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Question about death of Edward Cossaboom, 1914

Discussion in 'Accidents and Incidents' started by Jake, Oct 29, 2020.

  1. Jake

    Jake ScubaBoard Supporter ScubaBoard Supporter

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    Hopefully this is the right forum; if not, maybe mods can be so kind as to move this post.

    Warning: this post might also count as a little graphic.

    In his book "Dark Descent," Kevin F. McMurray describes the death of hard hat diver Edward Cossaboom who was doing salvage work on the recently sunk Empress of Ireland. I don't quite understand the physics of his death and was hoping someone could shed some light on the situation.

    While doing his work, Cossaboom lost his footing at 75 feet and fell to the riverbed at 140 feet. His tenders weren't able to respond in time and the pressure differential shoved most of him up into the helmet:

    By the time he hit the bottom the invading sea pressure had stripped the flesh from his bones. His skin and organs were pile-driven into the only part of his suit that was resistant to the pressure, his copper diving helmet.
    McMurray explains that by breathing gas at ambient pressure we maintain enough internal pressure in our blood and organs to avoid being crushed. Free divers and other mammals routinely dive well below 140 feet without matching ambient pressure, and bodies are commonly recovered below that depth without having imploded. McMurray's explanation of needing to match ambient pressure therefore seems incomplete with respect to what happened to Cossaboom.

    So...what am I missing? Does the helmet and the air supply hose in this situation really present that much of a pressure differential when adding 2ATM of pressure?
     
  2. Julius SCHMIDT

    Julius SCHMIDT Nassau Grouper

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    Location: Alexandra Headland
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  3. Jake

    Jake ScubaBoard Supporter ScubaBoard Supporter

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    Thanks @Julius SCHMIDT. I was definitely just overthinking it, but I guess I'm still surprised that 2atm of change is enough to do that to someone. Hopefully he went quickly, as that does not sound like a fun way to go if it's slow.
     
    Julius SCHMIDT likes this.
  4. John the Pom

    John the Pom Nassau Grouper

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    Mythbusters tried the experiment ...

     
    fisheater, Hoyden, dmaziuk and 2 others like this.
  5. Julius SCHMIDT

    Julius SCHMIDT Nassau Grouper

    # of Dives: 500 - 999
    Location: Alexandra Headland
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    Even in a tight fitting neoprene drysuit it's not pretty think of a machine with claws grabbing your inner thigh x10
     
  6. rjack321

    rjack321 ScubaBoard Supporter ScubaBoard Supporter

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    The same phenomenon is responsible for "mask squeeze", usually in new divers who are overwhelmed, holding their nose trying to clear their ears. The mask space doesn't equalize and they get 2 black eyes or blood vessels in their sclera break and they have some blood in there. 2ATA is quite a bit of pressure, plenty to cause mask squeeze, or kill Cossaboom
    Scuba Dive Mask Squeeze — Medical Dive Article — DAN | Divers Alert Network
     
  7. TravisD

    TravisD Assistant Instructor

    # of Dives: 200 - 499
    Location: Westminster, MD
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    Hmm... Say average surface area of a human is 3000 in^2. Times 14psi = 84,000 pounds of pressure, pushing against the only opening - say a 1" air fitting - 0.79 in^2 area.

    Math is probably wrong, but you get the idea...
     
  8. Jake

    Jake ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: CA
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    When you put it that way, it's pretty incredible that we don't feel any of that when properly equalized.

    Thanks everyone for the replies.
     
  9. Jake

    Jake ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: CA
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    Well, that's horrifying! :)
     
    kelemvor likes this.
  10. drl

    drl Manta Ray

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    Yes it was horrifying! I really thought they would bust that myth and was shocked that it was confirmed, given just the right circumstances.
     

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