Titanic tourist submersible goes missing with search under way

[OpanaPointer]

Concur with all your above. B/Z

[wadinga]

Hello All,

As those of us who have worked on ships well know, the Sea makes no allowances, accepts no excuses, and takes no prisoners. It is one of the last places where the individual can be truly free, and that freedom includes the ability to make bad choices and suffer the consequences. Even the most seaworthy craft with an experienced and well-informed crew can be unlucky, but if the worst comes to the worst they at least know they have done their best to minimize the risk.

I'm sure we all feel sympathy for the families of those lost.

All the best

wadinga

[marcelo_malara]

Finally it seems that it was not the ballast nor the propulsion, the hull just did not withstand the pressure. As a minor comfort, that would have been quick. Let them rest in peace.

Regards.

[Steve Crandell]

Indeed, and hopefully it will result in improved safety margins for tourist craft like that one.

Apparently the USN ocean surveillance system heard the implosion and reported it to the Coast Guard commander of the operation, but he felt they should continue to search in the hope that it was a false indication. They really needed to find the wreckage for closure anyway.

[paul.mercer]

Apparently some large pieces of wreckage has been located, I presume they will be salvaged to find out exactly what caused the failure.
I believe that the Magallen sub is being shipped from the Channel Islands by the US air force, this is apparently capable of lifting the wreckage to the surface.
On another note, the Magellen crew recently completed a huge survey of all the Titanic wreckage, now all this is available for the public to see, plus the fact that over the years since she was first discovered, many artifacts have already been lifted from the site, should Titanic be left in peace to gently rust away?

[wadinga]

Hi All,

I'm a great fan of James Cameron's movies but his comment

Not only did he condemn the "prolonged" search for the sub after it lost contact, but he also said he "knew" the sub was sitting exactly under its last known position.

is not helpful. He displays extreme hindsight in that the SOSUS information was not definitive and the search had to continue. The wider search pattern was based on concerns the sub might have been carried away by currents after a power failure.

He added:

A number of the top players in the deep-submergence engineering community even wrote letters to the company saying that what they were doing was too experimental to carry passengers and that needed to be certified and so on.

Presumably if these qualms had been made more public by the "community" there would have been litigation by the operators, but they should have braved it out.

US authorities have said they are “not sure” they can recover the bodies of five people who died on board the Titan submersible

Anybody have any thoughts on what happens to the human body at normal atmospheric pressure when it is suddenly exposed to seawater at 3500m pressure (about 5087 psi)? I imagine it is instantaneously smushed to pulp.

"On a sailor's grave no roses bloom"

All the best

wadinga

[OpanaPointer]

https://en.wikipedia.org/wiki/Kursk_submarine_disaster

[marcelo_malara]

Hi All,

I'm a great fan of James Cameron's movies but his comment

Not only did he condemn the "prolonged" search for the sub after it lost contact, but he also said he "knew" the sub was sitting exactly under its last known position.

is not helpful. He displays extreme hindsight in that the SOSUS information was not definitive and the search had to continue. The wider search pattern was based on concerns the sub might have been carried away by currents after a power failure.


wadinga

This is logical. A sub in distress can go two ways, up to the surface and down to the bottom, as it is almost impossible for the sub to be buoyancy neutral to remain at mid depth. If it was not on the surface...it was on the bottom, and at depth (in my knowledge) the ocean currents are not so strong as in the surface. So it was logical that the wreck would be below it last known position.

Regards

[wadinga]

Hi All,

Hi Marcelo, a great deal of effort goes into achieving neutral buoyancy so those tiny little up and down thrusters can move it vertically. The people carrying out the extended search pattern were covering all bases. Accounts of Titanic missions say they have to use thrusters to stay in position.

Hi Opanapointer, Water pressure in Kursk disaster at 108 m 164.7 lbs per sq in. So in that case bodies would remain intact but with 5000+ lbs on every sq in of a body things are probably a bit different.

All the best

wadinga

[marcelo_malara]

Guys, look at this, from wiki. This looks bad.

Testing and inspection
OceanGate claimed on its website as of 2023 that the Titan was "designed and engineered by OceanGate Inc. in collaboration [with] experts from NASA, Boeing, and the University of Washington." A 1⁄3-scale model of the Cyclops 2 pressure vessel was built and tested at the University of Washington Applied Physics Laboratory; the model was able to sustain a pressure of 4,285 psi (29.54 MPa; 291.6 atm), corresponding to a depth of approximately 3,000 m (9,800 ft).[39] After the disappearance of the Titan in 2023, the University of Washington stated that the Applied Physics Laboratory had no involvement in "design, engineering, or testing of the Titan submersible." A Boeing spokesperson also said that Boeing "was not a partner on the Titan and did not design or build it." A NASA spokesperson said that NASA's Marshall Space Flight Center had a Space Act Agreement with OceanGate, but "did not conduct testing and manufacturing via its workforce or facilities".[40] Rush had touted partnerships with NASA, Boeing, and UW to Pogue in 2022 in response to a question about the perceived "MacGyvery jerry-rigged-ness [sic]" improvisational design based on the use of off-the-shelf components.[33][41]

[paul.mercer]

https://en.wikipedia.org/wiki/Kursk_submarine_disaster

Hi OpanaPointer,
Thanks for posting that link it made for some fascinating reading, what an almighty ..... up - and cover up by the Russians!

[Byron Angel]

Some sources I have read, who are familiar with deep sea submersible technology, theorize that the failure point was most likely the wound carbon fiber + adhesive central cylinder. Their opinion is that a succession of dives over time would produce a series of truly immense pressure loads followed by complete relaxation and a series of such cycles would, over time, cause micro delaminations that would be extremely difficult to detect. Development of a single weak point anywhere along the cylinder would result in the sort of catastrophe we have apparently witnessed.

The next chapter in this drama will commence with a great gathering of attorneys representing the estates of the very wealthy victims.

Byron

[marcelo_malara]

Some sources I have read, who are familiar with deep sea submersible technology, theorize that the failure point was most likely the wound carbon fiber + adhesive central cylinder. Their opinion is that a succession of dives over time would produce a series of truly immense pressure loads followed by complete relaxation and a series of such cycles would, over time, cause micro delaminations that would be extremely difficult to detect. Development of a single weak point anywhere along the cylinder would result in the sort of catastrophe we have apparently witnessed.

The next chapter in this drama will commence with a great gathering of attorneys representing the estates of the very wealthy victims.

Byron

I read that too. What is called fatigue, one load that can be withstand by a piece, but that when applied cyclically can make the piece fail.

Not only is the fiber the problem of the central cylinder , but the cylinder would have to withstand two efforts, the radial from the pressure, but also a longitudinal compression due to the pressure of water acting on the titanium ends. A sphere will not have this second load, just the radial one.

Regards

[dunmunro]

Some sources I have read, who are familiar with deep sea submersible technology, theorize that the failure point was most likely the wound carbon fiber + adhesive central cylinder. Their opinion is that a succession of dives over time would produce a series of truly immense pressure loads followed by complete relaxation and a series of such cycles would, over time, cause micro delaminations that would be extremely difficult to detect. Development of a single weak point anywhere along the cylinder would result in the sort of catastrophe we have apparently witnessed.

The next chapter in this drama will commence with a great gathering of attorneys representing the estates of the very wealthy victims.

Byron

I read that too. What is called fatigue, one load that can be withstand by a piece, but that when applied cyclically can make the piece fail.

Not only is the fiber the problem of the central cylinder , but the cylinder would have to withstand two efforts, the radial from the pressure, but also a longitudinal compression due to the pressure of water acting on the titanium ends. A sphere will not have this second load, just the radial one.

Regards

Apparently the Titan was showing signs of cyclic fatigue and was derated to 10K ft depth until it underwent repairs in 2020. I suspect the implosion happened just after it passed 10k ft.

I have to say that I am more than bit annoyed that the USN detected the implosion via SOSUS, and informed the family members, but not the media. The RCN, CCG, and USCG wasted millions and undertook hazardous missions searching for a sub that was known to have imploded!

[Byron Angel]

There are claims making the rounds that Biden insisted upon a delay in release of the event to the press for “political reasons” related to the timing of the DOJ announcement of his son’s plea deal.

Byron