instead of SI units.
- I thought the same way, then became an American engineer. Fuck a horsepower, because it's so goddamned context dependent.

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?
- 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
  
  Ahhh yeah that's where I've heard it before, WTYP had an episode on that!
  
  210 lbs will certainly keep you stuck there though
  
  from a different reply I understood the meaning of the last two words: https://en.m.wikipedia.org/wiki/Byford_Dolphin
  
  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)
- Is 5m enough for that? I feel like no, but i have no idea.
- Yup.

This unfortunately happened in real life.
Edit: other way around though. The divers were on the air side (habitable quarters) of the chamber.
- 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
  
  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.
  
  No one fucked up, they finally settled on it being a mechanical failure.
  Edit: the company and government fucked up, I meant to imply none of the divers fucked up.
- Some parts of that article are straight horror.
  
  👋 not reading it
- 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)

But where's Saddam?

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?
- Delta-p hazard
  
  I just remembered that meme "SpongeBob Experiences Delta-P and Dies Instantly"
  Although I'm having a Mandela Effect moment where I swear I saw a version where Patrick talked a lot longer with much more technical information.
- https://www.youtube.com/watch?v=PXgKxWlTt8A
  Like that, but with people.
  
  Ouch!
  And just to think, we're all gradually evolving into crabs..
  
  Delta P

When it’s got ya, it’s got ya.

This really Byfords my Dolphin

Wouldn't this human in theory become a crumpled sausage like what happened to the crab by the leaking underwater pipe?
- https://en.m.wikipedia.org/wiki/Byford_Dolphin#Diving_bell_accident
  Fuck all of this
  
  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....
  
  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...
- 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
  
  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.
  
  Yeah I read the entire Wikipedia entry on the Byford Dolphin and I almost threw up because how vivid the description is. I think this would be my third time saying this but that's not a nice way to go (to die) at all.

DELTA P 🗣️🗣️

I'm unfamiliar with fluid dynamics. How intense would the Delta p problem be in this situation?
- Soup like homogenate
  
  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.
- I feel like a delta of less than 10 psi doesn't sound so bad
  
  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.
- Big succ P

anon's in trouble because they're using psi instead of bar.
Edit: also fuck high pressures are a scary thing.
- Pascal FTW.
  
  He is so dreamy
  
  Think you mean mmHg

Do NOT put your dick or butthole there
- Big 'Guts' vibes here
- Well if you have both, and disregard this warning, it will be hard to separate the two

Wtf is a psi
- Muricas version of pressure.
  
  It would kill you regardless of where you live
  
  Freedom units
- pounds per square inch. the us version of bar or n/m²
  
  Why is your comment highlighted blue in Lemmy Connect?
- It's what you need to power your Protoss army
- It's the Imperial Gangnam Style unit
- 100.000 PSI is equal to 1 bar(if I remember correctly)
  
  Unfortunately no, 1 bar (1 atmosphere) is 100,000 pascal
  PSI is pounds per square inch and is roughly 14.5 PSI to 1 bar, and to me, way less intuitive than bar
  
  That’s metric
  
  no, not at all. bar is a logical metric unit, psi is imperial. because the us doesn't know what powers of 10 are, there's never a nice conversion factor.