OCEANGATE Titan's FATAL FLAW Identified - But Does It Make Sense?

[@slim-yin]

The pressure on the external of the end cap would have kept the cylinder sealed to it . I think the carbon collapsed !

[@SciHeartJourney]

You're thinking like that pressure was just pushing the end-caps onto the hull, but the hull itself was subjected to being collapsed by the pressure from the sides. The epoxy (glue) that held on the end-caps could have been compromised there. Once is started caving in, it didn't take long to fail totally.

[@slim-yin]

@@SciHeartJourney Yes , I agree , But if the carbon was not compromised it would not have crushed and left the rings in tact !

[@SG-dg6oi]

And you got your PhD in engineering from the Facebook University of Engineering!??

[@RealButcher]

Yess, of course! ❤

[@joesaiditstrue]

According to this gentleman in the video, the fatigue from submerging/ascending to the surface caused the carbon fiber hull's bond (to the end cap) to weaken. Yes, the pressure at depth does compress the end caps to the hull itself. But you need more than water pressure to keep the caps bonded to the hull. They used a glue/resin as the bonding agent. But the expansion/compression cycles caused the bond to weaken and water to slowly seep past the glue and sheered the cap flush off

[@johnscustomsaws]

Im definitely NO engineer... but working with carbon fiber and different metals for a living makes me wonder WHY ANYONE thought using 2 vastly different materials in a pressure vessel was a good idea. I have to think that "cost" was the reason they did not use titanium throughout...

[@mikemiller659]

of course

[@mementomori4972]

They did testing with carbon fiber domes in the beginning and all tests failed. It's not that they used two different materials, but that they used a material which degrades with every pressure cycle. The best they could do in testing was x1.18 full depth before catastrophic failure. I can't believe that Stockton Rush wasn't aware that it would fail at some point. It's delusional. The reason they didn't use titanium, is because it's three times heavier than carbon fiber, which of course would lead to problems with buoyancy.

[@dominicm2175]

@@johnscustomsaws I believe I read that weight was an issue, and that using carbon fiber was the only material that would give the submersible positive buoyancy

[@philshorten3221]

The American Navy also made a test vessel that was Titanium end caps with a Carbon Fibre Cylinder. I don't know what happened to it, but the Titan wasn't the first to try this general configuration. However as far as we know, the American Navy did NOT start building manned submersibles with a Titanium / Carbon Fibre mix. I assume their test results are all "classified".

[@philshorten3221]

If as suggested it was the Glue that failed, and NOT the Carbon, I don't understand why the Carbon would have collapsed into the rear end cap? Surely if just the glue failed ultra high pressure water would have blasted in, almost instantaneously filling the sub and if anything, I would expect a "rebound" to blow the carbon out, not in. Afterall, the Titanium and Glue wasn't their to prevent the Carbon collapsing, so if you removed the glue the Carbon should maintain itd shape. It looks like the Carbon failed and at that moment it happened to tear itself away from the front ring but probably could just as easily gone the other way. With the air space acting more like a complete vacuum, everything got "sucked" into the rear end cap. The front end would then be blasted out, the Window blasted out, and the shock wave would throw off the tail section. I don't think the glue "failed", it simply wasn't strong enough to keep hold of any of the collapsing Carbon. So I think the Carbon ripped itself away from the Titanium. Cause of death - Arrogance.

[@CatBuddha]

Part of the problem with the glue could also be from the lack of a clean room for application. The people applying it weren't even wearing head gear to prevent stray hairs. Several times people were touching the surface with bare hands, which leave oils. All it takes is one tiny flaw, or all it took.

[@kristofvandycke6687]

I’ve cooked dinners with more attention to detail and contamination than those jokers did.

[@CKing-388]

It would be so hard to get that glue 100% even in all spots. That’s why most pressure vessels are one solid medium. Like all titanium.

[@iro6758]

@@kristofvandycke6687 That video is so mind-blowing. I pad printed for years (think putting logos on T-shirts or pens) And we practiced better "clean room" etiquette than they did, even down to gloves. If the room temperature goes above around 80 degrees(iirc) the hardener goes wonky, below 60(iirc) and the thinner goes wonky - and any particulates in the air can visibly screw up a print. (can mix with ink, and with static literally moves ink around - and static is a common issue because of the nature of that style of printing) TLDR; T-shirts are made with higher standards, than the Titan Sub. It's actually crazy how literal and serious I'm being when I say that.

[@bogdiworksV2]

@iro i believe you 😂 i still got a t-shirt i bought off a stall in Camden Market for £5 in 2007. Ink is still there, at least 200 washes later and i wasn't particularly kind to a £5 shirt, even though I'm very fond of it. Good work, that screen printer. I have more up market t-shirts that have not held up nearly as well.

[@alexandros8361]

And believe it or not, there are also lots of AI nanotechnology elastic fibres / hairworms floating around everywhere. That seem like hairs, fluff, cotton etc. And they can actively break apart almost anything.

[@SarahWRah]

As a complete layperson, I had been appalled at the young, inexperienced team that applied the glue during fabrication, with no apparent quality control. Now that I hear testimony, I'm increasintly surprised the Titan sub survived any dive events before the final implosion.

[@rtqii]

I saw all kinds of problems... Using a dirty rag to wipe the metal, there were ungloved hands touching parts. The glue was hand mixed with a thickening agent and had not been degassed in a vacuum...

[@SciHeartJourney]

@@rtqii thank you for pointing out the lack of a vacuum pump on that epoxy! I also noticed how dumb that was. I do a lot of reading on this, and they all mention using a vacuum system to de-gass the epoxy. That pump is hurdle for the hobbiest, like myself.

[@paulsimmonds2030]

The guy that was filmed wiping the titanium ring with a cloth was also putting his bare hands on it and transferring sweat and grease onto the metal. And why was the titanium so smooth where glue was to be applied. Shouldn’t it have been roughened somewhat to give a key to the adhesive?

[@digitaurus]

@@rtqii I believe the video to which you are referring is not for the construction of this version of Titan but for the previous one. I don't believe they made a video of the second version which may or may not have been more professionally fabricated, I don't know.

[@Eyewonder3210]

It's glue. Glue is not a magic unbreakable seal to anything. It's just glue. The faith in it that I have witnessed throughout my life has been a puzzle to me. But who am I to argue with anyone about their faith in glue?

[@oxyfee6486]

The catastrophic failure was named Stockton Rush.

[@BRITISH87PATRIOT]

Your absolutely spot on mate 👍 👌

[@earth0128]

[@scottdelong1]

Good one Sam.

[@joefish6091]

He did have helpful minions.

[@bogdiworksV2]

I agree, after listening to these depositions or whatever they are, it sounds to me like the vessel was shoddily built and was coming apart from all sides for quite a while before the implosion. There were a lot of enablers involved but ultimately it was up to SR to have reasonable standards and insist on a quality build, neither of which he did, instead flying by the seat of his pants and hoping he was smarter than the laws of physics. These "wiz kid" types ultimately get high on their own supply of hype.

[@louiefrancuz3282]

The original assumption that the Titan failed mid span was logical considering the initial infomation and evidence. Now a failure at the forward joint makes more sense. The epoxy wasn’t applied under clean room conditions and wasn’t adequately cured to ensure there were no voids. Voids were the key flaw. The forward joint had to support the swinging end cap causing an eccentric load on the ring. Titan was stored outdoors in Nova Scotia and any water trapped in the voids would subject the joint to freeze/thaw damage. Towing in rough North Atlantic conditions would cause the much denser and heavier end cap to shake and overload the epoxy joint. Finally, in service, the mid span of the carbon fiber hull could slightly relieve itself by deflecting inward due to the pressure but the carbon fiber attached to the ring could not causing a stress concentration there causing the inelastic carbon fiber to fail. There was so much cyclic activity applied to the forward epoxy joint hastening the possibility of degradation and ultimate failure.

[@joefish6091]

and the horrendous road trips on a flat bed truck, strapped down by the skid, shaken to pieces. the pictures of it sitting in the parking lot show the support frame horizontals bowed upwards.

[@keithposter5543]

Exactly. The hemispheres weighed ~3500lbs IIRC.

[@mistermatix8241]

@@louiefrancuz3282 You got to ask..... WHY WERE THEY USING EPOXY GLUE IN THE FIRST PLACE? NO OTHER DEEPSEA SUBMERSIBLE USES THAT CONSTRUCTION METHODOLOGY.....AND THEY'RE STILL HERE

[@forgogeorge9806]

Very brilliant 👏 way !! You described it what probably happened to this doomed Submersible which looks very poorly designed? Put together! Very carelessly.

[@spookshow6999]

It doesn't matter how it was put on. The whole design was flawed.

[@Roger_and_the_Goose]

I've probably said this before, but using glue and resin with carbon fibre/fibreglass on such a vessel is utterly stupid. Resin of any description when cured is inflexible or ridgid. They were relying wholly on the strength of the resin. Adding on top of this, leaving Titan out in the elements with temperatures getting to below zero, will cause major problems with any resin. The engineering team on Titan had little to no understanding or experience in grasping these concepts and doing little to no testing was ultimately it's downfall.

[@gottanikoncamera]

I’m not an engineer or science guy but as a mountain biker, our general sense is you want to retire your carbon fiber handlebars after a few years because you don’t want them failing at the wrong time. So it astounds me that people would even consider it as a material for such a high pressure application. Then again, perhaps we’ve been wrong to replace our carbon handlebars and frames so hastily.

[@TravisBrady-wn8fr]

I retrofitted a septic tank with saran wrapped interior and an old Atari joystick for mobility. Two motors off junk I robots turn my Nerf propellers. I'm off to the Mariana trench.

[@blu3622]

I'm dying😅

[@brandyl2183]

lol 😂

[@joefish6091]

Stockon Rush's first lake submersible was made from a large propane tank.

[@TravisBrady-wn8fr]

@joefish6091 that sounds more sturdy than the Titan design

[@mistermatix8241]

@@TravisBrady-wn8fr you got the job, kid! When can you start? Welcome to OceanGate! The place where the terms "bodge" and "botching" mean Progressive Thinking! Who needs those stupid "precision" Titanium parts when chewing gum and duct tape will suffice! A gap in a vital seal? Shove a few cut up playing cards in there! It'll do!

[@PaulTaylor1]

When you've been conditioned for years by Stockton Rush never to say anything negative about the use of carbon fibre on the Titan... it becomes easier to say nothing at all.

[@msrobynlee456]

@@PaulTaylor1 Cos he will shoot you down every time. Hes right, were wrong, and look where it got him and 4 other innocent lives taken over his stupidity. He was warned so many times and ignored everybody.

[@raumshen9298]

The carbon fibre didn't fail isn't it?

[@msrobynlee456]

@@raumshen9298 The whole thing failed. Who in their right mind would build a Submersible out of Carbon fibre? Stockton Rush did and was advised by so many people to not build it and he refused to listen. He thought he knew everything and knew better. OMG, 🤦‍♀️ I wouldn’t board anything that’s not sea worthy and hasn’t passed all inspections and sea trials. The fact that it was sitting out in the harsh elements of the Carpark at OCEAN GATE would be enough to weaken the entire system. You know yourself if you leave something out in the sun long enough it becomes weak and brittle, and that’s what would’ve happened to the Titan Submersible.

[@marinamccogan5251]

Or easier to lie

[@TommyKing-m3f]

It was most definitely the glue brother. The bond held on the back end. It came off clean all the way around on the front hatch. That hemisphere is heavy af. I’m sure that didn’t help either. Everytime they opened it it would put insane amounts of leverage on that glue as well. Then they stopped using the sling and started picking the whole craft up by the titanium rings as well. Just crazy. Stockton was careless. That’s clear.

[@TCRS]

The Coast Guard don't seem to think so. And trust OceanGate to defend carbon fiber to the last man.

[@smokejaguarsix7757]

Just curious...point out the carbon hull in the pics? Dont say its attached to the back, thats the bottom metal hull and flooring. You dont see it. Why? Its shattered all over the ocean floor. Thats what all thise little black chunks are scattered around. If it was just the glue the water would have just popped that back off and shot through the cylinder, not blown out the acrylic porthole. Also, where is that pesky porthole. Sure, its acrylic but it couldnt have gone far. Yet...they cant find it? Well, you cant.find something like that if its shattered.

[@gunt-her]

I think the glue's a red herring to distract from the carbon fiber (horrible material for this application). a) you can't rely on glue to hold a pressure vessel together b) I think water cut into the glue until it reached the carbon fiber ends, then delaminated it from the front end, weakening it and allowing the clean shear. c) It's specifically the properties of carbon fiber that allow this "failure of the glue". How poorly the glue was applied wouldn't matter one bit with a titanium cylinder, as there would be no micro-imperfections for the water to cut through, and the pressure would hold the ends on as ocean gate's calculations predicted.

[@Flowersofromance6-fs4pb]

Well, the navy use glue in nuclear sub construction. One of those odd facts like them also using games controllers. Better glue, and glue better applied obvs, but it can't actually be treated as an outlandish concept.

[@smokejaguarsix7757]

@@Flowersofromance6-fs4pb glue is used on planes and ships and in construction of buildings in Egypt that have lasted thousands if years. I listened to a lot of that testimony and it struck me that the NTSB and Coasties werent buying what Oceangate's witness was selling. Bottom line, its not in oceangates best interest to admit the carbon fiber failed.

[@majik-k8j]

You cannot glue to plastic. Carbon fibre flexes, titanium ring stays rigid. X number of compression/ decompression the joint fails.

[@j81851]

Exactly. Equilibrium of pressure applied to the entire vessel (not just the ends OR the middle) will find the weakest link.

[@dougaschenbrenner802]

Right- when safety is the priority. It's been well established that Mr. Rush was clearly infatuated with the money end of it, more than any real safety.

[@sunsetlane3924]

Dragging it behind a ship for 400 miles in the rough seas can't be good for the sub.

[@joefish6091]

Nor the road trips on a flatbed.

[@Sam-gw5pl]

Bonding two different materials together with glue under that kind of pressure, is always going to fail.

[@NalaRichenbach]

Rush said it was like peanut butter.

[@Sam-gw5pl]

@@NalaRichenbach not great then.

[@420styletomatoes6]

​@@NalaRichenbach Rush said a lot of things, most of them have come back to bite him in the butt.

[@Sam-gw5pl]

@@420styletomatoes6more than that, it killed him.

[@420styletomatoes6]

@@Sam-gw5pl it certainly did

[@TheOne-pv4rz]

I think both the glue and carbon hull had cyclical fatigue. There were no tests done if the carbon and titanium rings would act differently from eachother under those extreme pressures or not. Most engineers agree they would most likely act differently unless they tested it properly to find the right configuration which they didn't do. Also I heard an expert say that the surface on the ring was smooth which is not ideal for glue as it's much stronger if there's some texture to hold onto. So the breach happened somewhere in the front section as the implosion pushed everything to the back dome which we can see in the vid. If the viewport was the failure then there should have been some acrylic debris in the back dome I would imagine, but they didn't find anything. This increases the chance that the breach happened somewhere else and the viewport was blown out in the other direction (the front) from the counter force of the implosion which makes sense.

[@57Jimmy]

Can you imagine just what kind of force would be required to blow it out and not yet be found?😮

[@kmetze]

"There were no tests done if the carbon and titanium rings would act differently from eachother under those extreme pressures or not." I think this is called 'Young's Modulus'. The values for both carbon fibre and titanium are known: 200 to 500GPa and 120GPa respectively. Carbon fibre is easier to compress than titanium. So the diameter of the carbon fibre tube would get smaller than the titanium domes. The glue would have to make up for that difference. Either by expanding or taking the stress. I don't know which. At least, that is my limited understanding :)

[@rtqii]

Watch the OceanGate video of the assembly of one of the titanium rings to one end of the carbon fiber cylinder. This assembly was not clean when the glue was applied. The glue had been hand mixed with a thickening agent, not machine mixed, and it had not been degassed in a vacuum prior to application. The glue failed.

[@johnwright291]

I agree. These people were obviously arm chair sub builders jumped to high places. It was very amateurish.

[@mikemiller659]

Epoxy

[@gunt-her]

You can't rely on glue to hold a pressure vessel together like that full stop.

[@trayjosass]

Interesting ty

[@lordvlygar2963]

The ring was also almost a mirror finish where the glue was applied and the application was in a non-sterile environment.

[@GeorgeExpat-o2j]

doing epoxies and so on for a living, I was shocked about the way this has been glued. Highly thixotropic adhesive mixed by hand, applied by hand, no excess coming out of the ring, mixing and application at normal pressure (why you use vacuum chambers ???), no clean environment, no hairnets, gloves.....

[@gunt-her]

I don't blame the glue, you can't rely on glue to hold a pressure vessel together. Probably it failed around that point, but it failed because the joint relied on the glue to stay together, rather than a geometry that eliminates tension forces, which are the cause of the cyclic fatigue accumulation in the glue. There's a reason why everyone else uses the sphere (think Roman arches, same principle), the geometry keeps the craft/structure together under load, rather than bolts and glue which become a weakpoint. And I'm not excusing the carbon fiber. I postulate that as the CF flexed under load, water worked it's way through the glue joint, creating micro channels between the glue/CF interface, eventually making it to the longitudinal end of the CF/titanium interface and working it's way into imperfections in the carbon fiber, resulting in sufficient delamination of the CF at the interface to trigger

[@lordvlygar2963]

@@gunt-her The carbon fiber was applied two different ways. Straight fibers that were already pre-glued, and circular fibers that were glued after application. That second one is called wet layup. In wet layup, bubbles form in the resin as it is applied, leaving plenty of room for cavitation and water to enter the fibers.

[@hicksrobin42]

Epoxy needs a surface that's roughed up to 'grab' on to. Watching the videos on the assembly of Titan, the titanium ring surface is perfectly smooth, combined with the flexing of carbon-fiber, you're playing Russian Roulette.

[@chrisward4576]

I think he's right, Hydraulic pressure is equal in every direction. The carbon fiber collapsed. 8 Million pounds of pressure overall. The safest and most reliable shape is a sphere. Just like the LIMITING FACTOR

[@Guardianapophis]

i am a mechanical engineer and no matter the material i worked with, a glued connection was always the weak point. Sure they should not say hey that's it because one guy said it. But i think with the Titanium Ring and what he discovered there it kind of makes sense. Also the pieces in the wreckage, like they were shot in this one direction could be an indicator, so i think he was correct because also his explanation totally makes sense.

[@torben777]

The debris field (as far as we can see it on pictures) supports his analysis. The failures had to happen at the forward dome to push all the debris into the aft dome. If it was the carbon fibre as such, it would tend to happen in the middle of the carbon fibre tube, which is the weak spot. Also, all experts I have seen comment on this point to the joining of carbon fibre and titanium as the weak spot, because the two materials do not expant and subtrack the same under pressure, which again points to the place where they are joined, which is where it was glued.

[@robinmiller5256]

These titan defenders should have to make another vessel just like the one that imploded, with 4 dummies and all, send it down with cameras and see what happens. Just a thought..recreate the scene.

[@57Jimmy]

And I hope the 4 dummies you refer to are the real ones who put it together!

[@patrickmccarthy4089]

There is some good analysis from a year ago, mostly by engineers -- presented professionally. I believe the simulated computer rendering of the implosion of the pressure vessel shown in this video has been dismissed as unlikely by some of those same engineers, a year back and now. And, to repeat myself, for those condemning carbon fiber for submersibles again I will point to the AUSS, the Advanced Unmanned Search System built by the US Navy with titanium end caps and a main body of carbon fiber, launched in 1983 after 12 years of research and development, capable to dive depths to 20,000 feet. It made 114 dives, is 17' x 31" with a weight 2800 lbs. Granted unmanned. And obviously OceanGate did not have the budget of the US Navy, but there was a precedent to a successful carbon fiber/titanium submersible. And when you view the analysis of those experienced joining titanium to carbon fiber, and all the critical requirements for that joint to hold, I believe it's likely that faulty inadequate glue joints doomed the Titan.

[@flipflopski2951]

Size is the biggest factor here. Comparing a 31" unmanned robot to Titan is ridiculous...

[@patrickmccarthy4089]

​@@flipflopski2951Mentioned to point to a precedent in submersible construct. And yes certainly a difference, like a torpedo to a minivan. In the future will differ to you for comparisons of size. PMc

[@duanemansel5704]

If the glue fails, and the interface ring is sheared off on the inside of the socket, this guy is absolutely correct. I disagree with you

[@bstar777777]

I agree. If you listen to the fired engineer he said that the glue application was horrific (gaps and glue lines) and other experts have said this is not a proper way to mate carbon fiber with titanium.

[@suestreet9934]

And Tony Nissan commented on the glue being less flexible than he was happy with. The uni guys weren’t happy about the lack of consideration of the titanium / carbon fibre system. It was always a recognised risk that caused alarm.

[@brent57]

I think if the glue fails, the carbon fiber interface ring would not be in the socket. Glued joints should be stronger than the surrounding material. And if there isn't chunks of carbon fiber inside the titanium ring where the CF interfaces and adheres to the dome, then I believe the glued joint failed.

[@smokejaguarsix7757]

@@duanemansel5704 except if you look at the wreckage you'll see the front and end rings are shoved together at the back of the Titan. That means he is probably not in fact correct. I noticed they didnt ask him questions about his opinion here. Why? Because they already know the answers. These hearings are official oublic inquiries but thry have already done the majority of the investigation. This is them putting these people's responses on the record. They dont ask questions they dont already know the answers to. To put it another way, this is like when an attorney asks questions in court. They are getting the responses in the record. They are not generally trying to get new info from them. They are putting it on record. Thats where people get into trouble, they try to outwit the investigators and do some CYA but they already have the answers. They are letting people jam themselves up.

[@smokejaguarsix7757]

@@brent57 well, if its shattered the glue isnt going to hold it either, not at that depth. When carbon shatters like that theres nothing for the glue to hold...like holding sand. Its not gonna stick. Im sure youve seen glass glued to metal before when it shatters the glue wont hold it either. Also, they used straps tied around the ring to raise it. Those loose ropes could have easily scraped the inside clean of any residual carbon fiber as the ring rotated.

[@merphul]

There's no reason that the glue and the use of carbon fiber were both potential factors for failure. Carbon fiber being strong under tension but not compression is a factor. The differential in compression of titanium vs carbon fiber is a factor. Joining parts, particularly parts of different materials usually introduces a point of weakness. Having materials held together with only glue is another potential point of failure. The seams between domes and cylinder are an inherent weak point combined with joining 2 different materials. The shell was always a potential area of failure but the joins were a somewhat riskier point of failure. Glue being the only thing to compensate for the compression differential makes that weak point that much weaker.

[@hellonearth9347]

Looking at the footage the front dome is clean off and the back dome has everything pushed into it. So its the front part thats failed not the middle of the hull.

[@arthurwilnow9795]

In UK, there is a popular confectionary called 'Smarties', sold in cardboard tubes with recessed cardboard endcap , and plastic lid insert. As kids, it was quite a fun trick to reclose the empty tube, hold it in palm of hand, smash down other fist, firing the plastic lid across the room. Catterson essentially describes the same process.

[@johndefalque5061]

I love that karl Stanley interview with ACE, McCallum also tried to warn everyone as well as Lockridge. With these three sounding the horn-HTF could Rush get away with it? Rings, glue, differential materials, delamination, port window, tipping point steep descent, loss of contact, so many possibilities of failure. The arrogance, hubris and recklessness of Rush himself.

[@doliver5447]

Saying they knew nothing of danger and didn’t suffer is just denial by a person involved. They probably heard tons of noise, like on previous dives, and were deeply fearful. That counts as suffering, sir.

[@Mr.Blonde92]

Yea im sick of hearing that they knew nothing and heard nothing, some are basing that just on the comms from that day, like who trusts this company to tell the truth first off? I dont believe anything they say, i think they knew within the last 1 minute and definitely heard crakcing etc

[@toddkurzbard]

I am in no way a deep-sea submersible expert, but I HAVE been studying the TITANIC for about 45 years, and the wreck since it was found, so I've learned some amount of rudimentary knowledge (when the news about the TITAN first broke, when it had only just "disappeared", my very first reaction was, "it imploded"). I say, IMO, he is telling the truth. I believe him. Yes, I know he's (was?) a representative of the company, but, to me at least, it all makes sense. It's pretty much the conclusion I would have analyzed with my limited knowledge.

[@johnh1932]

This is a nightmare scenario, esp for the teenager. My instinct is that they did have an inkling that this was about to happen and the last 5 miinutes were like 5 yrs of sheer terror.

[@MrShobar]

Please await the final report. None of the witnesses have any firm analysis to support a particular theory of failure. The recovered remains will tell the story. I suspect that the NTSB (experts at failure analysis) will formulate a pausible theory.

[@ttrev007]

but it is fun to guess. But, i do hope they are able to definitely determine the cause. so many possibilities

[@AlexanderMcNally-c1p]

I believe it failed at the forward ring. He had said that it was clean. If the hull of carbon fibre had collapsed it wouldn’t have pulled clean away( I believe)! It would have ripped apart like the aft end of the titan! A few people have commented on how the area when gluing was not sterile and on video you can see one of the team rubbing it down with a cloth and touching it with his other hand, with no glove. Any oil on that face with that amount of pressure would have eventually had a catastrophic impact on the craft!

[@SoloSailing77]

The word flexing is probably not the best word to use. He is talking more about the entire cylinder being compressed. When it compressed it would pull at glue inside that end ring. When watch the video when they glue the rings on, the metal looked shiny and smooth. It that was the case, the glue didn't have much to grip to. If the glue didn't fail, then there would still be pieces of carbon fiber or glue remnants still inside the ring. The ring where it WAS glued, was clean and shiny when it came up. So, yes he is right. Look at the rear ring, and you see black carbon still inside the rear ring. If the glue didn't fail, then there would still be some in there. Once I understood flexing was compression it makes perfect sense. Like wrapping something around the end and squeezing.

[@LadyHeathersLair]

Just as in airplane crashes, investigators say there is always more than one reason, I don’t think there was only one reason for this. Carbon fiber? Glue? Two different materials? How it was piloted? Me:all of the above! JMO.

[@paulsimmonds2030]

Personally, I believe there were multiple reasons for the catastrophic failure. Trying to mate titanium with carbon fibre was a bad choice. They both react differently to changes to both the pressure cycle and temperature. This would have lead to the glue falling. Also, the carbon fibre was past its use by date and I believe was wound wrongly to form the pressure tube. The pressure cycle would have caused fatigue due to delamination of the carbon fibre layers. The Titan was on borrowed time the first moment it entered the water.

[@Skankhunter420]

The viewport was made to be completely clear in water. It will be essentially invisible forever now.

[@dorbie]

Yes it makes sense. It's actually similar to the Space Shuttle Challenger SRB segment failure but with the opposite flexion. I speculated that this was a likely failure mode a year ago. It's one witness though and based on his initial observations so it's not conclusive. The evenly sheared flange all the way around is compelling evidence.

[@rehabmax]

Can you imagine if Boeing glued the wings on a 737 ? What could go wrong ?

[@lordvlygar2963]

It seems that the difference in material strain caused the failure at the bow ring. It could be the failure of the glue, it could be the failure of the carbon fiber at the interface, it could be both. The wreckage shows little doubt that the implosion started at that spot. What is surprising is how tight the wreckage is, meaning that the implosion happened much closer to the floor than the moment they lost communication. I really hope to see a reconstruction video showing the wreckage in reverse back up to it being whole. I think that will answer most of the questions that are left. We have most of the data: the rate of descent every minute, pressure on the sub, location of the sub at last communication, placement of the wreckage, and angles of the wreckage hitting the floor.

[@dworkin7110]

There is really no reason, without physical evidence to analyse, to assume that Ketterson is wrong about the glue being the problem. He is suggesting the the carbon fibre cylinder flexed from the middle out which makes sense. He then says this flexing creates a cantilever effect on the titanium ring which WILL flex the glue joint (it just has to be true even if it didn't fail because of this flexing). He goes on to say that the ring split off in one go - no carbon left attached and this must have happened in micro seconds otherwise it wouldn't "pop" off cleanly.. This makes sense too.. Whether he is actually correct is another matter entirely. However, the whole thing is ridiculous. Whilst the US navy had been testing submersibles with carbon fibre compostites there is no way this poorly tested vessel should have undertaken these missions with civilians on board.

[@griffia]

The glue line and the interface between the carbon and ring is likely the place where the smallest amounts of deformation and delamination would have the most effec, suddenly only a few layers of carbon are attached to the glue and not 5 inches. Add that in with the bangs and the force applied to the ring when the front bell sheares off its bolts.

[@kathleenbarton3981]

Thank you so much for your coverage of this catastrophic event. I will be anxious to hear what Karl Stanley says in his upcoming testimony. Previously, he has identified the

[@kathleenbarton3981]

Contd...carbon fiber hull as the fatal flaw.

[@ramair3judge]

There were several things that were experimental. The glue was just one of them. The carbon fiber is the most obvious. I think it started to delaminate on every dive. I also think it was layered up in a incorrect manner when they made it. I don't think there was great enough cross hatch pattern as the fibers were wound. They basically wound the fibers like thread on a spool with minimal cross hatch. They also use rhino liner to coat the exterior as an additional measure to seal things up. They were basically going broke and needed investors (passengers) to finance operations as they went along.

[@birgittabirgersdatter8082]

The glue idea makes perfect sense. Titanium and carbon fibre do not shrink and stretch at the same rate. Glue fatigue makes sense.

[@johncmitchell4941]

I agree that the front dome must have sheared completely in a microsecond. See the pile of CF chunks crammed against the back dome, with all but the floor apparently crushed to the rear by the inrush of water. We hear that not much of the hull was strewn vs still attached. Not a stretch to think the tail cone broke off from the jolt. The viewing dome would be secured against outside pressure vs from inside. The violent inrush as the break occurred might have just popped it out forward.

[@RunningInLondon]

Thanks for these summaries! The lives happen when I work and I don't have enough time to watch them. Appreciate it.

[@ordinaryman2299]

what are you talking about this dude is completely right !!! it collapsed at the front and bent and twisted and shoved all the remaining parts toward the back of the craft !!!

[@user-lk2qf4rt3m]

"About one hour into the dive, the Titan sent a message at a depth of 3,346m that would be its last. The crew communicated it had dropped two weights." - BBC news. Correct me if I'm wrong but if the sub was descending, why would it have dropped weights? Surely this is done in order to ascend? Maybe I'm incorrect. But if the weights were being dropped doesn't that indicate they were attempting to ascend?

[@TCRS]

It could, but it seems the weights were dropped to slow the descent, since they were almost at their destination depth-wise.

[@GWNorth-db8vn]

@@TCRS - Trimming the buoyancy must have been an interesting set of math problems. Water actually does compress with pressure, so at Titanic depth the water is about 4% more dense than at the surface. An object that's neutrally buoyant at the surface will have positive buoyancy at depth as it displaces a greater mass of water. Titan must have had a flotation tank to keep it neutral near the surface, then flooded it to sink with enough extra weight to reach the bottom, then dumped ballast to achieve a new neutral trim for the depth. They had to dump a lot of ballast to get enough positive buoyancy to reach the surface. If they didn't dump enough, the sub would hit a depth where it was in equilibrium and wouldn't rise any higher. James Cameron was on a dive in a Russian submersible where they got stuck at 80 feet below the surface for hours before the pilot realized there was an emergency ballast he could drop.

[@dawnanderson4967]

They were descending too fast, that’s why they dropped the weights. The truth will come out eventually.😒

[@GWNorth-db8vn]

@@dawnanderson4967 - It's routine.

[@mikemiller659]

slow decent

[@andrewtaylor940]

The joining of the Titanium rings to the hull has always clearly been the weakest link in this entire series of poor engineering. At those joints front and rear there was a direct channel for the full water pressure of the ocean depth. This channel was only blocked by the glue they used. Using any disparate materials as part of the pressure hull for a deep ocean submersible has always been a key point of failure. Because the three (four) materials used in these joinings have different expansion/contraction characteristics and behave differently to temperature and pressure changes. You had the titanium, the carbon fiber, the carbon fiber resin, and the industrial glue used to attach them. Further a failure of that joint would perfectly explain the wreckage found. The glue joint failed totally. It was reported that the glue facing surface on the recovered titanium ring was perfectly, almost surgically clean. The glue completely lost adhesion to the metal. When this happened the pressure wave entered the sub all around the circumference of the hull. Resulting in three waves of force. From the point of the glue joint were pressure waves blasting forward and rearward within the sub. Blasting the window outwards and knocking the front dome free of its rings. Going rearward are two forces. One is pushing straight rearward, sweeping everything in the sub towards the rear dome. At the same time the outside pressure pressing inwards is causing the now unsupported front edge of the carbon fiber hull to fail and roll inwards and rearward. Once the front titanium ring detached everything behind it folded itself up into the rear dome.

[@garabaldimmm2875]

He is correct. The dome had previously fallen off when the submersible was inadvertently dropped according to other testimony. In addition the rear dome which is clearly visible in the underwater video has carbon fiber fragments still attached to it. Why would the other dome come up with no debris attached if the glue hadn’t failed

[@maegenyoungs2591]

Also if there was a void and it separated, and air was in there, It probably propagated pushing the air along that. But the coast guard thinks it started with the dome swinging open. And stressing the ring. It weighed almost a ton. That much weight hanging it broke the bond. It was designed for pressure not pull. That dome hanging off the front of the vessel. He said the glue because he was told when it bent the hinges. I believe he is correct. Remember they have data. Good or bad they looked at it for days. But to say they didn’t see it. I think the last person to get crushed. Stockton. Did. But never had a chance for his heartbeat to change or realize what happened. That’s enough for me.. And we still don’t know what they heard just before.

[@spookshow6999]

Yes. It's common sense. But i don't believe they didn't know it was coming. The whole thing was flawed. The whole thing. They tried to abort.

[@bills6093]

I think the viewport is a critical piece that needs to be located. We can see that everything has been shoved into the rear titanium end cap, so we know the failure was likely towards the front.

[@jdaniel3068]

Ronald Wagner had some professional engineering simulations from a year ago showing the 3 scenarios for the implosion. The glued rings were one of the runs, and the entire video is fantastic.

[@jessicaarce7803]

Thank You! Watching that next.

[@jdaniel3068]

@jessicaarce7803 he has quite a few good videos. I'm not an engineer, so it took some pausing and rewatching, but great simulations nonetheless.

[@sallyb7472]

Well why would that have happened… they glued incompatible materials together with who knows what without the benefit of a clean room.

[@metal--babble346]

During the previous dive before the tragic implosion, the recovery barge for Titan partially sank. The submersible was getting pounded by rough seas, and slamming into the platform for approximately 1 hour. This Oceangate contractor shrugged his shoulders, and claimed it was no big deal.

[@Greatdome99]

The Ti and the GREP didn't flex at the same rate, so cracks at their interface would develop on each dive.

[@justaviewer111]

Cyclical fatigue of the glue makes sense. Many others have mentioned cyclical fatigue of the carbon fibre itself which makes even more sense to me. I'm guessing the failure began where the carbon fibre attached to the forward titanium ring. Look how clean that ring was and how the channel was blown clean off.

[@ashghinn4630]

It makes sense to me that the immediate failure point during the implosion was the inner lip of the forward titanium ring. Once the adhesive at that interface had been seriously weakened by cyclic loading, the lip would be taking far too much load at depth. In the Oceangate video showing an interface ring being lowered onto the the carbon fibre hull during manufacture, that lip only looks a few millimetres thick. The sheer stresses on that lip on each dive would be enormous, so I would love to hear expert analysis of the damage to that sheered lip .

[@roberta.6399]

That thing was nothing more than a toy built by backyard mechanics. To put people in it was criminal.

[@girlingoldboots5273]

Glad you went back and listened to Tym's testimony, I certainly found it one of the most enlightening so far.

[@eastbrecht]

I guess the carbon bends but the glue cracks first. Next step high pressure water sips into cracks and acts as lubricant. The rest is physics.

[@whiteroseangel1511]

Happy Sunday, all!! Thanks for covering this story impeccably, Nick! Give Timmy scratches! 🙏😇😎🐕‍🦺🐈‍⬛

[@BrianPseivaD]

You need to get a DJ to produce a remix from your theme tune…….you have a number 1 EDM track on your hands!

[@Inletwatcher1965]

+ Reminds me of David Bowie

[@kentuckwhite6701]

Even if the glue failed, the pressure of the surrounding water is 'pushing' the end cap and the carbon fiber 'tube' together, so the carbon fiber had to fail, correct? OR was the carbon fiber glued INSIDE of the end cap?? If so, the carbon fiber should have been glued on the OUTSIDE of the end cap, that way the surrounding pressure would push them together. Reversely, if the carbon fiber was glued inside of the end cap, then a glue failure is very likely, which also makes this a carbon fiber failure because of it's contraction which broke away from the glued end cap.

[@wally7856]

At depth the water pressure is about 6,000 psi, that would put about 15,000,000 pounds force on each end cap inwards. To me, the glue's sole purpose was to hold the thing together on the surface. Not even necessary once at depth.

[@gunt-her]

Correct. Glue is a red herring.

[@kentuckwhite6701]

@@wally7856 But my point is that the pressure 'pushes' the two together, so glue is not needed. The force is pushing inward, not pulling outward.

[@wally7856]

@@kentuckwhite6701 Yup. 15 million pounds pushing in on each end. That's why I said the glue was only needed on the surface to hold the ends on. Underwater it wasn't necessary except maybe to act as a gasket.

[@sandyfoot]

I agree with glue failure. The carbon fibre flexing was predicted but Rush said the glue would be enough to maintain the interface between the difference in flexing of the carbon fibre tube and the steel rim of the viewing window. The mistake was the use of different materials for the hull and the steel caps without a suitable interface that could accommodate two incompatible amounts of flexing. It was the weak spot. It explains why it sheared off.

[@FlorianGeyer210]

I am no engineer but from seeing the remains of the wreck I am inclined to believe that the carbon fibre mid section failed due to the pressure.

[@Flowersofromance6-fs4pb]

Apart from anything, it's always got me how much could you actually see anyway, 5 of you crammed in there peering through a little porthole. You can obviously see much more, including inside the ship, from the drone type footage available for some years. I think there's an element of feeling special, entitled in having 'the experience'.and don't doubt it's highly atmospheric down there. But still, that one portable - how much could they actually see for real.

[@kentuckwhite6701]

No one will ever know what really happened, but there is a possibility that the sub lost control and the weight shifted to one end as it plummeted deeper to the bottom of the ocean. All of the occupants would fall to the front end of the sub's interior and possibly even in total darkness. Panic would have set in as the sub sank too deeply and too quickly and then imploded. No matter what happened, we can almost all agree that when it finally did implode, none of them had time to know or feel it.

[@christophercripps7639]

Based upon: (1) what others (“OEs” other experts) who sound like they know enough of what they are saying to be trusted; this conclusion is based upon what I know about materials science & engineering ( have Bachelor of Mechanical Engineering Engineering); (2) these OEs have noted the differing elastic and thermal expansion characteristic and differing failure modes of titanium and carbon fiber reinforced resin composite (CFRRC); (3) Catterson’s testimony; and (4) examination of the wreckage footage here’s my opinion: Under repeated compression and thermal cycles the “glue” allowed water to infiltrate between the end edge of the CFRRC cylinder and the titanium (Ti) ring. The hull itself may also have experienced delamination elsewhere. The water began to delaminate the CFRRC between the layers. Once a crack reached a *critical crack length* the crack propagates virtually instantaneously (ar or above the speed of sound in the material). The final critical crack may join up with other delaminated sections. The pressure of the water: >blows some of the hull CFRRC outward (the debris seen to the left of the wreckage at 4:19) - this debris had water infiltration between it and the hull interior; >blows/rushes inwards and forward blasting the forward dome and acrylic view port off - this sheared off the rim of the firward Ti ring at the ringCFRRC hull interface/joint (Catterson testimony); >along with the radial inward pressure on the sides of the hull rolls up and compresses most of the CFRRC hull into the aft dome-ring. (Imagine wrapping your hand around a paper cup at the open end then squeeze it inward while pressing down on the base; the sides will be crushed into the base.) The occupants may have heard or not some groaning or creaking; but Rush seems to “normalized” such sounds. The acoustic monitoring IMO was of no use because the time between any failure detection (& alarm) and implosion was too short for the brain to process. *OEs say CFRRC behave as brittle materials in failure. Even a small scratch/crack can lead to instantaneous failure. Window glass is brittle can be snapped with a small scoring line. Ti is more ductile and once a fatigue crack reaches a critical length the crack propagates instantly.

[@Longjohnsilver58]

Geez. This entire argument is kind of absurd. Anyplace on the hull could have failed anywhere, and when it failed it would go all at once. The glue connecting the hull to the caps was a weak point. The port hole was a weak point. The whole vehicle was a collective failure. IF you have a well engineered vehicle, then you might be able to nail it down but this vehicle had multiple critical failures😊.

[@madonnabuiter733]

I'm not an engineer but my significant other is and aerospace engineer. He agrees with the analysts who point to a failure of the seal of the forward dome - whether it's the glue or not but the forward end cap clearly was blown clear of the main field and the carbon cylinder was pushed into the aft dome as it collapsed as a result of rapid, catastrophic failure of the forward dome seal. If the centre of the carbon cylinder failed, not the seal to the forward end cap you would expect the carbon fibre fragments to be distributed between both end caps not the majority shoved into the aft end cap.

[@rustyheckler8766]

If not the glue, but the torsion between the titanium ring and the carbon fiber. I guess the question is, is there carbon fiber hull left in the titanium ring channel? If there is than it sheared clean, hull failure and a magnified stress area. If that channel was clean, like it was popped right off, than that would lean towards an adhesive failure at a magnified point of stress.

[@spacecat3198]

Whether it was the carbon fiber cyclic fatigue or glue it failed at the front. There were a lot of factors not just the carbon fiber but how the sub was treated, it was exposed to the elements for a long while, towed, repeated dives, lack of testing, crashing, platform malfunction, just so many factors. A previous CF tube had shown cracks near the front. The implosion started there and pushed everything towards the back.

[@JosephBoxmeyer-u3d]

I have had experience with engine gasket failure. Those gaskets assure closure between two machined metal parts. Sometimes it is merely failure of the gasket material. Sometimes it is due to the head warping . But the Titan's glue bonded two very dissimilar materials, where there were not bolts to exert the primary joinder. Also that testimony was probably correct that some flexing of the carbon fiber body stressed the glue. I would have preferred to machine the two titanium end rings with drilled flanges on inside and outside. And then run many solid rods the full length inside and outside of the cylindrical cabin, of course threaded on both ends to be fastened with nuts. The end rings would need to be quadruple the present thickness and much larger. Perhaps "O" rings should enhance the seal on the outside. But the joinder of two so dissimilar materials is never the first choice, especially due to such contrasted behavior from temperature, pressure, interaction from stresses. With the tight shimming between such long bolts and the carbon fiber body flexing of the body might be minimized. We are probably thinking about such bolts being centered at four inch spacing.

[@purplehayes5718]

I believe the glue and the thin inner flange of the end ring that the carbon fiber fits into were to blame. What I would like to know is did that flange sheer off. All of the pressure on the carbon fiber was transferred onto that thin titanium flange that appears to be about 13mm or 1/2 inch thick. As the circumference of the carbon fiber body was reduced from the pressure, the diameter at both ends glued inside the Titanium ring did not. That enormous pressure would be transferred from the carbon fiber body to the 13mm or 1/2 inch thick ring flange. What a horrible design. Edited: I found a photo of the forward ring that I was talking about, it's in the KZbin video below. At 1:37 into the video, you will see the forward ring and two titanium ribbons of steel one to the left and one to the right of the ring these will be the titanium inner flange I described three days ago I have no doubt this is the failure point of the Titan sub. I don't know why this is not being mentioned. Are they trying to hide it? kzbin.info/www/bejne/hoK3gY2hhtd1q6s

[@joek511]

I think his assertion is extremely accurate. Why? Physics and construction. The forward ring only had about 1 inch of inset for the carbon fiber. The rear had about 6 inches . As the middle compressed the forward glue would have more deflection due to the limited insert. That deflection would for the most part be uniform around the entire radius. It would fail first. As soon as it failed, the forward section of the CF would have crushed inward and toward the rear. As seen 4:20, CF packed into the rear At the same time the air in the nose would have been compressed forward. Hitting the view port from the inside and blowing it out. Shearing off the bolts in the retaining ring . A bullet from a gun barrel. Where is it? In one piece, on the bottom, clear plexiglass , like dropping clear glass in a glass full of water. You can't see it but it's there. Add to that the sediment , you could be looking right at it but only see the sediment it sits on. Invisible

[@anthonynapolitano9061]

As an M.E. (with zero experience in submersibles I NOTE) from videos of the construction along with the videos of the wreckage, my first thoughts go to #2 things. #1 - I question the amount of "Purchase" the Titanium dome had with the CFRP cylinder - it appeared insufficient. #2 - given it appears that a majority of the CFRP was jammed into one of the partially attached domes, while the other titanium ring came up clean leads me to believe the Glue failed! Just my opinion!

[@jlvandat69]

Extremely high probability that the epoxy interface will be identified as the source of failure. That joint was challenged by multiple forces. Besides the "cyclic fatigue" mentioned, due to very minor flexing in the CF shell, the joint was also subjected to mostly shearing forces due to the differences in mechanical properties between Titanium and CF. These 2 materials expand and contract at different, albeit minor degrees when subjected to temperature and pressure changes. Additionally, it's been determined there was potentially damaging vibration on the joint when the vessel was transported. IMO, cracks and possibly delamination in the epoxy developed and at extreme pressure one of these created an opening large enough for full intrusion = immediate, catastrophic failure of the Titanium/CF joint. We'll see.

[@thurin84]

the fatal flaw in the operation was mr dunning kruger, stockton rush. the fatal flaw in the sub was the use of reject carbon fiber glued to the titanium flanges. im no engineer but i know enough about the stresses involved to have made changes to the design to make it more durable. 1 do not use 2nd hand reject carbon fiber, 2. dont wind the fiber in only 1 direction. alternate between verticle, diagonal, and horizontal 3 give the hull a much more tapered cigar shape to direct the stresses better 4 wind the fibrer AROUND AND OVER flanges on the titanium domes that extend inward a significant amount so that the compression stresses would made a tigher seal between the carbon fiber and the titanium. have the domes be all 1 piece. ingress couldve been through a hatch made out of the viewport similar to other deep sea submersibles. it still wouldve eventually fail due to the limitations of carbon fiber where compression stresses are concerned, but it wouldve been a more durable design than titan.

[@57Jimmy]

Let’s see… Carbon Fibre… Titanium… Bonding Glue… All put together in not much more than a backyard garage as facilities go… 4-5000psi over how many Cycles?… Three dissimilar products coming together with an overlap of what..4-6 inches? Stupid is as stupid does😢

[@gunt-her]

I think he's partly right, but the glue is a red herring. I postulate high pressure water cut through the glue until it reaches the ends of the carbon fiber cylinder, where it starts cutting into the fiber, causing delamination from the front end. Of course given enough dives it would fail eventually anyway, presumably around the midpoint as per the calculations. So if I'm correct, it's actually worse, because it failed before most of us predicted.

[@forgogeorge9806]

Very good narrative!! Well explained good presentation !! Bravo 👏👍!!!

[@miguelmartins7577]

There is another issue with the joints forgotten, the "peanut butter video" was made when they applied the joints to the first Carbon Fiber Hull (Spencer Composites) , the hull failed in 2020 and was replaced by the imploded, that was made by Electro Impact, Stockton order to use the same titanium domes, so they could have become damaged removing the old hull from them...

[@GWNorth-db8vn]

I'd like to see some analysis of whether the carbon fiber imploding might have pulled the glue off the metal rather than the glue failing and causing the implosion. If the tube cracked , the shards would be moving at supersonic speed within a millisecond, and the bond between the glue and metal would have been weaker than between the glue and carbon fiber. There'd be more mechanical bonding with the roughness of the tube than the smooth metal of the ring.

[@MariaPetrescu]

The key is apparently in the difference between what the front and back titanium domes look like. Had the implosion started because of a failure in the carbon fibre hull, it would be reasonable to expect both domes to look the same. But, from what the testimony tells us, they don't.

[@GWNorth-db8vn]

@@MariaPetrescu - I think it was a cascade of failures with many factors. Delamination of the tube, cyclic fatigue in the epoxy both at the joint in inside the carbon fiber material, water infiltration of joints and tube, separation of the glue from the metal, mechanical hard points with a built-in weak point in the undercuts. The whole thing is a collection of questionable decisions.

[@MariaPetrescu]

@@GWNorth-db8vn oh, absolutely! I suppose we can only follow the rest of the hearings and see what official conclusion is reached.

[@gmdyt1]

It makes sense. The cf cylinder was fitted into the ring. The materials had different compression values. The glue on the outer flange failed, then the inner flange failed

[@randomami8176]

The glue. I’m not sure if this dismantle the theory kept until now about the carbon fiber skull, OR, if it was a combination of both. In any case, just to the host of this video about “what we think”: I’m not scientist to this level of deep knowledge of physics and chemistry, so I’ll be super simplistic. Yesterday I heard something dropping in the basement and it was a canvas (light ,maybe 3 lbs) picture that fell. It was hanged with one of those heavy duty adhesive hooks (up to 35Lb). The picture been there for more than 3 years, yet when I saw the hook, it’s glueing capability has been degraded so much it didn’t even made damage to the wall when it broke, it just simply fell down. It was probably environmental (humidity, heat, whatever)… My point being that it is quite possible this was the case, or at least one of them. IMO.

[@deltasyn7434]

Basically, the carbon fibre hull is essentially what's on trial. Rush did alot of things to sideskirt U.S. laws and regulations due to the carbon fibre hull. Furthermore, it is the one component where Rush most misrepresented the truth. So, I think alot of this comes down If OceanGate lackeys can assign blame to another component or contributing factor, the Ocean can theoretically reduce their liability in the case. If they can somehow prove that it wasn't the carbon fibre hull, then they could lessen their charges.

[@Queenskid19]

I agree the viewport was made to seal from the outside so when it imploded it shot out like a bullet im sure. And its Clear you will never find it.

[@iitzfizz]

"Let the public know that nobody was suffering in there, they were probably happy" That's an insult to the families.

[@ryancraig2795]

If the first point of failure was the seal between the carbon fibre tube and the forward interface ring, wouldn't you expect to have seen the carbon fibre tube blown out and away, not imploded in? I don't really know, I'll leave it to the experts to figure that one out, if they can. It may never be possible to figure out exactly what the mode of failure was. This is why you don't test experimental designs with people inside them.

[@WishIhadacabinonthemoon]

I agree with the glue, plus seeing the carbon fiber being stuffed to the back of the hull.

[@firestunt]

There's footage of the rear ring that sows the end of the cylinder didn't even touch the glue in places, Another analysis mentions that no Glue squeezed out at all when the front cap was put on. Also, the death may have been instant & painless, but we don't know what they heard before it collapsed.

[@bradleybeauchamp5582]

I agree that the glue wasn't the reason specifically necessarily that the Titan imploded but a combination of the area around where the glue was at. The two very different materials, one being Titanium and the other Carbon Fiber being against each other and glue in between holding them together was more of a problem and a possible cause for the implosion. Those two different materials are going to compress and contract at very different rates. The Titanium being the strongest would have likely caused stress fractures along the edge of the Carbon Fiber as it was compressed into it on each dive. That would have weakened and stretched the glue to a point where water could have eventually made its way into the joint and caused it to fail.

[@nono-wo9ky]

They needed to seal it better than only with 1 type of a sealer 😮

[@lindsayjenions2795]

Glue! Takes the cake! Had this so-called safe sub glued together! Ridiculous! No wonder they all died... going to the bottom of the ocean in a glued together cooldrink can with a window to look through and a computer games thing to control everything!

[@blkcoupequattro]

It's pretty clear that there is more surface area on the carbon fiber hull than the end caps, suggesting that the mechanical forces over came the hull which probably shattered like glass to some degree starting at the lip, the inner lip failure on the end caps sounds like a sound analysis by lead engineer, but it's my belief that ultimately the hull was overcome which started a cascading failure. You can also see in the images how the carbon fiber hull debris was pushed in to the front end cap, popping the door open from the frame, and the window portal being shot out like a unsecured cap on tube of toothpaste. There is reason most deep dive subs are made they way they are, and being said that the US Navy has already tested this type of material in a much deeper situation says they know the inherent risks of using this type of material at those extreem pressures. I'd say this type of design is fine for shallower dives, but it's obviously not perfected yet in it's use or uses at this point.

[@Thor_Asgard_]

the glue definitely had a big role to play, as it was unevenly distributet. Sheer forces caused by this wouldve separated the layers. Water intrusion therefore could lead to the pressure directly applying to lower layers of the hull, as the rhino liner didnt perfectly seal those edges. therefor the implosion most likely started at the front end and sheered off the inner edge clean. But layer separation was a big problem in several dives i bet.

[@GoronCityOfficial]

Odd he said they didn't know yet part of the report suggested the sub tilted oddly. How do we know when dropping the weights the submersible didn't tilt tossing the crew forward moments before implosion