Oceangate 2024: The world's first multi-physics simulation of the Oceangate TITAN

[@hnrwagner]

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[@eroero830]

u say the people on the titan didn't know that it was going to implode and didn't feel anything. i think that's short sighted. they obviously knew it was going to implode for some time because of the early warning system, unless you're saying that was broken

[@Vladimirthetiny]

Much prefer your real voice..

[@shamancredible8632]

An 18 minute video about an event that happened in a few milliseconds, plus an ad for something I will never buy. I'm glad I can skip through the video

[@AndyGunslinger]

There is a dislike for rudely putting in your sponsors anywhere but at the end of video. Insert it at the END if you just have to do it.

[@hnrwagner]

​@@AndyGunslinger lol why at the end, most don't watch until the end

[@TheNefastor]

Fun fact : it really is the world's first because even Ocenagate didn't make a simulation.

[@hnrwagner]

the strange thing is also that it was a year ago, and one would expect more simulation to appear

[@TheNefastor]

@@hnrwagner not really. It's pretty clear to most people why you don't build a submarine the way they did. We don't need to simulate triangular wheels made of porcelain. Same kind of situation.

[@AlexRojas-db6yd]

@@TheNefastor Yes we fucking DO. Sim Fucking EVERYTHING (Even if only for entertainment)

[@TheNefastor]

@@AlexRojas-db6yd hey maybe you have time to waste. And money for the sim tools licenses. The rest of us have to work for a living, so no, nobody but jobless hackers "simulate everything".

[@AlexRojas-db6yd]

@@TheNefastor You seem irrationally upset about this which leads me to conclude it triggered you due to some tangentially related but otherwise indirect reason. It's OK man, I'm mad about poor allocation of resources too.

[@zebazz86]

The bit with the interview caught me off guard, that was hilarious 😂 and funny transition to your sponsor

[@hnrwagner]

Thanks, i like the idea of using David clips for such presentations

[@richardwellons5138]

As a retired submariner, sub test eng [nuc] /test director [HM&E], etc, you've presented the best vid yet, from engineering perspective and justifications, thru the simulations. As we said in the old days [and who know, perhaps even now, "OUTSTANDING SIR" Thanks.

[@hnrwagner]

Woah thanks, really appreciate it

[@derekclay9314]

More like excelsior😂😂😂

[@cliveramsbotty6077]

impressive credentials for someone who can barely put together a coherent sentence

[@mann_idonotreadreplies]

@clive give em a break his name's Richard 😁

[@darylmorse]

I really enjoyed the interview with Stockton Rush.

[@hnrwagner]

Thanks

[@glennllewellyn7369]

Agreed. Inspiring!

[@JediBuddhist]

Yes indeed.. very intimate and touching. How was it obtained. Did the family release it.?

[@thesaddestdude3575]

@@hnrwagner This video is gold

[@Robert08010]

I didn't know he was a red-head!

[@BergStark]

Passengers were talking about shotgun like bangs which Rush dismissed as just the weaker fibers settling. Cycle fatigue for sure.

[@hnrwagner]

I think so too, CFRP should never crack during operation but that is just me

[@mbrusyda9437]

What does settling mean here

[@BergStark]

@@mbrusyda9437 The bangs was "just" the weaker fibers breaking, but don't worry the stronger fibers should be enough.

[@Robert08010]

Those were acoustical cries for help!

[@Robert08010]

@@BergStark Yeah, with that huge 1.4 safety margarine, clearly they didn't need all the fibers that had.

[@moiraatkinson]

What comes across as most important here, is how good the engineering knowledge is of the creator. That’s the most thorough explanation of the factors involved which caused the implosion of Titan. I learned something watching this. I’ve seen a lot of engineering explanations by various people, but this was the best. It was also interesting and presented so anyone could follow. Good video 👍.

[@hnrwagner]

thanks

[@linuxsuperuser]

It's actually kind of amazing it went on for as long as it did.

[@hnrwagner]

I would like to see an ultra sonic scan of the CFRP cylinder before the last dive, damn that would be interesting and shocking at the same time

[@sambranton3346]

Almost like something happened to make it fail the moment it did. Now what story was breaking when every news channel in the world cut to this story for 2 weeks? It won't be coincidence.

[@TylerDurdan241]

It must've been pretty strong at the outset, as it was marooned for 20hrs at Titanic depth on a previous dive when it had an electrical malfunction.

[@mstecker]

It's not 'amazing'. It shows their calculations were valid. We barely had any safety factor when we made it to the moon. We got lucky there wasn't an accident. If we had lost an apollo 13, these voices would have damned the whole program.

[@linuxsuperuser]

@@mstecker The calculations were valid for the first dive only. otherwise Titan ran on concentrated luck. Unlike metal which can safely flex without loosing strength. Fibers break as the hull is slightly distorted under extreme pressure. The breaks accumulate and can not be repaired. The Titan Hull RTM system used microphones to listen and count these noises to anticipate failure - they knew. Stockton Rush cut every corner he could to keep oceangate going. why?

[@harrie205]

it was bad design by someone who does not know enough about composites. No measures where taken to deal with snap buckling/interlaminar shear stress.

[@hnrwagner]

probably yes

[@bastian6173]

IMO this is not the problem. The problem is how can someone with the intelligence of a monkey just go ahead and do this? Why no agency holding him back? Is it his charisma? People just don't care?

[@KidCorporate]

It's almost like he should've hired some "old white dudes."

[@harrie205]

@@KidCorporate I think he tried to save money (this carbon winding can be much cheaper then titanium hulls(they basically build a smaller spherical titanium hull and increased its internal volume massively by the carbon tube)) But the cost savings only accounts for manufacturing and not development where it seams like they cut costs (quoting wrong safety factors shows that they did not know there design/validate their calculations)

[@sayorancode]

@@KidCorporate boeing did that .. maybe just hire someone who knows about how to build a submersible regardless of appearance (james cameron)

[@JeaneGenie]

It's freaky to think that one second they were normal and the next they were all a pulverised soup dispersing into the ocean.

[@hnrwagner]

a few sec later the soul of Stockton Rush thinks, "damn what just happened"

[@Dwuudz]

@@hnrwagnersuddenly connected to Poseidon’s WiFi.

[@LawtonDigital]

The word you are looking for is "chum".

[@Aux-vox]

@@hnrwagner The Captain of the Titanic hands him a Punch Romaine and a commiserating slap on the back.

[@jahnkaplank8626]

not one second.... 6 milliseconds

[@rtqii]

I am at 0:06 and there you have it. At the depth of the Titanic, even seawater is compressed some. People say, or think, that water is incompressible, but it actually gets a little bit more dense the deeper you go. Even titanium compresses a tiny, tiny amount under the pressure at Titanic depths. The carbon fiber composite compresses, more than seawater, more than titanium. The glue joint between the carbon and the titanium was never designed to move or flex with these different rates of compression. Plus the view port design and construction were never meant for that depth. In the images of the recovered debris being unloaded in port, the viewport was separated from the titanium hemisphere.

[@hnrwagner]

I have found a diploma thesis "Adhesive Joining of Metal End-caps to Composite Pressure Vessels ", I will study it and present the results, maybe you find your thoughts back in it

[@rtqii]

@@hnrwagner They cleaned the bonding surface with a dirty rag, and you can see the technician touch the surface with his bare hands after wiping with the dirty rag. This was clearly shown in an Oceangate video.

[@rtqii]

@@hnrwagner They mixed the glue by hand, and probably used additives to thicken it, and I doubt it was properly mixed in. They also stirred in lots of air, and never degassed the glue. Bubbles in the joint material would be bad news as well.

[@k53847]

@@rtqii That was the first PV. The second one was done by electroimpact, which is a quite reputable company that does a lot of aerospace composite work. They ended up abandoning the first PV and hired electroimpact to make a new PV.

[@wobblyboost]

@@rtqii I feel you're right about the trapped contaminants and especially the air bubbles, the CFC shell basically got 'the bends' in more ways than one. Delamination from air being compressed out of the layers, it's presence reducing the overall bonding and the compression expulsion decreasing the mass. In an interview with Karl Stanley, who was onboard for a test dive, he remarked that the noise of fireworks from the CFC was almost constant, not only on the way down to 2000 metres, but all the way back up until 300 metres. To me this would indicate the compression of the CFC's mass itself while descending, likely with lateral folding of individual fibres, then on ascenscion the 'wrinkled'/weakened fibres are snapping apart as the CFC shell expands again. Even though the ends of the cylinder only suffered one quarter of the total compression, I feel these lateral forces were woefully underestimated. Karl strongly recommended they should cancel all plans for passengers until they built something else far more robust. He wasn't on the team, he'd built deep sea tour subs and they wanted his input and he was very keen to ride, however oceangate sacked several of their own engineers who also recommended scrapping the design and ignored any cautions from the international submersible society.

[@hnrwagner]

Timecodes: Chapter 1 - Introduction: 0:00 Chapter 2 - What is CFRP: 1:05 CFRP vs. Titanium: 2:58 Chapter 3 - Design of Oceangates CFRP cylinder: 4:34 Manufacturing of the CFPR cylinder: 4:39 Analytical Design of the CFRP cylinder: 6:35 Numerical Design of the CFRP cylinder: 7:47 Interview with Stockton Rush on Safety Margin: 10:26 What a proper testing program look like: 12:50 CFRP cylinder with safety factor of 6: 14:21 Chapter 4 - Implosion: 14:32 Cycle Fatigue explained: 14:38 Debris of the TITAN: 14:51 Implosion vs Human body: 15:11 Best TITAN Implosion Simulation: 16:41 How a safe cylindrical submersible looks like: 17:48 Google Scholar: scholar.google.de/citations?user=a4sKEKsAAAAJ&hl=en Researchgate: www.researchgate.net/profile/Ronald-Wagner OrcID: orcid.org/my-orcid?orcid=0000-0003-2749-1455 GitHub: github.com/hnrwagner ABAQUS like FREE to use FEA Software: prepomax.fs.um.si/

[@PetesGuide]

Nobody is seeing this because you haven’t pinned the comment yet. Pin it and then more people will get the benefit of your time points here.

[@spitefulwar]

Listening to Stockton Rush's interview sniplets is like watching one of those notorious YT videos of pakistani repair jobs where - at the undertone that material sciences are but a joke for westerners - completely destroyed machinery parts are nursed back to 30-50% of structural grade and put back to work - only to break just in time for the next miracle repair video take.

[@hnrwagner]

unfortunately yes

[@HerbertTowers]

Nasty RACISM.

[@life_of_riley88]

*Bunch of dudes in sandals working on a dirt floor*

[@Robert08010]

I see it as a slightly higher class version of Jackass.

[@triumphbobberbiker]

And yet it was not the Pakistanis who built that sub

[@stargazer7644]

AI voiceovers are terrible.

[@stevelane5885]

Why can’t the producers find an actor who knows the subtleties of the English language to read the script? This AI voiceover is irritating and distracting.

[@jannikheidemann3805]

Espicialy if you feed them bad input like "wounded carbon fiber" or "Titaninum".

[@legionofyuri]

True. Much rather have some Indian guy with a heavy accent narrating than an AI, at least the Indian put effort into it.

[@barneystafford]

Especially when the script writer cannot spell

[@Robert08010]

I usually thumbs down for that re3ason but in this case I didn't because I believe he was quoting from another video, an AI generated video.

[@whatsmyusername1231]

Why do they need to wound the carbon fiber? Won't it hurt?

[@hnrwagner]

ups looks like I need to improve my english skills

[@ralph17p]

@@hnrwagner English is a bitch. Same spelling, different pronunciation, entirely different meaning. So you got the word right, the narration picked the wrong version (I'm assuming it's text to speech)

[@wobblyboost]

They should apply a compress to the wound.

[@Rietto]

TTS outed itself?

[@johndunn4228]

A friend of mine used a 50 gal petrol drum, once in the water he pulled the plug from inside. It sank beautifully.

[@Skankhunter420]

The chimp washing socks killed me bro 🤣 😂

[@hnrwagner]

glad you liked it

[@eeehan77]

I'd just like to let known my severe objection to the use of David Attenborough's voice for the AI narration generated for this video. It's inappropriate, unnecessary and the great man himself would surely object.

[@hnrwagner]

now I know, but I like it still

[@teamidris]

Wounded carbon fibre and mpa said instead of mega pascals. The dyslexic engineer in me couldn’t handle it.

[@StLaparole]

Yes what is that all about? It's not a light topic, is it? So why add this humorous touch to it? Why not narrate the video yourself? Computer voices give a cheap or even disingenuous impression anyway. We all make mistakes, so even if you yourself think little of your performance as narrator, it's probably still way better than this.

[@anthonytimpson4975]

@@hnrwagner maybe we should send this to youtube or Attenborough's lawyers?

[@jannikheidemann3805]

@@teamidris "Titaninum" at 3:35 is also wrong.

[@BD12]

The hull collapsed, yet incredibly Stockton's hairpiece was retrieved intact. Maybe you can run a simulation on that thing too

[@IARRCSim]

Hopefully they make the next sub from many of his hair pieces.

[@josue_kay]

The hairpiece was allegedly made from wound titanium. Thank goodness it wasn't made of carbon fibre.

[@Robert08010]

Test IT to crush depth!!!

[@SleutherStrode]

😂😂😂😂😂😂

[@o-hogameplay185]

what temperatures would the air bubble be heated up during the implosion? from my rough calculations i got 1300-1700 celsius

[@hnrwagner]

not sure how to calculate this, how did you do it? It is not my expertise

[@NGC-gu6dz]

@@hnrwagner Probably using adiabatic temperature-pressure. I get 1695k, about 1500c.

[@o-hogameplay185]

@@hnrwagner i have did some assumptions. i could not find any sources about the internal volume, so i approximated it with a 2.5m long cylinder with 1.5m radius. so the initial volume is 4.42 m^3. i also assumed 1 atm inside before implosion then, for the initial temperature, i am not sure. there was 5 average sized people there, so they were heating up the air with ~500w in total, but the water around them is very cold, but to my knowledge carbon fibre is bad heat conductor. so i just went with a 25c initial temperature. the final pressure is 400atm. the issue is that i cant really write equations here very well, so i just write the final one. essentially i used the Boyle's law and ideal gas law. the final equation is T2 = T1 * (P2 / P1)^((γ - 1) / γ), where y is 1.4 (y is the adiabatic index, 1.4 for air) this is assuming that no heat is excanged during the implosion. so T2= 298.15*400^0.286, so around 1600K while there are assumptions and simplifications, i think it is at least somewhat correct, but i can be wrong

[@o-hogameplay185]

@@NGC-gu6dz okay, so our calculations are close enough

[@wobblyboost]

Either way it was all over in 6 milliseconds, so sudden their nervous system ceased to function before it could register anything. It's no surprise they were unable to find bodies nor cylinder, would have been atomised.

[@utube321piotr]

The Titan was towed for 3 days 600 miles across the ocean on teeter-toter tin pontoons. It's structural integrity was shaken to pieces on the stormy Atlantic. On top of that any sensible maintenance/servicing was not possible on a tender leash.

[@spitefulwar]

The Titan was flimsy in terms of deep see operations but not as flimsy as you describe. Yes maybe internal panels were most likely shock loose but those were held in place by magnets iirc. Sea wave induced amplitudes couldn't have done much, if any to it's integrity.

[@utube321piotr]

@@spitefulwar you obviously didn't analyze the design of Titan or pontoon platform it was floating upon

[@hnrwagner]

actually good point never thought of it

[@utube321piotr]

@@hnrwagner each titanium cap was attached to a steel structure, while rather heavy carbon tube was suspended in air, the left/right pontoons were effectively twisting each end cap in random directions, this torsional effect was not ideal for the glue bonding joints at each end of carbon tube; must understand, those thin aluminum pontoons were designed for a lake not for 5m Atlantic waves;

[@spitefulwar]

@@utube321piotr wow ok I take that back... I thought they were using common sense (against my better judgement) I take my argument thus back

[@geraldtn3175]

Mr. Rush was criminally overconfident. Scary dude

[@baronhelmut2701]

You know what we normal folk call criminal overconfidence ? Stupidity.

[@KendallSeabury]

would it be possible to get updated simulation? from the newly related video footage of the wreck it looks like the failure started at the interface with the titanium ring. hence one end popped off and the other smashed up with carbon fiber. it would be interesting to see of the simulation would show that too.

[@Chaos8282]

Still remember sitting here at my desk when the news broke of this. The wife was talking to me. I said, yup they're all dead. Turned into pink paste before they knew it was happening. There is a reason more people have been to the moon than to the deepest part of the ocean. It's easier.

[@highvelocitywilliam]

Noone went to the moon 😉

[@Puddlef1sh]

Same. I knew what happened immediately. The whole oxygen thing was ridiculous.

[@Blu3_SK33]

They have never been to the moon anyway....

[@highvelocitywilliam]

@@Blu3_SK33 true… NASA says they “lost”the technology lol

[@krummja4823]

@@Blu3_SK33 Multiple countries have photographed the Apollo landing site. There's a reflector on the moon that we can shine a laser at and measure. It's absolutely, 100% certain that we went to the moon.

[@dysfunctional_vet]

your interview with stockton was amazing.....

[@LittleHatori]

agreed. It's TRUE JOURNALISM

[@thomassutrina7469]

The navy I understand built a graphite epoxy composite submersible and tested to depths similar to Titan. They published a paper and likely the designers of Titan read it. The flaw of the Titan probably existed in the navy test vehicle which only made a few dives. No where near the number the Titan made. Your analysis was before the images of the Titan remains were presented at the inquiry. Failure seems to have been the interface between the ring bonded to the composite at the front. The remains of the composite is pushed against the end half sphere and ring. I agree that the failure was cyclic caused damage. The number of cycles are far lower then one experiences with typical cycle failures for the safety factor. There is an accelerating factor you didn't mention, hydraulic pressure forcing water filling the voids of the composite thus totally changing the forces applied. I am an aerospace engineer building prototypes through testing. Involved in proposals from the propulsion components in deep space probes; military and commercial jets electrical systems. Worked on a thermal a torpedo engine in service with the British navy and built a prototype electric motor drive for the US navy. I designed, had built, and tested composites components. The biggest factor is that the design ignored the nature of ALL COMPOSITES. No EXCEPTIONS. Not a single composite doesn't have delamination of the fiber to the epoxy somewhere and typically small and distributed. The strength of the composite takes voids into account so the finite element analysis that anyone does do not recognize their existence. We see this is the analysis papered through the many videos of the Titan. Including yours. Under atmospheric pressure to vacuum seen by 99.99% of composites and all composites only under tension this is a good assumption, voids typically can be ignored. However; the Titan composite cylinder was under compression and very high hydraulic pressure of the ocean. Can not be ignored but was. I have not detect in anything I know about the Titan that anything was done to prevent water from finding delamination of the fiber/epoxy interface and filling that void and applying depth pressure internally. Further the higher resulting stress and strain would expand all the voids. Failure was going to happen and due to strain failure at the interface epoxy bond to the metal ring is just as likely as the weakest center of the cylinder. They had an opportunity to prevent this disaster, but didn't include this in their fault table, check list. The Titan ascent speed if one could check would have been slower on the last dive before this one. The communication for this dive told of a faster then normal descent. The procedure for a dive was to adjust weights added to achieve the same level of buoyancy for every dive. That means the ascent and descent speed would be consistent. The Titan was HEAVIER, less buoyancy. And water filling voids in the composite cylinder is the only easily missed way to gain weight.

[@hnrwagner]

thanks for the thoughtful comment

[@briantampa1164]

This is ine of the better videos breaking down what happened to the Titan submersible. You just earned a subscriber.

[@hnrwagner]

thanks

[@TheEldon3379]

There are two great tragedies the emerged from the implosion of the Titan. First and foremost, the loss of the passengers. And second, the fact that Stockton Rush never found out that his hubris caused the death of four people.

[@butchs.4239]

I would like to think at some point before the implosion he knew this was Titan's last trip and he'd never see the sun again.

[@majorbruster5916]

​@butchs.4239 Yes, I got the feeling that he must have known something. The tragedy is that he killed others along with his massive ego.

[@JamesBarnett-v5e]

Wow, this is an incredibly in-depth video. It must've taken a lot of time and work. Kudos!

[@hnrwagner]

thanks, yes it was a lot of work but i was also fun to do :)

[@mattilindstrom]

Cabon fiber pressure vessels are very good at resisting internal overpressure since the loading can be engineered to produce almost purely stretching forces on the fibers. Using it to resist external overpressure is an astonishingly bad idea. In the composite formation process control has to be extreme, and the inspection of the material would have to be high tech, meticulous, and frequent. Just the delusional attitude to safety is something the responsible parties should be prosecuted for.

[@pete540Z]

In the early 90s I worked at David Taylor Research Center with engineers that were designing, testing and building composite submarine hulls. They knew what they were doing. I worked in other applications in composite materials and did my Masters Thesis on composites. We had a saying: "You can't push on a rope" The composite sub hulls they designed were for much shallower use that what the idiot Rush was trying to do.

[@Shinobubu]

using fibers of any sort for compressive loads is akin to pushing rope..

[@Robert08010]

One might investigate the timeline of his bypassing safety testing v.s. his decision to avoid needed certifications by declaring every passenger to be a "mission specialist" and part of the "crew". If it can be shown that he came up with that idea of making all passengers crew to avoid the need for certifications, then I'd say that should qualify his company for murder charges.

[@Robert08010]

@@pete540Z That's another point: if he had used this submersible more reasonably, and kept to shallower depths, it might have gone on being useful for many many years.

[@spacecase13]

I've been looking forward to seeing your simulation ever since seeing it referenced in jefostroff's "Best Titan Sub Implosion Simulation video" a week ago. Thank you for posting your video, it was well worth the wait!

[@hnrwagner]

Thanks, dont know the KZbinr can you share a link plz

[@jacksondodd8835]

Based on the fact that they had dropped their ballast before the implosion, I am guessing that everybody knew what was coming, there would’ve been a large amount of cracking and creaking so much so that it scared them enough to drop the emergency weight, which had never been done before at that depth.

[@Aux-vox]

"more sounds aft." is their last transmission.

[@HarryBalzak]

The collapse warning system was, according to an unconfirmed comms leak, warning of imminent implosion for about 19 minutes, IIRC. If that is true, that must have been so terrifying.

[@karlos543]

Wrong!

[@jacksondodd8835]

@@karlos543 what do you mean?

[@mcgherkinstudios]

They dropped weight to slow their descent, this was a normal operation for the phase of the dive they were at i.e. approaching the wreck site.

[@90_98]

I just realized that starting from 0:24, the description of the Titan seemed to have been pulled straight from Wikipedia

[@angrybabushka]

It is entirely possible that he also wrote the description in the Wikipedia article

[@aarenfourever]

That "interview w/rush in borneo" is hilarious!!!

[@Bapate-rh9be]

These calculations overestimate the strenght of the submarine in my opinion: I do not think that the standard composite failure models and strength calculations can be applied to a submarine as hydrostatic pressure leads to carbon fibers becoming thinner, but longer, the epoxy reacts homogeniously by just reducing its volume, with a much lower overall volume modulus that is. This leads to additional stresses at the fiber matrix interface and different failure modes - you would expect the overall resistance of the vessel to be much lower than predicted with current failure models. In addition: If the panels had even minor leaks water would have entered the cracks forming in the composite (because composite) which would have moved the point where the water pressure acts on the structure into the composite in the affected areas leading to stresses directly delaminating the composite and promoting buckling which would have removed structural integrity.

[@hnrwagner]

Proving my point that the margin of safety was too low

[@Bapate-rh9be]

@@hnrwagner Yes, indeed.

[@silver_surfer88]

Cant get enough of this intriguing engineering story, will watch later thank you!

[@hnrwagner]

glad you like it

[@jannikheidemann3805]

3:35 What is "Titaninum"?

[@VickersDoorter]

I presume this is an AI bot voice. 5:17 "...as the core around which the carbon fibres are wound", with wound pronounced woond instead of wownd.

[@HughPryor]

I think it's David Attenborough's voice - Ronald Wagner has a thick German accent...

[@wattage2007]

Yeah, there are a number of givaways on this. Any AI voice documentary gets an automatic thumbs down from me.

[@mxcollin95]

A slightly DIFFERENT implosion theory: That simulation makes sense if the carbon fiber tube failed and the end caps essentially smashed together with tremendous force thereby compressing and heating everything in between them. However, we know the window wasn’t rated for the pressure it experienced so what would the simulation look like if the window failing was the start of the implosion? In that case, logically it seems like the window would be traveling inward at a high velocity being pushed by an extremely powerful jet of water thereby causing a different implosion sequence. One reason I thought that might’ve happened was because the end caps that were recovered appeared to be undamaged at there flanges where they mated with the carbon fiber cylinder. If the cylinder had failed and the end caps were forced together with tremendous force and speed then you’d think they possibly would’ve contracted each other with sufficient force to cause noticeable damage to the end cap flanges. Does anyone think the window implosion theory is plausible? Lastly , great video! I think it would be really interesting to see the implosion sequence slowed down even further. 👍

[@wobblyboost]

An implosion in this scenario is followed by an instant catastrophic explosion. Perhaps you can consider a diesel engine, although they generally have a glow plug now, earlier models did not as this only assists combustion, unlike a spark plug that initiates it in petrol/gas engines. So what actually ignites the diesel/air mix is the heat from the sudden compression of the air by the upward stroke of the piston. An implosion catalyzed explosion is the same physics, the 1 atmosphere air void that the high pressure water is rushing in to, to equalise the overall pressure; is instantly compressed to above that of the surrounding water and the temperature soars, then the explosively expanding super-heated air also turns the surrounding water to steam which also expands. Voila, an explosion equal to 1 ton of TNT, which would level a city block.

[@mxcollin95]

@@_andre99 that all makes sense. Watching the implosion simulation presented in the video and seeing how the two end caps came together in “4 milliseconds” was what got me wondering about having two seemingly undamaged end caps. That whole sub would be imploding at several hundred mph so you’d think the momentum of the end caps coming together would leave obvious signs of damage. Although, that implosion video was obviously only an approximation because if you watch it closely it shows parts of the cfrp cylinder proceeding through the bodies of the end caps which we know didn’t happen based on the recovered undamaged end caps. I guess we’ll never know exactly what happened but it’s definitely interesting to think about.

[@TlalocTemporal]

I though the window was found mostly intact outside the wreckage?

[@kimthreadgold2755]

He made three successful trips. Probably figured he knew more then the other experts

[@ryancraig2795]

Rush's talk about how they were monitoring this hull for microscopic cracking noises and that this would make it all ok was chilling. Personally, I'd want to hear or see NO cracking and creaking coming from the hull.

[@conradmeek5142]

Rush was misapplying technologies from the aviation industry meant to predict component failure over time. The type of system employed is effective in measuring vibrations using accelerometers and computer analysis on key components such as drive shafts, engines, bearings, generators, et cetera. Problem is these technologies require someone to know what the failure mode truly looks like and it is clear it was never tested enough to figure out any baseline. I believe it was more a marketing measure to "promote" a culture of safety where no enhancement of safety actually existed. To a person without knowledge of how these things work his BS would have persuaded many.

[@jahnkaplank8626]

personally, I would NEVER get in a plastic tube to go see the bottom of the ocean, especially if I was a billionaire...

[@conradmeek5142]

@@jahnkaplank8626 This was not a 'plastic' tube. You are correct in refusing to go based on the information available. You probably lack the perspective of a billionaire. There are safer ways to do this type of research. There is a fair argument that carbon fiber hulls can be useful in comparable applications. However, much research and testing is needed, something Ocean Gate deliberately avoided. Ocean Gate hurt the industry they were supposedly supporting in their actions.

[@trishsinis5301]

This is a nightmare. I would not have been anywhere near that thing.

[@jerardnorgren3411]

That's why carbon fiber was NEVER considered safe to use in deep water environments. That's why people wrote letters to the oceanic communities that govern accreditation to WARN of the dangers that Oceangate chose to ignore. It's nothing short of murder what Stockton Rush and Ocean gate did.

[@C.AMohammedMeeran]

Good video. What software have you used for the simulation?

[@hnrwagner]

@@C.AMohammedMeeran prepomax and abaqus

[@SovereignStatesman]

CFRP also _fatigues_ more in than Titanium. So the Titan did fine for about 50 dives, as they ignored all the stress on the hull. Then the last time-- CRUSH.

[@marcusott2973]

Much awaited, much appreciated excellent insights as always from you.

[@hnrwagner]

Thanks a lot, I am working on more videos like this

[@markgrayson7514]

Please edit the soundtrack to remove the sibilance sound (Ssss) by tapering off above 5,000Hz. You may then want to add reverb using a preset, perhaps one named 'small room.' In future recordings, use a sibilance filter (made for the mic or use pantyhose stretched around a bent coat hanger).

[@hnrwagner]

Not really understand your comment but I will check

[@Yggdrasil42]

It's an AI voice so the filtering will need to be done on the audio file instead of a real mic. But I agree. The sibilance gets annoying.

[@bjh3661]

a pop-filter is what you describe. a pop filter will not tame sibillance

[@ctrlaltdebug]

@@bjh3661 he's describing a low-pass filter.

[@Hiram1000]

It's AI generated narration using David Attenborough's voice. Why?

[@Thefreakyfreek]

can somone explain to me why it needed ligt wiegt matirials like titanium and carbon its suposed to sink and whit that water displasment it wil float

[@hnrwagner]

it was supposed to have a positive buoyancy when it released its weights, so it could return easily to the surface, that's why it was built with a CFRP cylinder

[@k53847]

Exactly like the expert says, further it is very difficult to provide things like working ballast tanks at the depth they wanted to go to. So if the sub isn't inherently buoyant it is a very hard problem to solve, particularly for something small that is supposed to maneuver.

[@bigfootape]

Neutral buoyancy meant the submersible was lighter without a need for syntactic foam. This reduced construction costs and made operations cheaper. Sadly, CFRP compressive pressure vessels are an underdeveloped field and Oceangate didn't invest the time and money to properly build out their experience base.

[@josue_kay]

Requires less energy to manoeuvre underwater, and more importantly, to refloat back to the surface.

[@k53847]

@@josue_kay You could in theory build a negatively buoyant sub that relies on hydrodynamic lift or propulsion to control depth, but the failure mode of this is not ideal.

[@joaohanhoerster]

In 9:20 you have more thickness and even with that the stresses are higher? Shouldn't it be the opposite since you have more material countering the effects?

[@hnrwagner]

The buckling pressure increases if you increase the thickness of the structure, I think you mean "stress = Force/cross-section area" where the stress reduces if the cross-section area increases through thickness increase

[@joaohanhoerster]

@@hnrwagner Well, I re-watched the video and saw the analytical equation. With that it's easy to check the increase in stresses with the increase in thickness. When I saw the simulations results it just pooped the euler relation and that's why i had this "feeling" that was wrong because there as the "J" increases, higher is the critical load to buckle, leading to this assumption which is probably wrong. Could you tell the reference from where that equation is from? Thanks a lot, your videos are awesome

[@hnrwagner]

@@joaohanhoerster its from the NASA SP-8007 guideline , handbook for cylindrical shells

[@olivercouch1651]

I had the same confusion. I think he's plotting/calculating the stress at buckling onset, or perhaps the external water pressure at buckling onset - it's not clear.

[@xchazz86]

David Attenborough will live on forever on the inter-webs.

[@hnrwagner]

@@xchazz86 yes

[@joblo341]

You need to talk about that last image, "hexmersible". What material is it built from?

[@dronelabs556]

Id trust the Hexmersible.

[@hnrwagner]

me to; I tested it already using simulation, its very sturdy

[@wobblyboost]

@@hnrwagner Is that model 100% titanium or also CFC laminated cylinder?

[@hnrwagner]

@@wobblyboost all titanium

[@wobblyboost]

@@hnrwagner He really should have gone with it, the fact it would have added extra 20+ ton to overall vessel, mostly in larger thrust motors and batteries and the floatation chambers would make it way bigger, requiring a much larger launch vessel, is why he baulked at the design. Promises had been made and he was impatient to get paying passengers. I really think he should have just gone 100% Titanium and had the dang thing on a cable, used a deployable anchored floating rig or similar. Could still be manouverable but with much lighter thrusters and batteries with the option for emergency cable power. But he had his heart set on a mini sub like he saw on thunderbirds.

[@davidmescher2526]

Hexagons are the bestagons.

[@kylesargert3336]

Professor please forgive my ignorance, but could you see if a design like this could work if it we properly designed? Just a question from a layman.

[@hnrwagner]

I worked for 5 years as a Composite Engineer at the German Aerospace Center and I would not build a Submersible using CFRP, it is not made for such applications, CFRP is great for thin-walled structures but not for thick-walled or solid structures. I think titanium is the better material for deep sea application

[@hinz1]

Sucks, but on the other hand, probably one of the most painless ways to go. Probably didn't see it coming and boom, gone....

[@gearloose703]

Would be easier to get your hands on a metric ton of tnt though, but pretty ok would do again.

[@riaganbogenspanner]

The event might be fast, but there might were some loud cracks beforehand.

[@himalayo]

@@riaganbogenspanner even a miniscule crack would be enough to cause the implosion, hence why it happened in the first place

[@wobblyboost]

@@riaganbogenspanner According to Karl Stanley who went on a test dive in it, it made a noise like fireworks all the way down and up again, only ceasing above 300 M.

[@riaganbogenspanner]

@@wobblyboost Yeah, this would be terrifying me.😅

[@7spower998]

Thank you Dr. Wagner for the in-depth explanation of the CFRP hull. I noticed the lack of frame stations along the length of the hull, I.e. aircraft fuselage.

[@craigdenman428]

You know it’s AI when it can’t tell the difference between wound and wound

[@hnrwagner]

i am sure that I would have made the same error, so not that bad

[@sklerp386]

​@@hnrwagner Boooo

[@garyb6219]

Thank you.

[@LegendLength]

Do planes use a big carbon fiber helix to make the fuselage? Or is it a 2 piece clam?

[@jiioannidis7215]

The orangutan bit was sheer genius

[@hnrwagner]

Oh wait till u See my next Video on fiu bridge collapse

[@ahaha8]

Any idea why they not did an umtrasonic scan of tbe hull after each dive??? Seems to be an easy call or not?

[@hnrwagner]

it was to expensive, I have seen an interview which stated about 20 k

[@DemoNinja79]

Despite his insistence, there was nothing innovative about what Stockton Rush was doing. All they were doing was cutting corners.

[@kirbywaite1586]

How the tapering tail secured to the hull?

[@davidrowley-ic6dx]

I was pleased to see that you did make reference to the potential for material property data variability associated with such analyses. There have been a number of these failure simulations since the Titan loss. I have not seen any detailed presentation against material property data used … the simulations seem to be generally created more for dramatic impact than a genuine study of the specific case. There are 2 major factors that appear (to me) to be consistently ignored: 1 - The challenges associated with creating monolithic laminates of 100mm thickness or greater (the effort required to develop an appropriate manufacture/cure cycle to control the innate exothermic process and the consequences of failing to understand the resultant effect on “assumed” material property data. How was degassing of such a tremendous monolithic laminate controlled through the cure cycle? 2 - The challenges associated with developing an appropriate adhesive bond; both in terms of the CFRP/Ti connection and in terms of the way the load will transfer across that interface as the CFRP cylinder will deform compared to the Ti end rings. A lack of basic understanding and qualification appears to manifest in the (admittedly limited) visual evidence in the apparently clean surfaces of the Ti rings when they were recovered … no apparent evidence of residual adhesive or trace of laminate indicating the failure as being adhesive rather than cohesive. Such failure is not surprising to me given the on-line video evidence of the adhesive application and assembly of the Ti rings to the CFRP. What primer/pre-treatment was performed to both the Ti and the CFRP? How was adhesive thickness and uniformity controlled? How was the adhesive cure process developed and controlled with due consideration to the thermal properties of both materials? So many questions. There has been much maligning of the use of CFRP in this application .. and I am not saying it was the optimal choice .. but if a typical aerospace development process had been applied, it might have become a proven alternative to a traditional solution. However, it would have required a very protracted learning curve and very extensive test programme (small scale coupon tests through to varying degrees of test samples) before ever thinking of bolting a human inside and subjecting them to such slim safety margins and I have not identified any indication of such effort being undertaken. Perhaps, one day, an appropriate solution employing advanced materials will make the ocean depths more accessible … but not without an appropriately cautious development process.

[@hnrwagner]

I have built like 10 years ago a 65 mm thick CFRP plate and thought it was very thick, the curing cycle was every 10 mm and it had a pretty good quality. From an old oceagate video I saw that they cured like every inch (25.4mm). I am not a fan of such thick composite structures. I have found a diploma thesis regarding the CFRP-TI interface and will present the results in the coming days, I am not an adhesive specialist though.

[@GrahamHomes]

Not to mention the negative effects of the intrusive nature of high pressure water!

[@zapfanzapfan]

13:20 No one building deep sea submersibles has done those kind of tests. But that might be because titanium and steel are considered known materials? The testing done on the spheres of Deep Sea Challenger and DSV Limiting Factor have been to put them under about 25% higher pressure than their maximum dive depth (and maximum ocean depth...). Pressure of 14 000 meters compared to max dive depth of 11 000 meters.

[@b1lleman]

I hate to be that guy but I guess you didn't have permission from David Attenborough to 'use' his voice ? I would have appreciated the video more without this -possibly- ethical issue.

[@cbnewham_ai]

Doesn't sound like his voice at all. I find Attenborough bloody annoying. This was only half annoying.

[@stargazer7644]

It's an annoying AI voiceover.

[@jungbolosse3034]

If a sailboat with a fiberglass hull is subject to osmosis, is it possible that the water pressure gradually forced water inside the carbon fiber hull structure over time and weakened it?

[@bubblesses8046]

Not sure if the voice is AI or an inexperienced voice artist. Either way, it's not great. The whistling and mistakes are very distracting. Use your own voice, you do an excellent job!

[@kellyannsparks1186]

Finally another comment about the whistling. I couldn’t even make it two minutes

[@cianoconnell1845]

Did you use abaqus to make this simulation? Great video

[@ranmanfl5597]

as a science/engineering enthusiast this is the BEST disaster analysis I have ever watched on youtube. Ronald Wagner and his team are genius science explainers - kudos to you 🏆🥇⛑️💥🤯⭐️⭐️⭐️⭐️⭐️

[@reginawagnerbiolife7867]

Thanks ❤

[@hnrwagner]

thanks , great comment, love it

[@Thefreakyfreek]

3:49 was expecting a serius boring but wel infornmed and unbiased invstagatinon i got that but also meme wich is good

[@hnrwagner]

I want to make more of this kinda documentary-with-memes-David in the future it's funny and informative also I am sick of making tutorials

[@wobblyboost]

@@hnrwagner I enjoyed it, good mix of dry nerd data and cheeky satire. Probably the first video I've ever watched where the AI voice wasn't repellent or used decietfully. I dare say even David Attabro would approve.

[@hnrwagner]

@@wobblyboost thanks for the best comment, really appreciate it

[@Solid3d-Melb]

From a former student in engineering materials, I salute you. Best video in KZbin regarding the Titan's demise. Clear, concise and to the point. Thank you for your service.

[@abcde_fz]

David Attenborough would have known how to pronounce the word "wound".

[@Bollibompa]

Why did you private your old videos on this topic?

[@hnrwagner]

they are partially outdated and wrong

[@michelalphonso6945]

@@hnrwagner I was sad to see your video of you testing my first sub design sketch was gone.

[@Bollibompa]

​@@hnrwagner I forgot to mention that I get why you presented it like this but do know this; your voice is very soothing and nice to listen to.

[@mwm48]

If this is the “world’s first”, how come I’ve already watched about five of these things? 🤔

[@hnrwagner]

link or it didnt happen

[@jamesgibson3582]

What was that last image with a honeycomb structure?

[@hnrwagner]

this video is just a teaser for a longer one which comes in October 2024 , there I will show more of the hexmersible

[@jamesgibson3582]

@@hnrwagner looking forward to that! Thanks for the video and the reply.

[@jerome1lm]

I didn't know that Asmon's editor was into engineering, nice.

[@hnrwagner]

I think zack does not mind if i get his editor from time to time

[@engineerncook6138]

If your are not aware, the US Coast Guard Marine Board of Investigation hearings are being streamed live as of 16 Sep 2024 on KZbin and elsewhere. Past hearings are available in full on KZbin as well. USCG has also published a summary of facts available on the USCG website. Lots of new (and some shocking) information being revealed in the hearings.

[@hnrwagner]

woah great news thanks

[@catface3473]

This video starte.d with a plea for money from a well known children's hospital on my phone...I gave to the charity...my info was promptly sold elsewhere...I received over 60 different beggers in the mail several times each..it has taken me months to slow it down and my time and money...I now only donate to one or two and only anonamously...watch out...😢

[@reynoldkissling7159]

Now that images and footage of the wreckage have been made public, and indicate that the failure occurred near the front of the vessel towards the bottom of the titanium ring, pushing the remaining contents towards the back titanium dome, would you consider crafting a new simulation to reflect the new data?

[@mer9706]

Wow, they severely flubbed the FEA! Great investigation.

[@hnrwagner]

yes, I wonder who did it

[@mer9706]

@@hnrwagner This is the reason I got out of aircraft maintenance. Too many sleepless nights wondering if I missed something.

[@wobblyboost]

@@hnrwagner They sacked and sued the engineer that told them much, much, much more testing was needed on the Titan prototype before selling tickets, forcing him to sign an NDA.

[@engineerncook6138]

​@@hnrwagner 2017 shell was analyzed with COMSOL/M by Spencer Composites who also fabricated it. 2020 shell was analyzed by Collier Aerospace with their HyperX software, fabrication by others. Given their customer base, I doubt HyperX is optimized for thick walled vessels at 60MPa external pressure.

[@j.heilig7239]

Why can’t you get your AI voice (stolen from a famous British actor, btw) to learn the difference between “wound” (an injury) and “wound” (past tense of “wind” - as in to wind a watch)? It’s supremely irritating to listen to crap like this.

[@mathtonight1084]

I love living in an era where we can get David Attenborough to narrate literally anything

[@hnrwagner]

same here

[@aperitifs]

What about the lithium batteries going into thermal runaway after the alarm went off, due to pushing the thrusters too hard in panic .

[@Kivancli79]

The video being narrated by Gandalf was a nice touch 🧙‍♂

[@danielfrancis3660]

My thoughts go out to those who died in the ocean gate implosion and their families and friends. There is a bit of ‘being wise after the event’ so this is just a few of my thoughts. I’m a former structural engineer working on various components including pressurised vessels. An engineering design will typically start off with a set of high level customer requirements ie An oceanic submersible vehicle, Self propelled, Carry a maximum of 6 passengers, a design life of X, capable of retaining its structural under an external design pressure of 50 MPa etc. In terms of design life and external pressure requirements this will require a material choice. Let us say that choice was a carbon fibre composite material. Material choice along with an initial design will enable us to carry out an initial structural analysis to establish a basic vessel thickness. Hold on, do we enough about the behaviour of carbon fibre composite stress vs strain behaviour under external pressure? Can the FEA code model this appropriately?. At this point it may be appropriate to initiate a material test program to establish constitutive behaviour. The point is there is a lot to consider in the design process and aspects of this seems to have been neglected at a guess.

[@hnrwagner]

@@danielfrancis3660 great and thoughtful comment, thanks

[@fiets38]

The AI voice was really annoying

[@gregorylammers8024]

Since the release of new video showing the destroyed Titan Submersible on the ocean floor, will you create an updated version of events from what is seen?

[@hnrwagner]

I have an update video in preparation for 17.10.2024

[@gregorylammers8024]

@@hnrwagner Thank you!

[@vastaria5247]

didnt they release the weight frame? that looked largely unaffected when raised to surface.

[@dondavis5633]

Your voice selection was a bit off the mark, with an irritating "squeaky-denture S" and mispronunciation of the word "wound," as in "He wound his watch." UGH!

[@i-love-comountains3850]

Enough missed words and phrases that I'm beginning to wonder if it's ole chatGPT 🤔

[@i-love-comountains3850]

3:36 ZERO PEOPLE call it Tie-tan-eye-nam what the whole frick???😂😂😂😂😂

[@Zarcondeegrissom]

yeah, I doubt David Attenborough actually read this script, definitely a lisp computer voice thing.

[@glennllewellyn7369]

Your tears are extra salty.

[@JediBuddhist]

I get your drift. But somehow a dottery old British professor somehow sounds forgivable compared to American A-Intellarations which sound more ignorant if that's the right word. LOLCANO :)

[@Tom-zy6ke]

Absolutely fascinating, the best video I've seen yet and the tongue in cheek interview with Stockton Rush was great. I would be interested in your views regarding the joints where the CFRP is joined to the end caps / Titanium rings as a source of weakness as the latest evidence seems to suggest that this may be where the failure started. I have seen video of Titan CFRP being wound but ONLY around the circumference of the pressure vessel and never longitudinally. Do we know if there was any longitudinal winding on Titan?

[@hnrwagner]

@@Tom-zy6ke i will update the video regarding the interface and also longitudinal cfrp fibers i have video material of it. Also thanks for the comment

[@maureenwalsh4305]

@@hnrwagnerAlso, do you know what type of tool was used to cut off both ends of the CFRP?

[@RodCornholio]

An expensive fish food maker.

[@LordSandwichII]

It would be interesting to see a follow-up video with any corrections now that the footage of the wreckage has been released.

[@tomm21]

Didn't make it past a minute and a half because of the lazy decision to use a cheap-fake computer-generated voice to read a script that wasn't proofread in the slightest.

[@hnrwagner]

your loss, it was peer-reviewed 2 times

[@mikhailiagacesa3406]

Algorithm.

[@hnrwagner]

thanks

[@toweleeielite]

remarkably accurate from the video of the debris! excellent work!

[@hnrwagner]

thanks

[@gregvassilakos]

The commentary glosses over the debonding/delamination failure mode shown in the slide at 4:26. The bending test shown at 3:28 shows debonding occurring at the right-hand end of the specimen. Take a pad of paper and push on the edges to place it in compression. The pages will buckle individually and separate. This likely happened as the Titan submerged. With every submergence cycle, the debonds propagated. That may have been the cracking that the occupants heard.

[@acb9896]

That old "woonded teeta neeumm" will get ya every time, I tell ya. Strange how Sir David cant seem to pronounce very common words in The Queens. Odd, that.

[@user-rs1fo2dd9b]

i love professors with a sense of humor, your students are blessed

[@ananayjoshi]

Hi dr, wagner, is it possible for you to tell how to write a umat for superelastic materials? there seems to a lot less content on that on yt

[@hnrwagner]

have only this one here kzbin.info/www/bejne/pXTHhqmujdRgrMksi=dDj5t5bz5HTt89Xt

[@Flea-Flicker]

This was a well presented video. I remember the day it went bang down there and watched the TV for days for good news but it never came. I must say, the part with the orangatan sawing wood and pounding nails had me busting a gut laughing. I agree, that is about the size of it. I watched James Cameron's dive to the deepest part of the ocean and the Titan looked like a toy made by inexperienced teenagers. The whole thing was cobbled together. The joystick by bluetooth there was no real equipment on board to speak of and a millionaire's smug and cavalier attitude cost the lives of all those onboard. When I saw they glued on the end caps it looked like someone glued two ping poing balls on the end of a toilet paper tube and sent it to the abyss.

[@DragonatorTrends]

What if something crashed into them under sea did ull ever think of that,then the hull got damaged which couldve caused the implosion

[@marcusjackson5837]

So they forced you to remove certain videos huh?

[@hnrwagner]

Who is they? and no no one forced me

[@marcusjackson5837]

@@hnrwagner YT for some reason made you disappeared from search engine, now that ur channel is searchable again, it just happen that the other vids related to the O.G. accident are gone from ur channel.

[@hnrwagner]

@@marcusjackson5837 AH ok now I know what you mean, yes this all happened as I released a video on the 911 attacks, afterwards all my videos were gone or hidden somehow, very strange, what is going on

[@wobblyboost]

@@hnrwagner lol yes, Mr. Stockton was born with the silver spoon to a family with a lot of connections to people in, well let's just say clubs we'll never be invited to. Folks that would well outrank YT CEO in the pecking order. ;)

[@thomasloper1205]

For what the pressure vessel must have cost to build, why not make it titanium in the first place?

[@FastTheFood]

The fact the recently images from the wreck shows something similar to this... amazing.