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

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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
This video was sponsored by Brilliant, I am disclosing that I have included a link to Brilliants products on this site and that I will earn an affiliate commission.
Google Scholar:
scholar.google.de/citations?u...
Researchgate:
www.researchgate.net/profile/...
OrcID:
orcid.org/my-orcid?orcid=0000...
GitHub:
github.com/hnrwagner
ABAQUS like FREE to use FEA Software:
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#oceangate #titanic #implosion

[@hnrwagner]

To try everything Brilliant has to offer-free-for a full 30 days, visit brilliant.org/RonaldWagner. You’ll also get 20% off an annual premium subscription.

[@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

[@farminky]

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.

[@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!

[@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

[@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

[@linuxuberuser]

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.

[@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.

[@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.

[@_andre99]

Excellent point. This whole thing is inhomogeneous and anisotropic. There will be bending at the CFC-Ti interface, this should be easy to calculate analytically. But another thing that I wonder about is this: Pushing on a string, alright, but here we have concentric circles of string, so if the outermost large circle of string moves 1 mm radially inwards, then there will be a certain amount of "pushing" corresponding to that, leading to buckling, but also the innermost, smallest circle of string now would experience much more "pushing" along the circular direction, because the radius is lower. So there would be more buckling. But not so fast: The pressure differential is spread over the wall thickness in some way, some UNKNOWN way, so those smallest circles of string may experience less delta pressure, and thus less buckling commensurate to their smaller diameter. This can get complicated.... Anybody have some ideas here?

[@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.

[@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.

[@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)

[@user-gi7vi9gm4t]

@@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"

[@dysfunctional_vet]

your interview with stockton was amazing.....

[@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.

[@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

[@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.

[@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)

[@_andre99]

Lol, well, they should have had a safe space for the wounded CF.

[@wobblyboost]

They should apply a compress to the wound.

[@Rietto]

TTS outed itself?

[@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!!!

[@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.

[@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.

[@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.

[@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.

[@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

[@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

[@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!

[@marcusott2973]

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

[@hnrwagner]

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

[@silver_surfer88]

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

[@hnrwagner]

glad you like it

[@headshot6959]

Well done for getting David Attenborough to narrate this.

[@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

[@_andre99]

P*V= n *k*T ideal gas law: So if you reduce V by a factor of 100, T goes up by a factor of 100, so from 300 Kelvin to 30,000 Kelvin. Thats if you compress it by 100, so from 5 cubic meters, down to 0.05 cubic meters, or 50 liters. My car has 4.6 liters of displacement. if we compress it to 5 liters, T = 300,000 Kelvin. Ideal gas law. But this assumes that P stays constant. For an isentropic process, where P and T are changing: T2/T1 = (V2/V1)^(1-gamma), so therefore delta T will be smaller than in the above example. en.wikipedia.org/wiki/Ideal_gas_law In reality it cant be calculated easily, because of inhomogeneities. It goes to infinity in a perfect spherical implosion. Look at sonoluminescence en.wikipedia.org/wiki/Sonoluminescence and cavitation.

[@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

[@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.

[@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.

[@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?

[@aperitifs]

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

[@hnrwagner]

what do you think would happen?

[@aperitifs]

@@hnrwagner lithium battery fires worldwide, why not here too.. massive battery packs inside and outside the titan . It rings true.

[@TheNemorosa]

The interviews with Rush were very enlightening.

[@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.😅

[@ThatGuy-ot1gt]

The David Attenborough bit killed me. 😂

[@copisetic1104]

Being inside a pressure chamber when it collapses is like being inside a diesel engine cylinder at a thousand atmospheres

[@tngtacticalmiata1219]

When I first heard about this and started looking into the design I seriously couldn't believe it. I thought someone was pulling some kind of prank or something. I'm not an engineer... But, I'm not stupid either. 5 minutes of research into the material properties made it obvious what was going to happen. Unreal....

[@assistantto007]

These artificial voices used for narration are getting better and better

[@hnrwagner]

Yes, thanks for the comment

[@reginawagnerbiolife7867]

Good job!

[@hnrwagner]

Thanks

[@Spasiboy]

That is comprehensive. Thank You for Your work.

[@hnrwagner]

thanks

[@user-rs1fo2dd9b]

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

[@joblo341]

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

[@chackken]

Brilliant collab, good for you! Gratz!

[@mxcollin95]

I remember several news outlets reported that some human remains were found, however they never said anything more than that.

[@psychojetenjoyer4678]

I'll watch it later but thanks for this original piece of art - I suppose you can call it like that

[@JediBuddhist]

Pros and Cons aside thanks for the upload.. its definitely worth it for Attenborough interview with SR. Brilliant!

[@hnrwagner]

thanks, I think we will similar interviews with David in the future

[@LichaelMewis]

Excellent video.

[@rubenbam]

It is so simple to understand: it's like putting pressure on a shoestring. No I don't mean hanging a load on a string. I mean press on a string. It will not take any force....

[@jenelle6132]

This is hilarious, and also educational. Love it!

[@AlexanderTzalumen]

Even under atmospheric pressure, cylinders drawn to near vacuum implode in a near instant once failure begins, so it's unsurprising that the Titan crushed even faster than that. The detailed background for the engineering makes the failure inevitable.

[@gemvac]

Beautiful video!!

[@abcde_fz]

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

[@WilliamHarbert69]

Brilliant.

[@hnrwagner]

yes

[@imacomputer1234]

Sorry, couldn't finish, the whistling was driving me nuts!

[@jasonkeating9958]

It's crazy that he even considering continuing with the same carbon fibre centre hull section especially as the 1st hull started deteriorating from pressure cycles and wear and tear plus the natural break down of the fibre layers and apoxy, Cosider the cost of the hull vs safe number of uses and use the word safe very loosely, How much was the cost of 2 carbon hulls with the obvious 3rd hull that would need manufacturing if they had survived, Also the most critical thing to remember is how simple this hull design was, It had no hatch to allow entry and exit and no windows and almost no complicated systems at all, Because it's literally just a plain tube connected to the 2 titanium bulkheads that's just connected by bolts this has to be the most simple submarine hull in modern history, it's literally a tube that's bolted to 2 titanium end caps in reality, This simple beyond belief tube would have been so easy and cheap in comparison to be made from titanium and would only be made once, I think that he probably spent more on the 2 carbon hulls than it would have cost to make it of titanium because of the basic machine would needed, And i definitely would have been cheaper had they survived with the upcoming 3rd hull, If anyone who reads this and has knowledge of titanium tube prices of a piece this size vs 2x carbon please let me know.

[@waterishdrake8693]

Wow you really crushed it!

[@fridaycaliforniaa236]

Also the fact that the only thing that held the CFRP tube to the titanium domes was some random glue, applied by hand (!). Not quite sure that the many inside/outside diving cycles in cold and salt waters were a good thing for something so fragile as a polymer. Stockton Crush knew his white diving pill was never gonna last long...

[@steveo601]

Trying to bond a titanium ring with Pippi Longstocking super gluer to a titanium ring, in a dusty building is suicidal for a pressure vessel trying to hold against 6000 psi.

[@Robert08010]

Here is an engineering question from a non-engineer: Buoyancy is all about the weight of the water the vessel displaces. I believe the "weight" of the water is affected by the depth of the sub. So what I am curious about is: how buoyancy is affected if that sub compresses even slightly? Particularly if it is compressing more and more as the dive proceeds. This question arose from the fact that the transcript of the dive indicates the sub was descending faster than planned BUT MORE THAN THAT, it was accelerating downward - even to a point the ship sounded concerned. This implies to me that the buoyancy was changing as the sub was diving. So what I am wondering is, might the hull have compressed enough to actually change the subs buoyancy? I'm under the impression that they were under pretty tight tolerances re buoyancy right from the beginning.

[@noradlark167]

This is very hard to answer without a detailed model. But my best guess is "No". The vehicle would be designed so that it would be very stiff and there would be very little compression before the implosion. Water also compresses very little. However, depth of submarines are controlled by pumping and dumping water into the vehicle (ballast tanks spesifically) to change its buoyancy. So, it is way more likely that they had some sort of leak in their ballast tanks.

[@Robert08010]

@@noradlark167 I don't believe the Titan had ballast tanks. It certainly was not a submarine in the traditional sense. It was supposed to be balanced between the weight of the passengers and ballast to descend but slowly. Then the ballast weights could be dropped when it was time to rise. They could also jettison "the frame" if necessary. This was supposed to insure they could always just float back up to the top no matter what went wrong. But their accelerating while descending implies something was changing about their buoyancy. That's why I suggested what I did. There are reports from other trips of LOUD noises happening - shotgun like noises. So that is why I am curious about a possible slow deformation of the hull leading up to implosion. I wish I understood the math behind buoyancy to calculate how the buoyancy would be affected if the hull deflected by even 1 mm.

[@ForensicCats]

Thank you for posting, I enjoyed the sawing "monkey"😅 ... A.I. voice is amazing. Congratulations on your sponsorship.

[@hnrwagner]

Thanks, yes one can make funny stuff with AI, I will try to make more of this kind in the future, the world needs more fun its serious enough

[@ForensicCats]

@@hnrwagner agreed, humor is also medicine against a broom up our arses. haha

[@aerotube7291]

'tiny pieces of game controller nestled.....'. that is great work.

[@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.

[@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. 👍

[@_andre99]

I think this is also plausible and consistent with the undamaged endcaps. We can have the window disappear and endcaps remain mostly stationary, or we could have the CFC implode radially, too fast, so the endcaps also remain mostly stationary.

[@_andre99]

However, in the window failure scenario, one would expect the destruction of the CFC to be less dramatic, less violent, so there might be remains of the CFC to be found. But it says that none were found. So that point speaks against the theory. However, we dont know how the details look and how long they searched, and what size of fragment they could resolve.

[@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?

[@alexanderchapman2525]

Once again, Herr Dr., excellent work. Best wishes for your Oktober presentation.

[@Dr_Do-Little]

One thing that baffle is I just recently learn they had numerous issues with previous pressure vessels. Like many i was lead to believe they scored successes all the way up to the fatal implosion. They had issues with their earlier subs and this was Titan's second pressure vessel. I'm getting to the point where I think Rush knew far too well one of these trip would soon be his last.

[@johnshaw359]

He prolly needed at least 10ft CF walls if he wasn't going to bother testing it.

[@steveo601]

10 feet😂😂😂😆😆. Well , it looks like he was cracking through at least 1/4 inch per dive so at least it would have lasted a little longer😂. Also the ring flanges needed to overlap outside and inside by about 15 inches. His Malignant narcissism and ego killed 5 people.

[@steveo601]

The story was explosive content. The physicists were under pressure to get the math right. Did they come close to cracking??

[@blurglide]

I'd think the cause is modulus differences between the CFRP and Ti. The CFRP wanted to contract, but the Ti wouldn't let it.

[@Balazs227]

Would horizontal bracing between the two hemispheres help?

[@hnrwagner]

cant say for sure but I think it would help. But then is less space for passengers I think

[@Bollibompa]

Why did you private your old videos on this topic?

[@hnrwagner]

they are partially outdated and wrong

[@kellyj1464]

I want to make sure you know, there is a substantial amount of audio distortion/clipping at the simulated implosion section of the video starting at 16:40. I'm not sure what you were doing there but you'll want to review your procedure.

[@_andre99]

If the implosion had happened as suggested by the simulation, then there should be two more or less flattened and fused together titanium endcaps. Because they have mass and inertia and after being accelerated violently along the cylindrical axis over a distance of a few meters, they meet and are instantly decelerated to v=0, massive forces and this deceleration should leave marks. But none are visible. Also: It seems highly unlikely that the CFC would buckle OUTWARDS as shown in the simulation.

[@oatlord]

I thought there's footage of the end caps being found. No windows.

[@wobblyboost]

It's really an implosion detonated explosion, the whole cycle is 6 milliseconds, the water rushes in to the 1 atmosphere air void with immense force in a fraction of a millisecond, super compressing the air which then heats up, (commenters here much smarter than me calculating approx1500 C), and expands with the 4.3 cubic meters of air and resultant super-heated steam throwing a compression wave of 1 ton of TNT. They would have heard it by ear onboard the launch vessel and most likely seen or even felt an upswell on the surface. I believe the simulation is only showing the initial buckling. The CFC shell would have shattered to dust, the titanium cylinder fragmented to sub mm particles and anything inside atomised. I can't wait to learn how far apart the endcaps were found. Stockton did not report an explosion, if he had it would have saved millions on the 3 day search for survivors.

[@nereanim]

If only the Titan was designed as a 5 dives maximum life limited sub with full replacement of the carbon fiber component, Rush could have pulled this off as a viable commercial operation.

[@jacklunsford7528]

Is David Attenborough narrating this?! Best lecture ever

[@folk.]

Probably Attenborough AI voice

[@jacklunsford7528]

@@folk. i didn’t think of that 🤔. I guess another case of, if it’s too good to be true…

[@gate7clamp]

11:19 lol I didn’t expect that part

[@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.

[@simonl7784]

AIttenbourogh... A fan-favourite to accompany a good meme.

[@aztec0112]

10:48 Savage, but fair!

[@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.

[@opium32]

5:22 wound rhymes with "bound" when it's the past tense of "wind" (as in fibre)

[@aarenfourever]

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

[@askhowiknow5527]

If I designed a submarine it would have support structures inside you’d have to straddle making it super claustrophobic.

[@maxenielsen]

Great presentation, Dr. Wagner. I would just as much have enjoyed your great English narration. Your English is far better than my German! Any chance the public will ever see the wreckage? Marks and scratches in the titanium end caps would tell us a lot about how the implosion progressed. That they still looked (from what little I’ve seen) hemispherical might suggest that the carbon fiber cylinder was nearly completely imploded before they started moving. I think your sim shows that. Thank you!

[@MichaelCasey1988]

Im interested in the Hexmersible

[@dcfromthev]

Good ol Stockton Crush.

[@DavidProper-f2r]

I've only read a few comments down, so forgive me if I repeat another's. As someone who has peer-reviewed papers on almost exclusively medical topics, one thing I "dinged' the author for, every time and without fail, was spelling errors. Someone should always proof-read a paper, essay, letter, anything that will be read by another, especially those whose job it is to identify not only errors of research and testing of a hypothesis, but also grammatical and spelling errors. How much do you "love your baby," as we call it, if you make mistakes that go uncorrected? So far, and I am literally at the 0.05 timestamp, I see that the word "acrylic" is spelled "aryclic." [sic] Since we live in a world where spell check has been ubiquitous for decades, it's simply inexcusable to present any work that another will see that contains errors of this nature. Even as I type this, my own machine's spell check wants to correct the intentional mistake I made by misspelling your own. Please, proofread your work before presenting it to SAMPE. I guarantee these types of errors will not go unnoticed, and though you may not be submitting for publication, and I somehow feel you are, it will still leave a bad taste in the mouth. I look forward to the rest of your video, as I am sure the science itself will be presentable, whether or not it is sound. Good luck to you. JDSMDPhD Addendum: At ca. 17:30, while demonstrating TNT equivalence in pressure gradients, did you mean to say "tons," or "metric (tonnes) or "tons?" As there is a difference. J

[@hnrwagner]

Thanks for the comment, I checked it for spelling errors and didn't find all of them. The video was sent for peer review 2 times. I hope you enjoyed it nevertheless.

[@DavidProper-f2r]

@@hnrwagner Very much so. your data was excellent.

[@theultimatereductionist7592]

And THERE'S that famous British humor! 10:26

[@felixcat9318]

When the wreckage was being craned off the recovery ship it could clearly be seen that the viewing port glazing was not in place, and that a lifting strap was actually passed through the viewing port aperture! I wonder if the viewing port was the point of failure. The bodies of the people aboard the stricken DSV would have literally come apart due to the magnitude of the implosion and would not have remained intact to allow for recovery to take place.

[@calummorrison6094]

The bait with the baboon He should consider you in comedy as well. 😂😂

[@unvergebeneid]

KZbin should be ashamed that something like this video, which to me clearly constitutes investigative journalism, is hindered by its copyright policy.

[@hnrwagner]

yes, I uploaded the video 10 times with different edits of the clip in which he said "safety is a pure waste" and always I got a copyright warning

[@unvergebeneid]

@@hnrwagner I mean, you might have gotten away with disputing the claim but this whole process is stacked against fair use so I don't think KZbin can get away with this excuse.

[@TMS5100]

The way the AI voice generator mispronounces stuff is as amusing as the interview with stockton rush.

[@wesleyashley99]

Carbon fiber has great tension strength but not good compression strength. There are ways to use high tension strength material to increase compression strength of other material but it has to be oriented differently. Imagine setting up a cylinder of concrete to compress on its axis. Now wrap it in circles around the outside with carbon fiber. Now the concrete will be stronger in compression because it can't spread out without stretching the carbon fiber. Building a geodesic of such wrapped cylinders might make a good internal frame for a high pressure sub but you still have to cover it with something to resist pressure in all the openings of the geodesic. Even though this may work in theory, the internal material may have enough room to fracture until it becomes fluid allowing the carbon fiber to lose it's wrapping orientation. Any new designs for something going that deep in the ocean needs a lot of testing before putting people in it because it's very hard to be sure the high pressure water won't eventually find a way to get in.

[@dragonball-dragonatoraa8395]

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

[@theultimatereductionist7592]

They didn't bring enough Duck Tape. Well there's your problem.

[@jannikheidemann3805]

3:35 What is "Titaninum"?

[@staffeyxneyx8420]

6 milliseconds, that's crazy

[@numbercrunched]

i wouldn't be surprised if Rusha or China made a sub this way.

[@mikebuck3252]

The search for the sub was a sham. It took 8 hours to report it missing. They knew it imploded that is alot of pressure being ejected from that sub. Hell the ship probably felt it. Def heard it

[@brigidsingleton1596]

I doubt Sir David would say "math"!! He's English... He can talk proper like what I does!!😊🏴󠁧󠁢󠁥󠁮󠁧󠁿

[@randylahey1232]

This AI narrator is trying to mimic David attenborough