5 ms·

Their bodies are also pressurized at 1 atms, after being exposed to 400 atms they instantly died. My guess is that they were effectively vaporized/liquified. M

Their bodies are also pressurized at 1 atms, after being exposed to 400 atms they instantly died. My guess is that they were effectively vaporized/liquified. Much better way to go then suffocate in darkness.

ceejayoz 3y ago
It's a good guess. https://en.wikipedia.org/wiki/Byford_Dolphin https://en.wikipedia.org/wiki/Byford_Dolphin > 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, 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, one section being found 10 metres (30 ft) vertically above the exterior pressure door. That's with a nine atmosphere pressure differential. The Titanic is at about 400 atmospheres.
- ilyt 3y ago
  I tried to find [1] how much pressure explosion of a grenade would cause. It would take a lot of grenades to get to 400 atmospheres... - [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5514183/#:~:text=268 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5514183/#:~:tex...
  - jacquesm 3y ago
    I wonder if you even could, given the fact that that stuff is trying to get away from each other you'd have to get the timing right to a ridiculous degree of precision.
    - deleted 3y ago
      [deleted]
- TechBro8615 3y ago
  That wiki page describes a decompression injury, which AFAIU is the opposite of implosion: > This resulted in the chamber being explosively decompressed from a pressure of nine atmospheres to the one atmosphere of the unsealed chamber system. Whereas an analogous description of the submarine implosion would describe the opposite, i.e. "explosively compressed from a pressure of one atmosphere to 400 atmospheres."
  - ceejayoz 3y ago
    The point is the extreme, rapid force involved. Imploding or exploding, nine atmospheres is gonna suck. 400 atmospheres is... like standing under a nuclear bomb. The good news is it doesn't hurt, at all. Someone else on the thread posted a video of a one atmosphere implosion (https://www.youtube.com/watch?v=Zz95_VvTxZM https://www.youtube.com/watch?v=Zz95_VvTxZM). 400x the pressure here.
    - TechBro8615 3y ago
      Indeed. I'd be curious if there would even be a body to find. I have to imagine it'd be compressed into paste. It's very disturbing to think about, but also a preferable way to die compared to suffering through 96 hours of uncertainty before slowly asphyxiating.
rightbyte 3y ago
Why are people assuming this? How about a leak that fills the sub with water? Is a leak impossible to keep stable at those depths?
- ceejayoz 3y ago
  A leak at 400 atmospheres doesn't stay a leak.
  - jacquesm 3y ago
    That highly depends on the source of the leak. But if it does start to leak you better surface pdq.
- pugworthy 3y ago
  A slow leak that filled the sub would not necessarily have lead to the vessel's destruction. That said, you can get leaks. I participated on a research cruise with a French submersible, and there was talk of small leaks with the main hatch seal occurring during descent. The "fix" was to go deeper so the pressure would essentially seal the hatch shut.
- sho_hn 3y ago
  > Why are people assuming this? How about a leak that fills the sub with water? Is a leak impossible to keep stable at those depths? Part of this is the use of carbon fibre, which is a very brittle material. In bike frame failures, for example, carbon fibre doesn't tend to rip a little or bend, it often fractures greatly or even shatters. Add the enormous pressure difference, and this is why most people assume instant catastrophic failure.
- alangibson 3y ago
  They found a debris field. That's pretty conclusively not a slow leak.
- twism 3y ago
  i think any small breach is an instant implosion at 400 atm
f38zf5vdt 3y ago
Probably combusted? At 400 atms their biomass would compress into a gelatinous hydrocarbon fat blob with the oxygen present, resulting in automatic combustion. The amount of compression their bodies would experience is an order of magnitude greater than a diesel engine cylinder. The explosion would immediately be quenched by the surrounding water and the only thing remaining of the occupants would be ash. This would happen on the order of milliseconds.
- pfdietz 3y ago
  Adiabatic compression of air to 400 bar increases the absolute temperature by about a factor of 5.5, which would be the temperature of a flame.
  - amluto 3y ago
    Water, fat, etc are not nearly as compressible as air, and the thermal mass of the air involved would be a couple orders of magnitude lower than everything else. 400 bar is (from some quick searching) fairly mild for industrial hydraulic systems, and hydraulic fluid doesn’t get especially hot while in use. On the other hand, a leak in a pressurized hydraulic system is extremely dangerous if you’re around it due to the extreme velocity of ejected fluid.
    - f38zf5vdt 3y ago
      Hydraulics don't get hot while in use unless you introduce air into the system, in which case they do get hot and explosive. This is called hydraulic dieseling and microdieseling. The passengers would have been surrounded by oxygen and CO2 gas, and the oxygen tank would rupture as soon as the capsule imploded.
- jamiek88 3y ago
  When it happened in that accident referred to elsewhere in the thread the water temp was elevated massively in that area (enclosed so measurable). Their blood would combust instantly. They found cooked blood after that accident too. Edit: https://en.wikipedia.org/wiki/Byford_Dolphin https://en.wikipedia.org/wiki/Byford_Dolphin

ceejayoz 3y ago

It's a good guess. https://en.wikipedia.org/wiki/Byford_Dolphin https://en.wikipedia.org/wiki/Byford_Dolphin > 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, 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, one section being found 10 metres (30 ft) vertically above the exterior pressure door. That's with a nine atmosphere pressure differential. The Titanic is at about 400 atmospheres.

ilyt 3y ago
I tried to find [1] how much pressure explosion of a grenade would cause. It would take a lot of grenades to get to 400 atmospheres... - [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5514183/#:~:text=268 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5514183/#:~:tex...
- jacquesm 3y ago
  I wonder if you even could, given the fact that that stuff is trying to get away from each other you'd have to get the timing right to a ridiculous degree of precision.
  - deleted 3y ago
    [deleted]
TechBro8615 3y ago
That wiki page describes a decompression injury, which AFAIU is the opposite of implosion: > This resulted in the chamber being explosively decompressed from a pressure of nine atmospheres to the one atmosphere of the unsealed chamber system. Whereas an analogous description of the submarine implosion would describe the opposite, i.e. "explosively compressed from a pressure of one atmosphere to 400 atmospheres."
- ceejayoz 3y ago
  The point is the extreme, rapid force involved. Imploding or exploding, nine atmospheres is gonna suck. 400 atmospheres is... like standing under a nuclear bomb. The good news is it doesn't hurt, at all. Someone else on the thread posted a video of a one atmosphere implosion (https://www.youtube.com/watch?v=Zz95_VvTxZM https://www.youtube.com/watch?v=Zz95_VvTxZM). 400x the pressure here.
  - TechBro8615 3y ago
    Indeed. I'd be curious if there would even be a body to find. I have to imagine it'd be compressed into paste. It's very disturbing to think about, but also a preferable way to die compared to suffering through 96 hours of uncertainty before slowly asphyxiating.

rightbyte 3y ago

Why are people assuming this? How about a leak that fills the sub with water? Is a leak impossible to keep stable at those depths?

ceejayoz 3y ago
A leak at 400 atmospheres doesn't stay a leak.
- jacquesm 3y ago
  That highly depends on the source of the leak. But if it does start to leak you better surface pdq.
pugworthy 3y ago
A slow leak that filled the sub would not necessarily have lead to the vessel's destruction. That said, you can get leaks. I participated on a research cruise with a French submersible, and there was talk of small leaks with the main hatch seal occurring during descent. The "fix" was to go deeper so the pressure would essentially seal the hatch shut.
sho_hn 3y ago
> Why are people assuming this? How about a leak that fills the sub with water? Is a leak impossible to keep stable at those depths? Part of this is the use of carbon fibre, which is a very brittle material. In bike frame failures, for example, carbon fibre doesn't tend to rip a little or bend, it often fractures greatly or even shatters. Add the enormous pressure difference, and this is why most people assume instant catastrophic failure.
alangibson 3y ago
They found a debris field. That's pretty conclusively not a slow leak.
twism 3y ago
i think any small breach is an instant implosion at 400 atm

f38zf5vdt 3y ago

Probably combusted? At 400 atms their biomass would compress into a gelatinous hydrocarbon fat blob with the oxygen present, resulting in automatic combustion. The amount of compression their bodies would experience is an order of magnitude greater than a diesel engine cylinder. The explosion would immediately be quenched by the surrounding water and the only thing remaining of the occupants would be ash. This would happen on the order of milliseconds.

pfdietz 3y ago
Adiabatic compression of air to 400 bar increases the absolute temperature by about a factor of 5.5, which would be the temperature of a flame.
- amluto 3y ago
  Water, fat, etc are not nearly as compressible as air, and the thermal mass of the air involved would be a couple orders of magnitude lower than everything else. 400 bar is (from some quick searching) fairly mild for industrial hydraulic systems, and hydraulic fluid doesn’t get especially hot while in use. On the other hand, a leak in a pressurized hydraulic system is extremely dangerous if you’re around it due to the extreme velocity of ejected fluid.
  - f38zf5vdt 3y ago
    Hydraulics don't get hot while in use unless you introduce air into the system, in which case they do get hot and explosive. This is called hydraulic dieseling and microdieseling. The passengers would have been surrounded by oxygen and CO2 gas, and the oxygen tank would rupture as soon as the capsule imploded.
jamiek88 3y ago
When it happened in that accident referred to elsewhere in the thread the water temp was elevated massively in that area (enclosed so measurable). Their blood would combust instantly. They found cooked blood after that accident too. Edit: https://en.wikipedia.org/wiki/Byford_Dolphin https://en.wikipedia.org/wiki/Byford_Dolphin