US Coast Guard Report on Titan Submersible(news.uscg.mil)
news.uscg.mil
US Coast Guard Report on Titan Submersible
https://www.news.uscg.mil/Press-Releases/Article/4265651/coast-guard-marine-board-of-investigation-releases-report-on-titan-submersible/
188 comments
It was very clearly very early on that critical risks were known, unmitigated, and misrepresented. I don't think the kind of person(s) that know and misrepresent are the kind to learn and avoid similar mistakes, though publicizing issues like this will increase pressure on them to hide their lies better. They had a messianic CEO dismissing concerns with bluster and bravado
One thing to keep in mind here is that the CEO didn't hide the flaws to make a profit, otherwise he wouldn't have been on board the submersible. He hid them because he believed they were wrong.
He believed they were wrong because they got in his way:
https://www.businessinsider.com/titan-submarine-ceo-complain...
In his way towards what?
Building a submersible without concern for the safety of his customers, or himself.
making money
Ultimately, yeah. Rush's goal was to make money by taking paying customers on undersea tours. Calling the Titan a "research vessel" was a farce; what little research it performed, like sampling ocean salinity at different depths, was a fig-leaf at best, not the purpose of its activities. (And, per the report, even that was neglected on some of the vessel's later dives.)
I think he caved in to the pressure from outside because his company was sinking and financially underwater.
> One thing to keep in mind here is that the CEO didn't hide the flaws to make a profit
Didn't they try to hide the fact that they had to recast the entire hull because the previous one had too many structural deficiencies? I mean, they were monitoring all the tears all the time and had several test hulls crack in the R&D phase.
He probably just thought he could take the gamble, thread the needle and come out victorious, the way SpaceX almost bankrupted before going to bigger things, and his financing issues would melt away. High risk tollerance and wishful thinking.
> One thing to keep in mind here is that the CEO didn't hide the flaws to make a profit
Didn't they try to hide the fact that they had to recast the entire hull because the previous one had too many structural deficiencies? I mean, they were monitoring all the tears all the time and had several test hulls crack in the R&D phase.
He probably just thought he could take the gamble, thread the needle and come out victorious, the way SpaceX almost bankrupted before going to bigger things, and his financing issues would melt away. High risk tollerance and wishful thinking.
"The most important thing is not to fool yourself, and you are the easiest person to fool."
You cannot divine the motives of a person with self-delusional tendencies by assuming that their behavior was rational.
How does one know the danger of something like this and then dismiss it? How do you convince yourself that you'll be okay? I don't understand that.
By convincing yourself that the existing rules are written by a bunch of paranoid bureaucrats that don't actually know what's going on. Which, to be fair, is easy to do when there's a lot of rules that are written by exactly those people, especially in safety-critical areas (my god there's a lot of stupid, ill-justified rules in the name of safety, because who can argue against that?). But the correct response isn't to just sweep them all aside as worthless, but to carefully and critically understand them, because some of them have important and not super obvious reasons behind them (and the unpredictability of composites under compression is exactly such an area, and one that is well known to experts in the area)
> there's a lot of rules that are written by exactly those people
I don't know if that is true. I do think we get rigid safety protocols or specifications that can make novel designs impossible. This happens in all bureaucracies.
I don't know if that is true. I do think we get rigid safety protocols or specifications that can make novel designs impossible. This happens in all bureaucracies.
There's a bit of that sometimes (and I think the general safety protocols in the submersable rating standards they ignored were kinda like that, though it wasn't impossible, it was just "If you're doing something nonstandard, you need to test the shit out of it", which involved needing to build multiple full-scale prototypes to do long and destructive tests on, which is hella expensive but also realistically the kind of thing I'd really like to see for something I'm going to put between me and the depths of the ocean). These rules were for the most part written by experts who knew what kinds of things can go wrong and how to build as much confidence in a new design as possible.
But on the other hand, you also get people making such rules who really don't know their stuff, and who have a reflexive tendancy to add rules 'just in case', without allowing for judgement or thought in the process. Because they don't know what's going on, they often produce rulesets that are both overconstraining and insufficient, sometimes in ways that are counterproductive to their goals. Areas where I've seen this: Medical device regulation (I've seen how the sausage is made, and it's shockingly easy to get absolute crap approved but a good design can get caught up in endless headaches by box-ticking), IT security processes (endless checklists of 'best practices', very little sensible risk assessment, threat modeling, or red-teaming, huge incentives for people to workaround the system as intended, creating more security holes). UL safety regs entered a bit of a spiral of this at one point as well: they started just playing whack-a-mole with rules and wound up with something that was really difficult to implement but didn't really improve safety. EU standards actually tend to be pretty sensible in this regard (at least outside medical areas). Company health and safety can easily fall into this trap as well, if run incompetently.
But on the other hand, you also get people making such rules who really don't know their stuff, and who have a reflexive tendancy to add rules 'just in case', without allowing for judgement or thought in the process. Because they don't know what's going on, they often produce rulesets that are both overconstraining and insufficient, sometimes in ways that are counterproductive to their goals. Areas where I've seen this: Medical device regulation (I've seen how the sausage is made, and it's shockingly easy to get absolute crap approved but a good design can get caught up in endless headaches by box-ticking), IT security processes (endless checklists of 'best practices', very little sensible risk assessment, threat modeling, or red-teaming, huge incentives for people to workaround the system as intended, creating more security holes). UL safety regs entered a bit of a spiral of this at one point as well: they started just playing whack-a-mole with rules and wound up with something that was really difficult to implement but didn't really improve safety. EU standards actually tend to be pretty sensible in this regard (at least outside medical areas). Company health and safety can easily fall into this trap as well, if run incompetently.
What you are describing is "bureaucratic collapse". Those extra rules are not meant to support outcomes for the ostensible goal, but a better outcome for the bureaucracy itself. Bureaucracy is not in and of itself bad, it is a very powerful tool, but when it is administered by non-aligned agents and not subject to the proper feedback loops it will always shift goals into protecting itself over its original mission.
Stockton Rush had the perfect storm of a personality that saw everything he hated in "rules" meant to constrain submersible engineering towards safe designs.
Stockton Rush had the perfect storm of a personality that saw everything he hated in "rules" meant to constrain submersible engineering towards safe designs.
Depends on the country.
I work globally installing high voltage switchgear.
In certain countries, safety culture is exactly how parent described. Layer upon layer upon layer of red tape to do the simplest thing, making everything needlessly hard to do. Quality suffers and I suspect safety as well.
Instead of training the personnel and putting faith in them, they are treated like children.
I am talking specifically about the UK.
I work globally installing high voltage switchgear.
In certain countries, safety culture is exactly how parent described. Layer upon layer upon layer of red tape to do the simplest thing, making everything needlessly hard to do. Quality suffers and I suspect safety as well.
Instead of training the personnel and putting faith in them, they are treated like children.
I am talking specifically about the UK.
> Instead of training the personnel and putting faith in them, they are treated like children.
Exactly this, so much time and effort gets expended on paranoid bureaucracy.
Ideally the decisions on these things should be taken by those with a good amount of practical experience, who've been held accountable in the past, know the kinds risks low-skill employees bring and the pressures vested interests bring to the table. The ivory tower types don't know any of that.
Exactly this, so much time and effort gets expended on paranoid bureaucracy.
Ideally the decisions on these things should be taken by those with a good amount of practical experience, who've been held accountable in the past, know the kinds risks low-skill employees bring and the pressures vested interests bring to the table. The ivory tower types don't know any of that.
The thing that I find amazing about this sub, is that the final hull survived all those trips, and then before the final one let everyone know it was toast, and Stockton ignored it. He was careless with peoples lives, but his sub actually did what he set out to do, and if he listened to the instruments, he'd still be alive, he could have made another hull, and he could be taking more trips down there for better of for worse. The porthole design was poor, the carbon fiber had tons of defects, the controller, everything was cobbled together, yet it held up until it didn't.
It didn't implode on next dive, it was much worse.
On dive 80 during surfacing people heard a "loud bang" from the submersible (according to a witness it sounded like a gunfire).
They looked at their "RTMS" system and found recording of loud noise from the hull. But only three days later they did the dive 81 (with customers). After this dive their tension sensors shown that their carbon hull no longer compresses under pressure like it used to. They then made plan to inspect the hull after dive 83. But instead they left Titan winter on the parking lot in Saint Johns where it was not protected from any exposure because that was cheaper.
During summer they hauled it for a dive 88 (I don't know why they jumped from 81 to 88, prolly cancelled dives because of the weather?). During hauling it become loose and started knocking against the hauling platform (LARS) because of the waves. Day later they did a dive where it imploded.
On side note, they had no way to access and inspect the carbon hull without having to completely dissemble vehicle, and that too was considered too pricy to do.
This was a disaster of organization with messianic CEO dismissing all concerns with bravado and legal treats that got what was coming to them. If you want to, here's transcript of him scolding and then laying out one of engineers because they took safety concerns outside of the company:
https://media.defense.gov/2024/Sep/20/2003550726/-1/-1/0/CG-...
On dive 80 during surfacing people heard a "loud bang" from the submersible (according to a witness it sounded like a gunfire).
They looked at their "RTMS" system and found recording of loud noise from the hull. But only three days later they did the dive 81 (with customers). After this dive their tension sensors shown that their carbon hull no longer compresses under pressure like it used to. They then made plan to inspect the hull after dive 83. But instead they left Titan winter on the parking lot in Saint Johns where it was not protected from any exposure because that was cheaper.
During summer they hauled it for a dive 88 (I don't know why they jumped from 81 to 88, prolly cancelled dives because of the weather?). During hauling it become loose and started knocking against the hauling platform (LARS) because of the waves. Day later they did a dive where it imploded.
On side note, they had no way to access and inspect the carbon hull without having to completely dissemble vehicle, and that too was considered too pricy to do.
This was a disaster of organization with messianic CEO dismissing all concerns with bravado and legal treats that got what was coming to them. If you want to, here's transcript of him scolding and then laying out one of engineers because they took safety concerns outside of the company:
https://media.defense.gov/2024/Sep/20/2003550726/-1/-1/0/CG-...
"Not at all, because carbon fiber is better compression then tension. And that's what nobody understands. It's completely opposite of what everyone else says. Everyone's, oh, carbon fiber can't handle compression. They're full of shit, and I've proven they're full of shit."
- Man crushed by custom carbon fiber submersible
- Man crushed by custom carbon fiber submersible
"Now, if it fails, then you have to stop, and it's -- again, this is not something that just happens all of a sudden. It doesn't just implode. It screams like a mother before it implodes."
- Man crushed by an instantly imploding submersible
- Man crushed by an instantly imploding submersible
To be fair, it did scream before it imploded.
They just disregarded the screams because they couldn't afford to make sure it was still working.
They just disregarded the screams because they couldn't afford to make sure it was still working.
Management classes will write textbooks about Stockton Rush, but not in the way he would have hoped
Right next to the O-rings will survive in temperatures colder than they were designed. At least Rush's backside cashed the check his mouth wrote where as the NASA engineers were still around after their decision. Does that make one better/worse than the other? Rush took other people with him though when he cashed that check.
For the record, NASA engineers recommended against launching, but were overridden by, as usual, management.
Why? There’s already a plentiful list of disastrously wrong arrogant cocksure assholes. Still doesn’t stop people from thinking they’re the Steve Jobs flavor of arrogant cocksure asshole.
Steve Jobs, who very famously died of pancreatic cancer because he delayed surgical treatment in favor of fruit juice? That Steve Jobs?
the disastrously wrong arrogant cocksure assholes don't hear that part, they just hear "people told him he was wrong" and "millions of dollars"
The funny thing is that it's trivially untrue of carbon fiber, which has a compressive strength ~40% of its tensile strength.
Being weaker in compression than in tension is not the same as being unable to handle compression. 40% of carbon fiber's tensile strength is still comparable to the compressive strength of high strength steel.
So there's a NASA/Lockheed report on this.
> https://ntrs.nasa.gov/citations/19810045017
As 95% of the carbon fiber market is T300, and as T300 hasn't changed in the years since, I think it holds up.
Long story short, raw carbon fiber has a high compressive strength, but it's still just ~40% of its tensile strength. Carbon fiber composite single-plies or tapes have a reduced, but still reasonably high, compressive strength. When you get to multi-ply 0/90° or 0/45/90° composite laminates, "allowable" A-Basis (<1% likelihood of failure) compressive strength is very low -- around 400MPa -- well under the compressive strength of good steel.
And that's under ideal conditions. You've got to apply knock-downs for ply angle, moisture, through-thickness shear, impact damage, and manufacturing defects.
...Hence the Titan sub failed at a compressive load of something like 200MPa.
I'm not accusing you of this, but one of the issues with carbon fiber is that people see on a specsheet that it has, e.g., a "tensile strength = 4000MPa" and they assume that composite parts will exhibit a practical tensile strength of 4000MPa. The properties of CFRP -- CF composites with epoxy or PEEK or whatever -- are always way reduced, and sometimes quite difficult to pin down.
That said, the tensile strength of CF is always high, as a rule of thumb. Its compressive strength really isn't.
> https://ntrs.nasa.gov/citations/19810045017
As 95% of the carbon fiber market is T300, and as T300 hasn't changed in the years since, I think it holds up.
Long story short, raw carbon fiber has a high compressive strength, but it's still just ~40% of its tensile strength. Carbon fiber composite single-plies or tapes have a reduced, but still reasonably high, compressive strength. When you get to multi-ply 0/90° or 0/45/90° composite laminates, "allowable" A-Basis (<1% likelihood of failure) compressive strength is very low -- around 400MPa -- well under the compressive strength of good steel.
And that's under ideal conditions. You've got to apply knock-downs for ply angle, moisture, through-thickness shear, impact damage, and manufacturing defects.
...Hence the Titan sub failed at a compressive load of something like 200MPa.
I'm not accusing you of this, but one of the issues with carbon fiber is that people see on a specsheet that it has, e.g., a "tensile strength = 4000MPa" and they assume that composite parts will exhibit a practical tensile strength of 4000MPa. The properties of CFRP -- CF composites with epoxy or PEEK or whatever -- are always way reduced, and sometimes quite difficult to pin down.
That said, the tensile strength of CF is always high, as a rule of thumb. Its compressive strength really isn't.
I would not call 400 MPa "very low" that's better than the best structural steel. Further, the important thing is the specific strength. CFRP has a density 5 times lower than steel, meaning you can use 5 times as much for the same weight, bearing 5 times the load. A good steel has a compressive strength around 1000 MPa, the best superalloys have compressive strength around 1500 MPa, the same weight of CFRP can withstand the equivalent of around 2000 MPa.
Sure this is idealized, but so is the strength of steel.
The concern with carbon fiber is its potential for delamination, not its compressive strength. Titan's failure was after delamination.
Sure this is idealized, but so is the strength of steel.
The concern with carbon fiber is its potential for delamination, not its compressive strength. Titan's failure was after delamination.
400 MPa is not better than the best structural steel. And 1000 MPa is way higher than the best structural steel (compressive strength and tensile strength are essentially equal for steel). Most structural steel has an ultimate tensile strength of around 500 MPa. Ultimate tensile strength is the comparable strength parameter when discussing rupture/fracture.
400 MPa is better than the best structural steel. 1000 MPa is not for structural steel, it is for high grade steel, the sort you make submarines out of. Why would I list 400 and 1000 for the same value?
Steel is weaker in compression than tension. It's more isotropic than say concrete, but the difference is meaningful in practice.
We're not discussing rupture here. That's for when the pressure is higher internally than externally. We are discussing a submarine, which is a pressure vessel under compression which must also remain buoyant. The specific yield compressive strength is the value which matters.
Steel is weaker in compression than tension. It's more isotropic than say concrete, but the difference is meaningful in practice.
We're not discussing rupture here. That's for when the pressure is higher internally than externally. We are discussing a submarine, which is a pressure vessel under compression which must also remain buoyant. The specific yield compressive strength is the value which matters.
When someone says "structural steel" they are normally talking about something similar to A572. A572 comes in multiple grades, with grade 42 being the lowest. Grade 42 has a yield strength of 42 ksi (hence grade 42) and a rupture strength of 60 ksi by spec. 60 ksi is 414 MPa. Even A36 (which is basically the weakest structural steel commercially available nowadays) has a rupture strength of around 60 ksi and a yield strength of 36 ksi. Hence, even the weakest "structural steels" have a rupture strength of around 400 MPa.
When I use the word "rupture" I am talking about the material property, not the specific submarine loading condition at play. When comparing steel, which is a ductile material, to carbon fiber, which is a brittle material, you should use the steel's rupture strength instead of yield strength. Steel is for all intents and purposes an isotropic material, and the difference between tensile strength and compressive strength is not material in practice (because steel in compression is nearly always governed by macro-scale geometric issues leading to buckling rather than the material strength in compression being exceeded).
When I use the word "rupture" I am talking about the material property, not the specific submarine loading condition at play. When comparing steel, which is a ductile material, to carbon fiber, which is a brittle material, you should use the steel's rupture strength instead of yield strength. Steel is for all intents and purposes an isotropic material, and the difference between tensile strength and compressive strength is not material in practice (because steel in compression is nearly always governed by macro-scale geometric issues leading to buckling rather than the material strength in compression being exceeded).
> Not at all, because carbon fiber is better compression then tension.
That's still false though.
That's still false though.
The '~' is important: composites are in general very difficult to predict, and under compression even more so.
(To build some intuition: carbon fibre, is just that, i.e. a fabric. No-one expects to be able to push on the edges of a sheet of fabric get any real resistance at all. If you then embed that it a plastic, i.e. make a composite, the plastic is mainly what makes it hold its shape. It's only really made stronger in tension by the fibers in it, why would you expect the compression to be better?)
(To build some intuition: carbon fibre, is just that, i.e. a fabric. No-one expects to be able to push on the edges of a sheet of fabric get any real resistance at all. If you then embed that it a plastic, i.e. make a composite, the plastic is mainly what makes it hold its shape. It's only really made stronger in tension by the fibers in it, why would you expect the compression to be better?)
"what are you gonna do, stab me"
- Man crushed by custom carbon fiber submersible
- Man crushed by custom carbon fiber submersible
“Now, you can Google this on Google”
> But instead they left Titan winter on the parking lot in Saint Johns where it was not protected from any exposure because that was cheaper.
This came up in the hearings. It's standard practice to do this but it's probably different leaving say the metallic Antipodes [1] outside than carbon fiber.
[1]: https://en.wikipedia.org/wiki/Antipodes_(submersible)
This came up in the hearings. It's standard practice to do this but it's probably different leaving say the metallic Antipodes [1] outside than carbon fiber.
[1]: https://en.wikipedia.org/wiki/Antipodes_(submersible)
The report here more or less outright says that leaving it outside was a major factor in the incident. The incident on dive 80 was adjudged to be partial delamination of the carbon fiber layers, and leaving it outside subjected it to freeze-thaw cycles that propagated the delamination into near-total delamination, which promptly failed the next time the hull was pressurized. Although there is also the aborted dive 87, which subjected to the submersible to a lot of percussive damage via wave action.
One wonders if any of these people have ever heard the term, "Don't poke the bear."
Reading this is like watching someone gamble their life savings away because they know the next round/hand is gonna be the one where they win it all back.
Reading this is like watching someone gamble their life savings away because they know the next round/hand is gonna be the one where they win it all back.
Some real gems here and learned some things I wasn't aware of.
> "Now, if it fails, then you have to stop, and it's -- again, this is not something that just happens all of a sudden. It doesn't just implode. It screams like a mother before it implodes."
> On dive 80 during surfacing people heard a "loud bang" from the submersible (according to a witness it sounded like a gunfire)
Well, there you go.
> But instead they left Titan <during the> winter on the parking lot in Saint Johns where it was not protected from any exposure because that was cheaper.
> During hauling it become loose and started knocking against the hauling platform (LARS) because of the waves. Day later they did a dive where it imploded.
Early on, it was made clear that carbon fiber hulls could not easily be inspected for integrity issues like metal hulls can be. I'm not an expert, but I'm guessing sensitive instruments have been around for a while for the purpose of inspection. Having a hull you cannot easily inspect would/should make most people/companies nervous.
> "Now, if it fails, then you have to stop, and it's -- again, this is not something that just happens all of a sudden. It doesn't just implode. It screams like a mother before it implodes."
> On dive 80 during surfacing people heard a "loud bang" from the submersible (according to a witness it sounded like a gunfire)
Well, there you go.
> But instead they left Titan <during the> winter on the parking lot in Saint Johns where it was not protected from any exposure because that was cheaper.
> During hauling it become loose and started knocking against the hauling platform (LARS) because of the waves. Day later they did a dive where it imploded.
Early on, it was made clear that carbon fiber hulls could not easily be inspected for integrity issues like metal hulls can be. I'm not an expert, but I'm guessing sensitive instruments have been around for a while for the purpose of inspection. Having a hull you cannot easily inspect would/should make most people/companies nervous.
This transcript is of CEO Stockton Rush interviewing redacted "Director of Marine Operations"? Do I have that right?
Why is there a transcript of the CEO interviewing one of his own employees, apparently in front of the NTSB, from 2018?
Edit: the transcript is between Stockton Rush and his former director of marine operations, David Lochridge, plus three other staff. [...] Lochridge: "That meeting turned out to be a two-hour, 10-minute discussion… on my termination and how my disagreements with the organisation, with regards to safety, didn't matter." [...] The 2018 meeting was recorded.
https://www.bbc.com/news/articles/c7819kx4498o
Why is there a transcript of the CEO interviewing one of his own employees, apparently in front of the NTSB, from 2018?
Edit: the transcript is between Stockton Rush and his former director of marine operations, David Lochridge, plus three other staff. [...] Lochridge: "That meeting turned out to be a two-hour, 10-minute discussion… on my termination and how my disagreements with the organisation, with regards to safety, didn't matter." [...] The 2018 meeting was recorded.
https://www.bbc.com/news/articles/c7819kx4498o
I believe it was a recorded phone call
Has anyone written up a narrative of this, presented that transcript in context, and so forth? If not, thank you for presenting it.
> They then made plan to inspect the hull after dive 83. But instead they left Titan winter on the parking lot in Saint Johns where it was not protected from any exposure because that was cheaper.
The things I'm working on have a much lower (zero?) chance of death but this is a tale as old as time. _Looks longingly into the backlog..._
The things I'm working on have a much lower (zero?) chance of death but this is a tale as old as time. _Looks longingly into the backlog..._
> This was a disaster of organization with messianic CEO dismissing all concerns with bravado
While I love this list, I do not like that you are blaming everything on CEO.
This company followed current ethical policies, and used them to exclude actual experts and skilled people. CEO operated in environment that supports this behaviour, and only cares about irelevant metrics!
While I love this list, I do not like that you are blaming everything on CEO.
This company followed current ethical policies, and used them to exclude actual experts and skilled people. CEO operated in environment that supports this behaviour, and only cares about irelevant metrics!
Its fair to blame Stockthon because he fired or treated to sue everyone who didn’t buy into his spiel about this being revolutionary disruption of private submarines. Leves of staff rotation were insane in this company, their lead eng. at the time of implosion was a software dev because everybody else left or was laid off.
High staff rotation is typical for such companies. Qualified person with other options, will not work in such toxic company, after CEO had racist and ageist rant!
My point is where such companies get funding?! They produce garbage and should go bankrupt pretty fast! But somehow "investors" kept feeding them money, because they are super "ethical"!
My point is where such companies get funding?! They produce garbage and should go bankrupt pretty fast! But somehow "investors" kept feeding them money, because they are super "ethical"!
Not surprised this is posted by a throwaway account. I would think this is Rush himself, if he was alive of course.
Start-up idea: LLM service that will post online to defend you after you die.
Or nice idea for a new black mirror episode.
In the Year Of Our Lord 2025, there is no difference between the two.
various estates (e.g. Tolken, etc) already have trusts that can and do hire lawyers and even marketing firms.
in this case you'd just hire a marketing org that uses AI a lot and hope that the trust has enough money to keep them doing their job for a while
in this case you'd just hire a marketing org that uses AI a lot and hope that the trust has enough money to keep them doing their job for a while
Maybe listen to some of his interviews. His opinion about "old" experts is on record. And old Oceangate HR pages are still in archives.
But again, this is not juzt about CEO (he deserves the blame), but why he was able to operate for so long, and why his critics vere silenced!
But again, this is not juzt about CEO (he deserves the blame), but why he was able to operate for so long, and why his critics vere silenced!
his critics were silenced? bro they were loud as hell and consistently so.
the dude did everything he could to fly under the radar, but only just enough. it is why the report is so damning -- much of what he did was just blatantly, balls-out bad, and all of the signs were there consistently.
the dude did everything he could to fly under the radar, but only just enough. it is why the report is so damning -- much of what he did was just blatantly, balls-out bad, and all of the signs were there consistently.
But that person is right. Co owners, board and even layer that knowingly helped to relatiate against whistle blower with fake accusations are all guilty too. At least in the ethical sense.
Rush is dead, so it is comfortable for the above to blame only him.
The board knew about the issues. The layer knew the accusation is fake and designed to shut up the whistleblower.
Rush is dead, so it is comfortable for the above to blame only him.
The board knew about the issues. The layer knew the accusation is fake and designed to shut up the whistleblower.
> The thing that I find amazing about this sub, is that the final hull survived all those trips, and then before the final one let everyone know it was toast, and Stockton ignored it. He was careless with peoples lives, but his sub actually did what he set out to do, and if he listened to the instruments, he'd still be alive...
I disagree. In fact, I think that's quite unlikely.
First, unlike a metal hull, carbon fiber hulls accumulate subtle damage on compression that's hard to detect. Then, when they fail, they tend to fail catastrophically. So "this hull worked before" isn't evidence of success in this case, as it normally would be, it's evidence that you're getting closer & closer to the disaster.
Second, I think Stockton would have just kept diving, even if this event hadn't failed. He might have even gotten more reckless (though per the report he was already extremely reckless). If you keep playing Russian Roulette, and occasionally add another bullet, eventually the game will end. There is no evidence he was going to stop until he was killed by his own decisions.
None of this takes away the tragedy of it. It's sad, and will remain so.
I disagree. In fact, I think that's quite unlikely.
First, unlike a metal hull, carbon fiber hulls accumulate subtle damage on compression that's hard to detect. Then, when they fail, they tend to fail catastrophically. So "this hull worked before" isn't evidence of success in this case, as it normally would be, it's evidence that you're getting closer & closer to the disaster.
Second, I think Stockton would have just kept diving, even if this event hadn't failed. He might have even gotten more reckless (though per the report he was already extremely reckless). If you keep playing Russian Roulette, and occasionally add another bullet, eventually the game will end. There is no evidence he was going to stop until he was killed by his own decisions.
None of this takes away the tragedy of it. It's sad, and will remain so.
> unlike a metal hull, carbon fiber hulls accumulate subtle damage on compression that's hard to detect
All metals suffer from that, too. It's called fatigue damage. It bedeviled the aviation industry for a long time because there was no reliable way to detect the fatigue damage.
Eventually, an ad hoc formula was developed to calculate the fatigue damage, and then replace parts that were getting close to the limits.
That's why airliners are scrapped after something like 62,000 flight cycles.
All metals suffer from that, too. It's called fatigue damage. It bedeviled the aviation industry for a long time because there was no reliable way to detect the fatigue damage.
Eventually, an ad hoc formula was developed to calculate the fatigue damage, and then replace parts that were getting close to the limits.
That's why airliners are scrapped after something like 62,000 flight cycles.
The standard testing for submarine involves 1000 cycles of going to full depth/pressure and up. And depth higher then the target depth.
Only after that you can use it for paying passangers. This submarine survived the depth around 23 times. (Most of the "trips" were 3m deep)
Only after that you can use it for paying passangers. This submarine survived the depth around 23 times. (Most of the "trips" were 3m deep)
Aluminum is especially bad this way. And we make airplanes out of it.
And if you're USAF, you practically strip the aircraft to its frame every few years, inspect, repair, and reassemble it. The dangers are known and the process around it is there to deal with those dangers.
Most aircraft fleets operated by people who care will do something similar but perhaps not as extreme. In fairness to them they don't expect to fly the plane as long as USAF does (70+ years for the B-52, 50+ for many fighters).
Most aircraft fleets operated by people who care will do something similar but perhaps not as extreme. In fairness to them they don't expect to fly the plane as long as USAF does (70+ years for the B-52, 50+ for many fighters).
These days it's carbon fiber.
Not all of them. The 787 yeah, but it seems the 747-8 is still somewhat metal.
I think you missed the thrust of OP. The submersible had instruments in it to report on the hull condition. They all were reporting it had previously experienced severe strain before the last dive, and they were designed as tripwires. If they tripped, the hull should have been considered unsafe and not used again. They were ignored.
It is a shock that they actually worked and reported the hull was unsafe before it failed. Given everything else, it's not a surprise in the slightest that they were ignored.
It is a shock that they actually worked and reported the hull was unsafe before it failed. Given everything else, it's not a surprise in the slightest that they were ignored.
To be extra clear here:
They used an unproven custom-designed sensor + controller system to monitor the health of the hull.
The monitoring system detected the beginning of total hull failure in the exact way they intended. They then ignored that monitoring system because hull failure would have been inconvenient.
Really that's the whole story of Stockton here. Massively motivated reasoning. Anything inconvenient was written off as wrong. A lot of normalization of deviance too as some of the written-off concerns turned out to be wrong. But not all of them.
I recently got my PPL and that's a massive risk for pilots. You fly in weather you shouldn't and get away with it for a while. Then it becomes normal. You've "proven" you can handle it. Then a situation comes along that requires more margin than you have left and you die.
They used an unproven custom-designed sensor + controller system to monitor the health of the hull.
The monitoring system detected the beginning of total hull failure in the exact way they intended. They then ignored that monitoring system because hull failure would have been inconvenient.
Really that's the whole story of Stockton here. Massively motivated reasoning. Anything inconvenient was written off as wrong. A lot of normalization of deviance too as some of the written-off concerns turned out to be wrong. But not all of them.
I recently got my PPL and that's a massive risk for pilots. You fly in weather you shouldn't and get away with it for a while. Then it becomes normal. You've "proven" you can handle it. Then a situation comes along that requires more margin than you have left and you die.
Exactly, the hull performed, then the instruments told them with a loud bang that it was toast.
Once again... The instruments reported the hull was no longer safe for use before the start of the last dive. That was well before the implosion. You keep ignoring this part to focus on how there was no engineering that would suggest that those instruments would actually give early warning. I'm halfway there with you. It is actually a surprise that they reported it was unsafe before the dive. But they did, and that makes the subsequent human failures even more egregious.
I'm not sure he had the money to make another hull. I think that's the crux of the issue, he didn't have a usable system and he didn't want to give up his ambition.
Money was a big part of the problem. The whole point of making it out of carbon fiber was to make it light and therefore cheap to operate. He could have made a long DSV with plenty of room for passengers out of metal, the Aluminaut DSV was such a craft with proven performance, but then he would have needed to buy or rent a more expensive ship to operate it with.
> Money was a big part of the problem.
Yep. There are a ton of incidents described in the report which all stink of penny-pinching. Probably one of the most obvious is reusing the titanium end cap components from the first submarine; this may have played a role in the failure of the Titan, as the mating surfaces may have been damaged or incompletely cleaned when rebonding them to the new hull.
Yep. There are a ton of incidents described in the report which all stink of penny-pinching. Probably one of the most obvious is reusing the titanium end cap components from the first submarine; this may have played a role in the failure of the Titan, as the mating surfaces may have been damaged or incompletely cleaned when rebonding them to the new hull.
All of this really should have made someone stop and ask if this was the part of the human experience that really needed cost reduction.
But it didn't, so... shrugs.
But it didn't, so... shrugs.
Well, I for one enjoy being able to fly in airplanes. I'm glad nobody back in the day decided that flight wasn't something most Americans should be able to do.
On the related topic, people did wonder if Rush was the right person to be leading this project and numerous people raised governmental complaints. However, mostly due to staffing issues within the government they weren't handled in any appropriate amount of time and any entity with the ability to stop him didn't.
On the related topic, people did wonder if Rush was the right person to be leading this project and numerous people raised governmental complaints. However, mostly due to staffing issues within the government they weren't handled in any appropriate amount of time and any entity with the ability to stop him didn't.
[deleted]
Other than the finances of it, he was a total narcissist who refused to believe anyone else knew more about anything than he did. Even when presented with hard data he chose to ignore it and killed himself as a result.
It didn't do a lot of dives before it failed. The dive number was the number of "dives" oceangate did using any hull. Additionally most of those dives were 20 feet down in a marina for testing.
>The porthole design was poor, the carbon fiber had tons of defects, the controller, everything was cobbled together, yet it held up until it didn't.
Emphasis mine.
Everybody hammers on the controller like using a gaming controller was somehow more indicative of the unseriousness of the endeavor than, you know, the firing of the guy who said the hull was unsafe. Based on what I've read, that was one of the few authentically competent design decisions of the whole bloody thing. Why waste time and resources building, designing, and most importantly lifetime testing something that you can buy off the shelf for $30 US?
The US Navy has been using off-the-shelf game controllers for years now[0], because they work. And as a bonus, the submarine designers can be confident that if Stockton Rush or Seaman Manchild or whoever throws his controller in a fit of rage when his submarine doesn't work right, the controller will still work afterwards.
Absolutely, there were problems with the control scheme (reportedly, the motors were wired into the control board wrong, so the x- and y-axes were reversed). But that's not the fault of some usb controller communicating with the control box. That's the fault of the people working on the actually bespoke portions of the submarine.
0. https://www.cnet.com/science/us-navy-launches-submarine-mane...
Emphasis mine.
Everybody hammers on the controller like using a gaming controller was somehow more indicative of the unseriousness of the endeavor than, you know, the firing of the guy who said the hull was unsafe. Based on what I've read, that was one of the few authentically competent design decisions of the whole bloody thing. Why waste time and resources building, designing, and most importantly lifetime testing something that you can buy off the shelf for $30 US?
The US Navy has been using off-the-shelf game controllers for years now[0], because they work. And as a bonus, the submarine designers can be confident that if Stockton Rush or Seaman Manchild or whoever throws his controller in a fit of rage when his submarine doesn't work right, the controller will still work afterwards.
Absolutely, there were problems with the control scheme (reportedly, the motors were wired into the control board wrong, so the x- and y-axes were reversed). But that's not the fault of some usb controller communicating with the control box. That's the fault of the people working on the actually bespoke portions of the submarine.
0. https://www.cnet.com/science/us-navy-launches-submarine-mane...
>Why waste time and resources building, designing, and most importantly lifetime testing something that you can buy off the shelf for $30 US?
That's fine, but you would think they would buy a high quality one (like $70), use a wired one, and maybe have a spare? I think that's a lot of where the ire comes from. It's the cheapest and easiest part of the system and still they skimped out (and it's memable for gamers, given how common the experience of 'third party controller the little brother/least favored friend has to use' is). I worked on a self-funded student project making an autonomous underwater vehicle and we still used a better controller than they did (the xbox 360 controller is the obvious choice for such things. It's ubiquitously understood, trivial to interface to, reasonably priced, and pretty damn solid)
That's fine, but you would think they would buy a high quality one (like $70), use a wired one, and maybe have a spare? I think that's a lot of where the ire comes from. It's the cheapest and easiest part of the system and still they skimped out (and it's memable for gamers, given how common the experience of 'third party controller the little brother/least favored friend has to use' is). I worked on a self-funded student project making an autonomous underwater vehicle and we still used a better controller than they did (the xbox 360 controller is the obvious choice for such things. It's ubiquitously understood, trivial to interface to, reasonably priced, and pretty damn solid)
It's not just that they used a game controller, they used a super cheap crappy controller instead of something backed my a major company with millions of R&D funding or a modern device with better sensors (hall effect/TMR) better suited for controlling vehicles in something other than an arcade game.
Like, they couldn't even spring an extra ten bucks for the same controllers that Navy uses.
Like, they couldn't even spring an extra ten bucks for the same controllers that Navy uses.
Is Logitech not a major company, backed by decades of experience building these things? Its not MadCatz, that's for sure. I mean, logitech is the undisputed king of low-to-mid-range joysticks, and has held that title more or less since microsoft stopped making joysticks and gamepads in 2002. Microsoft didn't make a PC-friendly controller again until 2005. They basically ceded the market during that period of time. Of course, logitech hasn't sold as many units. But they know what they're doing.
Granted, a Logitech controller not the first party controllers, and I'm prepared to believe that the Xbox people made a generally better controller, but I'm not convinced it was so much better as to be an actively bad idea to use the Logitech device. Like, once you get to the "pretty good, people won't return it" phase of controller development, its just fine tuning for gameplay performance, and there's absolutely nothing about controlling a tourist submarine that makes e.g. controller latency or even signal integrity above and beyond the baseline the bottleneck. I'd wager that the real reason they picked it likely devolved down to "what driver is our embedded controls engineer most comfortable integrating into our system?", which has a much larger impact on system safety.
I agree with a sibling that there's an argument for using a wired controller. But that's pretty much as far as that criticism goes for me, speaking as someone who writes firmware that does need to be reliably low-latency and responsive, game controllers barely even register on my radar, except that I wouldn't do it myself if I didn't have a specific use case for it.
Granted, a Logitech controller not the first party controllers, and I'm prepared to believe that the Xbox people made a generally better controller, but I'm not convinced it was so much better as to be an actively bad idea to use the Logitech device. Like, once you get to the "pretty good, people won't return it" phase of controller development, its just fine tuning for gameplay performance, and there's absolutely nothing about controlling a tourist submarine that makes e.g. controller latency or even signal integrity above and beyond the baseline the bottleneck. I'd wager that the real reason they picked it likely devolved down to "what driver is our embedded controls engineer most comfortable integrating into our system?", which has a much larger impact on system safety.
I agree with a sibling that there's an argument for using a wired controller. But that's pretty much as far as that criticism goes for me, speaking as someone who writes firmware that does need to be reliably low-latency and responsive, game controllers barely even register on my radar, except that I wouldn't do it myself if I didn't have a specific use case for it.
Logitech is _so bad_. They use these crappy jittery potentiometers and then charge way too much for their plastic crap. Then it breaks within a few years
Better alternatives:
Gamepads: 8bitdo, Gamesir
Joysticks/HOTAS: VKB, Virpil, Winwing
Wheels: Moza, basically anything with direct drive
Any of the above will last _decades_ and greatly outperform a Logitech in precision, in a way that is qualitatively important to realistic vehicle control.
Better alternatives:
Gamepads: 8bitdo, Gamesir
Joysticks/HOTAS: VKB, Virpil, Winwing
Wheels: Moza, basically anything with direct drive
Any of the above will last _decades_ and greatly outperform a Logitech in precision, in a way that is qualitatively important to realistic vehicle control.
There's a documentary about it on Netflix and the impression I came away with is that, while there are fundamental engineering problems associated with a carbon fiber design, they could have probably overcome them in one way or another.
The problem with oceangate is that their CEO was an arrogant narcissist who thought he knew better than everyone, and if anyone stood in his way he would explode with anger at them and fire them. It was a company with absolutely no culture of safety and a cult of personality where people were punished for being honest. The CEO knew about the problems and still somehow believed, to his core, that everyone else (including hard data!) was wrong. He believed in his own infallibility so deeply that it killed him
The problem with oceangate is that their CEO was an arrogant narcissist who thought he knew better than everyone, and if anyone stood in his way he would explode with anger at them and fire them. It was a company with absolutely no culture of safety and a cult of personality where people were punished for being honest. The CEO knew about the problems and still somehow believed, to his core, that everyone else (including hard data!) was wrong. He believed in his own infallibility so deeply that it killed him
I've heard both assertions. I tend to believe that Carbon Fiber is a fine material to use.
This submersible used untested techniques. They didn't adhere the layers together properly and apparently never bothered to X-ray the tube as that would have shown at least some of the defects. It also seems like there were other design issues with how the tube was paired to the ends.
Most importantly, the deaths were caused by negligence during operation and maintenance. They had the data showing when the hull was damaged on the previous expedition, but either never did their due diligence and analyze it or ignored the results. Even during their last expedition, they may well have avoided death if the alarms had been heeded.
EDIT: to answer the people who seem skeptical, there are companies making carbon fiber vessels that have successfully gone much deeper than those Titanic dives. We're still in the learning stages with the technology, but we'll eventually find the combinations and standards that can make it safe to use (at which point, it may become better than our current solutions). Until then, maybe we shouldn't be shoving people into damaged experimental vessels to see what happens.
https://www.compositeenergytechnologies.com/underwater-carbo...
https://www.researchgate.net/publication/376273321_Carbon_Fi...
This submersible used untested techniques. They didn't adhere the layers together properly and apparently never bothered to X-ray the tube as that would have shown at least some of the defects. It also seems like there were other design issues with how the tube was paired to the ends.
Most importantly, the deaths were caused by negligence during operation and maintenance. They had the data showing when the hull was damaged on the previous expedition, but either never did their due diligence and analyze it or ignored the results. Even during their last expedition, they may well have avoided death if the alarms had been heeded.
EDIT: to answer the people who seem skeptical, there are companies making carbon fiber vessels that have successfully gone much deeper than those Titanic dives. We're still in the learning stages with the technology, but we'll eventually find the combinations and standards that can make it safe to use (at which point, it may become better than our current solutions). Until then, maybe we shouldn't be shoving people into damaged experimental vessels to see what happens.
https://www.compositeenergytechnologies.com/underwater-carbo...
https://www.researchgate.net/publication/376273321_Carbon_Fi...
The Coast Guard report section “5.6 Insufficient Understanding of Carbon Fiber Material Properties for Deep-Sea Applications” addresses your arguments.
Yes. It can be safe. The problem is that its crystalline structure can fail instantaneously without any ability to detect beforehand. In this case the sub was likely improperly manufactured and improperly stored and damaged from previous dives and from transport. The company “planned” to inspect but as no non destructive testing was possible, they didn’t bother.
Yes. It can be safe. The problem is that its crystalline structure can fail instantaneously without any ability to detect beforehand. In this case the sub was likely improperly manufactured and improperly stored and damaged from previous dives and from transport. The company “planned” to inspect but as no non destructive testing was possible, they didn’t bother.
There is a YouTube channel that anaylzes the core problem in depth. Compression vs. tension is really a red herring because in a closed convex structure compression somewhere is tension elsewhere. The real problem is the carbon fiber maxtrix was wapped around the epoxy filler without tension like paper mache. So it had insufficient strength and non homogeneous strength. The sub was built up like an onion. Concentric layers of carbon fiber epoxy thermoset. I think it was something like 5 layers. Anyway because the layers were not wrapped tight before curing there were ripples in the surface of each layer. Subsequent layers were applied after sanding down high spots and applying a wrap of double sided adhesive tape between each layer (no joke). So not only were the carbon fibers not pretensioned but also they were cut in hundreds of spots. This is somewhat like if one were to pour layers of reinforced concrete by throwing a bunch of loose rebar in a hole, pouring concrete over it and then cuting pieces of rebar that stuck up before applying the next layer after putting a layer of plaster over it. For carbon fiber composites and concrete to be strong tension bearing elements need to be able to bear tension. If they are loose in the matrix or cut the composite will not be strong. Thus carbon fiber was not the problem but rather its manufacturing process. Anyone who has ever done drywall joints or autobody can understand the problem. It doesn't take an engineering degree to understand that if you wreck the tensile components of your composite it will be much less strong than if the composite is laid down properly!
This is the video https://m.youtube.com/watch?v=sE4uSjQoa3A
Their carbon fiber laying system sure looks an awful lot like the one used by oceangate. Can anybody here explain the nuances I'm missing?
> I tend to believe that Carbon Fiber is a fine material to use.
It's a fine material to use for unmanned submersibles!
It's a fine material to use for unmanned submersibles!
>I tend to believe that Carbon Fiber is a fine material to use.
For deep underwater? Apart from the series of stupidities you go on to list, I'd love to hear your reasons as to why?
I'm a carbon f bike rider, even down to carbon spokes and I do not trust the material, knowing that pressure, or force, applied in the wrong direction will make it crack!. As for carbon in a circle...no way.
For deep underwater? Apart from the series of stupidities you go on to list, I'd love to hear your reasons as to why?
I'm a carbon f bike rider, even down to carbon spokes and I do not trust the material, knowing that pressure, or force, applied in the wrong direction will make it crack!. As for carbon in a circle...no way.
I think it's not ideal in the same way that plastics don't belong in an automotive engine bay and concrete doesn't belong" in tension. Add a little bit of fancy chemistry or some steel and fancy math and they both work fine for cheap.
With care and engineering trickery CF in a submersible (compression) probably can work. They still managed to make a few good dives with it despite comically bad decisions in just about every key area. The manufacturing process was primitive, the QC basically nonexistent and procedures didn't make any allocations for the materials (they beat on the thing like it was made of steel). Imagine what a well funded company with experience in CF, robust QC and careful operating procedures could do.
With care and engineering trickery CF in a submersible (compression) probably can work. They still managed to make a few good dives with it despite comically bad decisions in just about every key area. The manufacturing process was primitive, the QC basically nonexistent and procedures didn't make any allocations for the materials (they beat on the thing like it was made of steel). Imagine what a well funded company with experience in CF, robust QC and careful operating procedures could do.
> I'd love to hear your reasons as to why?
It's been proven to work?.
A submersible constructed of carbon fiber went to depths that many metallic submarines and submersibles cannot.
If somebody constructs a submersible and then tests it to 5000m and finds it fails on the 200th run after exhibiting for the past 50 dives bad acoustic data. Wouldn't you think it's fine for them to take people on the same designed submersible that's only done 100th runs and still has good data?
Everything is a consumable in the long run. They didn't have data on what Titan looks like before a failure. Although in hindsight the acoustic data looks really bad, the issue really is just the specific design didn't have a known lifespan. A submserible without that defect is going to be a lot safer.
It's been proven to work?.
A submersible constructed of carbon fiber went to depths that many metallic submarines and submersibles cannot.
If somebody constructs a submersible and then tests it to 5000m and finds it fails on the 200th run after exhibiting for the past 50 dives bad acoustic data. Wouldn't you think it's fine for them to take people on the same designed submersible that's only done 100th runs and still has good data?
Everything is a consumable in the long run. They didn't have data on what Titan looks like before a failure. Although in hindsight the acoustic data looks really bad, the issue really is just the specific design didn't have a known lifespan. A submserible without that defect is going to be a lot safer.
Trek 2100. The first carbon fiber bike affordable by upper middle class people.
Their trick was pre-formed carbon tubing glued to aluminum lugs. Sound familiar?
Good, because they had a massive recall because the carbon at the joinst started to chip and crack. Member of our club had to call a friend to come get him because his top tube came apart fifteen miles from town. Took em a while to replace it too. Eventually he ended up on a Serotta (Titanium with extra metalurgical tricks to make it lighter still).
Their trick was pre-formed carbon tubing glued to aluminum lugs. Sound familiar?
Good, because they had a massive recall because the carbon at the joinst started to chip and crack. Member of our club had to call a friend to come get him because his top tube came apart fifteen miles from town. Took em a while to replace it too. Eventually he ended up on a Serotta (Titanium with extra metalurgical tricks to make it lighter still).
I've linked this elsewhere in thread, but here's testing results from a US Navy pilot project for carbon fiber unmanned subs. It looks like this found it pretty viable.
https://apps.dtic.mil/sti/pdfs/ADA270438.pdf
https://apps.dtic.mil/sti/pdfs/ADA270438.pdf
What's the issue with CF in a circle? My bike is mainly CF (mainly just brakes and drivechain are metal) and of course that means CF wheels which I think are great (CF means that you can have deep section "aero" wheels without much of a weight penalty).
Well designed carbon rims are surprisingly durable:
https://youtu.be/VfjjiHGuHoc
When carbon fiber rims were new we still had not transitioned to disk brakes. You had to keep an extra eye out for misaligned brake pads to make sure they weren't dragging on surfaces not meant for friction contact. Now they make more sense. But also different loads on a wheel under braking than before, but also more like a wheel under acceleration, which is torsional force on the other side of the axle and pointed the opposite direction.
You don't need to watch Netflix series. There is a transcript of entire conversation between Stockthon and David Lochridge where the former scolds the latter for taking his safety concerns outside of company and firing him:
https://media.defense.gov/2024/Sep/20/2003550726/-1/-1/0/CG-...
https://media.defense.gov/2024/Sep/20/2003550726/-1/-1/0/CG-...
The Netflix documentary has some extra interviews with employees, clients, etc. which are interesting. (1hr 51min runtime though)
Quote:
>Not at all, because carbon fiber is better compression than tension. And that's what nobody understands. It's completely opposite of what everyone else says. Everyone's, oh, carbon fiber can't handle compression. They're full of shit, and I've proven they're full of shit. If you want to see that, you take a look at the third scale model that we tested.
My favorite quote:
> [redacted]: (...) (indiscernable) say my goodbyes to ya
> Mr. Rush: OK, it's never easy
> [redacted]: Some are easier than others
> (whereupon, the interview was concluded)
> [redacted]: (...) (indiscernable) say my goodbyes to ya
> Mr. Rush: OK, it's never easy
> [redacted]: Some are easier than others
> (whereupon, the interview was concluded)
Carbon Fiber just isn't suited for submarine type of loads. It really doesn't like being compressed, and it tends to give you no warning before snapping.
This isn't the first carbon fiber submarine, although it is the first manned one. The US Navy tried out an unmanned model in the 80s, and got much better results- they were expecting at least 1000 successful dives before stress fatigue was an issue.
Here's a detailed report on it. Pages 32-33 has their take on material analysis, probably the most relevant to this failure
https://apps.dtic.mil/sti/pdfs/ADA270438.pdf
I'm personally more suspicious of oceangates manufacturing process than the material, but I'm far from an expert here.
Here's a detailed report on it. Pages 32-33 has their take on material analysis, probably the most relevant to this failure
https://apps.dtic.mil/sti/pdfs/ADA270438.pdf
I'm personally more suspicious of oceangates manufacturing process than the material, but I'm far from an expert here.
It’s the unpredictable nature of failure that’s at issue here. For unmanned subs it doesn’t matter if 10% of failures occur well below the expected lifespan but that’s a huge issue for manned subs.
I'm not even sure it's the first manned carbon fiber submersible.
Deepflight Challenger [...] is the first deep-diving sub to be constructed with a pressure hull (central tube portion) of carbon fibre composite, built by Spencer Composites for HOT. Its carbon fiber design would later influence the tube for the sub Titan,[12] which imploded...
https://en.wikipedia.org/wiki/DeepFlight_Challenger
Deepflight Challenger [...] is the first deep-diving sub to be constructed with a pressure hull (central tube portion) of carbon fibre composite, built by Spencer Composites for HOT. Its carbon fiber design would later influence the tube for the sub Titan,[12] which imploded...
https://en.wikipedia.org/wiki/DeepFlight_Challenger
Notable from that page is this paragraph though:
""" 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. """
""" 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. """
Being manned is a major difference. Humans need a lot of space. Pressure grows with volume, which is cubic, but the hull grows with area. You can also submerge components in oil, which is much better at resisting pressure than air.
Pressure doesn't grow with volume. The exterior design pressure is constant. The stress on the wall scales linearly with the diameter. Making submarines bigger actually makes it easier because the buoyancy scales cubically with the volume while the weight scales linearly with the perimeter, so the larger the submarine the thicker the walls can be.
There’s several kinds of scaling involved, once the radius increases enough thicker walls are less efficient than internal bracing.
It’s impractical to build something like an Ohio class submarine that can reach the bottom of the Mariana Trench when you also want multiple internal compartments in case of damage.
It’s impractical to build something like an Ohio class submarine that can reach the bottom of the Mariana Trench when you also want multiple internal compartments in case of damage.
Internal bracing is to resist buckling. You need it as your cylinder gets longer (as military subs tend to be), but has nothing to do with the diameter. It's also good for torsional strength, which is not really a concern for a pressure vessel but is important for a ship that's going to be in the actual ocean. But for just resisting pressure, once your diameter exceeds 20 times the wall thickness, the relationship is linear.
You can get better efficiency with multiple spherical pressure vessels joined together over a cylindrical vessel, as spherical pressure vessels better distribute the loads than cylinders. This is done in some particularly deep diving military subs, which are then surrounded by an unpressurized cylinder for hydrodynamics.
You can get better efficiency with multiple spherical pressure vessels joined together over a cylindrical vessel, as spherical pressure vessels better distribute the loads than cylinders. This is done in some particularly deep diving military subs, which are then surrounded by an unpressurized cylinder for hydrodynamics.
Even with a spherical sub the diameter impacts a lot of things. For example a large sphere sees significantly lower pressure across the side facing the surface than the side facing the sea floor.
At the depth of the titanic to see a 1% variation in pressure between the top most and bottom most points of a sphere, the sphere would need to be 40 meters in diameter. For context, the pressure vessels of the largest submarine in the world have a diameter of 10.9 meters. Note that pressure at a given depth varies due to things like temperature fluctuations, ocean currents, and even variation in Earth's gravity. Further, the walls of pressure vessels distribute the load - any variations of the pressure get averaged out. It's the same principle as a dome - every element of the sphere is pushing against the adjacent elements and resisting being pushed by those adjacent elements. At the size scale where this is no longer the case, you're not building a pressure vessel. If you're making a dam or a hollow column going down into water, or perhaps a massive dome on the ocean floor, you would need different equations. Even for a submarine you may be concerned with things besides pressure resistance, like collision or sea keeping, as previously stated. But from a pressure resistance standpoint the diameter to wall thickness requirement holds equally true for small exploratory subs and the largest military subs.
A sphere is a great shape for dealing with such forces but it’s just a more complicated system. Rotation can cause metal fatigue, openings get more complicated, etc.
> For context, the pressure vessels of the largest submarine in the world have a diameter of 10.9 meters.
Few subs can reach the titanic at 12,500 feet, at more common crush depths and especially non spherical geometries it’s very much worth considering. Subs often dive and surface at a significant angle.
> For context, the pressure vessels of the largest submarine in the world have a diameter of 10.9 meters.
Few subs can reach the titanic at 12,500 feet, at more common crush depths and especially non spherical geometries it’s very much worth considering. Subs often dive and surface at a significant angle.
Carbon fiber is actually a pretty good material for submarine type loads. Submarines have to balance their need for an extremely strong hull with the need for buoyancy. For a given size, to make your hull stronger, you must make your walls thicker, which makes you heavier. The only options are to make the sub bigger, increasing the internal volume, or making the hull out of something with a better strength to weight ratio, or more accurately a better strength to specific gravity ratio.
In carbon fiber composite, it's actually the epoxy which provides the compressive strength, and while it has very good compressive strength, the real advantage is its very low density. It is only just barely denser than water, so you can make your hull extremely thick with essentially no loss in buoyancy. Carbon fiber does fail catastrophically, but they could have just made the hull so thick that they were never getting anywhere near the failure point. Further, since carbon fiber is built up in plied layers, you don't have the same sorts of processing limits as with thick metal plates.
The basic concept of Titan was sound, it was just horribly horribly executed. With their flagrant violation of basic engineering and safety practices, they would have killed people no matter what they made their sub out of.
In carbon fiber composite, it's actually the epoxy which provides the compressive strength, and while it has very good compressive strength, the real advantage is its very low density. It is only just barely denser than water, so you can make your hull extremely thick with essentially no loss in buoyancy. Carbon fiber does fail catastrophically, but they could have just made the hull so thick that they were never getting anywhere near the failure point. Further, since carbon fiber is built up in plied layers, you don't have the same sorts of processing limits as with thick metal plates.
The basic concept of Titan was sound, it was just horribly horribly executed. With their flagrant violation of basic engineering and safety practices, they would have killed people no matter what they made their sub out of.
"Isn't suited" is a stretch. They still managed to make a few good dives with it despite comically bad decisions in just about every key area. Imagine what a well funded company with experience in CF, robust QC and non-laughable operating procedures could do.
It's not ideal on a first pass analysis in the same way concrete can't to shit in tension yet with a bunch of carefully placed steel and number crunching magic it works great. I think they proved that CF has the same potential. A more serious attempt could likely work in some capacity.
It's not ideal on a first pass analysis in the same way concrete can't to shit in tension yet with a bunch of carefully placed steel and number crunching magic it works great. I think they proved that CF has the same potential. A more serious attempt could likely work in some capacity.
Around 23 plunges into the target depth with two different hulls both failing is not all that great result.
There's been a vibe shift. A cult of personality around an arrogant narcissist who fires people for publishing hard data when it contradicts him is apparently what a lot of people seem to want right now.
Yeah, now we're all in the sub.
nah that's been a thing since Iacocca, Jack Welch, Steve Jobs, etc.
And we'll have entirely predictable results from the shift.
I think it's how selfishness manifests under (neo)liberalism, as self-promotion. The narcissists are extremes of that.
> The problem with oceangate is that their CEO was an arrogant narcissist who thought he knew better than everyone, and if anyone stood in his way he would explode with anger at them and fire them. It was a company with absolutely no culture of safety and a cult of personality where people were punished for being honest.
Sounds like someone else that's been in the news these last few months.
Sounds like someone else that's been in the news these last few months.
Months?
Try decade.
Try decade.
> The problem with oceangate is that their CEO was an arrogant narcissist who thought he knew better than everyone, and if anyone stood in his way he would explode with anger at them and fire them.
There has to be a point at which you go "fuck it" and stop working for such a guy, even if you haven't been the target of his temper. I lasted 9 months at a company that had a CEO who wasn't explosive, but toxic in so many ways. His company had a 90% staff turnover over any given 18 month period, primarily everyone outside of senior leadership. If senior leadership had stopped propping him up, and quit that company would have been dead and buried far quicker. Thankfully that company wasn't involved in anything that could endanger anyone's lives.
There has to be a point at which you go "fuck it" and stop working for such a guy, even if you haven't been the target of his temper. I lasted 9 months at a company that had a CEO who wasn't explosive, but toxic in so many ways. His company had a 90% staff turnover over any given 18 month period, primarily everyone outside of senior leadership. If senior leadership had stopped propping him up, and quit that company would have been dead and buried far quicker. Thankfully that company wasn't involved in anything that could endanger anyone's lives.
Stockton Rush would have fit right in in Silicon Valley. Rush and stock on.
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> Investigators determined the Titan’s real-time monitoring system generated data that should have been analyzed and acted on during the 2022 Titanic expedition. However, OceanGate did not take any action related to the data, conduct any preventative maintenance or properly store the Titan during the extended off season before its 2023 Titanic expedition.
So, a bunch of giant red warning flags AND they didn't bother to properly store the casket. I feel bad for the passengers, Stockton got the FAFO award he deserved.
So, a bunch of giant red warning flags AND they didn't bother to properly store the casket. I feel bad for the passengers, Stockton got the FAFO award he deserved.
The Netflix documentary was great and the thing that I took away from it most was that in fractions of a second all the passengers literally blinked out of existence: They were here and then within a ms, they literally vanished (I assume... they didn't elaborate on it but I can guess!)
The temperature and pressure in that tiny fraction of a second was probably 10s of thousands of degrees and hundreds of jumbo jets smashing into them so fast that their bodies didn't even register the trauma.
Blew my mind.
Nearly forgot that they heard the explosion on the surface ship, 2 miles above the sub... that kinda screws with my head tbh!
The temperature and pressure in that tiny fraction of a second was probably 10s of thousands of degrees and hundreds of jumbo jets smashing into them so fast that their bodies didn't even register the trauma.
Blew my mind.
Nearly forgot that they heard the explosion on the surface ship, 2 miles above the sub... that kinda screws with my head tbh!
It is quite interesting. The implosion took about 10 milliseconds.
It takes the brain 13 milliseconds to register an image.
It takes the brain 100-200 milliseconds to register pain.
They could have heard some cracks but most likely had no knowledge of the implosion. Their bodies just turned into mist.
It takes the brain 13 milliseconds to register an image.
It takes the brain 100-200 milliseconds to register pain.
They could have heard some cracks but most likely had no knowledge of the implosion. Their bodies just turned into mist.
Mist is kind of the exact opposite of what their bodies turned into. Compression does really, really interesting things to meat and bone sacks with lots and lots of tiny airspaces. They wouldn’t have been conscious of anything, but they would have been more mince / paste / goo / frothy clot than anything as clean and homogenous sounding as mist.
I found it wild that fragments of their clothes were found, plus a pen and Rush’s business card.
Can you think of a better way to die? The only thing missing here is knowing it beforehand.
The only better way is going to bed and dying of old age. The Titan way is quite harsh on families though.
You're missing the "laying in bed" time that varies between 10 hours and 20 years. My grandpa chose the latter. No thanks.
tbh I think I prefer the 10 ms death over dying of old age. The months leading up to a death-by-old-age are still usually pretty unpleasant. Agreed that the toll on the family is rough though
*Months/years/decades
I'm angling to die in bed of old age, but at full cognition and perfect awareness of what lies ahead I'm sure a lot of people would pick the Titan over the toll slow death and it's related miseries takes on a family (this is a very weird sentence to type about the Titan, lol)
I'm angling to die in bed of old age, but at full cognition and perfect awareness of what lies ahead I'm sure a lot of people would pick the Titan over the toll slow death and it's related miseries takes on a family (this is a very weird sentence to type about the Titan, lol)
"Dying of old age" is often an agonizing death from multiple organ failure.
This would be pretty fun.
https://en.wikipedia.org/wiki/Euthanasia_Coaster
https://en.wikipedia.org/wiki/Euthanasia_Coaster
> Nearly forgot that they heard the explosion on the surface ship, 2 miles above the sub... that kinda screws with my head tbh!
Water carries sound really well. Whale songs can still be detected what, thousands of miles away or something ridiculous?
It is kinda freaky to think about.
Water carries sound really well. Whale songs can still be detected what, thousands of miles away or something ridiculous?
It is kinda freaky to think about.
All of that was already familiar to people who had seen The Abyss (1989)
this also happened rapidly: https://en.m.wikipedia.org/wiki/Byford_Dolphin
Fiber-reinforced composites are basically analogous to spaghetti dispersed in glue. Really strong in tension, when the (in this case, carbon) fibers are taking nearly all of the load. In compression, the fibers have nearly zero resistance to flexure, and the load is mainly being taken up by the glue (the matrix, in composite-speak). When the fiber/matrix interface fails due to fiber flex-induced shear force, you're done.
I just can't imagine why a submersible structural designer would select composites for this application. IMHO, this project was doomed from the moment of that design decision, even setting aside all the other idiocy.
I just can't imagine why a submersible structural designer would select composites for this application. IMHO, this project was doomed from the moment of that design decision, even setting aside all the other idiocy.
Well the "glue" in this case is actually a very good material for the application. Epoxy has compressive strength comparable to structural steel, and more importantly its density is almost the same as water. This means you can make incredibly thick walls for a small internal volume while remaining buoyant. It also resists biofouling and corrosion, which is why it's popular in other marine applications.
Submarines of this size should be using composites, once sufficient data is gathered on their behavior to develop proper factors of safety. The issue was all the idiocy that came after. This team was going to kill people no matter no matter what they made the sub out of.
Submarines of this size should be using composites, once sufficient data is gathered on their behavior to develop proper factors of safety. The issue was all the idiocy that came after. This team was going to kill people no matter no matter what they made the sub out of.
> I can't imagine why ...
"Cheap, cheap, cheap" ain't just a thing that birdies say.
"Cheap, cheap, cheap" ain't just a thing that birdies say.
> I just can't imagine why a submersible structural designer would select composites for this application
Maybe it's easier to imagine if you consider the designer in question not as a submersible structural designer per se, but rather a nepo baby cosplaying as one.
Maybe it's easier to imagine if you consider the designer in question not as a submersible structural designer per se, but rather a nepo baby cosplaying as one.
The USCG hearing was fascinating, especially Matthew McCoy's testimony -
https://www.newsweek.com/oceangate-employee-resigned-co-foun...
https://www.youtube.com/live/AvAw9YFW2i0&t=782
https://www.newsweek.com/oceangate-employee-resigned-co-foun...
https://www.youtube.com/live/AvAw9YFW2i0&t=782
James Cameron gave an interview that did a great job explaining the problems. In particular, carbon fiber is great for planes, but a terrible idea for compressive forces like going deep underwater. See: "James Cameron on the OceanGate sub disaster" https://www.youtube.com/watch?v=EwSaZfwBrz8
Looking at interview footage of Stockton Rush, it seems he really wanted to be a disruptor and accomplish something which everyone else (i.e., experts) deemed impossible.
He thought he could do what SpaceX did for space, but for underwater exploration.
> He thought he could do what SpaceX did for space
Even SpaceX, with unlimited resources, tried carbon fibre, couldn't get it to work, and switched to stainless steel. Different application but still. It's not a budget material.
Even SpaceX, with unlimited resources, tried carbon fibre, couldn't get it to work, and switched to stainless steel. Different application but still. It's not a budget material.
Problem is anyone can make a boat and kill themselves in it. Hard to hide a Falcon 9 rocket and get astronauts to go on it. It's highly regulated. You can put anyone on a dingy in the ocean and die.
Rush could be placed in Wikipedia under hubris.
His hubris killed people. He ignored experts. He ignored warnings. This outcome was predictable.
His hubris killed people. He ignored experts. He ignored warnings. This outcome was predictable.
The problem is that SpaceX was told the same and it succeeded despite the ods. History is harsh to people who fail.
SpaceX did not send manned missions for a while.
If the hull failed without people it would be no big deal. However, Rush was running out of money so he felt rushed and got reckless.
If the hull failed without people it would be no big deal. However, Rush was running out of money so he felt rushed and got reckless.
That's every startup founder to an extent.
What differentiates a good founder from a bad one is being right.
What differentiates a good founder from a bad one is being right.
This is a weird way to think of it, making it seem as thought its just a matter of chance whether the founder is right or not. The difference, if there is one, is that some founders can pivot when they see their approach won't work or, at least, throw in the towel before people die or too much many is wasted.
Maybe that makes them bad startup founders? I don't know. In my opinion "Startup Founder" is a role which should play second to "ethical human being."
Maybe that makes them bad startup founders? I don't know. In my opinion "Startup Founder" is a role which should play second to "ethical human being."
Nah, it is about finding ways to fail an experiment without failing the whole business, bonus points for not killing anyone in the process.
I don't know how anything works at sea.
Assume I have the money to go on a trip, am I supposed to do background checks on people and technology by myself?
From this report I gather that either the sea industry is completely unregulated, or this guy ignored all rules and nobody did a check even after something like 80 dives.
Both options sound kinda insane to be honest.
Can anyone more knowledgeable elaborate?
Assume I have the money to go on a trip, am I supposed to do background checks on people and technology by myself?
From this report I gather that either the sea industry is completely unregulated, or this guy ignored all rules and nobody did a check even after something like 80 dives.
Both options sound kinda insane to be honest.
Can anyone more knowledgeable elaborate?
Typically ships need to be certified by a classification society (an organization that inspects ships and makes sure they meet technical safety standards) in order to operate commercially. The Oceangate sub was not certified by any of these authorities because certification was viewed as “red tape” in the way of their “innovations”, and they would have almost certainly failed to be certified (a bad look if you are trying to convince people it is safe).
I think the rules/laws around commercial deep sea sub companies were unclear because most deep sea subs are research vessels or private projects (e.g. James Cameron’s sub), not tourist operations.
I think the rules/laws around commercial deep sea sub companies were unclear because most deep sea subs are research vessels or private projects (e.g. James Cameron’s sub), not tourist operations.
Traditionally deep sea exploration has been under regulated and gotten by because everyone involved is very cautious and spending a ton of money on over engineering. Rush wanted to change that in order to make it an accessible tourist industry thing, so we might see safety regulations now.
If you're going on a trip, just avoid signing a contract that looks like this
https://media.defense.gov/2024/Oct/22/2003569244/-1/-1/0/CG-...
> The experimental submersible vessel has not been approved or certified by any regulatory body and is constructed of materials that have not been widely used for manned submersibles. As of the date of this Release, the experimental submersible vessel has conducted fewer than 90 dives
Or a contract that redefines you from a passenger to a "mission specialist"
https://media.defense.gov/2024/Sep/20/2003550574/-1/-1/0/CG-...
https://media.defense.gov/2024/Oct/22/2003569244/-1/-1/0/CG-...
> The experimental submersible vessel has not been approved or certified by any regulatory body and is constructed of materials that have not been widely used for manned submersibles. As of the date of this Release, the experimental submersible vessel has conducted fewer than 90 dives
Or a contract that redefines you from a passenger to a "mission specialist"
https://media.defense.gov/2024/Sep/20/2003550574/-1/-1/0/CG-...
Maritime regulation exists in layers (flag states, classification societies, port authorities), but OceanGate deliberately operated in regulatory gaps by classifying Titan as an "experimental" vessel and launching from international waters to bypass oversight.
And there were no "passengers", legally speaking, just "mission specialists".
Move fast & break things plus zero regulations seem to be what our American oligarchs want on land too. Seems like the same attitude.
Thank god things can be both funny and horrible, because this story delighted and horrified me.
Put "Moved Fast and Broke Stuff" on Rush's tombstone.
Put "Moved Fast and Broke Stuff" on Rush's tombstone.
*cenotaph
This seems like the logical conclusion of move fast and break things + regulation is evil culture. Most regulation is there for a reason and most safety rules are written in blood. You don’t get to pretend that’s not true because they would slow you down. You’re not built different.
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It seems insane to me that anyone would ever consider relying on carbon fiber strands in a structure subject to massive compression. Pushing on rope, is after all, the canonical example of futility.
It really was, in essence, an epoxy tube with titanium end caps.
Yikes
It really was, in essence, an epoxy tube with titanium end caps.
Yikes
I don’t know why he insisted on sticking with Carbon fiber when multiple tests over and over again the strands would snap during tests. There is a reason other deep water submersible use Titanium.
The Netflix documentary says that vessel big enough to have 5 people on board would have been far larger when made out of a more conventional material. This was another business-driven decision as they wanted to charge for rides and more people = more money.
Titanium was proven and well-known and established for the use. You can't be a disruptive innovator challenging the dogmatic establishment and trailblaze a new way to make money by being boring and doing what is well-known and established for the domain you are working in.
You have to defy all the voices telling you are wrong and its going to fail.
(Of course, most of the time those voices are right, so if it is something with lives on the line, you also should be making sure you have the resources to test it thoroughly so even if it isn't well-establlished and known before you start on it, it is well-established and known through your team's work before you start putting it in the position to kill people.)
You have to defy all the voices telling you are wrong and its going to fail.
(Of course, most of the time those voices are right, so if it is something with lives on the line, you also should be making sure you have the resources to test it thoroughly so even if it isn't well-establlished and known before you start on it, it is well-established and known through your team's work before you start putting it in the position to kill people.)
The submersible would have been much heavier, hence would have required a much bigger ship, with bigger crane, to haul it, which is times more expensive.
Money, and wanting to be seen as an innovator.
Death by business model. The company was based on the concept that existing regulations and design constraints were overly conservative, and their customers paid the price.
I mean at least all involved willingly went on this suicide mission?
So simple thinking could view this as some wreckless narcissist CEO defrauding some naive customers, and hence a "tragedy".
But alternatively, since the CEO's attitude and the safety record was publicly known, you could instead interpret it as an elaborate suicide pact.
So simple thinking could view this as some wreckless narcissist CEO defrauding some naive customers, and hence a "tragedy".
But alternatively, since the CEO's attitude and the safety record was publicly known, you could instead interpret it as an elaborate suicide pact.
You know one of the people who died (a child) was extremely concerned about the safety of the sub, right? The CEO mislead and lied. To blame the victims here is disrespectful to say the least.
This position is grotesquely immoral.
The attitude that you have no responsibility at all for confirming the safety yourself, simply because a salesman says it's safe, despite clear existing public evidence they could have easily discovered that it's not, is collaboration in evil.
It's always easy and comfortable to falsely deal in absolutes, black and white, that one guy is the bad one and the other voluntary participants were the "victims". 100% vs 0%. But doing so is what lets people get away with aiding and abetting wrongdoing.
That "child" was a 19 year old university student, which is beyond draft age. He made his choice. Not that that exculpates the role of his mother in his death.
This position is disrespectful of everyone who doesn't make such reckless, and mostly showing off driven, risks.
The attitude that you have no responsibility at all for confirming the safety yourself, simply because a salesman says it's safe, despite clear existing public evidence they could have easily discovered that it's not, is collaboration in evil.
It's always easy and comfortable to falsely deal in absolutes, black and white, that one guy is the bad one and the other voluntary participants were the "victims". 100% vs 0%. But doing so is what lets people get away with aiding and abetting wrongdoing.
That "child" was a 19 year old university student, which is beyond draft age. He made his choice. Not that that exculpates the role of his mother in his death.
This position is disrespectful of everyone who doesn't make such reckless, and mostly showing off driven, risks.
This is the fence that will someday become Chestertonian.
every single expert knew carbon fiber was a bad idea (and why) beforehand. it's not a Chesterton's Fence if it's painted "DO NOT REMOVE" in large scary letters and a followup explanation in short easy-to-read words stapled underneath
Some day the story of why the fence(regulation) was created will be lost to time and the sign will have fallen off.
There basically isn't
regulation for submersibles in the first place, that's why the Titan could be built like this. Nobody's going to forget the structural properties of carbon fiber.
It sounds like you think they didn't know it was a deathtrap?
PHYSICAL CAUSES
"4.2.4.4. American Bureau of Shipping (ABS) Classification Society Background" ... "The ABS Underwater Rules do not permit the use of carbon fiber composites for Pressure Vessels for Human Occupancy (PVHOs)"
"4.2.4.5. Det Norske Veritas and Germanischer Lloyd (DNV GL)" ... 4.2.4.5.3. According to a DNV Surveyor, carbon fiber has not been accepted as suitable material for the construction of submersible PVHOs, especially when subject to external pressure experienced at ocean depths. According to DNV GL, carbon fibers are not considered suitable for significant compressive loading conditions."
"5.1. Inadequacy of Structural Engineering Analysis. OceanGate’s TITAN submersible design was a complex, high-risk, deep-sea submersible. The design and testing processes for TITAN did not adequately address many of the fundamental engineering principles that are considered crucial for ensuring safety and reliability for operations in such an inherently hazardous environment..."
"5.6 Insufficient Understanding of Carbon Fiber Material Properties for Deep-Sea Application. The TITAN’s pressure hull was constructed using carbon fiber, a material chosen by Mr. Rush for its “impressive” strength-to-weight ratio. [However] the use of carbon fiber in deep-sea environments remains unproven—unlike the materials with established safety records. There are currently no recognized national or international standards that approve of the use of carbon fiber pressure hulls for submersibles. Carbon fiber has demonstrated its effectiveness in other applications where the material is primarily under tension (e.g., aircraft hulls where the pressure inside the passenger compartment is pressing outwards). However, in deep-sea conditions, the pressure hull experiences extreme compressive forces, a scenario for which carbon fiber has no established track record and is generally understood to be less effective."
* * *
HUMAN DECISIONS
The physics is just the physics. There was no law of nature that forced them to take the steps they took. Instead, we have points like these:
"5.12. OceanGate’s Toxic Safety Culture. OceanGate’s operational and safety practices were critically flawed, which contributed to the catastrophic implosion of the TITAN submersible. At the core of these failures was a disconnect between the company's stated safety protocols and its actual practices. ... This highlighted systemic issues where submersible safety protocols were either egregiously inadequate or willfully disregarded, leaving critical risks unmitigated. The analysis reveals a disturbing pattern of misrepresentation and reckless disregard for safety in OceanGate's operation of the TITAN submersible, with Mr. Rush seemingly using inflated numbers to bolster the perceived safety and dive count of the final TITAN hull...
Examples of OceanGate CEO’s disdain for traditional submersible safety protocols were abundant. For example... This dismissive approach to safety culture was not limited to engineering decisions. OceanGate’s management actively retaliated against employees who raised legitimate compliance related concerns..."
This was a tragedy, because people died and this was all completely avoidable. It's the only event like this in many, many decades. I hope others will leran and avoid making similar mistakes.