I see alot of talk of implosion and instant death.

I have some experience designing and testing pressure housings for high external pressures. Sure catastrophic implosion is a possibility but so is a seal opening up or a somewhat more gradual leak. Lets hope it was the former.

I am still suspicious of that titanium carbon fiber Butt joint, but just speculation

Perhaps of interest (old articles):

https://www.compositesworld.com/news/oceangate-ceo-pilots-carbon-fiber-submersible-in-4000-m-solo-dive

https://www.geekwire.com/2020/oceangate-picks-toray-cma-make-carbon-fiber-titanic-worthy-submersibles/

I don't want to wait until 3:00. I want the coast guard update now!

I suspect a slow(ish) leak at the carbon fibre - titanium glued lap joint. The elastic modulus mismatch of these 2 materials means that they move at different rates when exposed to loading (external pressure in this case). I’ve used engineering adhesives in downhole tools for 15 years. These tools see as much as 15000 psi (3 times the hydrostatic pressure at the titanic) but the loading scenario is different.

It sounds like this may have the 2nd best case conclusion, the best case being finding those on board alive and unharmed. In this case, the families can get closure (if the debris is indeed from the submersible).

I’m surprised there is a debris field if my suspicions are correct - the sub should be mostly intact.

We will see.

debris field means it was over in the blink of an eye.

so at least no suffering.


expect a discovery channel documentary within the year.

https://www.dailymail.co.uk/news/article-12223805/Debris-field-discovered-search-area-near-Titanic.html

What type of tools did you work on? We may have been over this, but that is my background as well. Did a lot of work on downhole load and vibration measurements tools as well as some rotary steerable development.

5.5 ksi is just getting started in the downhole world.

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At this point, implosion is - not good news, but the best of bad alternatives.

He is responsible. His statements and behavior are very worthy of disdain

the other thing to be suspicious of the carbon itself.

its very hard to build carbon fiber without any inclusions. and carbon fiber is carbon fibers in glue, ie its many layers of glue/fiber/glue/fiber ... all those layers compress and decompress with every dive. any imperfections in that, are stress concentrators, which, are site for crack initiation and propagation. so you compress and decompress this system, and you start propagating cracks.

it sounds like the sub was designed with some kind of acoustic emission monitoring system to listen in the carbon fiber to hear these crack popping. but there is no way to tell the size, shape, location etc of the cracks, just know they are happening.



this is why the guy was fired. he was hired to do non-destructive analysis on the hull, looking for inclusions/cracking and such. he said it was a deathtrap and was promptly fired.

so i mean, that, to me, sounds like the issue.



its also worthy to note that carbon fiber is not used in submarine design commonly.

Based on my experience, and I still own a a minority stake in a non-autoclave composite manufacturing company going on ten years, I think you are correct.

I'll wait for more evidence if we get any, but the signs are there. That, and have others have mentioned, the connection points between the composites and the other more traditional hull components are of concern.

As JYL wrote, this was the best of bad outcomes for the crew and passengers.

Debris confirmed to be from Titan. Consistent with implosion.

Hopefully, just as changes came about after the sinking of the titanic, we will see if the same for mini subs and similar. Guidelines, certifications, etc.

One point.

Implosion is not usually spectacular like Explosion.

The tube would have collapsed and the pressures equalized.

One end may have shot off and the contents spilled out.

I can’t understand the talk of a debris field.

This... The debris field they're chasing could be from the Titanic.

I've got a really bad feeling. This Sub may never be found.

Having no expertise in composites I am still a bit confused why the choice of carbon fiber here. Makes perfect sense if the pressure was internal.

Is light weight really an advantage for the vessel itself or does it just a convenience for handling operations?

Interesting paper 100% on subject, just skimmed but says tube started delaminating at pressure less than predicted by FE computational methods.
https://www.iccm-central.org/Proceedings/ICCM12proceedings/site/papers/pap631.pdf

Stick me in a Inconel, titanium of high grade stainless tube please. Save the composites for planes, bikes, and sportscar theatre

I just read part of the coast guard release.

The rear cap of the vessel has been found. The debris is likely whatever stuff was in the way of it as it rapidly detached.

http://forums.pelicanparts.com/uploa...1687462295.png

weight is important because only certain vessels (presumably the expensive ones) can handle heavier subs off the back. heavier, also makes them bigger. bigger again, you need more specialized (read: $$$) ships to handle it.

this thing seems to have tried to get around this with the submersible/towable support system too.

all about keeping the costs low. i wonder what doing it properly costs? wonder what a seat in one of these other submersibles that actually works costs? gotta be a million plus a ticket.

I think there are 2 reasons for carbon fibre…

1. This appears to have been designed by engineering students as a capstone project. I have been an industry panelist reviewing student Capstone Projects at SAIT since 2004. Without fail, every year, a group of students plans to make their project out of ‘Carbon Fiber, or Titanium, or both. This year was no exception with a group planning to make rear bumpers for comment vehicles out of carbon fibre to save weight…

2. In one of the reports I watched on this (I’ve been infatuated with this story), one of the experts said that making the body out of steel, the thickness and resulting weight made it impossible to achieve neutral buoyancy. I have not done any calcs to verify this.

Terrible news... The worst possible outcome. RIP. And may their families find peace.

Whoever wrote the online story for Fox needs to be fired. Incredibly unclear.


My thought is this is the best realistically possible scenario. Sound like the poor souls never knew what happened to them. Hopefully at least.

Very sad outcome.

Hopefully death was swift and painless . RIP

If implosion then it sounds as merciful an end as one may hope under the circumstance.

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edit for the truly macabre: is it likely that the remains are intact enough to recover for the families?

This morning, all judgement aside, I was pretty bummed thinking about them running out of air on the ocean floor. Hell of a way to go. I was especially bummed thinking about the dad getting his kid into it. He would have been really kicking himself.

At least implosion was instantaneous. The wreckage will be found. There will be closure. None of this Malaysian flight 370 crap. In a thought of pure macabre insanity, I kind of hoped they crashed onto Titanic's hull. They paid the ultimate price, might as well get a front row seat.

Well, probably like one of those eerie movies where the ghosts of the Titanic slowly come out of the portholes and greet them. Thinking they are still alive but confused, they turn around and see the remains of the mini sub. And then it dawns on them... Like a near death experience where you look down on your own body.

And meanwhile there's a crew member up top with the one last forgotten bolt for the hatch in his pocket thinking "Uh Oh..."

Very informative video in this link:

https://redstate.com/brutalbrittany/2023/06/22/wreckage-of-lost-titanic-sub-titan-confirmed-condolences-given-by-us-coast-guard-in-somber-briefing-n765482

I have to say the combined efforts from all the unified command countries involved is, as usual in search and rescue, about as good as it gets.

I have been there and tip my hat to all the men and women racing to save the stricken.

RIP.

I have read a news story that indicated that Mr. Rush's wife is related to a couple that passed away in that same area in 1912.

Very sad.

I think the implosion and instant death is probably about the best miracle that they could have hoped for at this point (vs long drawn out suffocation with 3 days of terror).

Exactly. 5 deaths is not good news, but 5 quick, merciful deaths compared to slow terror filled deaths is what I'd choose.

Yes, and since there was no non-routine message before communication was lost (right?), it seems at least possible that the occupants might have had no pre-warning that anything was wrong.

In other words, it is possible that they died instantly, without having the slightest idea that anything was happening - their last thought being "this is going great, in another hour we'll be at the Tita---".

Like dying in your sleep. Which is, I'd think, the exit many of us would choose.

That's how I'm going to imagine things.

My impression, from very little reading, is that an implosion at say half the depth of the Titanic would leave no effectively human remains to recover.

Wreckage was found 500m from the bow of Titanic… hopefully they atleast got the see
The Titanic before things went terribly wrong. We may never know.

I really want to see what the imploded hull looks like… the video that Flatty posted has me wondering if the rapid compression of the air inside could have resulted in an explosion (like a diesel engine). I’ve never considered this before and may have learned something new… only 5750 psi though…

I know of 2 incidents where compressed air in an oil well has resulted in an explosion. One killed a former coworker, one killed an acquaintance. The difference was that these were in the presence of a liquid hydrocarbon.

The little experience I have with CF tells me that not much of the hull will have survived.

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Sad, but expected

https://www.youtube.com/watch?v=__edp8NgPx0

New news keeps coming out, even the glass was not pressure certified to that depth and the manufacture of it to that level was turned down by the CEO.

At least some comfort is at least he went down with the ship too.

I don't get it. Didn't James Cameron take a sub down to the bottom of the Mariana Trench, like 6-7 miles? Why not use that sub for a mere two miles and change?

The James Cameron sub wasn’t built on a shoe string and probably incorporated the advice of 50 year old white men with actual submarine experience…

If I recall correctly, it has been reported that CF material was used to allow a more reasonable weight for a larger vessel-- one that could carry more people.

Another news story from the past (just prior to Pandemic):

https://www.geekwire.com/2020/oceangate-raises-18m-build-bigger-submersible-fleet-get-set-titanic-trips/

"This is shaping up as a rebuilding year for the nearly 11-year-old venture, based in Everett, Wash. The main task on the agenda is to build two new submersibles capable of diving as deep as 6,000 meters (3.7 miles), which is more than a mile deeper than the part of the North Atlantic ocean floor where the Titanic is resting.

OceanGate will take advantage of lessons learned during the construction of its carbon-hulled Titan submersible, which was originally built for Titanic journeys. Rush said tests that were conducted at the Deep Ocean Test Facility in Annapolis, Md., revealed that the Titan’s hull “showed signs of cyclic fatigue.” As a result, the hull’s depth rating was reduced to 3,000 meters.

“Not enough to get to the Titanic,” Rush said.

That meant the Titanic trips — which had been planned at first for 2018, then 2019, then 2020 — had to be put off until mid-2021. By that time, Rush expects the new submersibles to be ready to enter service. He said mission specialists who have paid more than $100,000 each to participate in the Titanic expeditions were “generally supportive but disappointed” by the delay.

Completing the latest funding round will open the way for proceeding with the Titanic trips and other expeditions on OceanGate’s agenda."

11 year old company at that point closed on $18m.

Serious question. How deep was the vessel at less than the 2 hour mark when it lost communication?
Is that deep enough to cause a catastrophic implosion?
My simple math puts them at less than 900 ft below the surface if they happen to travel at the same speed the whole decent.