Will the Titanic claim a few more?

[twistedtree]

The article was quite good.

Doing stupid things, and ignoring engineering and physics is not “innovative”, it’s ignorant and reckless.

Innovation is devising new approaches that are well engineered and observe and respect physics, and that stand up to peer critique.

 

[CaptTom]

I just read that the pattern and distribution of wreckage suggests that ballast had been jettisoned prior to the implosion...suggesting that the crew were attempting an emergency ascent....

One thing I read (or was it an interview I watched?) suggested that the last communication was that they were dropping ballast and ascending. It seems the surface support team was well aware that there was a problem, and by at least one report actually heard the implosion. I sort of assumed from the beginning that they knew what happened but couldn't say publicly until they were sure. Fair enough. I'd have done the same.

 

[Hippocampus]

My mistake i misinterpreted your post. Thought it applied as a passenger. My apologies. Find it informative when someone thinks differently than you. View it as an opportunity to learn and/or refine your own thinking.

 

[AlaskaProf]

I sort of assumed from the beginning that they knew what happened but couldn't say publicly until they were sure. Fair enough. I'd have done the same.

Seems to me that would be a serious dereliction, to accept vast amounts of personnel and materiel without sharing critical information which would define the nature and area of the search.

 

[psneeld]

Seems to me that would be a serious dereliction, to accept vast amounts of personnel and materiel without sharing critical information which would define the nature and area of the search.

May be much like the info the Navy had from underwater listening....

What was shared with the incident commander and the public might be 2 different things. Even if the incident commander had certain info...unless conclusive, like the Navy info, proceeding with the search may have been as much for data collection as rescue.

My opinion of the public needing to know anything these days is pretty shaky....seems to me while I like transparency...the IQ of the general public seems barely competent to be able to count their own fingers and toes.

News reports are about at the same level.

 

[Benthic2]

If the sub was intact on the bottom but withour power, it would automatically drop its ballast after 16 hours* even if everyone inside was unconcious. I think if they didn't return to the surface about midnight on the first day then it seems very likely that the sub suffered an implosion, and there was no need to bring in the other ROV's

*I bet an uncontrolled ascent from 13,000 feet would be quite a ride. The vessel would probably launch itself 20 feet in the air when it broke the surface!

 

[psneeld]

If the sub was intact on the bottom but withour power, it would automatically drop its ballast after 16 hours* even if everyone inside was unconcious. I think if they didn't return to the surface about midnight on the first day then it seems very likely that the sub suffered an implosion, and there was no need to bring in the other ROV's

*I bet an uncontrolled ascent from 13,000 feet would be quite a ride. The vessel would probably launch itself 20 feet in the air when it broke the surface!

You are assuming decisions were only made for SAR and no further reasons.

 

[Delta Riverat]

The article was quite good.

Doing stupid things, and ignoring engineering and physics is not “innovative”, it’s ignorant and reckless.

Innovation is devising new approaches that are well engineered and observe and respect physics, and that stand up to peer critique.

I agree. I'm all for innovation, hey we're using it now eh?

I'm also an engineer and there is just so much wrong with this.

 

[Benthic2]

You are assuming decisions were only made for SAR and no further reasons.

Why else would they be out there ?

 

[soin2la]

One thing I read (or was it an interview I watched?) suggested that the last communication was that they were dropping ballast and ascending. It seems the surface support team was well aware that there was a problem, and by at least one report actually heard the implosion. I sort of assumed from the beginning that they knew what happened but couldn't say publicly until they were sure. Fair enough. I'd have done the same.

James Cameron has maintained from the very beginning they had dropped balast and were in ascent.

 

[psneeld]

Why else would they be out there ?

Doing what they have been doing since they found and positively ID the debris field.

Here is your post #5

"My guess would be entanglement. If they ditched ballast and were bobbing along on the surface, an epirpb would have been sent. I suspect since they have done this trip many times, implosion isn't very likely. After 7 hours w/o communication I would think the chances of a positive outcome are very slim."

Here is my post #3 (long before all the speculators had run their course)....

"What about....Imploded? "

 

[Hippocampus]

Who will do the equivalent of a post? Will that investigation be released to the general public? In whose jurisdiction is that part of the ocean or is it determined by the documentation of the involved vessel?
Much of this thread has been based on interpretations and assumptions. One would think access to the official record of events and post event investigations would clear the fog produced by such speculations.

 

[Nick F]

*I bet an uncontrolled ascent from 13,000 feet would be quite a ride. The vessel would probably launch itself 20 feet in the air when it broke the surface!

Not at all - the sub would be only slightly positively buoyant and would have an ascent rate of a few feet/sec.

 

[Nick14]

An interesting article today in the New York Times today on the Titan fiasco, which describes the multiple cost-cutting design flaws that led to it's predicted failure.

https://www.nytimes.com/interactive/2023/07/14/us/titan-submersible-implode-design.html

The two images below from the article (among many others) are telling. The first one shows the inherent problem of using two dissimilar materials for the pressure hill, titanium and carbon fiber, and the resulting (again predicted) differences in how they respond to pressure.

The second image is a comparison of the interiors of the Titan vs. the Alvin, which has successfully made over 4,500 deep dives - clearly a well-proven design. I think the pics tell the story - cost-cutting on the left, and the right way to do it on the right, with multiple redundant controls and safety systems.

As others have said, it's a story of hubris, when wealthy egomaniacs think they're smarter than the laws of physics. Physics wins every time.

 

[CaptTom]

Has anyone seen the supposed transcript of the last comms with the sub?

I know there's controversy about whether or not the transcript is legit. If so, it means the crew knew there was a problem and they were beginning to ascend. If it's fake, then it's a good fake, which offers one very likely sequence of events.

 

[wkearney99]

Has anyone seen the supposed transcript of the last comms with the sub?.

If it's not fake, yikes, descending too fast and then 19 minutes of 'uh oh' as they tried to ascend.

 

[Nick F]

An interesting article today in the New York Times today on the Titan fiasco, which describes the multiple cost-cutting design flaws that led to it's predicted failure.

https://www.nytimes.com/interactive/2023/07/14/us/titan-submersible-implode-design.html

Thanks for this Nick. Interesting, but (IMHO) a bit simplistic. To say that the "pill" shape (having a cylindrical centre section) is unsafe is simply ridiculous - every submarine in the world has this hull shape. This is a design trade-off between useable hull interior volume and weight/cost/exterior size.

I suspect that cyclic loading in compression of the carbon fibre cylindrical section caused flaws to develop which led to buckling collapse. Typically, a tubular shape under external pressure collapses from an "O" shape into a "figure 8" shape, although this applies to ductile material and carbon fibre composite probably behaves differently.

One of the problems in testing is the rarity (possibly none at this time) and high cost of hyperbaric test chambers large enough to contain the complete hull and apply a pressure of over 6500psi. I see from the article that some 1/3 scale testing was performed - it will be interesting to know more about this.
Link about test chambers: https://www.nui.no/test-facilities/

Assuming the transcript to be true, I wonder two things:

1 Increased descent rate - this implies increase of weight (slow leak?) or reduced buoyancy, presumably due to decrease of external volume (inward flexing of hull?).

2 What were the occupants hearing/sensing during the 19 minutes and why was there no spoken description of the symptoms? Was Rush trying to play it cool and not unnerve his passengers? Was there a "black box" aboard, recording data and audio?

 

[psneeld]

Thanks for this Nick. Interesting, but (IMHO) a bit simplistic. To say that the "pill" shape (having a cylindrical centre section) is unsafe is simply ridiculous - every submarine in the world has this hull shape. This is a design trade-off between useable hull interior volume and weight/cost/exterior size.

I suspect that cyclic loading in compression of the carbon fibre cylindrical section caused flaws to develop which led to buckling collapse. Typically, a tubular shape under external pressure collapses from an "O" shape into a "figure 8" shape, although this applies to ductile material and carbon fibre composite probably behaves differently.

One of the problems in testing is the lack of a test chamber large enough to contain the complete hull and apply a pressure of 6500psi plus, say, 10%. I see from the article that some 1/3 scale testing was performed - it will be interesting to know more about this.

Aren't all "deepest" diving submersibles generally the same pressure hull shape of a sphere?.....and regular subs crush depth is but just a fraction so other shapes are more possible?

 

[Nick F]

Aren't all "deepest" diving submersibles generally the same pressure hull shape of a sphere?.....and regular subs crush depth is but just a fraction so other shapes are more possible?

I believe you are correct, but these spherical hull submersibles may not be economically viable for tourist applications. As I said, IMHO it is a trade-off.

 

[wkearney99]

I suspect that cyclic loading in compression of the carbon fibre cylindrical section caused flaws to develop which led to buckling collapse.

I think what gets left out from some people's understanding is that this sub had done this trip before. At least 3 times to the Titanic's depth and over 200 dives elsewhere. So it wasn't like the vessel was just slapped together and down we go!

While it's not directly related, F1 race cars, dragsters and other high performance race vehicles push the limits of a lot of materials. But they're broken down and overhauled pretty much after EVERY race. Lots of pieces pushed to/beyond limits and they have to get swapped out/replaced. The difference being if they screw up it's a crash at ground level, not thousands of feet below the seas. From the limited bits I've read thus far it does not seem like this sub underwent anywhere the same degree of re-testing and re-building after such extreme dives (if any at all).

 

[psneeld]

I believe you are correct, but these spherical hull submersibles may not be economically viable for tourist applications. As I said, IMHO it is a trade-off.

Tradeoff is safe or unsafe? I am the first to agree that everything has risks...but after 2 careers that involved life and limb to a degree, understanding risks and only taking those that are necessary is the mantra.

Isn't this the "first" to employ composite and non-spherical for very deep dives?

I think I read that just about everyone well versed in this endeavor advised against both.

To me, as long as everyone was well versed in the risks and willing to die...and all the SAR resource operators were well aware of the "risk takers actual risks"...then all is OK by me..... I just suspect that this wasn't the case.

It might have been a great tradeoff for much shallower dives...but in this case something went wrong and hopefully someone will figure it all out and keep the future industry more safe.

 

[Nick F]

Tradeoff is safe or unsafe? I am the first to agree that everything has risks...but after 2 careers that involved life and limb to a degree, understanding risks and only taking those that are necessary is the mantra.

Isn't this the "first" to employ composite and non-spherical for very deep dives?

Scott - for me, safety is an absolute - it is not part of the design trade-off.

I am only trying to be logical and to separate the hull configuration issue from the choice of material issue (and apparently its inadequate application). IMHO the choice of obround hull is not a showstopper.

I think that the NY Times article misleads people on the importance of the geometry issue.

 

[psneeld]

Scott - for me, safety is an absolute - it is not part of the design trade-off.

I am only trying to be logical and to separate the hull configuration issue from the choice of material issue (and apparently its inadequate application). IMHO the choice of obround hull is not a showstopper.

I think that the NY Times article misleads people on the importance of the geometry issue.

I couldn't read the Times article, but while the search was still going on, a lot of other people in that particular endeavor all commented that for subs and medium diving submersibles non-spherical may be OK... my understanding is almost every imploding tragedy (if the real cause was ever really determined) was not with the deep spherical shape... it was for a shallower diving shape that either got to deep for some reason or sank from fatigue failure leaks.

If the Times article is misleading I can't say, but there has been a lot of commenting on both shape and/or materials in this case. I do get that anyone with even remote experience gets a call to comment and it's easy to be critical, but supposedly a bunch of experts sent letters to the company saying they were headed down the wrong path.

Some people here are mislead by media reports all the time...look at all the regular boat sinkings posters make judgement on with a few tidbits (true or not) from articles and broadcasts....

I don't disagree shapes other than spheres could be practical for recreational submersibles, just not deep diving ones till they get the materials issue worked out.

 

[twistedtree]

I expect if they had gone through full testing for certification, the weaknesses would have been exposed before killing people. But I gather that's counter to "innovation".

 

[psneeld]

The twist I see in this whole thing is that it technically was an experimental craft with a "crew" and not passengers...but then again I haven't been following it too closely to say for sure.

I am not sure where the guy's son fit in to "the crew" vs a passenger.

Hey, test pilots of aircraft or submersibles can ride to the bottom of the ocean or fly into space in a craft made from glued together water bottles for all I care. Population control at it's best.

But passengers..... they need the full brief or protection through a well regulated system with appropriate testing and certification as many have posted.

Isn't some posters mantra something like "just because you get away with something previously doesn't mean it's right."

 

[AlaskaProf]

I am not sure where the guy's son fit in to "the crew" vs a passenger.


But passengers..... they need the full brief or protection through a well regulated system with appropriate testing and certification as many have posted.

There's the rub, he had no passengers, only "mission specialists." Used to be a common (usually unsuccessful) evasion in aviation. Something like, " I wasn't carrying them for hire, I was showing real estate..."

 

[CaptTom]

...
2 What were the occupants hearing/sensing during the 19 minutes and why was there no spoken description of the symptoms? Was Rush trying to play it cool and not unnerve his passengers? Was there a "black box" aboard, recording data and audio?

My understanding is that the only comms capability was text, and even that wasn't very reliable. I have yet to read anything about a data or voice recorder.

I think the best we're going to get is the official report, which will at least confirm or disprove the authenticity of the transcript.

 

[OBXSkipper]

Well this is the link, I see no reason why someone would fake something like this, I suppose the best way to form an opinion would be to view it if You choose .

 

[psneeld]

Who was that youtuber?

All I know is I feel pretty nauseous after watching it and I skipped though it just to hear enough.

What she commented on most of the time revealed to me not much in the way of solid accident investigation of summation skills....mostly small potato stuff or opinion....she may have hit on a few key points...but they were lost on me as I couldn't sit though most of it .....even the other person sitting with me in the same room was "what the heck?"

As far as I know/have read.... no one can confirm the released transcription is real or not.

 

[Delta Riverat]

All the wisdom of the world can be found in rock & roll.

"It's interesting when people die" - Don Henley

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