Technical Analysis on Titan Sub (Titanic Sub)

[DaveE]

And if the US imposes restrictions and high fees, they can just register elsewhere.

True. But western governments and regulatory agencies can have an outsized effect in the perception of quality/safety, and perhaps the funding for this sort of thing. Of course we can't control what the Somalis do, but that doesn't mean we can't or shouldn't try.

Liberian registered ships still have to be allowed to enter Western ports. Some of that "flag shopping" is about regulations (mostly "red tape"), but much of it is really about taxes.

 

[Astronuc]

Apparently Paul-Henri Nargeolet (77), a former French Navy commander, diver, submersible pilot, . . . had 35 dives to the Titanic site (Wikipedia article).
https://en.wikipedia.org/wiki/2023_Titan_submersible_incident#Fatalities

James Cameron has visited the Titanic site 33 times.
https://www.npr.org/2023/06/23/1183975136/james-cameron-titanic-titan-sub

Cameron "also dove the Mariana Trench — the deepest-known point on Earth, about three times deeper than the Titanic wreck site — in 2012, in a 24-foot cylindrical submersible he spent seven years building." I'm guessing it wasn't carbon fiber composite.

The personnel/pilot capsule was a spherical structure.
https://en.wikipedia.org/wiki/Deepsea_Challenger

Cameron and many others in the deep submergence community had long been concerned about the vessel's safety and OceanGate's experimental approach, he said on Thursday, lamenting that the company had ignored experts' calls to undergo a standard certification process.

I'd like to know more about the 'standard' certification process, which apparently OceanGate ignored.

It's clear that OceanGate "shouldn't have been doing what it was doing," he told Reuters, adding that he had declined an invitation from CEO Stockton Rush to go diving with them this season.

Cameron described OceanGate's use of a carbon-fiber hull as "fundamentally flawed" and said he had warned another company several years ago against using that same design principle. He said he regrets not speaking up more this time around.

https://en.wikipedia.org/wiki/2023_Titan_submersible_incident#Safety

Because Titan operated in international waters and did not carry passengers from a port, it was not subject to safety regulations. The vessel was not certified as seaworthy by any regulatory agency or third-party organization. . . . A 2019 article published in Smithsonian magazine referred to Rush as a "daredevil inventor". In the article, Rush is described as having said the U.S. Passenger Vessel Safety Act of 1993 "needlessly prioritized passenger safety over commercial innovation".

The Challenger Deep mission for DeepFlight Challenger was scrapped after Virgin discovered it was worthy of only a single dive, not the repeated missions planned.
https://en.wikipedia.org/wiki/Deepsea_Challenger#Similar_efforts

OceanGate promoted the Titan’s carbon fiber construction — with titanium endcaps — as “lighter in weight and more efficient to mobilize than other deep diving submersibles” on its website. It also said the vessel was designed to dive four kilometers (2.4 miles) “with a comfortable safety margin,” according to court documents.

https://www.pbs.org/newshour/nation...onal-design-may-have-destined-it-for-disaster

If Rush claimed Titan was designed to 4000 m, or whatever, it was probably a misleading or apotentially false statement, given the lack of design review and certification; I have to wonder if the designers adhered to any standards. I'd like to see the buckling analysis and stress analysis on the CFC. Does it account for the reduction of structural capability with each dive?

Edit/upate:
A prospective Titan passenger said of Rush,

“He basically told me he knew I'm a helicopter pilot, and he said, 'This is safer than flying a helicopter. It's safer than scuba diving.' And at lunch he said, 'It's safer than crossing the street,' " Jay recounts. "He was a good guy, great heart, really believed in what he was doing and saying. But he didn't want to hear anything that conflicted with his world view, and he would just dismiss it.”

“He absolutely believed what he was saying," he continues. "But I didn't want to get into the safety concerns anymore, because he was so vested in his position. And anybody who questioned it just had a differing opinion."

https://www.yahoo.com/entertainment/titan-family-tragedy-averted-due-201531030.html
We don't do proper engineering and science on 'belief'. We need hard objective evidence based on experience and due diligence.

 

[gmax137]

There are international safety standards for passenger-carrying ships, things like how many lifeboats are required, that ironically were put into place following the sinking of the Titanic. SOLAS hes evolved to include design requirements and ongoing inspections (see https://en.wikipedia.org/wiki/SOLAS_Convention).

This is entirely different from something like Cameron's Deep Sea Challenger, a vessel he had built and dove in by himself.

 

[Baluncore]

There are international safety standards for passenger-carrying ships, ...

Titan did not carry passengers.
The "mission specialists" made donations to support the company.

 

[gmax137]

Titan did not carry passengers.
The "mission specialists" made donations to support the company.

Is that really the stance being taken? I hope not, that's shameful.

 

[DaveC426913]

You want your vessel to have about the same density as water. Too much less and it doesn't go down. Too much more and it doesn't come up.

You design the pressure vessel to be as light as practical, so it wants to rise to safety naturally. Then you neutralize the buoyancy with detachible weights on its superstructure.
.

 

[Baluncore]

Is that really the stance being taken? I hope not, that's shameful.

Customers who travelled to the Titanic with OceanGate, referred to as "mission specialists" by the company,[37] paid US$250,000 each for the eight-day expedition.[33][38][39]

https://en.wikipedia.org/wiki/2023_Titan_submersible_incident#Expeditions_to_the_Titanic

 

[gmax137]

That Wiki page is inconsistent. Just above the line you quoted it says:

Titan made its first dive to the Titanic in July 2021. In total, OceanGate undertook six dives to the Titanic in 2021 and seven in 2022. ... Each dive typically had a pilot, a guide and three paying passengers on board.

emphasis added

And following:

Because Titan operated in international waters and did not carry passengers from a port, it was not subject to safety regulations.

Is that a valid legal argument? Sounds kind of murky.

 

[Astronuc]

Is that a valid legal argument? Sounds kind of murky.

I presume the support ship carried the passengers (mission specialists). Then they were transferred in international waters. I suppose they will try that technicality.

 

[Frabjous]

The dead undoubtedly signed safety waivers. A lawsuit would need to prove negligence in order to invalidate them.

 

[Vanadium 50]

That Wiki page is inconsistent

Unlike any other Wikipedia page?

The dead undoubtedly signed safety waivers.

According to David Pogue (full disclosure - I worked with him decades ago. I think I have a signed copy of his novel somewhere) the word "death" appears three times on the first page.

 

[hutchphd]

This is entirely different from something like Cameron's Deep Sea Challenger, a vessel he had built and dove in by himself.

Mr Cameron was involved in the design process but did not cast the metal nor hand-cut the bolts. He relied on many other people. He did it in a thoughtful and considered fashion. It was an experimental vehicle. The fact that he was alone as pilot does not change the process. If he had a cohort aboard , then each of them should have done an independent analysis.

If misrepresentations were made to Titan passengers about testing or safety analysis, then there is a problem, but it may be problem meting out justice.
I'm a little tired of the badmouthing of the "rich oligarchs". There is a point at which human fallibility will win.
I am instead reminded of watching the Challenger explosion where there was (IMHO) no really honest attempt at informed consent by an otherwise often impressive agency. At best they were delusional. That injustice is still palpable to me.
You can't do better than Feynman (Roger's commission report conclusion) :
"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled."

 

[jrmichler]

You can't do better than Feynman (Roger's commission report conclusion) :
"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled."

Which brings us to this old poster:

 

[gmax137]

Mr Cameron was involved in the design process but did not cast the metal nor hand-cut the bolts. He relied on many other people.

That's why I said "he had built..." I see now that may be ambiguous (as in maybe I meant "he built it in the past"). I meant, he "had it built" for him by skilled people.

I'm a little tired of the badmouthing of the "rich oligarchs".

Me too, I suspect that if one were to investigate, you would find that Rush and his wife gave to many worthy charities.

 

[Astronuc]

An engineer's commentary on the Titan event. I can't vouch for his qualifications, but there is an interesting comment about the use of carbon composites. With repeated compression and decompression (cyclic fatigue), the ability to resistant deformation or cracking is diminished. Apparently this is well know.

The video has a comment on the DeepFlight Challenger that Richard Branson purchased following the death of Steve Fossett. Branson wanted to do five dives, but the manufacturer, Spencer Composites, indicated that the design was suitable for only one dive. The discussion starts about 10:00 in the video

Article about Adam Wright
https://engineering.berkeley.edu/news/2013/11/diving-to-the-edge-of-darkness/

Based on testing at high pressure, the DeepFlight Challenger was determined to be suitable only for a single dive, not the repeated uses that had been planned as part of Virgin Oceanic service. As such, in 2014, Virgin Oceanic scrapped plans for the five dives project using the DeepFlight Challenger, as originally conceived, putting plans on hold until more suitable technologies are developed.

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

 

[Vanadium 50]

There are international safety standards for passenger-carrying ships, things like how many lifeboats are required, that ironically were put into place following the sinking of the Titanic.

But are there for deep sea submersibles?

Is there some organization out there that says "If you do X, Y and Z, we will certify that diving to 13000 feet is safe"? (And if there is, would you believe them?)

If the position is "there's no body that will certify this as safe, therefore we ban it for everyone" where do we draw the line for what we ban? I have a list upthread of other candidates.

Diving to 13000 feet is dangerous. We all know that, and everyone aboard should have known that - even the 19 year old. Requiring it to be "safe" is the same as banning it.

Now, if you want to argue it should be safER, OK, how much safer? Factor of 2? Factor of 10? And how do you verify this number?

This is roughly as dangerous as manned space flight or climbing Everest, It is much safer than going down Niagara falls in a barrel. Possibly one notch worse than BASE jumping.

 

[Vanadium 50]

To expand - I understand the "there outta be a law" reaction to tragedy. But how much in the way of resources should we spend saving stupid rich people from themselves?

• This poses no risk to the population at large.
• If the death of the designer is not a deterrent, rules and regulations won't be either.
• Rich people can circumvent these restrictions, Does anyone think Michael Jackson's many cosmetic surgeries were medically necessary? Or even a good idea?
• If we ban - or regulate into oblivion - this, do we really think stupid rich people will take up knitting instead? Or will they do some else, somethintg we hope is marginally less dangerous?

Deep-sea tourism kills, on average, one person per year. Smoking kills half a million. Perspective, people.

 

[gmax137]

But are there for deep sea submersibles?

I dunno. Sounds like something the lawyers could argue about until we see a proton decay.

 

[Astronuc]

An AP News article on the murky regulations of deep-sea expeditions
https://apnews.com/article/titanic-sub-accident-laws-deep-sea-6d1e100f39a46091ae9895706adbcceb

 

[pinball1970]

There is a claim that ascent weights were dropped.
The claim is here https://www.independent.co.uk/news/world/americas/james-cameron-titanic-sub-implosion-b2363050.html
The source is James Cameron, and his source is the “community."

Something the investigation will shed light on?

 

[hutchphd]

To expand - I understand the "there outta be a law" reaction to tragedy. But how much in the way of resources should we spend saving stupid rich people from themselves?

Absolutely. This is a textbook self-limiting problem.

 

[Astronuc]

Something the investigation will shed light on?

The US Coast Guard has initiated an inquiry. Ostensibly, they will do a thorough investigation, which will include events leading up to and including the implosion.

The Coast Guard convened a Marine Board of Investigation (MBI) into the loss of the Titan submersible and the five people on board. The crew of the Polar Prince research vessel lost contact with the Titan submersible 1 hour and 45 minutes into its dive on Sunday, June 18, 2023. After an extensive search and rescue effort, wreckage of the Titan submersible was located on the ocean floor approximately 500 meters off the bow of the Titanic. An MBI is the highest level of investigation in the Coast Guard. Upon completion of the investigation, the Board will issue a report to the Commandant with the evidence collected, the facts established, its conclusions, and recommendations.

During the course of the MBI, the Board will work to determine:

• The cause of the casualty, including the cause of any death.
• Whether an act of misconduct, incompetence, negligence, unskillfulness, or willful violation of law committed by any individual licensed, certificated, or documented has contributed to the cause of the casualty, or to a death involved in the casualty, so that appropriate remedial action may be taken.
• Whether an act of misconduct, incompetence, negligence, unskillfulness, or willful violation of law committed by any person, including an officer, employee, or member of the Coast Guard, contributed to the cause of the casualty, or to a death involved in the casualty.
• Whether there is evidence that an act subjecting the offender to a civil penalty under that laws of the United States has been committed, so that appropriate action may be undertaken to collect a penalty.
• Whether there is evidence that a criminal act under the laws of the United States has been committed, so that the matter may be referred to appropriate authorities for prosecution.
• Whether there is need for new laws or regulations, or amendment or repeal of existing laws or regulations, to prevent the recurrence of the casualty.

https://www.news.uscg.mil/Press-Rel...ard-of-investigation-into-loss-of-titan-subm/

And the Canadian TSB launches investigation into a marine occurrence involving the Canadian-flagged vessel Polar Prince and the submersible Titan
https://www.bst-tsb.gc.ca/eng/medias-media/deploiement-deployment/marine/2023/m23a0169-20230623.html
https://www.bst-tsb.gc.ca/eng/enquetes-investigations/marine/2023/m23a0169/m23a0169.html

The occurrence​

On 18 June 2023, the Canadian-flagged cargo vessel Polar Prince was at the Titanic wreck site, 325 nautical miles south-southeast of Cape Race, Newfoundland and Labrador, providing surface support to the submersible Titan. There were 17 crew members and 24 people on board the Polar Prince. Five people from the Polar Prince were on board the Titan and approximately 1 hour and 45 minutes after the submersible began its descent, the support vessel lost contact.

On 22 June 2023, the United States Coast Guard confirmed that the debris found on the ocean floor near the Titanic wreckage consisted of pieces of the missing submersible. As a result, the five people on board the Titan are presumed dead.

In accordance with the Canadian Transportation Accident Investigation and Safety Board Act and international agreements, the TSB, as the investigation authority of the flag state of the support vessel involved in the occurrence, will conduct a safety investigation regarding the circumstances of this operation conducted by the Canadian-flagged vessel Polar Prince.

I expect the Canadian TSB will cooperate with the US CG MBI.

 

[Vanadium 50]

Something the investigation will shed light on?

I'm not sure how. The weights are at the bottom of the ocean, and even if recovered, what do they tell you about when they were dropped?

One thing that surprises me is the lack of telemetry involved. Add an optical fiber to the umbilical and you have all the bandwidth you need - a text every 15 minutes? You could ping every second, and have a duplicate display of every instrument, and have audio and video communication with the occupants. With 90+% of the bandwidth to spare.

Indeed, I am a little surprised that the "guide" was not on the surface. That would have allowed them to sell 4 seats instead of 3. OK, maybe not the best idea when the pilot is old enough to have danced to Glenn Miller* but I am surprised that the average college sports game is better instrumented.

* OK, not quite.

 

[pinball1970]

I'm not sure how. The weights are at the bottom of the ocean, and even if recovered, what do they tell you about when they were dropped?

One thing that surprises me is the lack of telemetry involved. Add an optical fiber to the umbilical and you have all the bandwidth you need - a text every 15 minutes? You could ping every second, and have a duplicate display of every instrument, and have audio and video communication with the occupants. With 90+% of the bandwidth to spare.

Indeed, I am a little surprised that the "guide" was not on the surface. That would have allowed them to sell 4 seats instead of 3. OK, maybe not the best idea when the pilot is old enough to have danced to Glenn Miller* but I am surprised that the average college sports game is better instrumented.

* OK, not quite.

If they were released first they would show less sign of damage?

 

[Astronuc]

If they were released first they would show less sign of damage?

Not necessarily. In theory, they weights would drop straight down and be relatively close today. It would be useful to know where they lie with respect to the debris field.

I'm curious to know how it was determined the weights were dropped. Was it a text message to the support ship? That would be the only way to know, before they lost communication.

Titan was apparently 1 hour and 45 minutes into what is apparently a 2 hour descent, so they were perhaps 7/8 (0.875) of the depth to Titanic. So, they were possibly at 3300-3400 m instead of 3800. The lack of telemetry or black box is problematic. Ideally, there would be some record of what happened leading up to the failure.

 

[pinball1970]

Not necessarily. In theory, they weights would drop straight down and be relatively close today. It would be useful to know where they lie with respect to the debris field.

I'm curious to know how it was determined the weights were dropped. Was it a text message to the support ship? That would be the only way to know, before they lost communication.

Titan was apparently 1 hour and 45 minutes into what is apparently a 2 hour descent, so they were perhaps 7/8 (0.875) of the depth to Titanic. So, they were possibly at 3300-3400 m instead of 3800. The lack of telemetry or black box is problematic. Ideally, there would be some record of what happened leading up to the failure.

From the claim in #110.

 

[Vanadium 50]

In theory, they weights would drop straight down and be relatively close today.

As the great philosopher, L.P. Berra once said "In theory, there is no difference between theory and practice. In practice there is."

The incident seems to have occurred somewhere between 1/2 and 1 mile from the bottom. That;s a long way to drop, and there are ocean currents.

I think it is hopeless to tell when it was dropped. It seems much more promising to see how it was dropped - what is still attached at what is not may provide some information. Ideally this was designed in from the beginning.

 

[Astronuc]

The incident seems to have occurred somewhere between 1/2 and 1 mile from the bottom. That;s a long way to drop, and there are ocean currents.

Perhaps closer to 1/2 mile, or 500 m. The weights could be lead or depleted U, and they probably drop fairly quickly, and the would fall into the ooze, so not a lot of time to drift on the current.

Since the debris of the Titan was found about 1600 ft (~490 m) from the Titanic, I would expect the weights to be nearby. I wonder how deep in the ooze they would be.

 

[Rive]

The weights could be lead or depleted U

These are not recoverable, I guess?
Simple lumps of steel would feel more appropriate.

 

[JT Smith]

James Cameron said that the only way they would have known the weights were dropped were if it had been communicated to the surface ship. If that's true there's a good chance it will come out in an investigation.