4 ms·

Truly bizarre. Failures like this happen in milliseconds, it doesn't matter how realtime your realtime monitoring is. I'm not arguing in favor of the classific

Truly bizarre. Failures like this happen in milliseconds, it doesn't matter how realtime your realtime monitoring is. I'm not arguing in favor of the classification system, but, I think if you went to them and framed things as simply as they are here "you require validation every 3 years, we're doing it on every single dive" they would say "that's more than once per 3 years, APPROVED!" so the situation is clearly far more complicated than they are indicating.

_yb2s 3y ago
Yes, I don't understand this acoustic monitoring concept... I'm curious what the logic behind it was. It just doesn't seem like there would be enough time to take action once the monitor starts to detect failure.
- jnwatson 3y ago
  It depends on the material. It might work for certain tours of steel, since the failure state is gradual. Carbon fiber, however, is not known to gradually fail.
- mustacheemperor 3y ago
  It seems they felt this was one of the novel innovations that enabled this design - that the monitoring system was so good, they'd never be at risk in the pressure hull at depth. James Cameron said it looks like they had dropped their emergency ascent ballast before the implosion, so they may have gotten enough warning to take action. But I would guess that system was never tested to failure in real life. It will be interesting to see which of the novel innovations supposedly enabling this unconventional design failed, if it can be determined. Rush also lampshaded the fact that his company had "successfully" bonded the titanium endcaps to carbon fiber despite that being contradictory to conventional materials science wisdom, reading the patent for the monitoring system it looks like it may have been intended to provide warning about those bonds failing too.
  - _yb2s 3y ago
    It seems like it would be trivial to test how much early warning such a system gives by bringing smaller/cheaper test hulls to failure, either in the ocean, or in a pressure testing chamber. I wonder if they did that?
  - dm319 3y ago
    Do you know in what way it was 'acoustic'? I.e. was it listening for sounds, or was it more like sonar?
    - mustacheemperor 3y ago
      I looked over the patent yesterday, I think someone linked it in this thread. It would “listen” for the sounds of impending structural failure, by comparing the sounds in the hull to a dataset of previous test dives. One of the passengers on Titan’s 2nd dive said it made cracking and popping noises as it got deeper but the patent intended to detect a change in acoustics (in conjunction with stress sensors) far enough in advance for corrective action.

_yb2s 3y ago

Yes, I don't understand this acoustic monitoring concept... I'm curious what the logic behind it was. It just doesn't seem like there would be enough time to take action once the monitor starts to detect failure.

jnwatson 3y ago
It depends on the material. It might work for certain tours of steel, since the failure state is gradual. Carbon fiber, however, is not known to gradually fail.
mustacheemperor 3y ago
It seems they felt this was one of the novel innovations that enabled this design - that the monitoring system was so good, they'd never be at risk in the pressure hull at depth. James Cameron said it looks like they had dropped their emergency ascent ballast before the implosion, so they may have gotten enough warning to take action. But I would guess that system was never tested to failure in real life. It will be interesting to see which of the novel innovations supposedly enabling this unconventional design failed, if it can be determined. Rush also lampshaded the fact that his company had "successfully" bonded the titanium endcaps to carbon fiber despite that being contradictory to conventional materials science wisdom, reading the patent for the monitoring system it looks like it may have been intended to provide warning about those bonds failing too.
- _yb2s 3y ago
  It seems like it would be trivial to test how much early warning such a system gives by bringing smaller/cheaper test hulls to failure, either in the ocean, or in a pressure testing chamber. I wonder if they did that?
- dm319 3y ago
  Do you know in what way it was 'acoustic'? I.e. was it listening for sounds, or was it more like sonar?
  - mustacheemperor 3y ago
    I looked over the patent yesterday, I think someone linked it in this thread. It would “listen” for the sounds of impending structural failure, by comparing the sounds in the hull to a dataset of previous test dives. One of the passengers on Titan’s 2nd dive said it made cracking and popping noises as it got deeper but the patent intended to detect a change in acoustics (in conjunction with stress sensors) far enough in advance for corrective action.