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/

by rwmj • 12 months ago

177 182 12 months ago

news.uscg.mil

ortusdux• 12 months ago

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

kelseyfrog3• 12 months ago

This is the fence that will someday become Chestertonian.

roywiggins3• 12 months ago

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

kelseyfrog3• 12 months ago

Some day the story of why the fence(regulation) was created will be lost to time and the sign will have fallen off.

post_break2• 12 months ago

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.

lesuorac4• 12 months ago

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.

shortrounddev25• 12 months ago

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.

lupusreal2• 12 months ago

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.

shortrounddev25• 12 months ago

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

Ralfp4• 12 months ago

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-...

6SixTy• 12 months ago

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.

hajile• 12 months ago

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...

loudmax• 12 months ago

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.

throw0101c• 12 months ago

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.

Twirrim• 12 months ago

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.

morpheos1373• 12 months ago

Stockton Rush would have fit right in in Silicon Valley. Rush and stock on.

Ralfp4• 12 months ago

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-...

lesuorac4• 12 months ago

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)

throw93949443• 12 months ago

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!

dogleash2• 12 months ago

"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

joshstrange• 12 months ago

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..._

js2• 12 months ago

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

iJohnDoe• 12 months ago

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.

Noumenon72• 12 months ago

Has anyone written up a narrative of this, presented that transcript in context, and so forth? If not, thank you for presenting it.

jordanb• 12 months ago

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.

dwheeler3• 12 months ago

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.

chowells2• 12 months ago

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.

WalterBright2• 12 months ago

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.

petsfed2• 12 months ago

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...

rcxdude4• 12 months ago

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)

trenchpilgrim2• 12 months ago

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.

cogman102• 12 months ago

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.

ItsBob• 12 months ago

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!

tantalor• 12 months ago

All of that was already familiar to people who had seen The Abyss (1989)

avgDev5• 12 months ago

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.

bapak2• 12 months ago

Can you think of a better way to die? The only thing missing here is knowing it beforehand.

yawpitch• 12 months ago

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.

myvoiceismypass2• 12 months ago

I found it wild that fragments of their clothes were found, plus a pen and Rush’s business card.

dmoy• 12 months ago

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.

jcgrillo• 12 months ago

this also happened rapidly: https://en.m.wikipedia.org/wiki/Byford_Dolphin

dwheeler3• 12 months ago

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

bouchard2• 12 months ago

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.

avgDev5• 12 months ago

Rush could be placed in Wikipedia under hubris.

His hubris killed people. He ignored experts. He ignored warnings. This outcome was predictable.

xeromal• 12 months ago

The problem is that SpaceX was told the same and it succeeded despite the ods. History is harsh to people who fail.

jjmarr• 12 months ago

That's every startup founder to an extent.

What differentiates a good founder from a bad one is being right.

nathan_compton2• 12 months ago

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."

eptcyka• 12 months ago

Nah, it is about finding ways to fail an experiment without failing the whole business, bonus points for not killing anyone in the process.

zarzavat• 12 months ago

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.

firesteelrain• 12 months ago

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.

dwheeler3• 12 months ago

The report has many gems about the tragedy. Basically, there were clear physical causes, which in turn were caused by hubris:

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.

QuantumGood• 12 months ago

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

stavros2• 12 months ago

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.

HumblyTossed• 12 months ago

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.

rcxdude4• 12 months ago

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)

nodesocket• 12 months ago

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.

bathtub365• 12 months ago

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.

culebron21• 12 months ago

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.

roywiggins3• 12 months ago

Money, and wanting to be seen as an innovator.

dragonwriter2• 12 months ago

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.)

nathan_compton2• 12 months ago

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.

lupusreal2• 12 months ago

*cenotaph

Luker88• 12 months ago

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?

nemomarx• 12 months ago

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.

csb6• 12 months ago

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.

ethan_smith• 12 months ago

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.

throwawayoldie3• 12 months ago

And there were no "passengers", legally speaking, just "mission specialists".

kalleboo• 12 months ago

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-...

myvoiceismypass2• 12 months ago

Move fast & break things plus zero regulations seem to be what our American oligarchs want on land too. Seems like the same attitude.

ridgeguy• 12 months ago

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.

bell-cot• 12 months ago

I can't imagine why ...

"Cheap, cheap, cheap" ain't just a thing that birdies say.

throwawayoldie3• 12 months ago

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.

jjk1668• 12 months ago

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.

danjl• 12 months ago

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.

TheCleric• 12 months ago

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.

mikewarot• 12 months ago

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

jalapenos2• 12 months ago

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.

chriswalz• 12 months ago

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.

jalapenos2• 12 months ago

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.

US Coast Guard Report on Titan Submersible

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