7 ms·

Would the implosion have been loud enough? I mean the thing was a tiny 7x3m cylinder located 700Km from the nearest coast...

jprd 3y ago
I've never been in the military, not a sub-mariner, 1000% SOSUS could detect that. SOSUS could detect that in the 1970s, if not earlier.
- jprd 3y ago
  https://archive.is/pSpem https://archive.is/pSpem
can16358p 3y ago
Sound can travel MUCH further and fast underwater, so in the event of an implosion, it might create enough of a spike in hydrophones that is statistically significant. Also the experts might be able to analyze the signal's signature to confirm (or bet) it's an implosion. Crossmatch that with the time of loss of communication and it's safe to assume that it's it.
- analog31 3y ago
  Indeed, and moreover, the ability to detect underwater sound is probably aided by the lack of localized turbulence (wind noise in microphones) and the degree of sophistication sought after by navies due to the detection and counter-detection of military submarines. Without any actual knowledge, I imagine that a ship or sub could be festooned with hydrophones, enabling it to detect faint noises, but also to determine their direction from phase information.
margalabargala 3y ago
I have no idea specifically how loud it would have been. However with some probably-reasonable guesses, it looks like it actually would have been quite loud. Here's a naval study where they measured underwater sound propagation: https://www.navymarinespeciesmonitoring.us/files/7514/2780/4918/Soloway_and_Dahl_2015_Noise_Measurement_Trial_at_SSTC_5Feb2015.pdf https://www.navymarinespeciesmonitoring.us/files/7514/2780/4... They found that a 10lb block of C4 exploding produced ~210db of underwater sound. If we use that sound level as an approximation of the implosion of 200 cubic meters of submersible, which seems not completely unreasonable, then we can use the inverse square law to calculate the perceived sound far away. Halifax, NS is 1100km from the Titanic wreck. A sound that is 210db at 1 meter, is 89db at 1100000 meters. Boston is 1700km away; at that distance it would be 85db. 85db is really quite loud. You would be able to hear that, if you were underwater and paying attention. If the implosion was instead, say, 180db, then it would have been 55db in Boston harbor. Still easily detectable by instruments. For reference, when divers are performing construction using e.g. rock drills, those commonly reach 170db. The implosion of close to 200 cubic meters of air seems like it would produce a louder noise than a rock drill.
- rfreiberger 3y ago
  The sad part to ponder is most likely the team on the ship knew the sub was gone right when the communications was lost but kept the information to themselves.
  - eterm 3y ago
    Apparently they've "lost communications" in many of their other trips, which is why also hints at why they didn't raise the alarm for many hours.
    - avgDev 3y ago
      From what I read and watched the company didn't take safety very seriously at all. A former employee claims they were fired after brining up concerns about safety. The glass apparently was not rated for the depth required to see the titanic.
    - at-fates-hands 3y ago
      Which begs the question why there were no additional safety measures put in place after so many "skin of the teeth" trips making it back. IMHO this was a get rich scheme the two founders spun up that went sideways. They spent the absolute minimum on safety and repeatedly cut corners on the sub in order to get it up and running, then charged people a ton of money to take a trip down deeper than the sub was clearly capable of going.
      - variaga 3y ago
        Look up "normalization of deviance". Perversely, a bunch of near-disasters can reduce people's concern and make them less likely to demand fixes because "it did that last time too and everything turned out okay" is a powerful rationalization.
        tialaramex 3y ago
        Very few industries are safe enough to actually capture the "That could have been bad" events, that's what ASRS https://asrs.arc.nasa.gov/ https://asrs.arc.nasa.gov/ does for the Aviation industry (there are equivalent agencies in various other wealthy countries e.g. CHIRP in the UK) In the absence of a proper means to report "That could have been bad" as you say it can cause normalization. But it's understandable that you don't implement something like ASRS when you haven't solved most of your "That was bad" problems. If you regularly have CI failures due to the code not even compiling, "We need more unit tests" isn't top of the list of your problems.
dylan604 3y ago
Navy sonar equipment can hear so much more than you would ever expect. Sound travels very well in water. The navy has software that pretty much tunes all of that out, similar to how radar ignores things under certain speeds as it's just not interesting to them. However, if they want, they can see/hear the raw data. There's all sorts of Navy stories about what can be heard, and not all of them are untrue.
mindslight 3y ago
How do submarines commonly fail? Is the assumption of a violent implosion warranted? I would think another failure mode could be water rushing in without the overall structure catastrophically failing, which would actually relieve pressure on the structure as it happened and be much less energetic.
- can16358p 3y ago
  Just note that the body was experimental: while the hull indeed have a thick titanium body, it was mixed with (don't know exactly how and where though) carbon fibers, which are known to catastrophically break under pressure if there's even a microscopic impurity or damage. At least that's what the experts say. Carbon fibers is great for lightweight things that need to bend, terrible for things to be relied under pressure.
  - kamranjon 3y ago
    It was just the end caps that were titanium - the entire tube was just a 5inch thick carbon fiber wrap. In one of the videos with the CEO I saw him saying that he was a rule breaker because common consensus was that you shouldn't build a submarine out of carbon fiber and titanium.
    - jonah 3y ago
      It was actually the second try at a CF tube. The first had flaws and issues and was either "repaired" or replaced by other manufacturing companies.
      - jonah 3y ago
        Reference to the repair/replacement of the cf tube: https://techcrunch.com/2023/06/20/a-whistleblower-raised-safety-concerns-about-oceangates-submersible-in-2018-then-he-was-fired https://techcrunch.com/2023/06/20/a-whistleblower-raised-saf... "The Spencer-built composite cylindrical hull either was repaired or replaced by Electroimpact and Janicki Industries in 2020 or 2021, prior to the first trips to Titanic."
el_benhameen 3y ago
I worked at an aquarium for a while, and IIRC one of the exhibits discussed how a device equivalent to an average home stereo placed in the water in Japan could be easily heard on the coast of California.
worewood 3y ago
Like evryone else I have no idea but I do know implosions tend to be pretty impressive events and can easily be supersonic generating a shockwave, so pretty loud!

jprd 3y ago

I've never been in the military, not a sub-mariner, 1000% SOSUS could detect that. SOSUS could detect that in the 1970s, if not earlier.

jprd 3y ago
https://archive.is/pSpem https://archive.is/pSpem

can16358p 3y ago

Sound can travel MUCH further and fast underwater, so in the event of an implosion, it might create enough of a spike in hydrophones that is statistically significant. Also the experts might be able to analyze the signal's signature to confirm (or bet) it's an implosion. Crossmatch that with the time of loss of communication and it's safe to assume that it's it.

analog31 3y ago
Indeed, and moreover, the ability to detect underwater sound is probably aided by the lack of localized turbulence (wind noise in microphones) and the degree of sophistication sought after by navies due to the detection and counter-detection of military submarines. Without any actual knowledge, I imagine that a ship or sub could be festooned with hydrophones, enabling it to detect faint noises, but also to determine their direction from phase information.

margalabargala 3y ago

I have no idea specifically how loud it would have been. However with some probably-reasonable guesses, it looks like it actually would have been quite loud. Here's a naval study where they measured underwater sound propagation: https://www.navymarinespeciesmonitoring.us/files/7514/2780/4918/Soloway_and_Dahl_2015_Noise_Measurement_Trial_at_SSTC_5Feb2015.pdf https://www.navymarinespeciesmonitoring.us/files/7514/2780/4... They found that a 10lb block of C4 exploding produced ~210db of underwater sound. If we use that sound level as an approximation of the implosion of 200 cubic meters of submersible, which seems not completely unreasonable, then we can use the inverse square law to calculate the perceived sound far away. Halifax, NS is 1100km from the Titanic wreck. A sound that is 210db at 1 meter, is 89db at 1100000 meters. Boston is 1700km away; at that distance it would be 85db. 85db is really quite loud. You would be able to hear that, if you were underwater and paying attention. If the implosion was instead, say, 180db, then it would have been 55db in Boston harbor. Still easily detectable by instruments. For reference, when divers are performing construction using e.g. rock drills, those commonly reach 170db. The implosion of close to 200 cubic meters of air seems like it would produce a louder noise than a rock drill.

rfreiberger 3y ago
The sad part to ponder is most likely the team on the ship knew the sub was gone right when the communications was lost but kept the information to themselves.
- eterm 3y ago
  Apparently they've "lost communications" in many of their other trips, which is why also hints at why they didn't raise the alarm for many hours.
  - avgDev 3y ago
    From what I read and watched the company didn't take safety very seriously at all. A former employee claims they were fired after brining up concerns about safety. The glass apparently was not rated for the depth required to see the titanic.
  - at-fates-hands 3y ago
    Which begs the question why there were no additional safety measures put in place after so many "skin of the teeth" trips making it back. IMHO this was a get rich scheme the two founders spun up that went sideways. They spent the absolute minimum on safety and repeatedly cut corners on the sub in order to get it up and running, then charged people a ton of money to take a trip down deeper than the sub was clearly capable of going.
    - variaga 3y ago
      Look up "normalization of deviance". Perversely, a bunch of near-disasters can reduce people's concern and make them less likely to demand fixes because "it did that last time too and everything turned out okay" is a powerful rationalization.
      - tialaramex 3y ago
        Very few industries are safe enough to actually capture the "That could have been bad" events, that's what ASRS https://asrs.arc.nasa.gov/ https://asrs.arc.nasa.gov/ does for the Aviation industry (there are equivalent agencies in various other wealthy countries e.g. CHIRP in the UK) In the absence of a proper means to report "That could have been bad" as you say it can cause normalization. But it's understandable that you don't implement something like ASRS when you haven't solved most of your "That was bad" problems. If you regularly have CI failures due to the code not even compiling, "We need more unit tests" isn't top of the list of your problems.

dylan604 3y ago

Navy sonar equipment can hear so much more than you would ever expect. Sound travels very well in water. The navy has software that pretty much tunes all of that out, similar to how radar ignores things under certain speeds as it's just not interesting to them. However, if they want, they can see/hear the raw data. There's all sorts of Navy stories about what can be heard, and not all of them are untrue.

mindslight 3y ago

How do submarines commonly fail? Is the assumption of a violent implosion warranted? I would think another failure mode could be water rushing in without the overall structure catastrophically failing, which would actually relieve pressure on the structure as it happened and be much less energetic.

can16358p 3y ago
Just note that the body was experimental: while the hull indeed have a thick titanium body, it was mixed with (don't know exactly how and where though) carbon fibers, which are known to catastrophically break under pressure if there's even a microscopic impurity or damage. At least that's what the experts say. Carbon fibers is great for lightweight things that need to bend, terrible for things to be relied under pressure.
- kamranjon 3y ago
  It was just the end caps that were titanium - the entire tube was just a 5inch thick carbon fiber wrap. In one of the videos with the CEO I saw him saying that he was a rule breaker because common consensus was that you shouldn't build a submarine out of carbon fiber and titanium.
  - jonah 3y ago
    It was actually the second try at a CF tube. The first had flaws and issues and was either "repaired" or replaced by other manufacturing companies.
    - jonah 3y ago
      Reference to the repair/replacement of the cf tube: https://techcrunch.com/2023/06/20/a-whistleblower-raised-safety-concerns-about-oceangates-submersible-in-2018-then-he-was-fired https://techcrunch.com/2023/06/20/a-whistleblower-raised-saf... "The Spencer-built composite cylindrical hull either was repaired or replaced by Electroimpact and Janicki Industries in 2020 or 2021, prior to the first trips to Titanic."

el_benhameen 3y ago

I worked at an aquarium for a while, and IIRC one of the exhibits discussed how a device equivalent to an average home stereo placed in the water in Japan could be easily heard on the coast of California.

worewood 3y ago

Like evryone else I have no idea but I do know implosions tend to be pretty impressive events and can easily be supersonic generating a shockwave, so pretty loud!