Photos of the Titan sub's wreckage support the theory that the carbon-fiber hull failed first, exper

[mystery-ak]

Photos of the Titan sub's wreckage support the theory that the carbon-fiber hull failed first, expert says
Marianne Guenot
Jun 30, 2023, 9:48 AM CDT



An annotated image of part of the Titan submersible being moved ashore after its catastrophic implosion under the North Atlantic in June. CBC News/Insider


    Onlookers caught glimpses of the Titan submersible wreckage as its crews brought its remains ashore.

    These provide clues to what may have happened while a formal investigation is underway.

    Though it's difficult to know for sure, an expert said the carbon-fiber hull likely failed first.

Photos of the Titan submersible wreckage support the theory that the vessel's carbon-fiber hull may have led to its catastrophic implosion, an expert told Insider.

The US Coast Guard brought debris from the Titan submersible ashore this week, giving onlookers a brief, imperfect glimpse as it was taken away for analysis.

Jasper Graham-Jones, an associate professor of mechanical and marine engineering at Plymouth University, analyzed footage and photos for Insider.

Though it is impossible to reach a definitive conclusion from these pictures alone, he said the most likely scenario was that the carbon-fiber hull gave way under the enormous pressure of the ocean depths.

Another possibility is that the ship's small front viewport gave way.

Here's why, picture by picture.
 
1. The titanium structural rings are intact



An annotated picture of the titanium structural rings pulled from the wreckage of the Titan submersible. CBC News/Insider

The picture above, taken by Canada's CBC News, shows structural titanium rings that supported the structure of the submersible. They are intact and, therefore, do not seem to have failed.

OceanGate Expeditions' controversial Titan submersible is thought to have imploded within hours of its descent toward the wreckage of the Titanic on June 18. The five passengers on board the submersible are presumed dead.

A forensic investigation is underway to determine the exact sequence of events and will conduct an exhaustive analysis on the remains to build a conclusive picture. In the meantime, photos, the Titan's own history, and expert opinions give us something to go on.

OceanGate's design of the submersible received heavy criticism over the years, especially for its use of a carbon-fiber-composite hull.

Most submersibles are made out of titanium, and many deep-sea experts told OceanGate that they were wary about the company using carbon fiber, which is not as strong.

The Titan's design featured two titanium rings bound to the carbon-fiber hull. The rings seem to have held firm, Graham-Jones said.


An annotated picture points to the approximate location of the structural titanium rings. OceanGate Expeditions/Reuters/Insider

"It shows that titanium was the right material to use, and linking with the composite was possibly the wrong material to use," he said.

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https://www.businessinsider.com/titanic-sub-photos-suggest-carbon-fiber-hull-to-blame-expert-says-2023-6

[DB]

In the top photo the clear plastic view port is missing. If it went inward it was the source of the failure. If it went outward it was not. There is likely evidence which way it went. If it went outwards it is probably still intact among the debris. If it wasn't the source then it pretty much had to be the carbon fiber tube where any deformity from perfectly round would quickly escalate.

[Kamaji]

In the top photo the clear plastic view port is missing. If it went inward it was the source of the failure. If it went outward it was not. There is likely evidence which way it went. If it went outwards it is probably still intact among the debris. If it wasn't the source then it pretty much had to be the carbon fiber tube where any deformity from perfectly round would quickly escalate.

[bigheadfred]

In the top photo the clear plastic view port is missing. If it went inward it was the source of the failure. If it went outward it was not. There is likely evidence which way it went. If it went outwards it is probably still intact among the debris. If it wasn't the source then it pretty much had to be the carbon fiber tube where any deformity from perfectly round would quickly escalate.

I'm going with the view port blew out from the force of the implosion when the hull failed. If it was the source wouldn't the sub be filled with water with the hull remaining intact?

[DB]

I'm going with the view port blew out from the force of the implosion when the hull failed. If it was the source wouldn't the sub be filled with water with the hull remaining intact?

If the window failed, the water rushes in at very high speed and then will come to a very abrupt stop once the void is filled causing extreme pressure due to the momentum of the water. That would likely cause the hull to explode instead of implode.

[Kamaji]

If the window failed, the water rushes in at very high speed and then will come to a very abrupt stop once the void is filled causing extreme pressure due to the momentum of the water. That would likely cause the hull to explode instead of implode.

If the port failed inward, the incoming pressure would have compressed the air toward the rear, and that would most likely have caused the rear titanium ring to pull away from the carbon fiber hull, or, with a little less likelihood, the forward ring to have failed and pulled away from the carbon fiber hull.  In either event, there would most likely have been carbon fiber attached to one of the two rings that was just recovered.

The fact that the two rings were recovered without significant carbon fiber remnants attached suggests that the primary failure was the carbon fiber itself, and that it collapsed under an implosion.

[DB]

If the port failed inward, the incoming pressure would have compressed the air toward the rear, and that would most likely have caused the rear titanium ring to pull away from the carbon fiber hull, or, with a little less likelihood, the forward ring to have failed and pulled away from the carbon fiber hull.  In either event, there would most likely have been carbon fiber attached to one of the two rings that was just recovered.

The fact that the two rings were recovered without significant carbon fiber remnants attached suggests that the primary failure was the carbon fiber itself, and that it collapsed under an implosion.

The water filling the inner void is moving extremely fast and has a lot of mass. Once that void is filled, the water's momentum wants to keep going but can't because there's nowhere to go. Water hammer in the extreme. That sudden momentum stop generates extreme forces because there is nothing elastic to absorb it. That could blow apart the entire sub. The bonding between the rings and carbon fiber doesn't have to be all that strong because the whole thing is normally in extreme compression holding it together.

Note that the view port end opens for boarding access into the sub at the outer ring the connects to the carbon fiber. The end cap dome and ring are bolted together. The picture doesn't seem to show the ring that bolts to the end piece. The ring that is glued to the carbon fiber. So it appears that the ring and end cap are also separated which took internal pressure to shear the bolts.

Obviously just speculation...

We'll just have to wait for more information.

[Smokin Joe]

The water filling the inner void is moving extremely fast and has a lot of mass. Once that void is filled, the water's momentum wants to keep going but can't because there's nowhere to go. Water hammer in the extreme. That sudden momentum stop generates extreme forces because there is nothing elastic to absorb it. That could blow apart the entire sub. The bonding between the rings and carbon fiber doesn't have to be all that strong because the whole thing is normally in extreme compression holding it together.

Note that the view port end opens for boarding access into the sub at the outer ring the connects to the carbon fiber. The end cap dome and ring are bolted together. The picture doesn't seem to show the ring that bolts to the end piece. The ring that is glued to the carbon fiber. So it appears that the ring and end cap are also separated which took internal pressure to shear the bolts.

Obviously just speculation...

We'll just have to wait for more information.

Well, there is one compressible thing in there: air. But going from 1 atmosphere to 5500 PSI would reduce the volume to just under 27/10,000 of its previous volume. Anything combustible would flash burn in the millisecond before the water put it out.