OceanGate Expeditions Titan DSV loss

[jstar]

Joining that composite cylinder to the titanium hemisphere seems fraught as one would want the two materials to match pressure vs deflection across the joint. My guess, which is somewhat educated, is that the failure started at that join.

Novel designs need more testing than conservative ones; FEM analysis is a wonderful thing but joins between such dissimilar materials in pressure vessels for human occupancy are not mature technology.

From an interview Rush gave in 2021: "The carbon fiber and titanium – there's a rule you don't do that," Rush said, speaking of the materials used to construct the sub. "Well, I did. It's picking the rules that you break that are the ones that will add value to others and add value to society, and that really to me is about innovation."

 

[Scott Kenny]

Joining that composite cylinder to the titanium hemisphere seems fraught as one would want the two materials to match pressure vs deflection across the joint. My guess, which is somewhat educated, is that the failure started at that join.

Novel designs need more testing than conservative ones; FEM analysis is a wonderful thing but joins between such dissimilar materials in pressure vessels for human occupancy are not mature technology.

From an interview Rush gave in 2021: "The carbon fiber and titanium – there's a rule you don't do that," Rush said, speaking of the materials used to construct the sub. "Well, I did. It's picking the rules that you break that are the ones that will add value to others and add value to society, and that really to me is about innovation."

Ah, yes, breaking the rules without understanding why they are there.

Classic sign of arrogance, if not utter incompetence.

 

[southwestforests]

Based on the comments this analysis of the submersible would be very much worth the 22 minutes,

Jun 23, 2023
A preview of a world where 'regulation does not stifle innovation'. I wanted to clear up some points that have been widely misreported whilst discussing how mechanical failures of subsea vessels have been avoided for decades until now. This video could have been hours long if I spoke about everything in length, so consider it a brief summary.I speak in present tense during the video, but it was made public that the crew are deceased as the video was rendering. Despite the remarkable predictability of this failure, the families of the victims have my sympathy.Sources used:

 

[quellish]

Quellish, thank you for posting that, very interesting. Listening to Mr. Hawkes, the selection of CF for DeepFlight Challenger's hull material sounds like a tradeoff - new, unproven technology, but will do the job for that particular mission within a given budget. CompositesWorld has an article providing a bit more detail on Cyclops 2 / Titan hull construction. According to the article, it's hull was manufactured by the same company (Spencer Composites) as DeepFlight Challenger's hull.

The composites world article is interesting. To complicate things further, apparently the original hull (described in the composite world article) was having issues during their initial test dives:

Investigation broadens into Titanic-bound submersible implosion as questions mount over craft's safety — CNN

The international investigation into the fatal Titan submersible implosion broadened on Saturday, with the Royal Canadian Mounted Police saying it's looking into whether "criminal, federal, or provincial laws may possibly have been broken."

apple.news

"What we heard, in my opinion ... sounded like a flaw/defect in one area being acted on by the tremendous pressures and being crushed/damaged," Stanley wrote in the email, a copy of which has been obtained by CNN.
"From the intensity of the sounds, the fact that they never totally stopped at depth, and the fact that there were sounds at about 300 feet that indicated a relaxing of stored energy /would indicate that there is an area of the hull that is breaking down/ getting spongy," Stanley continued.

That hull was scrapped and a new one was constructed in 2018/2019. The new hull was apparently made with carbon fiber bought from Boeing at a discount - discounted because it was past its shelf life date.

OceanGate CEO admitted Titan sub's hull was made with carbon fibre from Boeing that was past its shelf life — The Mirror

OceanGate CEO Stockton Rush reportedly said that the carbon fibre used for the vessel's hull came at a "big discount" from Boeing as it was past its aeroplane shelf life

apple.news

Mr Weissmann wrote that he was told by CEO Stockton Rush that "he had gotten the carbon fibre used to make the Titan at a big discount from Boeing because it was past its shelf life for you in airplanes".
He recalled asking Mr Rush whether that was a problem, but said he was told that the shelf-life dates "were set far before they had to be".

The new hull made out of material past its shelf life would be the one used on the last dive.

And, notably, the carbon pressure vessel of DeepFlight Challenger was only certified for ONE dive. The original idea was for Fosset to dive the trench and then give it to the Smithsonian. After his death Chris Welsh bought it and Branson became involved, with a plan to dive the deepest points in the 5 oceans. Hawkes would not back this plan as the carbon hull was not intended for multiple dives and would not be safe doing so.

Sir Richard Branson quietly shelves Virgin submarine plan

www.telegraph.co.uk

But the company that built DeepFlight Challenger has told The Telegraph it refused to back the project, insisting the submarine was suitable for only one dive and could not be reused because of the pressure on its structure at such depths.

Welsh kept DeepFlight Challenger in Newport Beach, CA and continued to work on it. He passed in 2021, I do not know what may have happened to the sub and the catamaran that supported it.

 

[DrRansom]

Its a miracle it lasted as long as it did.

 

[MrTopaz]

Its a miracle it lasted as long as it did.

From everything that's come out about this guy's approach to safety, it's a miracle he didn't die twice.

 

[Scott Kenny]

Quellish, thank you for posting that, very interesting. Listening to Mr. Hawkes, the selection of CF for DeepFlight Challenger's hull material sounds like a tradeoff - new, unproven technology, but will do the job for that particular mission within a given budget. CompositesWorld has an article providing a bit more detail on Cyclops 2 / Titan hull construction. According to the article, it's hull was manufactured by the same company (Spencer Composites) as DeepFlight Challenger's hull.

The composites world article is interesting. To complicate things further, apparently the original hull (described in the composite world article) was having issues during their initial test dives:

Investigation broadens into Titanic-bound submersible implosion as questions mount over craft's safety — CNN

The international investigation into the fatal Titan submersible implosion broadened on Saturday, with the Royal Canadian Mounted Police saying it's looking into whether "criminal, federal, or provincial laws may possibly have been broken."

apple.news

"What we heard, in my opinion ... sounded like a flaw/defect in one area being acted on by the tremendous pressures and being crushed/damaged," Stanley wrote in the email, a copy of which has been obtained by CNN.
"From the intensity of the sounds, the fact that they never totally stopped at depth, and the fact that there were sounds at about 300 feet that indicated a relaxing of stored energy /would indicate that there is an area of the hull that is breaking down/ getting spongy," Stanley continued.

That hull was scrapped and a new one was constructed in 2018/2019. The new hull was apparently made with carbon fiber bought from Boeing at a discount - discounted because it was past its shelf life date.

OceanGate CEO admitted Titan sub's hull was made with carbon fibre from Boeing that was past its shelf life — The Mirror

OceanGate CEO Stockton Rush reportedly said that the carbon fibre used for the vessel's hull came at a "big discount" from Boeing as it was past its aeroplane shelf life

apple.news

Mr Weissmann wrote that he was told by CEO Stockton Rush that "he had gotten the carbon fibre used to make the Titan at a big discount from Boeing because it was past its shelf life for you in airplanes".
He recalled asking Mr Rush whether that was a problem, but said he was told that the shelf-life dates "were set far before they had to be".

The new hull made out of material past its shelf life would be the one used on the last dive.

Oh, FFS. The more I hear about this the cheaper this (expletives deleted) waste of oxygen sounds.

So, Boeing can't use this carbon fiber because it's out of date for planes, so we're going to put it under far more force in a submersible! Brilliant! (/sarcasm)

 

[uk 75]

The plot of this old children's TV show carries an awful warning

Hepcat

Hepcat Sub was a mini submarine piloted by two groovy fellows, Joe and Frank. The Hepcat was piloted by Joe and Frank, who wanted to deep dive to search for a legendary undersea forest that supposedly grew precious gems. When they tried to obtain a certificate from Marineville so they could deep...

stingray.fandom.com

 

[Archibald]

Ok, Stockton Rush really deserves to win the 2024 IG-nobel prize, even postumously.

"Well, I did. It's picking the rules that you break that are the ones that will add value to others and add value to society, and that really to me is about innovation."

"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled." Richard Feynman.

 

[1635yankee]

Joining that composite cylinder to the titanium hemisphere seems fraught as one would want the two materials to match pressure vs deflection across the joint. My guess, which is somewhat educated, is that the failure started at that join.

Novel designs need more testing than conservative ones; FEM analysis is a wonderful thing but joins between such dissimilar materials in pressure vessels for human occupancy are not mature technology.

From an interview Rush gave in 2021: "The carbon fiber and titanium – there's a rule you don't do that," Rush said, speaking of the materials used to construct the sub. "Well, I did. It's picking the rules that you break that are the ones that will add value to others and add value to society, and that really to me is about innovation."

Methinks Rush forgot engineering rules aren't quite like those against mixing stripes and plaids; the cost for breaking them is frequently paid in blood. The only way to break them safely is extensive, careful analysis and physical testing. [added in edit]
I'm not sure about the level of analysis, but the level of testing seems to have been inadequate and the results not taken sufficiently seriously.

 

[Halcyon66]

I have read that some said the fact that the Titan imploded in the first dive of the season may have been relevant.

Possibility that saltwater had been trapped in between different materials in the vessel from dives in 2021 and 2022, and worked its way through fibers and softened it up. Added to the different material properties.

Again a cycle issue, sooner or later.

Everything above shows this guy had no idea about anything other than trying to get funding sorted and an ego. Personally flying to Vegas to try and get another father/son on the dive who declined the invitation due to all the concerns that have been previously voiced.

Regards,

 

[publiusr]

Had that sub visited Britannic…would the failure been more gradual?

https://www.reddit.com/r/Damnthatsinteresting/comments/14hprj4

View: https://www.reddit.com/r/Damnthatsinteresting/comments/14hprj4/titanics_sister_ship_britannic_wreck_site_at/
The stepson of one of the victims seems not to be bothered

Titanic sub: Passenger’s stepson attends Blink-182 concert, flirts with OnlyFans model during search

Hamish Harding's stepson defends decision to attend show.

www.al.com

 

[Scott Kenny]

Had that sub visited Britannic…would the failure been more gradual?

https://www.reddit.com/r/Damnthatsinteresting/comments/14hprj4

View: https://www.reddit.com/r/Damnthatsinteresting/comments/14hprj4/titanics_sister_ship_britannic_wreck_site_at/

At 390ft, the pressure is only 1800psi, which may not have been enough to cause an implosion.

 

[publiusr]

From the New York Times:

Submersible Expert Raised Safety Concerns After 2019 Trip on Titan

After hearing a loud cracking sound during the dive, the expert, Karl Stanley, emailed OceanGate’s C.E.O., Stockton Rush, to urge him to hold off on future trips.

www.nytimes.com

And the Post

OceanGate listed job posting for ‘submersible pilot’ during doomed Titan rescue efforts

The company posted the ad in search of a “Submersible Pilot/Marine Technician” who would “help manage and operate our fleet of manned submersibles and support vessels.”

nypost.com

I wonder if Trieste could make it to Europa’s sea floor…as an ROV.

 

[Halcyon66]

On the job ad they list " Open Water SCUBA certification " as a desired prerequisite.

Not sure how that would help at 4000 meters.

Regards,

 

[aim9xray]

Launch and recovery.

 

[Orionblamblam]

Possibility that saltwater had been trapped in between different materials in the vessel from dives in 2021 and 2022, and worked its way through fibers and softened it up. Added to the different material properties.

I wonder if there might be something vaguely akin to the "cryopumping" issue that brought the composite tanks for the X-33 to ruin. In that case, cryogenic temperatures inside the tank transferred through the walls and supercooled the air outside, allowing liquid oxygen/nitrogen to soak into the slightly porous outer surface. When the propellant was expelled and the wall temperatures brought up to room temp, the liquid air soaked into the matrix could not simply leak back out, instead turned to gas and cracked the structure.

In the subs case... maybe something was forced into the outer surface of the composite as the pressure was brought up, but couldn't get back out quickly enough as the sub ascended, so there remained microscopic pockets of high pressure within the composite, causing stress and cracks.

Shrug.

 

[publiusr]

Salt crystals didn’t help.

Alan Stern was on that thing

Per aquas ad astra

OceanGate statement in full

nasawatch.com

 

[Halcyon66]

The Open Water SCUBA certification was meant as a joke

Along with the individual needed to be able to work under pressure

Salt would definitely be an issue, getting forced in under pressure only to slowly expand over time.

Regards,

 

[Archibald]

Stockton Crush and OceanCrate ... not very subtle, I know. But really - they'd better have dived to Titanic in a wooden crate. Did Stockton Rush really thought he was not only smarter than seasoned engineers and their certifications, but also smarter than the laws of physic ? what kind of egotic idiot is that ?
Quick sanity check: when diving at Titanic depths, you can not bend reality to your wishful thinking and magical world.

You know what happened ? as mentionned above, the composite hull was bound to suffer after more than a few dives, plus saltwater may gradually contaminates it. Still, the hull resisted a handful of dives in 2021 and 2022.

Then the way Rush mentality worked, it went the exact same way as the Shuttle O-ring erosion, 1981-1986. "So far, so good, so I'm right, and they are wrong. I'm the smartest ! I'm the best !" Yeah. Sure, dude. I would bet one of my testicles the more dives happened without serious incidents, the more Rush felt vindicated.
"Ha ha, they told me my submarine would be dangerous, but - dive after dive, it WORKS !! Ha ha, in your face, stupid pessimistic engineers ! I 'm smarter than you and, most importantly...

I'm thinking about Donald Gennaro in Jurassic Park.
[seeing the dinosaurs for the first time] We're gonna make a fortune with this place.

View: https://www.youtube.com/watch?v=6BRfq3SBTEY

 

[DrRansom]

At least in Jurassic Park, the lawyer wants facility and security upgrades.

I think looking for a cause of the submersible's destruction is a bit of a waste of time. It's like looking for a needle in a box of needles. What do you choose? Sub-par carbon fiber weave? Window not depth rated? Some other cause we don't know yet?

Rush had no idea how to the sub and all his previous passengers should find some monestary for a thanksgiving donation.

 

[Orionblamblam]

View: https://www.youtube.com/watch?v=8tW4zfTeJqM


Didn't fail quite the way I expected...

 

[sferrin]

The sub imploded an hour and 45 minutes into a two and a half hour descent, so it was still far from the Titanic. If it descended at a constant speed, it should have been about 8750 feet down... 3750 feet above the Titanic.

They lost comms 1:45 into their descent. Apparently losing comms on descent was a regular occurrence for them and did not immediately cause alarm.

Submersibles generally do not descend at a constant rate. Water conditions, submarine systems, etc. cause the rate of descent to change with a competent pilot. But obviously your mileage may vary, and this submersible was by design fairly different from other submersibles.

SOME articles report that SOSUS detected a bang around that time. Maybe it imploded when they lost comms, maybe later. There is no solid information at this point. Based on where the debris is I would guess - and only guess - that it imploded later in the descent, when it was closer to the bottom.

Is SOSUS, in its original form, even in use anymore?

SOSUS - Wikipedia

en.wikipedia.org

From FAS:

"Under operational command of the U.S. Navy's Commander Undersea Surveillance(CUS) IUSS shore systems are staffed and operated by uniformed U.S. Navypersonnel. System life cycle and engineering support is provided by carreer civilservants (NISE East Code 341) and contractor personnel located at the IUSSOperations Support Center (IOSC).

With the end of the Cold War, SOSUS hydrophone arrays in both the Atlantic and Pacific face an uncertain future of shutdowns and closings. Consolidation of SOSUS by array retermination, remoting, or closure will be complete by FY97. Recent closures include Bermuda, Adak, and Keflavik. All other arrays will remain operational. SOSUS in the North Pacific is currently being analyzed for low-frequency vocalizations from marine mammals living in the open ocean.

On 26 April 1999 Lockheed Martin Corp., Manassas, Va., was awarded a $107,031,978 firm-fixed-price contract for Phase II of a deep water, undersea surveillance system. This system is a long life, passive acoustic surveillance system that can be configured for multiple mission applications. It has the capability to provide long-term barrier and field acoustic surveillance, long-range acoustic surveillance coverage of open ocean areas, and acoustic surveillance in areas with high ambient noise. This contract contains one option, which, if exercised, would bring the total cumulative value of this contract to $153,234,288. Work will be performed in Manassas, Va., and is expected to be completed by September 2005. This contract was competitively procured through the Space and Naval Warfare Systems Command electronic commerce web site and Commerce Business Daily with two offers solicited and two offers received. Contract funds will not expire at the end of the fiscal year. The Space and Naval Warfare Systems Command, San Diego, Calif., is the contracting activity (N00039-99-C-2202)."

 

[1635yankee]

Possibility that saltwater had been trapped in between different materials in the vessel from dives in 2021 and 2022, and worked its way through fibers and softened it up. Added to the different material properties.

I wonder if there might be something vaguely akin to the "cryopumping" issue that brought the composite tanks for the X-33 to ruin. In that case, cryogenic temperatures inside the tank transferred through the walls and supercooled the air outside, allowing liquid oxygen/nitrogen to soak into the slightly porous outer surface. When the propellant was expelled and the wall temperatures brought up to room temp, the liquid air soaked into the matrix could not simply leak back out, instead turned to gas and cracked the structure.

In the subs case... maybe something was forced into the outer surface of the composite as the pressure was brought up, but couldn't get back out quickly enough as the sub ascended, so there remained microscopic pockets of high pressure within the composite, causing stress and cracks.

Shrug.

Like a composite version of the bends?

 

[Orionblamblam]

Like a composite version of the bends?

Essentially, yeah.

 

[Halcyon66]

How the 50 yr old white guys do it.

View: https://www.youtube.com/watch?v=YvnsI82PrRA

View: https://www.youtube.com/watch?v=pb5j9oeZCm0


Chalk and cheese, one could say.

Regards,

 

[publiusr]

View: https://www.youtube.com/watch?v=8tW4zfTeJqM


Didn't fail quite the way I expected...

I don’t think that scales well.
A pipeline might fail that way…and even then…

https://www.reddit.com/r/gifs/comments/3u0kly

View: https://www.reddit.com/r/gifs/comments/3u0kly/crab_sucked_into_a_pipeline_from_a_pressure/


The best is to repeat the Titan failure with crash test dummies and cameras.

I wonder if Trieste would make it to Europa’s sea floor…

The main mistake is applying aerospace thinking to benthic pressures.

If I were a kaiju…that somehow avoided being crushed by my own weight…and I picked up a mini-sub and gave it a mighty squeeze…I might muster half of what Titan was subjected to.

So the next person to think to use carbon fiber needs to be asked:

“Would you get into this knowing Gorgo would bite it?”

 

[1635yankee]

From the New York Times:

Submersible Expert Raised Safety Concerns After 2019 Trip on Titan

After hearing a loud cracking sound during the dive, the expert, Karl Stanley, emailed OceanGate’s C.E.O., Stockton Rush, to urge him to hold off on future trips.

www.nytimes.com

And the Post

OceanGate listed job posting for ‘submersible pilot’ during doomed Titan rescue efforts

The company posted the ad in search of a “Submersible Pilot/Marine Technician” who would “help manage and operate our fleet of manned submersibles and support vessels.”

nypost.com

I wonder if Trieste could make it to Europa’s sea floor…as an ROV.

The bathyscaphe Trieste? The one that reached the bottom of the deepest part of the ocean, Challenger Deep in the Marianas Trench?

The surface gravity on Europa is about 1.3 m/s^2. The density of water (ice is a bit less dense, salt water is more dense) is about 1000 kg/m^3. The ocean is about 150 km deep, under about 20 km of ice. Neglecting a) that acceleration due to gravity will change as one descends in the ocean and b) that water is compressible, so its density will increase with the depth, a WAG for the pressure is about 2200 bar. The pressure at the bottom of Challenger Deep is about 1080 bar, so about half that at the bottom of Europa's ocean[1]. A new cabin may be needed, but if it's an ROV, it would be smaller.

The other problems would include getting the ROV Trieste to Europa (estimate: $100,000/kg) and through 20 km of ice. The Trieste has a mass of about 50,000 kg (it's lighter than I thought), so getting it to Europa would only cost $5,000,000,000. Chump change! Of course, a major R&D effort would be needed to get the Trieste through 20,000 m of ice and control it from Earth.

 

[publiusr]

Europa’s ocean is even deeper, or so I heard.

That might crush even the Krupp built sphere.

 

[southwestforests]

Is SOSUS, in its original form, even in use anymore?

Two relevant articles,

US Navy Upgrading Undersea Sub-Detecting Sensor Network
New contract augments old Cold War “SOSUS” arrays.
By Steven Stashwick
November 04, 2016

US Navy Upgrading Undersea Sub-Detecting Sensor Network

New contract augments old Cold War “SOSUS” arrays.

thediplomat.com

One reason there were 30 IUSS sites during the Cold War is that the SOSUS systems had to be connected to collection facilities by underwater cable, requiring sites to be relatively local to the target area. But DRAPES will apparently use a new underwater communications system to transmit the acoustic data it collects to the three remaining Navy Operational Processing Facilities (NOPFs). These facilities combine data from the static SOSUS networks and SURTASS ships to provide “detection, localization, and tracking of submarines.” DRAPES’ ability to provide wide coverage from a fixed location in the ocean, apparently without the need for additional NOPF facility footprints, would be a substantial improvement over the old SOSUS network.

As China and Russia have asserted themselves anew as “pacing competitors,” as described by Undersecretary of Defense Robert Work, the U.S. Navy has taken a renewed interest in its traditional Cold War antisubmarine warfare mission. Together, DRAPES and SURTASS promise to provide a persistent, long-range ability to detect adversary submarines around the globe. Using cueing data from those platforms, improved local anti-submarine assets like the P-8 Poseidon sub hunter aircraft (which replaces the 50 year-old P-3 Orion) and surface combatants with new, improved towed sonar arrays of their own, like the Multi-Function Towed Array, can then close on a target, and track or engage it as needed.

and

The Sound Surveillance System (SOSUS)

With the end of the Cold War, SOSUS hydrophone arrays in both the Atlantic and Pacific face an uncertain future of shutdowns and closings. Consolidation of SOSUS by array retermination, remoting, or closure will be complete by FY97. Recent closures include Bermuda, Adak, and Keflavik. All other arrays will remain operational. SOSUS in the North Pacific is currently being analyzed for low-frequency vocalizations from marine mammals living in the open ocean.

On 26 April 1999 Lockheed Martin Corp., Manassas, Va., was awarded a $107,031,978 firm-fixed-price contract for Phase II of a deep water, undersea surveillance system. This system is a long life, passive acoustic surveillance system that can be configured for multiple mission applications. It has the capability to provide long-term barrier and field acoustic surveillance, long-range acoustic surveillance coverage of open ocean areas, and acoustic surveillance in areas with high ambient noise. This contract contains one option, which, if exercised, would bring the total cumulative value of this contract to $153,234,288. Work will be performed in Manassas, Va., and is expected to be completed by September 2005. This contract was competitively procured through the Space and Naval Warfare Systems Command electronic commerce web site and Commerce Business Daily with two offers solicited and two offers received. Contract funds will not expire at the end of the fiscal year. The Space and Naval Warfare Systems Command, San Diego, Calif., is the contracting activity (N00039-99-C-2202).

 

[TomS]

Pretty sure the thrusters were mounted on the outer casing. And yes, probably screwed to the fiberglass.

They weren't quite that stupid.
I mean, they were stupid enough in other ways, but not so dumb as to tap screw holes into a composite pressure vessel.

Just look at a picture. The thrusters were mounted on a separate skin (probably metal, maybe some sort of composite ) that was wrapped around the pressure vessel. You can see the seams where this overwrap was fastened together. Probably held to the pressure vessel by the rings that also held the landing feet and other systems.

 

[Rhinocrates]

Europa’s ocean is even deeper, or so I heard.

That might crush even the Krupp built sphere.

Much lower gravity though, so despite the great depth, the pressure is not as extreme as one might think. According to a quick search,

Europa's possible ocean is estimated to be 100-200km deep. Despite the great depth of the Europa's ocean, hydrostatic pressure at the seafloor would be 130-260 MPa, corresponding to 13-26 km depth of a theoretical Earth's ocean. The hydrostatic pressure is not beyond the edge of existing deep-sea technology.

Dive Europa: a search-for-life initiative - PubMed

Liquid water, underwater volcanoes and possibly life forms have been suggested to be present beneath the estimated 10 km-thick ice shell of Europa the Jovian satellite J2. Europa's possible ocean is estimated to be 100-200km deep. Despite the great depth of the Europa's ocean, hydrostatic...

pubmed.ncbi.nlm.nih.gov

 

[Scott Kenny]

Pretty sure the thrusters were mounted on the outer casing. And yes, probably screwed to the fiberglass.

They weren't quite that stupid.
I mean, they were stupid enough in other ways, but not so dumb as to tap screw holes into a composite pressure vessel.

Just look at a picture. The thrusters were mounted on a separate skin (probably metal, maybe some sort of composite ) that was wrapped around the pressure vessel. You can see the seams where this overwrap was fastened together. Probably held to the pressure vessel by the rings that also held the landing feet and other systems.



(image deleted for space)

That's what I meant. The thrusters are mounted to that outer wrap, which I think just attaches to the titanium rings at the end of the pressure hull. I just thought it was fiberglass.

 

[TomS]

That's what I meant. The thrusters are mounted to that outer wrap, which I think just attaches to the titanium rings at the end of the pressure hull. I just thought it was fiberglass.

Oops, sorry, I misunderstood you. I thought the "fiberglass" was a reference to the composite PV.

 

[quellish]

That's what I meant. The thrusters are mounted to that outer wrap, which I think just attaches to the titanium rings at the end of the pressure hull. I just thought it was fiberglass.

Oops, sorry, I misunderstood you. I thought the "fiberglass" was a reference to the composite PV.

I’m still trying to figure out where the batteries were. This is a weird design.

 

[Moose]

That's what I meant. The thrusters are mounted to that outer wrap, which I think just attaches to the titanium rings at the end of the pressure hull. I just thought it was fiberglass.

Oops, sorry, I misunderstood you. I thought the "fiberglass" was a reference to the composite PV.

I’m still trying to figure out where the batteries were. This is a weird design.

That's a word for it, though not the one I'd use.

 

[TomS]

I’m still trying to figure out where the batteries were. This is a weird design.

Under the cabin floor, I think. (Not 100% sure; this pic may be Cyclops 1 rather than Titan, but they seem to be similar in general config.)

 

[Archibald]

Don't look for any batteries, Stockton was smarter than the rest of the entire universe, no need for batteries...

 

[GTX]

What happens next with the wreckage of OceanGate's submersible Titan?

An international investigation into the cause of the undersea implosion of a tourist submersible that killed all five people on board is underway. So, what happens next?

www.abc.net.au

 

[robunos]

b) that water is compressible, so its density will increase with the depth

Whoa!! Who changed the Laws of Physics while I wasn't watching . . . ?

Water Compressibility | U.S. Geological Survey

Water is essentially incompressible, especially under normal conditions. Yet, in industrial applications water can be tremendously compressed and used to do things like cut through metal.

www.usgs.gov

cheers,
Robin.