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This whole thing just reminds me of that Futurama joke: "How many atmospheres can the ship withstand?!?" "Well its a space ship, so anywhere between 0 and 1"
The animation of the sub going down and crumpling before it goes up in a huge smokey explosion and shreds into pieces looks like it was outsourced to a high school graphic design class.
A submariner friend once told me the whole “race to the surface and deploy rafts” was just Hollywood. She calmly explained that just getting in a submarine meant accepting your own death.
That's not typically true of a properly designed submarine. That said, yeah, you aren't likely to be able to escape a sub once you're underwater. There are escape trunks on some subs but they are only viable if the depth isn't too great.
@@infernaldaedra The US Coast Guard has inspection and certification requirements for Passenger Carrying Submersible Vessels. Under the 1993 Passenger Vessels Act. Titan was subject to this both for reason of Oceangate being a U.S. Corporation (which they tried to hide by shifting ownership of the sub onto a Bahamanian registered sub corporation), but more importantly the US Coast Guard and NTSB maintains certification authority for Submersibles built in the US. One of the certification requirements is the submersible vessel must have an ingress/egress hatch that is 1 meter above the waterline when floating at the surface. People can get in or out without flooding the sub. Note this applies to vessels that carry Revenue Passengers. Which Oceangate was trying to desperately (and illegally) hide as “Mission Specialists”.
@@andrewtaylor940 Yeah and a hatch still doesn't do anything for you when your more than a few hundred meters depth and would destroy the vessel to open
In my line of work, I am regularly exposed to high-pressure water cutting, and I can unequivocally state that the nozzle plays a pivotal role in the cutting process.
@@JohnSmith-hn1qj Probably not only pressure but also speed of the water. There are diferent designs of the nozzle(like rocket engines) that are made for specific purposes and even accelerating fluid flow. Maybe the nozzle thunderfoot is using just isnt made for fluid velocity
@@robertjusic9097 Or most cheap electric pressure washers are simply weak sauce. Mine is advertised as 3500 psi but it's far weaker than a gas engine powered pressure washer rated at 3k psi
Agreed. The 'wait, what?' moment for me was when the video revealed that the sub's titanium was bonded to the carbon-fiber... with glue. I mean, even as someone who's completely unfamiliar with sub construction, it feels like the people building the sub had better options than _that._ The only thing that might make this make sense for me was hearing from other sources that the people who built the sub allegedly cut corners like crazy.
@@quentincoetzee4313 I'm not sure on what 'glue' they used, but 'glue' is rather strong these days. Lots of expensive cars are glued too. For example you can't weld steel and aluminium together(Even if they are touching you get corrosion which is deadly for any metal object), only way to get that to (safetly) stick together is glue.
@@Ikbenjounietsukkel glue holding two things together from shearing or breaking apart is one thing. Here the problem is, as Phil described, that your glue doesn't matter when an air tight seal isn't air tight at 300 bars; and glue is not gonna fix different deformation rates of metal and polymer
Real engineering has a great video about how composites are a horrible choice for a sub. He did his masters thesis on composite materials so I trust his judgement.
yea which doesnt mean he busted his own theory, its more like the pressure washer is a really cheap model. normaly they dont come with "easy 1 button switch nossle".
I don't think he cares. He made a segment for the 1 meter cubed interior volume and then dove-tailed it with: "Well, if there are any sticklers..." sub volume is closer to 5 meters just multiply... 8:58 I'm not in any way defending Ocean Gateway. Their practices were ridiculous! Thunderf00t is a chemist and not an engineer. Fusing dissimilar materials is not the same thing as a bonded joint. You would be surprised at what critical structural joints get bonded these days. Also, thanks to Poisson's ratio, transverse fibers in composites do carry a load under bulk compression. 21:08 I hope he reconsiders "a whole other video" about that. Not withstanding this was an improper application for a composite but Thunderf00t isn't qualified to explain it. Composites have complicated Mechanics because they are not homogeneous. He's right about needing to match Modulus' as best practice but its not clear if there is an interior flange in the connection. Also, the friction between mating surfaces is considerable due to the pressure on the exterior of the hemisphere. There are several possible failure modes and this is certainly one of them but not the only or even necessarily the most likely. We'll have to wait on the report to know for sure. His videos are entertaining but he's often out of his field...
7@@Ixions TH-camrs have been flocking to this tragedy like sharks and blood in the water. Everyone enjoys pointing out the engineering flaws, but without a detailed timeline of events, the engineering problems are second to pilot error. As far as I know, based on some transcripts that may or may not be true... It sounds like they dived too fast, had an issue, released their ballasts, and then couldn't ascend. Wouldn't be surprised if they collided with a ghost net or even the ocean floor
@@IxionsWhat he's doing is just a simple order of magnitude thought experiment. He's fixing all the values to simpler values that are still the same order of magnitude, just demonstrate the relative magnitude of things. It's a thing he commonly does in all of his videos. Simplifications like that just make it much easier to grasp without having to focus on the math itself. Notice how he was trying to get all the numbers to be multiples of 10 or 100. It's for illustrative purposes.
As a KFC food service worker, I can see that there were probably one or more reasons why the vessel failed: 1 - Poor adhesion in the composite plies; there may have been regions that weren't cured properly or the substrate didn't fully penetrate all of the plies. 2 - Adhesion between the composite plies and the titanium ends failed due to incomplete coverage. 3 - Differential stiffnesses between the titanium and the composite, meaning that there was a difference in material shrinkage across the composite/titanium interface, causing a shear-stress that caused the bond to fail [ You did address this but your demo showed the effects of a difference in thermal expansion coefficients, not stiffness due to pressure loading, although both may be significant and there can be an interaction e.g. if one component isn't that stiff at all, then it can accomodate the differences in thermal expansion but a risk of rupturing a bonded interface is still there. ] 4 - At 20:40 , the worker has his bare hand on the bond interface, which could add grease and compromise the bond strength. 5 - Not only are composites crap in compression, they are also crap in out-of-plane tension, which may occur at the bending loads across the length of the tube due to the water pressure.
@@FireOccator They set a high bar to work for the Colonel. Also had to get security background checks in order to handle the 11 secret herbs and spices and go on 2 years intensive training on the 7-10-7 breading method.
@@lewis72 Nice analysis, I was horrified to see guys on step ladders in and open dusty warehouse hand spooning adhesive on to the titanium interfaces. A very avoidable tragedy, you simply can't gamble with the pressures at 3000+m. it's about brute strength........not computer modelling. sad for those who lost their lives
Appreciate that you left in that failed water jet demonstration. Showing that you're both fallible but also transparent. Admitting your mistakes is one of the most important step ls of the scientific process after all
@@memkiii bigger issue in play is the plastic is smooth, textures surfaces interact more with the jet of water and energy is transferred more readily causing damage
@@memkiii yeah those electric pressure washers are pretty weak... if he had a gas powered real pressure washer it would have cut that plastic in half with the first jet.... i know this from experience.
Use the spinning jet. It has a smaller aperture than the non-fanned jet. It is designed to clean concrete by spalling the surface. The plastic spreads the pressure by deformation thus no hole. I use a 3500PSI (241bar) pressure cleaner to remove the mould and loose paint off of my deck and vinyl siding. I use the spinning jet on the vinyl siding. I use the fans on the deck. I did try the spinning jet on the deck once. ONCE. It tore through the paint, and chewed deeply into the wood. Oops.
Close to 100 PSI water jet from the pressure washer.. I've seen a 800 lb steam jet cut a broomstick. Probably don't need that much pressure for cutting wood.
he was proud to build a one million sub that had massive issues hence why the majority of planned launches to The Titanic were canceled before it began or when it just went down a few hundred feet
Dude used those dives to get free publicity and network among the mega-rich. Stage 2 would've been persuading one of the passengers to become an angel investor. Stage 3 is scaling up the operation, going public and then riding off into the sunset with bags of money.
It's utterly amazing it lasted, it honestly looks so home brewed by enthusiastic idiots who had a smattering of automobile repair skills between them and some intern who knew some electronics and computer stuff.
well the sub is designed with a safety factor in mind. probably the reason it wasn't able to be certified was because it required a higher safety factor, and the sub's safety factor most likely just put it very near the limit. thats bad because the limit is what you need to stay very far away from, thats why the safety factor required to certify it has to be very high
It didn't have 13 dives at full depth. Ten dives were not to the Titanic. This was precisely the 3rd time it descended to this depth. Not 13th. As documented. Note this was "Mission 5", but 2 missions were called off. Of the 3 missions at or close to full depth, there was a major failure on each of the 3. Propulsion failure from thruster mounted BACKWARDS. , communication FAILURE -wiring , hull - failure of design.
There might be a case for sudden catastrophic loss of hull integrity here too though since they DID use carbon fiber. Materials like this tend to be fine for a few stresses, but when you keep stressing them they fatigue and fail. Given that carbon fiber is pretty rigid, any structural failure would have given quite an impressive bit of destruction. Titanium's ability to deform rather than outright fail is a plus for this kind of application.
When you were doing your test with the power washer you forgot to include a whole chicken . The water might not do too much damage entering from a pinhole, unless it happens to strike a passenger. It will not easily cut a smooth surface as you saw with the plastic, but having used industrial high pressure washers, I know it cuts flesh easily.
water cutters also use fine sand in their jets. It's the sand that does the cutting. Any dirty water would do somewhat similar. Ocean water with the salt and other particles in it would cut better than tap water.
I saw a video online of a guy duying because of a pressure washer, but it wasn't clear from the video if the cause was concussive or if it was electrocution
Exactly what I commented previously, a hole at that depth is essentially a water jet. Phil if u ever need any supporting clips let me know I have a water jet at my shop. Thanks for covering this man.
I've watched you channel, however no one doubts a pinhole at that depth is going to cut exactly like..er.. a waterjet. His primary angst seems to be with anyone who says what destroyed the sub/killed the divers was pressure. Water compressability, speed of decompressing water, pinholes, etc, tangential bs. Part of the straight carbon fiber hull failed, pinhole, crack it doesn't matter. Because whatever it was it led to an almost instant catastrophic failure of that tube, likely on the order of milliseconds. If water did NOT compress, it would not make a whit of difference when we're talking about 6000psi. If this had been an old fashioned 360' diving bell that had a pinhole leak through 2-3" of titanium, then we could speculated on how many people would have been holed by that pinhole waterjet, and how long it would take to start taking on water, and people to drown or if slow enough, die from breathing high pressure normal air. 2 entirely different things.
They used methods that would make the sub suitable for depths less than a quarter of the depth they were taking it to. Even without your explanation, as soon as I saw them gluing it together I was looking at it in horror. The idea that they would just glue the ends together, trusting that the glue would hold everything together in such an extreme environment is just such an obvious flaw. Then adding the different materials with different compression rates and it's amazing it managed to last as long as it did.
I have no formal education in either engineering or physics and still my reaction to everything I've seen about how that thing was put together was "you have _got_ to be shitting me." Like not only gluing the parts together, but literally just wiping the surface with a dirty rag beforehand. The guy had his bare hand on the metal, wasn't even wearing a hairnet. You can't do that in a _sandwich shop,_ for crying out loud.
The glue was mostly to hold it together on the surface, once it gets to depth the pressure of the water actually holds the seals in place. That's not really the most egregious thing they did that's a common practice. When designing a seal the best thing you can do is make the environment it's going to be in work to hold it in place I do the same thing in my line of work with high pressure water lines.
@@taumctauface1886 if that glue is HPR 40, which it appears to be at a glance, then it is in fact considered stronger than the carbon fibre it's attaching. It is a rubberised epoxy resin that should maintain its bond even with slight differences in shape. That said the alarming part to me is the poor job in laminating the CF tube, with all those glossy areas being low points which a high performance part like this should never have. Especially on a mission critical part, that low level of skill would make me wonder if other areas are lacking, specifically how well they prepped the surfaces before bonding them together. Also , I can't tell how big the flange was that went inside the CF tube, and we have no idea of what the laminate looked like. The outer layers look like 0's so hopefully they had at least a few layers of 90's under that, spaced evenly throughout the laminate, and some 45 degree layers too. There was also some talk of the CF being expired material. Assuming it's pre-preg what's more important is that it was refrigerated at any time it wasn't being used, and any good factory will have those records on hand, exactly for this sort of accident.
@@taumctauface1886 But it isn't held in place. The carbon fiber tube shrinks more than the titanium endcaps and the titanium is on the outside. The pressure would try to tear apart the glue bond, not press it together.
@@torte007 Yeah. Right idea, wrong scenario. They were entirely relying on the glue as putting the more compressible material on the inside of the seal when that material has so much surface area to be compressed guarantees warping the seal eventually.
The fact about carbon fiber working well in tension and not compression is exactly what I was saying when I first heard about the composition of the "sub."
The fire part in fireball isn't too far off, considering that the air was instantly compressed and heated to a high temperature. Other sources say, it reached a temperature as hot as the sun, combusting anything combustible in the sub instantly, but this sounds very far out of scale. Maybe it got as toasty as a few hundred degrees in there, I haven't done the math myself. Clearly there shouldn't be a fireball coming off of it as if it spread in free air.
@@MrSaemichlaus Also read that, which seemed non-intuitive. However, if the sub imploded within a second of holing, the heat wouldn't have had much time to spread from wherever that compressed air ended up.
I think most people want to believe that Hamish didn't slowly drown to death, which is probably what happened. I bet his billions didn't prevent any of the pain of drowning.
When cutting carbon fiber with a water jet, i quickly found that you had to drill pilot holes or the material would delaminate due to internal pressure during a pierce operation. If water impregnated into the material its likely that the internal wall delaminated quickly due to the pressure difference.
@@ZadakLeader oceanside themselves have an old video out of the production. They're just simply rolling it up, in the open dusty environment as well. Not even braided pattern
I remember reading "2010 odyssey two" and part when they are doing atmospheric break manouvre around Jupiter and Floyd is thinking about what would be like if hull get crushed and his rather comforting thought that human nervous system couldn't physically transfer pain to the brain before it would stop existing.
My first introduction to 'Das Boot' was its soundtrack when I was a kid. It's one of the most captivating pieces of art of all time. The movie is on the same level, just as captivating and thrilling. I'd love to watch the full length cut in a theater.
It's based on a book with the same title of a guy who actually served on a Nazi submarine. He was very knowledgeable about the technology and dangers and experienced some intense situations himself.
I watched the TV series in my teens and it was one of the most tense and captivating pieces of tv I’d ever seen. It grabbed you by the throat and didn’t let up till the end!
The Hydrolic Press channel demonstrated implosions of steel and carbon fiber models of the sub in a pressurized water tank. The carbon fiber hull was crushed in an instant when it reached a certain pressure leaving the steel caps, similar to the recovered wreckage.
Nothing surprising, carbon fiber failure are pretty insane. The thing just shatter like glass. Probably just a case of delamination but no way to be sure the cylinder is probably in millions of pieces right now.
They've also demonstrated, with the help of gelatin to mimic flesh, the effects of a tiny hole (0.4mm iirc). It was insane. Some other expert on polymer bonding I stumbled across, mentioned using glue as a principle wasn't a problem. But he choked on seeing the cleaning being done in a warehouse rather than a cleanroom, and touching the cleaned surfaces adding grease. I'm certainly not qualified, but I was stomped to learn that glue could actually be a thing. Love youtube for all the unnecessary stuff we learn 🤣
@@legro19 Even if it wasn't, the only way to know is destructive testing (as far as I know.) To even know if there was a problem, they'd have to cut the carbon fiber, I don't believe it can be tested the same way metals can be.
The tube of the hull being made of glued layers surely meant that due to the compression and decompression of dive after dive it was only a matter of time before it started to delaminate regardless of how clean and well made the original tube was
Pretty much. If Stockton simply used the sub one or two times, he would have been fine. In fact, other people have made DSV from carbon fiber and retired it after a single trip. Stockton's mistake was trying to make a Carbon fiber sub into a tourist vehicle.
I know right?! I mean it's basically made of really, really good duct tape. Who the hell goes to the bottom of the ocean in a boat made of duct tape? I don't care how good the tape is.
By looking at the leaking chatlog people mentioned that the sub was descending too fast that day. If that is the case, it could have been avoided by canceling the dive. "Oh we are descending at 4 times the speed" that seems good
The one thing that supports the rapid implosion hypothesis , is that the end caps were displaced some distance from the other wreckage. Implying that the hull filled extremely quickly and that a water hammer effect feed kinetic energy into the end caps ,sending them in opposite directions.
I liked the experiment on hydraulic press channel where he made it in scale (not the old experiment but the brand new one), carbon fiber tube with caps. He got both results, he got one with a leakage where nothing really happened to the sub, it just filled with water, and 2nd result where the sub imploded carbon fiber just shattered.
I had a 60k psi water jet, and one of the high pressure stainless steel lines sprang a leak. The hole was so small you couldn't see it. The first indication of a problem was a fine mist near the hole. There was no way to stop the leak, and it just kept getting worse. A leak doesn't have to be big to be unstoppable at those pressures.
Don't you have to inspect all the lines before and during use? I know you said it's a small hole but you can still take a piece of paper and check for leaks or maybe notice the pressure gauge is off by a bit.
I had an excavator do that, obviously much less pressure but it sure made a mess a long way away from the leak in the form of an oil mist. A steel tube must have had a flaw, just started leaking in the middle of an untouched line.
I'm amazed they did that crucial adhesive bond without any hairnets on the fabricators. I would expect something looking more like clean room work than shop fabrication.
@@theweedfarmer419 Yes, the oils from your fingers will screw up the adhesion. In addition to cutting corners on material, they were clearly very sloppy when laying up the composites. The quality of the finished composite material is highly dependent on your process. Mistakes like that will burn you.
@@Skank_and_Gutterboy Also at about 20:15 , you can hear someone on the left saying "...of all the things to shortcut" hmmm. I wanna hear that convo. lol
Thank you for your thoroughness and attention to detail. The fact that you admit your less-than-expected results is admirable and only adds to your authenticity.
What a great video! You're power washer test reminded me of a tool show I went to back in the 90's. They showed a water jet cutting through 4" of mild steel. I think it was something around 400,000 psi. The jet nozzle didn't last too long😆
Water jet cutters start at about 30,000 PSI but can go 3x higher. A typical commercial jet washer will be about 2000 PSI. It's not surprising it didn't cut the plastic.
If water jet cutters were handed out to the public they would be classified as weapons. Imagine how many feet would've been severed by accident by people just trying it on.
"It´s pretty simple, but if we mess it up, there´s not a lot of recovery." I am just imagining those words going through his head over and over again, as he waits for his inevitable demise.
10-30 milliseconds for the delamination wave around the hull, 3 milliseconds for the pressure wave to hit him, less then 2 milliseconds before his brain's temperature reached thousand degrees celsius. I don't think he had much time left to think anything when the hull failed.
@@hans-joachimbierwirth4727 No, but it didn´t fail immediately, did it? The sub stopped working and started sinking long before the hull breach itself.
@@jirkazalabak1514 The implosion was recorded by naval observation posts, and the shattered debris of the pressure tube confirms a catastrophic structural failure. There are rumors claiming unusual descend speeds pointing to a pinhole but to my knowledge that isn't confirmed yet. The construction was based on passive descend and ascend mechanics driven by slightly negative buoyancy and one sacrificial ballast. Normal descend did not depend on anything working actively.
While the pressure washer didn't go through the plastic, I'm pretty sure it still left a small dent if you pay close enough attention. That's still material that's being eroded, even if it's not as visible as on the interior brick.
Hydraulic press channel made a pressure chamber to test the sub. Every time it failed, the failure mode was the seal, I'd recommend watching it as its probably the most accurate simulation of how the sub failed
@@PaulG.x Yes, but it's actually a good demonstration of the likely failure mode. Hydraulic press channel's "miniature sub" imploded at only 80 bars, compared to the 380 at the Titanic's depth. They wouldn't have been able to reach that pressure with their equipment anyway.
@@PaulG.x I agree, also they did only pressurize for a few seconds each time and at the end the conclusion was that after 20 cycles the model did NOT show any fatique and broke at teh same pressure as the "fresh" model. One model did fail at the seam, though, but it's still not the same as with a "real" model. They were just goofing around and they were actually admitting that.
I was absolutely stunned when I saw the videos of the carbon fibre being rolled out and how slapdash the glueing was. I put more time and energy into my childhood models than that subs creation lol.
@@0525ohhwell well yeah when they made it they should have had clean room level cleanliness so there was no contamination for maximum strength of the carbon fiber did they do that nope which contributed to it's early death sure they could also have had the carbon fiber on multiple axis for increased strength to but the point to be learned from this don't used carbon fiber for a sub and definitely don't use carbon fiber in a half fast cheapo build like they did they compromised on the strength of the sub in every area they could which is why it failed so quickly in it's life
@@raven4k998That's completely ridiculous; making a clean room is basically required if you're going to operate a factory making anything requiring secure bonding, of just about any material type. You want them if you're making PCs at large scale, so how did this rich pud skimp on it??
@@raven4k998 The sub went on ninety dives, thirteen to the same depth as the Titanic. Yes it was badly designed and made but if they had retired after ten super deep dives then there would be no story to tell. It did not fail quickly at all.
I believe the reason your pressure washer demo didn't work and big difference between a pressure washer and a water jet cutter is that your pressure washer aerates the water so you don't destroy the stuff you want to clean.
Yeah, I'd imagine they'd lean towards less ability to maim for all sorts of reasons. Liability, cost, safety. Bigger gas powered pressure washers can absolutely obliterate wood
Could also be that it didn't get enough water supplied to reach it's maximum pressure. Bigger pressure washers usually need to be hooked up to a buffer tank because a regular sized water pipe just can't supply water fast enough. The nozzle diameter is also something to consider.
Biggest difference between a pressure washer and a water jet cutter is the water jet is accelerating some fine grit abrasive like silica. Its the abrasive that does the cutting, not the water.
I used to work at a pressure washer place. Your washer is probably great for home use. If you're starting a business, you'll likely want a heavy duty unit. Something that pushes more water per minute. In either case, they sell this one piece, I forget the name but it's a big bronze piece that goes on the end and it has certain ceramic bits inside and it creates this highly concentrated jet of water. Like a small pinpoint of water. And if that doesn't remove your, whatever it is, likely nothing will. Pressure washers alone aren't really all that concentrated. They'll clean stuff well but if you want to cut with it, you need special equipment. Actually, now that I'm looking for it online, I'm not sure if it's even available to everyone. They do sell these turbo nozzles and stuff but that's not it. This thing is all metal and it's big. Like the size of a fist. It's brass or bronze or something. Like a goldish metal. And the ceramic would sometimes break so they'd bring them to us.
The speed at which water will shoot out of a hole in the submarine is derived from Bernoulli's Principle for compressible fluids. Basically, the speed v is determined by the formula v^2 ~ (Delta-P / B) * c^2 + g * h, (1) where Delta-P is the pressure differential, B is the bulk modulus of water, c is the speed of sound in water, g the gravitational constant, and h the depth. In our case, Delta-P ~ 400 atm, B ~ 2 GPa ~ 2 * 10^4 atm, c ~ 1500 m/s, g ~ 10 m/s^2, and h ~ 4 km. Taking the ratio of the two terms in the right-hand side of equation (1), we get (Delta-P / B) * c^2 / (g * h) ~ [2 * 10^(-2)] * [2 * 10^6] / {10 * [4 * 10^3]} = 1. In other words, the compressibility of water is just as important when it comes to determining the speed of the water shooting out of a (hypothetical) hole in the submarine's hull as gravitational potential energy.
The pressure spheres of many deep-submergence vehicles are in fact made in multiple sections, usually two halves, bolted together, with O-rings between them. The shape of the mating surface are designed so the increase of external pressure tends to press more and more on the seal. The perfectly spherical (machined to an extreme precision) shape of the hull allows a completely uniform stress on the joint and on the whole volume. The separation of both halves to inspect the seal is a regular maintenance task on such submarines.
The point is that the sections are the same material, not different ones. And spheres are the perfect shape to withstand insane amounts of pressure - but they are small, you can't put that many people in them (I think most of these deep-submergence vehicles can have 2 people in them, right?).
I was really surprised that they weren't gluing that thing back together after each use. It is absolutely insane. Quite surprised that it even held one dive. It makes me wonder if they didn't fake the debts of previous dives.
There is also the viewing portal that was only certified to 1,400m by the company that made it and Ocean gate wouldn't pay for a one certified to 4,000m. The dynamics of implosion are unique to every structure type. And the viewport window was missing from the fore titanium endcap as they were using a sling through it to lift it off the salvage vessel. Not a part of the wreckage you'd remove if it was still intact if you wished to analysis the failure mode later.
The port was designed and built to resist imploding into the sub underpressure. I would not be surprised is the implosion depending upon where it happened didn't compress an air pocket down part of the tube and just pop it out like spiting out a cherry pit. Doubt it reinforced to 5-6kPSI from the INSIDE...
Another engineer said they probably did remove it because there was no damage to the flange indicating it imploded like bolts still being their or torn out so I find it more likely that the tube failed.
I can't thank you enough for your videos. With every one I seem to learn more engineering concepts that I would have overlooked. Keep up the awesome work and making amazingly informative videos, I greatly appreciate them.
I'm not really concerned about the glue bond, because the end-domes are being pushed on with millions of pounds of force. The problem is the carbon fiber wants to shrink, but the titanium ring won't let it, resulting in an enormous stress concentration at the joint on the inside of the sub.
Logic is a bit flawed there. Yes, the pressure is pushing the end caps into the CF hull. However, that CF hull (as you yourself point out) moves somewhat independently, and differently than the end caps, or the glue itself. So there are multiple, competing stresses on that glue joint. I think it's the most likely failure point, next to the hull itself.
Yes, the fiber is the inconsistent element that itself was built with no sheer web whatsoever. The bonding operation itself probably had a lot of voids - but still that doesn't matter compared to the tube's complete lacking of sheer structure.
Well, because of what mentioned, when the cylinder begins to bow inward, the compressive force of the caps will begin to further cause the tube to collapse within itself. It will cause it to buckle inward in a feedback loop.
Thing is that they literally have the glue bond inside out, as the ring should have had an internal structure as well, to transfer the compression force from the carbon fibre to the inner titanium ring via the epoxy, not put a tensile pull on the epoxy join. That would lead to the carbon fibre delaminating with pressure cycles, and failing. They constructed that join surface as if the join was for a pipe with pressure inside, where the pressure will hold the epoxy onto the cap, not the other way round. Pipe shrank under pressure, and eventually some microscopic section of the join, likely with an embedded air bubble in it that had been compressed to have a sharp edge, caused a stress that started to propagate through the bulk resin, because there is no stress relief in the resin bond, and this then eventually grew to the outside, where water was able to fill the crack. Now the water is applying pressure to a section that can flex, and grows the crack into the joint further, aided by the tension in the epoxy join, and this then rapidly, basically the speed of sound in the epoxy as the growth speed, grew to open the joint to the inside. That joint should have had an inner and outer lip, and have been filled with epoxy with a slow cure time, and then have the shell pressed down into it, also with a coat of the epoxy on the surfaces, and then pressed together, with a few vent holes for the excess resin to flow out in the titanium, that later on would have a cap bolted and bonded to it. Or a thicker section that you put a setscrew in to fill the hole, while the resin is still not cured, after it has bottomed out, then left and heated to cure fully before removing the pressure. That join section should have been at least 3 times thicker, and longer, with a taper on the inside to allow a flexible sealer to be there, to allow the join to flex with pressure, not a solid non flex epoxy only. you want to not have stress risers, and a solid join with the different materials will have that stress riser. This hull was likely only going to last 3 cycles before you would have to replace it, they should have done testing, using a deep water area, and a cable and cage, to measure the number of cycles to failure first, not used the passengers as alpha testers.
Note how the titanium end cap has a lip to enclose both the outer and inner surfaces of the hull. The air inside that rim has nowhere to escape unless it displaces glue..
What surprises me is that knowing the differential compressibility, why not put the carbon tube on the outside of the ring, so that as it compresses at depth, it actually forms a tighter and tighter seal as the pressure increases. With a bit of engineering, you could find a suitable material to function as a sort of o-ring between the carbon fiber and titanium as well to form a proper seal rather than glue. (maybe a brass o ring)
Heck of an operation they had there. Assembly in some warehouse and the guy prepping the surface is wiping it down quickly with some rag while putting his hand on the area he already wiped. Good lord, thank god they got that in their video.
@@Nevergoingbackagainjust saying, if I had the money to go on the titan, I would of at least done some basic research into the company before I signed the waiver 😂
You can design pressure joints between dissimilar materials that will work fine. Industry does that all the time. Often the pressure will be used to seal the joint by pushing the joint together. Piston rings , for example , gas from the the high pressure side of the ring is directed behind the ring to force it against the cylinder bore.
I don't think you are using the right comparison. There is an oil film assisting the sealing of the piston ring too, and still, the seal is NEVER 100% prefect. In the case of the sub, it has to be.
The titanium caps did have a lip to hold the carbon fibre tube in place. So I don’t know if it was a glue failure But.. that difference in size would cause a bend in the carbon fibre, which would cause a difference in strain between the outside and inside of the tube, which is a perfect thing to cause delaminating.
So, its a bit more complicated than that. The lip would support the carbon at the ends, but the middle is still going to deflect. Imagine a ruler being supported on both ends by a couple of bricks or something. as you apply pressure onto the ruler, its going to bend in the middle, yeah? Now imagine that ruler was 5 inches thick and you deflected it the same amount. The top corner would move inward on each end as the middle is deflected downward. On the titan, this would have been the whole hull turning into an hourglass shape. that would also concentrate stress on the outermost edge of the glue joint in the hull, likely causing it to fracture. Now, I don't believe this to be the cause of the failure. What Thunderf00t alluded to with the carbon being strong in tension not compression is a key factor, and the fatigue properties of carbon fiber. Its likely it started delaminating, causing a cascading failure and then the subsequent catastrophic failure.
@@Gainn It's a brittle material and it's held together by adhesives, once it hit that critical point, it was splinter and delamanate/ sort of peel apart only inward as it imploded, maybe followed by an outward explosion after the inside of the sub was temporarily an internal combustion engine with all that force coming in rapidly, there wouldn't really be much left of it, sure there are probably pieces of it but good luck recovering any of it.
@@leecowell8165 Titanium shrinks very little when cold, I believe about half as much as many stainless alloys, though some are closer to TI. TI was the right choice.
I think it much more likely that the carbon-fiber tube buckled and both the titanium end caps were forced together. Previous passengers reported cracking sounds while descending which seems to suggest delamination within the matrix, weakening the strength of the tube. When HMS Scorpion imploded the stern was forced forward into the hull which they call - if I'm not mistaken - telescoping. Where the steel hull of the Scorpion more-or-less remained with extensive deformation, the Titan's carbon-fiber tube most likely shattered upon failure.
Think you mean USS Submarine - of the 11 HMS Scorpions, none were submarines. From wiki on USS Scorpion: The secondary Navy investigation ... suggested that Scorpion's hull was crushed by implosion forces as it sank below crush depth... The operations compartment was largely obliterated by sea pressure, and the engine room had telescoped 50 ft (15 m) forward into the hull due to collapse pressure, when the cone-to-cylinder transition junction failed between the auxiliary machine space and the engine room.
If the leaked transcript is real, it may have started with a pinhole leak in the aft section. The leaked transcript, according to a video from jeffostroff, mentions a "crackling sound at aft", which is apparently a walled off section where some of the equipment is. So perhaps there was a pinhole leak in the aft section that caused them to take on water in a compartment they couldn't see, which increased the rate of descent and led to equipment failure due to water damage ("trying to run diagnostics, ascending now. but very slow.... global RTM alert active all red... reading red on the A power bus. I switched to B... more sounds aft..."). Then perhaps eventually the pressure built up enough for the dividing wall to fail. Idk
@@dildswagginz3408 Oh, very well might be. I wrote that event from memory; the image of the stern shoved into the main hull is amazing. I have seen the transcript of the final communications explained. What I've seen from the insides of the Titan there is very little there. I have worked at a company building personal submersibles, and there is a lot more on the inside then there was with Titan. If there was a leak, you would know it and they would have reported that. As the disturbing sounds was emanating from the rear I suspect they may have had a problem with the battery-pack, air bottles, or diving tanks. They must have taken on quite a lot of water seeing how dropping ballast and the undergear barely gave them positive buoyancy rising 20 meters in a span of three minutes after dropping weights. If the dive tanks were compromised and increasingly hanging down in stead of pulling up it will have changed the load on the main hull, possibly inducing the failure.
Hydraulic Press Channel has a carbon fiber not-a-model-of-Titan being crushed under water pressure. It is instant and the carbon fiber was reduced to dust.
3/4ths certain the issue in your waterjet test was lack of pressure. I think you'd need to be up around 200psi (about double what you're running) to cut that plastic. Very well made proof of concept demonstration. Thank you for the effort.
You're mistaken, I'm afraid. He said his pressure washer was running at approximately 100 bar, which is nearly 1500 psi. Pretty standard for a home use model, though they do have some that are a bit more powerful. An industrial pressure washer, something like at your quarter car wash, States around 3500 psi. There's really no telling how high they go. I reckon that depends on what you are using it on. 1 bar of pressure is 14.7 lbs. It didn't destroy the plastic because it's water, likely filtered. If you were to use seawater, it would have more of an impact as a result of sediment and other particulate in the water. Like a water jet machine. They run around 20,000 psi. But they will not cut through steel and concrete and all the other things they use them for until you introduce an abrasive into the stream, then shit gets cut, which is why pressure washers contain filters, by the way, so that minerals and particles in the water won't just strip the paint off your home or car, or cut your foot off from an accidental blast.
@@philbert006 Pure water can easily cut soft materials, no need for an abrasive. It's actually common practice to cut plastics with water alone, because there's no reason to waste your relatively expensive abrasive on a soft material that has no need for it. The problem here is the nozzle, obviously you wouldn't design the nozzle for a pressure washer to be able to cut things. The orifice in a waterjet is very different from a pressure washer nozzle.
Carbon fiber has high tensile strength which makes it good for building aircraft fuselages and scuba tanks (where you need to contain high pressure inside the vessel). A submarine is different because the pressure is pushing from the outside in. The carbon fiber can't easily resist getting pushed inwards, so all it can do is make the epoxy resin more rigid. The epoxy cracks under compressive stress (because it's not as strong as carbon fiber), and the carbon fiber layers start to peel off from one another. You get an effect similar to metal fatigue, where the vessel is initially strong but the cracks grow with each dive/surface cycle, until catastrophic failure occurs.
@@criticalevent Kinda doomed before he started. Especially cycling pressure states embrittling the polymers let alone the cold. Planes go through regular appraisals of their integrity after known hours of abuse.
@@miinyoo Also according to the proposed transcript, the Titan was descending too fast and ascending too slow when the dumped their weights. They also lost power to Battery A (Indicating flooding in their electronics bay.) Anyway... Carbon fiber also does not like rapid increases in stress loads... it actually fails at a lower loads if the rate of increase is fast rather than slow. So Titan's rapid descent (nearly 2x faster than normal) might have been the straw that broke the camel's back.
Yes, composite overwrapped pressure vessels are common, but have a limited life at full pressure, and also a cycle life. I have one used as a water purifier, and while it is 10 years past it's life, it also is only used at 1bar of water pressure, not the rating of 10bar, and 20 bar test pressure. Should have a near indefinite life at that pressure, especially as it generally is not under pressure unless I need to draw water. I will probably wear out the threads changing the resin first.
That's my theory of the cause of the implosion, the carbon fibre started delaminating because the inner surface is under compression. But Thunderfoot raises a good point that the carbon fibre shell will be trying to shrink relative to the titanium rings, creating a shearing action at the join.
The fact that they used 2 materials that compress at vastly different rates, and GLUED them together in a device meant for the depths and PRESSURES of the deep ocean is absolutely insane to me...
It works, glue isn't that fixed joint as weld for example and glue can adapt to those changes.... once or twice, not multiple times in a row without any protection from the elemts, without maintance, etc.
Thank you! I was imagining the junction of the composite to titanium hemisphere as stressing at the bond from different strain modulus. For some reason I never thought of bulk modulus, in hindsight this is very clear ! Aside from this grotesque design error I was thinking they didn’t model LCF well, as I have seen others making the mistake of assuming perfect properties, ignoring the normal defects that arise in building a composite structure.
Being in a sub peacefully is scary enough. Being in a sub with hostile forces trying to MAKE the sub fail is another couple of orders of magnitudes even MORE scary. Holy shit!
Deep water diving in a sub should be done by highly trained personnel only. Trying to make this into a money making tourist attraction is reckless and stupid.
Its really amazing how you just document these incredibly insightful discoveries on various topics just casually time and time again, but none of your information becomes widely known to the public somehow
Shame he has no engineering knowledge and often makes things up. Example: 4:55 "You can pump out that water" Errr what? How are you going to pump out the water? And replace it with what? A vacuum? Phil aint too bright. The only way you clear ballast tanks below the water line is by blowing them with pressurised air.
What I've been thinking during time of my life after this incident, is that when you're in water oxygen wants to escape and water wants to break in, that alone to me is crazy physics, but i also think about how in space air wants to break out and nothing wants to take it away... And one is under the stress of gravity and the other is under no gravity.... And all the ships are essentially well sealed air metal boxes with mini air tanks, air filters, AC, video and audio... idk kinda trippy.
Excellent explanation. Weird how media just bought whatever one guy animated and did not even ask any scientists whether, "hey is this animation how it physically happened? Is it accurate?"
@richardsejour7731 It would have started as a leak, but the water leaking in would also be cutting the hole larger, so the leak would speed up, so cutting the hole even larger. This whole process would last a fraction of a second, and the whole could get large enough to completely destroy the carbon fibre part. It's a similar process to a dam collapsing from an initial tiny crack.
You must have media confused with journalism, which officially ended in Britain, at least, when islamists targeted kuffar little girls for their love of noncery, on an industrial scale.
Why is it excellent? There are like 3-4 different sub-theories branched out in the vid. The animation may be basic or crude, however all the experts seem to agree that basically it happened like that. If these experts where to jump into TF's area of expertise and start going of with theories on something he'd done a video on, I know I'd probably be more inclined to listen to TF as that is his area of expertise.
At 20:18 I sure hope that wasn't their official cleaning of the rings, wiping it down with a rag (presumably soaked with alcohol) before the glueing process with the other hand lagging behind depositing grease / oil back onto the surface. Even with mountain bikes, it's stated hundreds of times to never touch the surface of the brake rotor as the natural oils / grease on your hands will ruin the brake pads.
I feel like there's an oversight here in the idea that the water-jet would be contacting the material being cut at this distance. As you can see in the water-jet cutting videos, the water-jet nozzle is basically right up against the material being cut. Presumably in the sub, it would have been a few feet away from the other wall and the stream would be dispersed by the time it hits the other side. Water isn't a laser.
pinhole leak? Dude, at the depth they were going to... and given the wreckage found, they suffered an implosion, which happens instantly once the hull is compromised in any way. There is no 'getting filled with water', there is "crack" then "squish", almost instantly.
Yeah I think TF is incorrect here. Not wrong with the science stuff, but ignoring the fact that Naval vessels monitored a loud underwater sound that was consistent with an implosion, and also that the fragments recovered were basically end pieces and nothing from the carbon fiber body. The fact that they recovered "probable" human remains also suggests a violent event that rendered the bodies unrecognizable. So I gotta say I disagree with the analysis here, based on what we seen publicly reported.
You can have both. A pinhole leak is enough to create delamination that results in a big final implosion. If the leaked communications log is real, then the sub was too heavy all the way down. And they had 10 minutes of strange sounds before the loss of communication.
I haven't seen your videos pop up in ages, not a super massive fan, but I loved your debunk videos when I came across them, just about to watch this video and for once out of all these titan videos I'm sure the experiments are going to be legitimate.
Delamination was the likely cause of the Sub implosion, the noises heard from witnesses as the sub went down and up very low depth is likely to have been caused by internal delamination of the Carbon Fiber / Composite hull overtime
@@SoldererOfFortune There is an excellent video on the subject I watch just the other day from someone who did a PhD on just that scenario! Will post the link if I can find it again
@@SoldererOfFortune Nothing of the guesses in the video is uninformed. It's just another failure mode. If there will ever be a public report about the incident, maybe we will learn which failure mode was the most likely in this case. Sure, delamination is a probable one, but the mating area between two completely different materials is defenitely another probable one. Heck, even the 1300 m rated window was a probable failure. This thing was a red flag carrier.
This makes perfect since, the Titan was having problems surfacing, we all heard that part when they had only went up like 25 meters in 30 minutes after first dropping the ballast and doing everything they could to go up. They knew they were screwed there, they had already taken on water. This guy nailed it, the best explanation I've heard. I thought I had it figured out but I didn't. most of us probably knew it was in the joint between the carbon fiber and titanium... well I guess this was close to what I was thinking but this just clarified everything. This is the smartest guy I've seen on YT, I'm gonna check out his other content
The thing is, Oak Ridge were doing this exact same thing way back in 1988. CF hull with titanium ring pieces and titanium hemisphere end pieces. And *they* rated it for 100 dives on the full scale model. They used IM6 CF on a vessel with an interior diameter of just 2', and a hull thickness of 2.5". Astonishingly, they even used the same method of acoustic monitoring during pressure cycle testing as oceangate. These vessels were cycle tested to 9000 (yes, a nine) PSI and crushed at around 12000 PSI if i recall. Now granted, 100 cycle rating isn't great, and I have no idea how many *deep* cycles Titans second hull had endured, but the whole concept isn't quite as bat shit insane as we all initially thought. They even used the same 'lip on each side' of the titanium rings idea, and yes - it was glued. So why did Titan fail so catastrophically then? Honestly, I think (as pointed out by other commenters) its the construction process and a lack of thorough non-destructive testing. I also think that the way Oak Ridge hand-wave away acoustic events as NOT being evidence of progressive failure is dubious. Ultimately though, Oak Ridge only rated the AUSS mod 2 for AUTONOMOUS work. There was talk of further research into the viability of human rated submersibles with CF hulls, but as far as i'm aware it went no further. Without massive amounts of EXPENSIVE testing, Stockton Rush had NO business conducting real-world testing on an experimental vessel with paying passengers. Please take a look at the following report for more information: www.researchgate.net/publication/235179850_Graphite-Fiber-Reinforced_Plastic_Pressure_Hull_Mod_2_for_the_Advanced_Unmanned_Search_System_Vehicle
Are you on/off meds? " They used IM6 CF on a vessel with an interior diameter of just 2'" "Graphite-Fiber for Advanced UNMANNED Search System" Glad people like you aren't on some Safety Standards body.
There's an unverified transcript of communications between the sub and surface vessel in which the pilot observes creaking noises. The sub was also diving quite fast relative to other operators on the Titanic. If correct, the crew knew there was trouble for about 19 minutes.
It's super likely to be fake tbh. Lot's of stuff doesn't add up and no news agency covering it is a big red flag. Plus it was "leaked" on TikTok of all places. But most of all, if the transcript was true, that would be a massive story, because then the whole search and rescue operation should have never happened. OceanGate not giving the transcript to the rescue operation makes zero sense.
I think the carbon fiber went without any hint. I think that there was no pinhole at all, the entire (or at least huge part) carbon hill broke open with a bang. There are recorded audio verifying that bang. Glueing rigid (titanium) material with more flexible (carbon fiber) material ought to create displacement between the materials, and either the glue or the carbon fiber has to take the damage.
For the pressure washer demonstration, you didn't have a tight enough jet, it may say professional on the box it came in, but there's a bunch of consumer saftey baked in as well. So if it were necked down to say 1mm it would cut the plastic palnter tray
Insane thing, the CEO of the company (who built and owned the Titan) was inside that ridiculous, unseaworthy, monstrosity, on that fateful final journey.
P.S - regarding your 'previous video'... 26 March 2012, Director James Cameron reached the bottom of the Challenger Deep, the deepest part of the Mariana Trench. The maximum depth recorded during this record-setting dive was 10,908 metres (35,787 ft).
but most modern naval fatalities are due to user error, so they could just skip all the strict safety regulations and just throw random sciency crap (carbon fiber) together and call it a day
I honestly think this was well beyond simply being brash or cavalier; I think he actually got off on the death-defying element - like those parkour rooftop jumpers or people who climb without ropes - you can clearly see it in the look on his face when he talks about getting the glue right (the eyebrow-raise says it all) at 20:20 Which is fine if he wants to go by himself, like the mouthbreather who was going to prove the earth was flat with his rocket that couldn't get high enough to see the curvature of the earth. This fckwit killed 3 people with his thrill-seeking fetish.
To be fair: 3D animators are pretty expensive. Nobody wants to pay a dude in the basement to make a real simulation of something the target audience doesn´t understand anyway and paying them 35$+/h for it. Source: I´m one of these dudes in the basement. Edit: Guys, chill. This is a guessed average based on what a good friend of mine living in a developing country makes, which usually is the kind of person getting hired for such a job. I know the averages in US/EU are much higher than that.
@@bassmeo3937 It is. But like most things, it depends on where you are hiring. Usually such productions try to cheap out by hiring in countries like India.
I think one of the hydraulic press channels actually reproduced this - they increased pressure, nothing remarkable happened, but when they opened the container, they found that the sub model was full of water, without any significant signs of damage.
This story has a similar vibe to the "Mad" Mike Hughes flat earth rocket. Both were repeatedly told, "You're going to die" by people who knew what they were talking about. Both were cutting corners at the expense safety, while simultaneously claiming that safety was a #1 priority. Stockton Rush and Mike Hughes are two excellent examples of the Dunning Krueger effect in god-mode.
With stuff like that, the Hyperloop, Solar Freakin Roadways and Triton it sure feels like people are actively trying to invent new lines for the "dumb ways to die"-song.
"It's not the pressure that kills you it's the water expanding" has the same vibe to it as "It's not the gravity that kills you it's the stopping suddenly after a fall". Yeah. Why is the water compressed at depth? Because it's under pressure.
The porthole being made of plexiglass and the whole thing being held together with normal epoxy resin is crazy. Im suprised catastrophic failure took as long as it did.
The glue is referred to as "peanut butter" which is a term we often use in boat building to discuss thickened epoxy. Could it be that they're just using thickened epoxy and not some specialist glue that can take the enormous shear forces that will be caused by the relative compression? Also, that's a planar joint. I was expecting some sort of rim or overlap so that e.g. the titanium was surrounded by the carbon fibre, which could then compress *under tension* around the titanium and support the shrinkage. That's the thing carbon fibre is good at after all. But no, they just butted the two together with glue. The more I find out about this the more astounded I am.
Not quite a butt joint but as you point out they built it backwards, with the ring slipped over a thinned end of the cylinder instead of having the cylinder over the ring.
THIS. No lip on that ring made this thing a death trap in your 30ft deep marina let alone deep ocean. I used to repair power plant water mains (2ft diameter often) with carbon fiber and epoxy. Nobody does high pressure CF flange butt connections for a reason. I promise you a flat sheer point with no teeth or keyway on the titanium was engineering suicide. It's like this thing was designed to put on a deep sea fireworks show. 😅
@@tactileslut I was just thinking this. "Oh, it would be really smart if they put the more compressible material over the non-compressive material--WAIT WHAT ARE THEY DOING"
@seanprice7645 sheering force is still acting on a flat plane surface (less surface area to hold connection than lipped or grooved socket connections) and still would have a catastrophic failure mode due to the difference in material compression. The way an internal pressure vs external would fail different but the point has more to do with the poor design choice of connection. Not meant for high pressure deep sea anything. It was a carbon fiber playground they had the audacity to repeatedly risk peoples lives in. A thin seam overlap of CF on the outside wasn't a "lip" to hold anything from shifting, it was the beginning of it's delamination points in the structure. A groove should have been in the ti cap for a socket connection in a better design but still. Carbon fiber ain't that material. Keep that shit on race cars and aircraft
What I find fascinating is that the CF tube is *inside* the titanium tube. It should be *outside* so that the compression does an interference fit. Although that would not solve the flexing of the CF tube itself at the transition seem.
True, but I'm with you on that. Maybe it would just prolong the inevitable, but then again it might have given more obvious signs that some fuckery was afoot.
IDK i don't think it was a pinhole leak. As someone else mentioned the hydraulic press channel did a pretty good experiment and the results looked a lot like the recovered wreckage.
He didn't think it was a pinhole leak. He said at the end he thinks it was a crack, and the mad rush of water was powerful enough to dissisemble the vessel.
this thing imploded. It may have been a pinhole for a few microseconds but that was about it. This implosion was so violent that it probably shredded a good portion of that cylinder. heated up the air to a 1000c and roasted everybody before shredding them as well.
If you watch a recent video from jeffostroff about what might be the leaked transcript, apparently there was a "crackling sound at aft", which is apparently a walled off section where some of the equipment is. So perhaps there was a pinhole leak in the aft section that caused the increased rate of descent, very slow ascent and equipment failure reported in the apparent transcript: "trying to run diagnostics, ascending now. but very slow.... global RTM alert active all red... reading red on the A power bus. I switched to B... more sounds aft...". So unbeknownst to them, water might have been slowly building up in the aft section as they were descending due to a pinhole leak causing increased descent rate, eventually frying some of the equipment and finally causing a catastrophic failure. Or maybe the transcript was made up, idk.
If you imagine the titanium caps as concrete foundations for a tubular carbon fibre bridge, you can see how it would work for a while. Bridges hold significant compression/tension across multiple materials with differing bulk moduli. Essentially the carbon fibre was compressing but the titanium was anchoring it like a bridge support. I imagine a few load cycles worked the glue loose and bam.
I'm not well versed enough to give concrete(tish) reasons, however there is no need for such an analogy. You have 2 end caps of basically incompressible metal being pushed together/compressed axially? At the same time, that plastic toilet roll is being pressed from all 360' radially, as 5-6Kpsi. It seems even more possible/likely that one of the end caps had a failure where it was glued to the tube, and with the 1 meter diameter(IIRC) end cap you're looking at 5000psi * 4071sqi = 20,355,000# of force on that cap end which experiences a failure which propogates.
Didn't the US navy confirm it was a sudden implosion because implosions have a very distinct audio signature that was picked up by acoustic monitors designed to detect enemy submarines.
It was very likely an implosion. But if the communications log that has spread on the net is legitimate, then there was issues before the implosion. If the texts are true, then the sub descended 50% faster than normal alreadt from the start. Which indicates if was too heavy. Either waterlogged plastic (one of the issues with CF) or ot had a leak so there was water in the sub. Next thing is the leaked (if real) communication mentioned sounds maybe 10 minutes before the loss. And loss of one power bank while they drived to ascend. So a leak could have started the issue. Then the leak could finally have damaged the CF hull enough that instead of just getting a larger hole it totally imploded from loss of stiffness. A leak can delamination the CF bonding.
@@mikehawk5492 The point is a tiny leak would erode away at the material it's leaking through, combined with the fact that the material it's likely leaking through is glue thats constantly shifting throughout the dive it wouldn't be too long before it failed entirely and explosively. However the glue is just one theory, another is the hull was damaged and leaking, which like the glue would be essentially waterjet cut by the leak until it grew large enough to catastrophically fail. Hydrualic Press Channel already did a test (I think others have now as well) where they take a carbon fiber tube to depth and back in a pressure chamber 30-50 times and it suffered no noticeable loss in strength from the cyclic loading. However the timespan was so short that no leaks would have time to actually weaken the material by abrasion. It's unlikely the hull failed simply by cyclic loading but instead cumulative damage of some sort. Which brings us back to a sub millimeter leak that slowly ate away at something until it failed, similar to how hydraulic hoses or other hydraulic failures occur, they slowly seep and leak until they blowout without much visible progression.
I suppose the big difference between the pressure washer you used and the sub leak is when that leak expanded and the hole got bigger the pressure would remain pretty much the same irrespective of the jet size, it'd go from a tiny jet to a big jet to a sub breaking water hammer, all in a few seconds.
Dirty Garage Guy has a video with a simulation of the actual sub design and does a proper job explaining and showing what probably happened, if you have 2 hours to spend the whole video or 10-20 mins to watch the actual simulation at the end of the video. If you want the TLDR of it, it's likely to be the housing unit (cilinder made of titanium and carbon fiber) that compressed to the point where the glue that attached the housing unit to the titanium rings got so fatigued from multiple dives that it just popped open. That also sort of goes hand in hand with the leaked transcript (if it's the real one) where the crew reported 20 minutes of on and off crackling from the back of the vessel, which is probably the indication of the glue they used losing it's grip. So, the housing unit probably got compressed way too much one too many times, and the glue coming apart is very likely to be the teller of that. Just go watch the simulation he did, it makes things _very_ obvious.
There are special simulation software I saw one where the acrylic window gave way first. But the glue is a strong second contestor. The window was just rated for 1300 meters.
It was obviously leaking water on the outside from the moment they put it in the water that's why it was dropping too fast and that's why it wasn't Rising fast enough when they dropped the ballast
I'd rather bet on carbon fiber collapsing due to accumulated buckling damage. They used expired carbon fibers, wrapped them without weave patterns and likely didn't even vacuum cure the thing but just bagged it. This thing started to crackle and then collapsed.
And, considering information on other channels, carbon fiber was not only less then optimal choice and not weaved as it should and could have been, but also cured improperly.
This whole thing just reminds me of that Futurama joke: "How many atmospheres can the ship withstand?!?" "Well its a space ship, so anywhere between 0 and 1"
Ironically it’s probably easier to build the hull for a spacecraft since it is not under so much pressure.
@@Stuntman707Also where carbon fiber would have actually been useful.
@@Stuntman707why would that be ironic
If only they’d built 6001 hulls! When will they learn?!?
@@pretzelstick320bruh that ignorant. They knew it wasn't safe
The animation of the sub going down and crumpling before it goes up in a huge smokey explosion and shreds into pieces looks like it was outsourced to a high school graphic design class.
Did it convey its point?
@@ItIsYouAreNotYour I think we can safely conclude yes and no.
Looks like something from The Amazing Bulk
Smoke underwater? Even SpongeBob has better physics than this!
@@ItIsYouAreNotYour Sadly its point is inaccurate.
A submariner friend once told me the whole “race to the surface and deploy rafts” was just Hollywood. She calmly explained that just getting in a submarine meant accepting your own death.
Thats why the Screw down hatch is so easy to accept.
Every time you set foot (so to speak) upon the sea, you give your life to it. Usually -- _usually_ -- the sea gives it back.
That's not typically true of a properly designed submarine. That said, yeah, you aren't likely to be able to escape a sub once you're underwater. There are escape trunks on some subs but they are only viable if the depth isn't too great.
@@infernaldaedra The US Coast Guard has inspection and certification requirements for Passenger Carrying Submersible Vessels. Under the 1993 Passenger Vessels Act. Titan was subject to this both for reason of Oceangate being a U.S. Corporation (which they tried to hide by shifting ownership of the sub onto a Bahamanian registered sub corporation), but more importantly the US Coast Guard and NTSB maintains certification authority for Submersibles built in the US. One of the certification requirements is the submersible vessel must have an ingress/egress hatch that is 1 meter above the waterline when floating at the surface. People can get in or out without flooding the sub. Note this applies to vessels that carry Revenue Passengers. Which Oceangate was trying to desperately (and illegally) hide as “Mission Specialists”.
@@andrewtaylor940 Yeah and a hatch still doesn't do anything for you when your more than a few hundred meters depth and would destroy the vessel to open
In my line of work, I am regularly exposed to high-pressure water cutting, and I can unequivocally state that the nozzle plays a pivotal role in the cutting process.
@@JohnSmith-hn1qj Probably not only pressure but also speed of the water. There are diferent designs of the nozzle(like rocket engines) that are made for specific purposes and even accelerating fluid flow. Maybe the nozzle thunderfoot is using just isnt made for fluid velocity
@@robertjusic9097 Or most cheap electric pressure washers are simply weak sauce. Mine is advertised as 3500 psi but it's far weaker than a gas engine powered pressure washer rated at 3k psi
Honestly, the more you hear about the specifics of this debacle, the more surprised you get that it didn't end in disaster sooner...
Agreed. The 'wait, what?' moment for me was when the video revealed that the sub's titanium was bonded to the carbon-fiber... with glue.
I mean, even as someone who's completely unfamiliar with sub construction, it feels like the people building the sub had better options than _that._
The only thing that might make this make sense for me was hearing from other sources that the people who built the sub allegedly cut corners like crazy.
love your avatar - it's like a 3D version of B|
@@quentincoetzee4313
I'm not sure on what 'glue' they used, but 'glue' is rather strong these days.
Lots of expensive cars are glued too. For example you can't weld steel and aluminium together(Even if they are touching you get corrosion which is deadly for any metal object), only way to get that to (safetly) stick together is glue.
@@Ikbenjounietsukkel glue holding two things together from shearing or breaking apart is one thing. Here the problem is, as Phil described, that your glue doesn't matter when an air tight seal isn't air tight at 300 bars; and glue is not gonna fix different deformation rates of metal and polymer
Real engineering has a great video about how composites are a horrible choice for a sub.
He did his masters thesis on composite materials so I trust his judgement.
Props for showing the experiment, even when it didn't result in what you expected. That's the true spirit of a researcher.
That IS the scientific process.. that is why we watch thundrfoot. :) respectfully intended
yea which doesnt mean he busted his own theory, its more like the pressure washer is a really cheap model. normaly they dont come with "easy 1 button switch nossle".
I don't think he cares. He made a segment for the 1 meter cubed interior volume and then dove-tailed it with: "Well, if there are any sticklers..." sub volume is closer to 5 meters just multiply... 8:58
I'm not in any way defending Ocean Gateway. Their practices were ridiculous!
Thunderf00t is a chemist and not an engineer. Fusing dissimilar materials is not the same thing as a bonded joint. You would be surprised at what critical structural joints get bonded these days. Also, thanks to Poisson's ratio, transverse fibers in composites do carry a load under bulk compression. 21:08 I hope he reconsiders "a whole other video" about that. Not withstanding this was an improper application for a composite but Thunderf00t isn't qualified to explain it. Composites have complicated Mechanics because they are not homogeneous.
He's right about needing to match Modulus' as best practice but its not clear if there is an interior flange in the connection. Also, the friction between mating surfaces is considerable due to the pressure on the exterior of the hemisphere. There are several possible failure modes and this is certainly one of them but not the only or even necessarily the most likely. We'll have to wait on the report to know for sure.
His videos are entertaining but he's often out of his field...
7@@Ixions TH-camrs have been flocking to this tragedy like sharks and blood in the water. Everyone enjoys pointing out the engineering flaws, but without a detailed timeline of events, the engineering problems are second to pilot error.
As far as I know, based on some transcripts that may or may not be true... It sounds like they dived too fast, had an issue, released their ballasts, and then couldn't ascend. Wouldn't be surprised if they collided with a ghost net or even the ocean floor
@@IxionsWhat he's doing is just a simple order of magnitude thought experiment. He's fixing all the values to simpler values that are still the same order of magnitude, just demonstrate the relative magnitude of things. It's a thing he commonly does in all of his videos. Simplifications like that just make it much easier to grasp without having to focus on the math itself. Notice how he was trying to get all the numbers to be multiples of 10 or 100. It's for illustrative purposes.
As a KFC food service worker, I can see that there were probably one or more reasons why the vessel failed:
1 - Poor adhesion in the composite plies; there may have been regions that weren't cured properly or the substrate didn't fully penetrate all of the plies.
2 - Adhesion between the composite plies and the titanium ends failed due to incomplete coverage.
3 - Differential stiffnesses between the titanium and the composite, meaning that there was a difference in material shrinkage across the composite/titanium interface, causing a shear-stress that caused the bond to fail [ You did address this but your demo showed the effects of a difference in thermal expansion coefficients, not stiffness due to pressure loading, although both may be significant and there can be an interaction e.g. if one component isn't that stiff at all, then it can accomodate the differences in thermal expansion but a risk of rupturing a bonded interface is still there. ]
4 - At 20:40 , the worker has his bare hand on the bond interface, which could add grease and compromise the bond strength.
5 - Not only are composites crap in compression, they are also crap in out-of-plane tension, which may occur at the bending loads across the length of the tube due to the water pressure.
Holy hell, what do you people do there at KFC?
@@FireOccator
They set a high bar to work for the Colonel.
Also had to get security background checks in order to handle the 11 secret herbs and spices and go on 2 years intensive training on the 7-10-7 breading method.
@@lewis72 Nice analysis, I was horrified to see guys on step ladders in and open dusty warehouse hand spooning adhesive on to the titanium interfaces. A very avoidable tragedy, you simply can't gamble with the pressures at 3000+m. it's about brute strength........not computer modelling. sad for those who lost their lives
Appreciate that you left in that failed water jet demonstration. Showing that you're both fallible but also transparent. Admitting your mistakes is one of the most important step ls of the scientific process after all
I think it might just demonstrate that manufacturers claims as to how powerful their pressure washers are, is just complete BS.
@@memkiii bigger issue in play is the plastic is smooth, textures surfaces interact more with the jet of water and energy is transferred more readily causing damage
@@memkiii yeah those electric pressure washers are pretty weak... if he had a gas powered real pressure washer it would have cut that plastic in half with the first jet.... i know this from experience.
Use the spinning jet. It has a smaller aperture than the non-fanned jet. It is designed to clean concrete by spalling the surface. The plastic spreads the pressure by deformation thus no hole. I use a 3500PSI (241bar) pressure cleaner to remove the mould and loose paint off of my deck and vinyl siding. I use the spinning jet on the vinyl siding. I use the fans on the deck. I did try the spinning jet on the deck once. ONCE. It tore through the paint, and chewed deeply into the wood. Oops.
Close to 100 PSI water jet from the pressure washer..
I've seen a 800 lb steam jet cut a broomstick. Probably don't need that much pressure for cutting wood.
The dude expected to use the same submarine forever, I have no doubt about that.
he was proud to build a one million sub that had massive issues hence why the majority of planned launches to The Titanic were canceled before it began or when it just went down a few hundred feet
I saw in another video that he had been persuaded to replace the carbon fibre hull at a cost of about 1 million.
Dude used those dives to get free publicity and network among the mega-rich. Stage 2 would've been persuading one of the passengers to become an angel investor. Stage 3 is scaling up the operation, going public and then riding off into the sunset with bags of money.
He wasn't wrong. It lasted all his life.
It lasted him a lifetime!
I'm stunned it lasted one dive to the Titanic, let alone 13 dives.
It's utterly amazing it lasted, it honestly looks so home brewed by enthusiastic idiots who had a smattering of automobile repair skills between them and some intern who knew some electronics and computer stuff.
@@Dedubya- exactly, it looks like what some final year engineering students may have knocked together for some one off contest....
well the sub is designed with a safety factor in mind. probably the reason it wasn't able to be certified was because it required a higher safety factor, and the sub's safety factor most likely just put it very near the limit. thats bad because the limit is what you need to stay very far away from, thats why the safety factor required to certify it has to be very high
It didn't have 13 dives at full depth. Ten dives were not to the Titanic. This was precisely the 3rd time it descended to this depth. Not 13th. As documented. Note this was "Mission 5", but 2 missions were called off. Of the 3 missions at or close to full depth, there was a major failure on each of the 3. Propulsion failure from thruster mounted BACKWARDS. , communication FAILURE -wiring , hull - failure of design.
They could have lied
There might be a case for sudden catastrophic loss of hull integrity here too though since they DID use carbon fiber. Materials like this tend to be fine for a few stresses, but when you keep stressing them they fatigue and fail. Given that carbon fiber is pretty rigid, any structural failure would have given quite an impressive bit of destruction. Titanium's ability to deform rather than outright fail is a plus for this kind of application.
Once the hull was breached, the stresses on the carbon fiber rapidly dropped until it was negligible.
When you were doing your test with the power washer you forgot to include a whole chicken . The water might not do too much damage entering from a pinhole, unless it happens to strike a passenger. It will not easily cut a smooth surface as you saw with the plastic, but having used industrial high pressure washers, I know it cuts flesh easily.
Ya only if you're under a foot to 6in away from the pin hole.
water cutters also use fine sand in their jets. It's the sand that does the cutting. Any dirty water would do somewhat similar. Ocean water with the salt and other particles in it would cut better than tap water.
I saw a video online of a guy duying because of a pressure washer, but it wasn't clear from the video if the cause was concussive or if it was electrocution
@@chromatic2006 abrasives aren't necessary for all materials, only hard materials. Plastics can be cut easily with water alone, flesh even more so.
Exactly what I commented previously, a hole at that depth is essentially a water jet. Phil if u ever need any supporting clips let me know I have a water jet at my shop. Thanks for covering this man.
I enjoy your content and like your cars.
I've watched you channel, however no one doubts a pinhole at that depth is going to cut exactly like..er.. a waterjet.
His primary angst seems to be with anyone who says what destroyed the sub/killed the divers was pressure.
Water compressability, speed of decompressing water, pinholes, etc, tangential bs.
Part of the straight carbon fiber hull failed, pinhole, crack it doesn't matter. Because whatever it was it led to an almost instant catastrophic failure of that tube, likely on the order of milliseconds.
If water did NOT compress, it would not make a whit of difference when we're talking about 6000psi.
If this had been an old fashioned 360' diving bell that had a pinhole leak through 2-3" of titanium, then we could speculated on how many people would have been holed by that pinhole waterjet, and how long it would take to start taking on water, and people to drown or if slow enough, die from breathing high pressure normal air.
2 entirely different things.
Yooo, warped perception. The rocket car dude!
@@Make-Asylums-Great-Againthank you!!!
@@jacobrzeszewski6527lol... Only cause I haven't uploaded in a while, I truly like to stay diverse.
The ratio of fucking around to finding out is fairly balanced with this one
He fucked around.
Amen brother!
lol for real!
It's always about 1.0
No. I’d say it’s a ratio of 376:1
They used methods that would make the sub suitable for depths less than a quarter of the depth they were taking it to. Even without your explanation, as soon as I saw them gluing it together I was looking at it in horror. The idea that they would just glue the ends together, trusting that the glue would hold everything together in such an extreme environment is just such an obvious flaw. Then adding the different materials with different compression rates and it's amazing it managed to last as long as it did.
I have no formal education in either engineering or physics and still my reaction to everything I've seen about how that thing was put together was "you have _got_ to be shitting me." Like not only gluing the parts together, but literally just wiping the surface with a dirty rag beforehand. The guy had his bare hand on the metal, wasn't even wearing a hairnet. You can't do that in a _sandwich shop,_ for crying out loud.
The glue was mostly to hold it together on the surface, once it gets to depth the pressure of the water actually holds the seals in place. That's not really the most egregious thing they did that's a common practice. When designing a seal the best thing you can do is make the environment it's going to be in work to hold it in place I do the same thing in my line of work with high pressure water lines.
@@taumctauface1886 if that glue is HPR 40, which it appears to be at a glance, then it is in fact considered stronger than the carbon fibre it's attaching. It is a rubberised epoxy resin that should maintain its bond even with slight differences in shape. That said the alarming part to me is the poor job in laminating the CF tube, with all those glossy areas being low points which a high performance part like this should never have. Especially on a mission critical part, that low level of skill would make me wonder if other areas are lacking, specifically how well they prepped the surfaces before bonding them together. Also , I can't tell how big the flange was that went inside the CF tube, and we have no idea of what the laminate looked like. The outer layers look like 0's so hopefully they had at least a few layers of 90's under that, spaced evenly throughout the laminate, and some 45 degree layers too. There was also some talk of the CF being expired material. Assuming it's pre-preg what's more important is that it was refrigerated at any time it wasn't being used, and any good factory will have those records on hand, exactly for this sort of accident.
@@taumctauface1886 But it isn't held in place. The carbon fiber tube shrinks more than the titanium endcaps and the titanium is on the outside. The pressure would try to tear apart the glue bond, not press it together.
@@torte007 Yeah. Right idea, wrong scenario. They were entirely relying on the glue as putting the more compressible material on the inside of the seal when that material has so much surface area to be compressed guarantees warping the seal eventually.
The fact about carbon fiber working well in tension and not compression is exactly what I was saying when I first heard about the composition of the "sub."
The astounding thing is that this fundamental materials flaw was probably the 5th worst aspect of this sub/company.
He's an Engineer and he didn't know this? I guess not.
I love how the animation shows it exploding in a fireball. It’s amazing.
The fire part in fireball isn't too far off, considering that the air was instantly compressed and heated to a high temperature. Other sources say, it reached a temperature as hot as the sun, combusting anything combustible in the sub instantly, but this sounds very far out of scale. Maybe it got as toasty as a few hundred degrees in there, I haven't done the math myself. Clearly there shouldn't be a fireball coming off of it as if it spread in free air.
I think that animation was based on the "depth-charged by their competition" theory. 🤣
@@MrSaemichlaus And does that heat create steam too? Very complex situation.
@@MrSaemichlaus Also read that, which seemed non-intuitive.
However, if the sub imploded within a second of holing, the heat wouldn't have had much time to spread from wherever that compressed air ended up.
I think most people want to believe that Hamish didn't slowly drown to death, which is probably what happened. I bet his billions didn't prevent any of the pain of drowning.
When cutting carbon fiber with a water jet, i quickly found that you had to drill pilot holes or the material would delaminate due to internal pressure during a pierce operation. If water impregnated into the material its likely that the internal wall delaminated quickly due to the pressure difference.
I would agree with that assessment for sure.
Second that.
There is a whole video on that, apparently the carbon fiber wasn't made using an autoclave
@@ZadakLeader oceanside themselves have an old video out of the production. They're just simply rolling it up, in the open dusty environment as well. Not even braided pattern
@@mezkhalin Yeah
I remember reading "2010 odyssey two" and part when they are doing atmospheric break manouvre around Jupiter and Floyd is thinking about what would be like if hull get crushed and his rather comforting thought that human nervous system couldn't physically transfer pain to the brain before it would stop existing.
My first introduction to 'Das Boot' was its soundtrack when I was a kid. It's one of the most captivating pieces of art of all time. The movie is on the same level, just as captivating and thrilling. I'd love to watch the full length cut in a theater.
It's based on a book with the same title of a guy who actually served on a Nazi submarine. He was very knowledgeable about the technology and dangers and experienced some intense situations himself.
Well The Typ VII did rise again and reached his home base.
@@jarrad2000So every german sub of that time is a nazi sub now?
I watched the TV series in my teens and it was one of the most tense and captivating pieces of tv I’d ever seen. It grabbed you by the throat and didn’t let up till the end!
The Hydrolic Press channel demonstrated implosions of steel and carbon fiber models of the sub in a pressurized water tank. The carbon fiber hull was crushed in an instant when it reached a certain pressure leaving the steel caps, similar to the recovered wreckage.
Nothing surprising, carbon fiber failure are pretty insane. The thing just shatter like glass. Probably just a case of delamination but no way to be sure the cylinder is probably in millions of pieces right now.
They've also demonstrated, with the help of gelatin to mimic flesh, the effects of a tiny hole (0.4mm iirc). It was insane.
Some other expert on polymer bonding I stumbled across, mentioned using glue as a principle wasn't a problem.
But he choked on seeing the cleaning being done in a warehouse rather than a cleanroom, and touching the cleaned surfaces adding grease.
I'm certainly not qualified, but I was stomped to learn that glue could actually be a thing. Love youtube for all the unnecessary stuff we learn 🤣
@@gottagowork The OceanGate CEO said safety certification was a waste... Truly a Rush job.
@@legro19 Even if it wasn't, the only way to know is destructive testing (as far as I know.) To even know if there was a problem, they'd have to cut the carbon fiber, I don't believe it can be tested the same way metals can be.
@@leviathanops4524 Ultrasound inspection of CF is normal.
The tube of the hull being made of glued layers surely meant that due to the compression and decompression of dive after dive it was only a matter of time before it started to delaminate regardless of how clean and well made the original tube was
Pretty much. If Stockton simply used the sub one or two times, he would have been fine. In fact, other people have made DSV from carbon fiber and retired it after a single trip. Stockton's mistake was trying to make a Carbon fiber sub into a tourist vehicle.
Possibly if we autoclave it after each dive to turn the delamination back into laminate composite we could use 1 sub with 10s to 100s of missions.
I know right?! I mean it's basically made of really, really good duct tape. Who the hell goes to the bottom of the ocean in a boat made of duct tape? I don't care how good the tape is.
By looking at the leaking chatlog people mentioned that the sub was descending too fast that day. If that is the case, it could have been avoided by canceling the dive.
"Oh we are descending at 4 times the speed" that seems good
@@thejuggernautofspades9453autoclaving resin seems like a bad idea to me
The one thing that supports the rapid implosion hypothesis , is that the end caps were displaced some distance from the other wreckage. Implying that the hull filled extremely quickly and that a water hammer effect feed kinetic energy into the end caps ,sending them in opposite directions.
They would also drift as they fell, what I think is more evident is the pulverized carbon fibre
I liked the experiment on hydraulic press channel where he made it in scale (not the old experiment but the brand new one), carbon fiber tube with caps. He got both results, he got one with a leakage where nothing really happened to the sub, it just filled with water, and 2nd result where the sub imploded carbon fiber just shattered.
I had a 60k psi water jet, and one of the high pressure stainless steel lines sprang a leak. The hole was so small you couldn't see it. The first indication of a problem was a fine mist near the hole. There was no way to stop the leak, and it just kept getting worse. A leak doesn't have to be big to be unstoppable at those pressures.
Don't you have to inspect all the lines before and during use? I know you said it's a small hole but you can still take a piece of paper and check for leaks or maybe notice the pressure gauge is off by a bit.
I had an excavator do that, obviously much less pressure but it sure made a mess a long way away from the leak in the form of an oil mist. A steel tube must have had a flaw, just started leaking in the middle of an untouched line.
I had a Citroen do this...
For those that don't know these types of pinhole high pressure leak are rarther dangerous
@@carmadme Yes, high-pressure injection of any foreign substance is very deadly.
@@carmadme I have a citroen c5, please tell me more about what happen.
I'm amazed they did that crucial adhesive bond without any hairnets on the fabricators. I would expect something looking more like clean room work than shop fabrication.
even that dude was wiping it for some reason and imediatly put his hand there after
@@theweedfarmer419
Yes, the oils from your fingers will screw up the adhesion. In addition to cutting corners on material, they were clearly very sloppy when laying up the composites. The quality of the finished composite material is highly dependent on your process. Mistakes like that will burn you.
@@Skank_and_Gutterboy Also at about 20:15 , you can hear someone on the left saying "...of all the things to shortcut" hmmm. I wanna hear that convo. lol
@@luistigerfox From all the things to shortcut, have we missed any and did the proper industry tested thing?
@@luistigerfox
No doubt!!
Thank you for your thoroughness and attention to detail. The fact that you admit your less-than-expected results is admirable and only adds to your authenticity.
What a great video! You're power washer test reminded me of a tool show I went to back in the 90's. They showed a water jet cutting through 4" of mild steel. I think it was something around 400,000 psi. The jet nozzle didn't last too long😆
Water jet cutters start at about 30,000 PSI but can go 3x higher. A typical commercial jet washer will be about 2000 PSI. It's not surprising it didn't cut the plastic.
If water jet cutters were handed out to the public they would be classified as weapons. Imagine how many feet would've been severed by accident by people just trying it on.
His was probably1200max at the nozzle.
And maybe 1gpm.
4000psi at 4gpm would tear that plastic thing up pretty easy.
@@ingvarhallstrom2306Anyone can buy a water jet cutter. All you need is enough money and space to afford it.
My powerwasher destroyed my sunroof of my summer kitchen (made of plastic). Didnt cut it, but rather shot through it with pieces flying.
Its like Mach 7 or 8 correct?
Just an FYI, The Chicago Museum of Science and Industry has a German U-Boat that's available for tours. It's really interesting.
Does it cost extra to torpedo merchant vessels?
Si does the museum in Munich
"It´s pretty simple, but if we mess it up, there´s not a lot of recovery." I am just imagining those words going through his head over and over again, as he waits for his inevitable demise.
10-30 milliseconds for the delamination wave around the hull, 3 milliseconds for the pressure wave to hit him, less then 2 milliseconds before his brain's temperature reached thousand degrees celsius. I don't think he had much time left to think anything when the hull failed.
@@hans-joachimbierwirth4727 No, but it didn´t fail immediately, did it? The sub stopped working and started sinking long before the hull breach itself.
@@jirkazalabak1514 The implosion was recorded by naval observation posts, and the shattered debris of the pressure tube confirms a catastrophic structural failure. There are rumors claiming unusual descend speeds pointing to a pinhole but to my knowledge that isn't confirmed yet. The construction was based on passive descend and ascend mechanics driven by slightly negative buoyancy and one sacrificial ballast. Normal descend did not depend on anything working actively.
While the pressure washer didn't go through the plastic, I'm pretty sure it still left a small dent if you pay close enough attention. That's still material that's being eroded, even if it's not as visible as on the interior brick.
Hydraulic press channel made a pressure chamber to test the sub. Every time it failed, the failure mode was the seal, I'd recommend watching it as its probably the most accurate simulation of how the sub failed
Yep I saw that first and then this video. Taking both in account, this one explains the why, and the other corroborated the results
Hydraulic press channel did not use a scale model. They used scrap composite tubing and metal parts.
@@PaulG.x Yes, but it's actually a good demonstration of the likely failure mode. Hydraulic press channel's "miniature sub" imploded at only 80 bars, compared to the 380 at the Titanic's depth. They wouldn't have been able to reach that pressure with their equipment anyway.
@@PaulG.x I agree, also they did only pressurize for a few seconds each time and at the end the conclusion was that after 20 cycles the model did NOT show any fatique and broke at teh same pressure as the "fresh" model. One model did fail at the seam, though, but it's still not the same as with a "real" model. They were just goofing around and they were actually admitting that.
Tanks amigo I will check ✔️ perciate it.
I was absolutely stunned when I saw the videos of the carbon fibre being rolled out and how slapdash the glueing was. I put more time and energy into my childhood models than that subs creation lol.
yeah that and he contaminated the titanium after he cleaned it by touching it with his hand I mean what the hell was the point?
@@raven4k998 And the "cleaning" looked like a bartender in a western film.
@@0525ohhwell well yeah when they made it they should have had clean room level cleanliness so there was no contamination for maximum strength of the carbon fiber did they do that nope which contributed to it's early death sure they could also have had the carbon fiber on multiple axis for increased strength to but the point to be learned from this don't used carbon fiber for a sub and definitely don't use carbon fiber in a half fast cheapo build like they did they compromised on the strength of the sub in every area they could which is why it failed so quickly in it's life
@@raven4k998That's completely ridiculous; making a clean room is basically required if you're going to operate a factory making anything requiring secure bonding, of just about any material type. You want them if you're making PCs at large scale, so how did this rich pud skimp on it??
@@raven4k998 The sub went on ninety dives, thirteen to the same depth as the Titanic. Yes it was badly designed and made but if they had retired after ten super deep dives then there would be no story to tell. It did not fail quickly at all.
I love the guy cleaning the mating surface with his cloth then contaminating it with his greasy hand
3:25
"You are 6 axis of screwed."
Im stealing this, Thunderf00t! I love it too much not to. 😂
One of the experts that the media consulted about the sub failure said that the lap joint was a sub designer's nightmare.
Many pressure vessel design codes limit the use of lap joints to low requirements situations.
What on this thing wasn't a sub designers nightmare?
so you're saying the construction was sub standard?
@@andrewtaylor940 The 3.5 inch thick titanium end caps. Those were in the dreams of sub designers. The rest though......especially the glue
I believe the reason your pressure washer demo didn't work and big difference between a pressure washer and a water jet cutter is that your pressure washer aerates the water so you don't destroy the stuff you want to clean.
Yeah, I'd imagine they'd lean towards less ability to maim for all sorts of reasons. Liability, cost, safety. Bigger gas powered pressure washers can absolutely obliterate wood
Could also be that it didn't get enough water supplied to reach it's maximum pressure. Bigger pressure washers usually need to be hooked up to a buffer tank because a regular sized water pipe just can't supply water fast enough. The nozzle diameter is also something to consider.
Biggest difference between a pressure washer and a water jet cutter is the water jet is accelerating some fine grit abrasive like silica. Its the abrasive that does the cutting, not the water.
@@alexe589 There are water jet cutters with and without abrasives. Cutting with pure water works very well too, depending on the application.
I used to work at a pressure washer place. Your washer is probably great for home use. If you're starting a business, you'll likely want a heavy duty unit. Something that pushes more water per minute. In either case, they sell this one piece, I forget the name but it's a big bronze piece that goes on the end and it has certain ceramic bits inside and it creates this highly concentrated jet of water. Like a small pinpoint of water. And if that doesn't remove your, whatever it is, likely nothing will. Pressure washers alone aren't really all that concentrated. They'll clean stuff well but if you want to cut with it, you need special equipment.
Actually, now that I'm looking for it online, I'm not sure if it's even available to everyone. They do sell these turbo nozzles and stuff but that's not it. This thing is all metal and it's big. Like the size of a fist. It's brass or bronze or something. Like a goldish metal. And the ceramic would sometimes break so they'd bring them to us.
The speed at which water will shoot out of a hole in the submarine is derived from Bernoulli's Principle for compressible fluids.
Basically, the speed v is determined by the formula
v^2 ~ (Delta-P / B) * c^2 + g * h, (1)
where Delta-P is the pressure differential, B is the bulk modulus of water, c is the speed of sound in water, g the gravitational constant, and h the depth. In our case, Delta-P ~ 400 atm, B ~ 2 GPa ~ 2 * 10^4 atm, c ~ 1500 m/s, g ~ 10 m/s^2, and h ~ 4 km.
Taking the ratio of the two terms in the right-hand side of equation (1), we get
(Delta-P / B) * c^2 / (g * h) ~ [2 * 10^(-2)] * [2 * 10^6] / {10 * [4 * 10^3]} = 1.
In other words, the compressibility of water is just as important when it comes to determining the speed of the water shooting out of a (hypothetical) hole in the submarine's hull as gravitational potential energy.
The pressure spheres of many deep-submergence vehicles are in fact made in multiple sections, usually two halves, bolted together, with O-rings between them. The shape of the mating surface are designed so the increase of external pressure tends to press more and more on the seal. The perfectly spherical (machined to an extreme precision) shape of the hull allows a completely uniform stress on the joint and on the whole volume. The separation of both halves to inspect the seal is a regular maintenance task on such submarines.
The point is that the sections are the same material, not different ones. And spheres are the perfect shape to withstand insane amounts of pressure - but they are small, you can't put that many people in them (I think most of these deep-submergence vehicles can have 2 people in them, right?).
I was really surprised that they weren't gluing that thing back together after each use. It is absolutely insane. Quite surprised that it even held one dive. It makes me wonder if they didn't fake the debts of previous dives.
@@c.augustin there are 3 crew DSVs, 4 if you bend the crew correctly.
@@Damien.D "4 if you bend the crew correctly" - well, sounds kind of uncomfortable … 😉
@@c.augustin you want to see the Titanic? Well it will cost you an arm. Literally. Need to cut it, or you wont fit.
There is also the viewing portal that was only certified to 1,400m by the company that made it and Ocean gate wouldn't pay for a one certified to 4,000m. The dynamics of implosion are unique to every structure type. And the viewport window was missing from the fore titanium endcap as they were using a sling through it to lift it off the salvage vessel. Not a part of the wreckage you'd remove if it was still intact if you wished to analysis the failure mode later.
The port was designed and built to resist imploding into the sub underpressure. I would not be surprised is the implosion depending upon where it happened didn't compress an air pocket down part of the tube and just pop it out like spiting out a cherry pit. Doubt it reinforced to 5-6kPSI from the INSIDE...
Another engineer said they probably did remove it because there was no damage to the flange indicating it imploded like bolts still being their or torn out so I find it more likely that the tube failed.
I think if the failure occurred at the aft seal of the pressure vessel, the water hammer could have blown the viewport out of the front of the sub.
5:09
"Permission to blow?!!" and the follow-ups were some award-worthy meme making.
I can't thank you enough for your videos. With every one I seem to learn more engineering concepts that I would have overlooked. Keep up the awesome work and making amazingly informative videos, I greatly appreciate them.
I'm not really concerned about the glue bond, because the end-domes are being pushed on with millions of pounds of force. The problem is the carbon fiber wants to shrink, but the titanium ring won't let it, resulting in an enormous stress concentration at the joint on the inside of the sub.
150 million lb-f according to my cell phone calculator.
Logic is a bit flawed there. Yes, the pressure is pushing the end caps into the CF hull. However, that CF hull (as you yourself point out) moves somewhat independently, and differently than the end caps, or the glue itself. So there are multiple, competing stresses on that glue joint. I think it's the most likely failure point, next to the hull itself.
Yes, the fiber is the inconsistent element that itself was built with no sheer web whatsoever. The bonding operation itself probably had a lot of voids - but still that doesn't matter compared to the tube's complete lacking of sheer structure.
Well, because of what mentioned, when the cylinder begins to bow inward, the compressive force of the caps will begin to further cause the tube to collapse within itself. It will cause it to buckle inward in a feedback loop.
Thing is that they literally have the glue bond inside out, as the ring should have had an internal structure as well, to transfer the compression force from the carbon fibre to the inner titanium ring via the epoxy, not put a tensile pull on the epoxy join. That would lead to the carbon fibre delaminating with pressure cycles, and failing. They constructed that join surface as if the join was for a pipe with pressure inside, where the pressure will hold the epoxy onto the cap, not the other way round. Pipe shrank under pressure, and eventually some microscopic section of the join, likely with an embedded air bubble in it that had been compressed to have a sharp edge, caused a stress that started to propagate through the bulk resin, because there is no stress relief in the resin bond, and this then eventually grew to the outside, where water was able to fill the crack. Now the water is applying pressure to a section that can flex, and grows the crack into the joint further, aided by the tension in the epoxy join, and this then rapidly, basically the speed of sound in the epoxy as the growth speed, grew to open the joint to the inside.
That joint should have had an inner and outer lip, and have been filled with epoxy with a slow cure time, and then have the shell pressed down into it, also with a coat of the epoxy on the surfaces, and then pressed together, with a few vent holes for the excess resin to flow out in the titanium, that later on would have a cap bolted and bonded to it. Or a thicker section that you put a setscrew in to fill the hole, while the resin is still not cured, after it has bottomed out, then left and heated to cure fully before removing the pressure.
That join section should have been at least 3 times thicker, and longer, with a taper on the inside to allow a flexible sealer to be there, to allow the join to flex with pressure, not a solid non flex epoxy only. you want to not have stress risers, and a solid join with the different materials will have that stress riser. This hull was likely only going to last 3 cycles before you would have to replace it, they should have done testing, using a deep water area, and a cable and cage, to measure the number of cycles to failure first, not used the passengers as alpha testers.
Note how the titanium end cap has a lip to enclose both the outer and inner surfaces of the hull. The air inside that rim has nowhere to escape unless it displaces glue..
What surprises me is that knowing the differential compressibility, why not put the carbon tube on the outside of the ring, so that as it compresses at depth, it actually forms a tighter and tighter seal as the pressure increases. With a bit of engineering, you could find a suitable material to function as a sort of o-ring between the carbon fiber and titanium as well to form a proper seal rather than glue. (maybe a brass o ring)
Heck of an operation they had there. Assembly in some warehouse and the guy prepping the surface is wiping it down quickly with some rag while putting his hand on the area he already wiped. Good lord, thank god they got that in their video.
Spending like $250k on a coffin right before death is an insane way to go
I wouldn’t mind death for a trip to mars as long as I could live for a day
This is how they agreed to die. They signed a contract./ waiver.
shared coffin at that !
To be fair, one of the quickest ways to go. I hope I pass on that fast and painlessly when my time comes..
250K is all it cost? Not bad!
@@Nevergoingbackagainjust saying, if I had the money to go on the titan, I would of at least done some basic research into the company before I signed the waiver 😂
Notice the titanium rings when they were brought up: none had any residue of carbon fiber attached to them.
Yeah the carbon fiber hull collapsed
You can design pressure joints between dissimilar materials that will work fine. Industry does that all the time.
Often the pressure will be used to seal the joint by pushing the joint together.
Piston rings , for example , gas from the the high pressure side of the ring is directed behind the ring to force it against the cylinder bore.
I don't think you are using the right comparison. There is an oil film assisting the sealing of the piston ring too, and still, the seal is NEVER 100% prefect. In the case of the sub, it has to be.
The titanium caps did have a lip to hold the carbon fibre tube in place. So I don’t know if it was a glue failure
But.. that difference in size would cause a bend in the carbon fibre, which would cause a difference in strain between the outside and inside of the tube, which is a perfect thing to cause delaminating.
So, its a bit more complicated than that. The lip would support the carbon at the ends, but the middle is still going to deflect. Imagine a ruler being supported on both ends by a couple of bricks or something. as you apply pressure onto the ruler, its going to bend in the middle, yeah? Now imagine that ruler was 5 inches thick and you deflected it the same amount. The top corner would move inward on each end as the middle is deflected downward. On the titan, this would have been the whole hull turning into an hourglass shape. that would also concentrate stress on the outermost edge of the glue joint in the hull, likely causing it to fracture.
Now, I don't believe this to be the cause of the failure. What Thunderf00t alluded to with the carbon being strong in tension not compression is a key factor, and the fatigue properties of carbon fiber. Its likely it started delaminating, causing a cascading failure and then the subsequent catastrophic failure.
Well, they proved how resilient carbon fiber is. Shame they weren't capable of doing so with their Elmer's glue DIY project
Interesting fact how all titanium parts of wreckage looks like having almost no damage while "innovative carbon fiber" part completely disappeared.
A true "why didn't they build the plane out of the same material as the black box?" moment.
Because it suffered a catastrophic implosion.
Not this pressure washer shit TF is rattling on about.
@@Gainn It's a brittle material and it's held together by adhesives, once it hit that critical point, it was splinter and delamanate/ sort of peel apart only inward as it imploded, maybe followed by an outward explosion after the inside of the sub was temporarily an internal combustion engine with all that force coming in rapidly, there wouldn't really be much left of it, sure there are probably pieces of it but good luck recovering any of it.
I would not have used titanium I would have used stainless.
@@leecowell8165 Titanium shrinks very little when cold, I believe about half as much as many stainless alloys, though some are closer to TI. TI was the right choice.
I think it much more likely that the carbon-fiber tube buckled and both the titanium end caps were forced together. Previous passengers reported cracking sounds while descending which seems to suggest delamination within the matrix, weakening the strength of the tube.
When HMS Scorpion imploded the stern was forced forward into the hull which they call - if I'm not mistaken - telescoping. Where the steel hull of the Scorpion more-or-less remained with extensive deformation, the Titan's carbon-fiber tube most likely shattered upon failure.
Think you mean USS Submarine - of the 11 HMS Scorpions, none were submarines. From wiki on USS Scorpion: The secondary Navy investigation ... suggested that Scorpion's hull was crushed by implosion forces as it sank below crush depth... The operations compartment was largely obliterated by sea pressure, and the engine room had telescoped 50 ft (15 m) forward into the hull due to collapse pressure, when the cone-to-cylinder transition junction failed between the auxiliary machine space and the engine room.
If the leaked transcript is real, it may have started with a pinhole leak in the aft section. The leaked transcript, according to a video from jeffostroff, mentions a "crackling sound at aft", which is apparently a walled off section where some of the equipment is. So perhaps there was a pinhole leak in the aft section that caused them to take on water in a compartment they couldn't see, which increased the rate of descent and led to equipment failure due to water damage ("trying to run diagnostics, ascending now. but very slow.... global RTM alert active all red... reading red on the A power bus. I switched to B... more sounds aft..."). Then perhaps eventually the pressure built up enough for the dividing wall to fail. Idk
@@dildswagginz3408 Oh, very well might be. I wrote that event from memory; the image of the stern shoved into the main hull is amazing.
I have seen the transcript of the final communications explained. What I've seen from the insides of the Titan there is very little there. I have worked at a company building personal submersibles, and there is a lot more on the inside then there was with Titan. If there was a leak, you would know it and they would have reported that. As the disturbing sounds was emanating from the rear I suspect they may have had a problem with the battery-pack, air bottles, or diving tanks. They must have taken on quite a lot of water seeing how dropping ballast and the undergear barely gave them positive buoyancy rising 20 meters in a span of three minutes after dropping weights. If the dive tanks were compromised and increasingly hanging down in stead of pulling up it will have changed the load on the main hull, possibly inducing the failure.
Hydraulic Press Channel has a carbon fiber not-a-model-of-Titan being crushed under water pressure. It is instant and the carbon fiber was reduced to dust.
HMS Scorpion? Correction: USS Scorpion.
3/4ths certain the issue in your waterjet test was lack of pressure. I think you'd need to be up around 200psi (about double what you're running) to cut that plastic.
Very well made proof of concept demonstration. Thank you for the effort.
You're mistaken, I'm afraid. He said his pressure washer was running at approximately 100 bar, which is nearly 1500 psi. Pretty standard for a home use model, though they do have some that are a bit more powerful. An industrial pressure washer, something like at your quarter car wash, States around 3500 psi. There's really no telling how high they go. I reckon that depends on what you are using it on. 1 bar of pressure is 14.7 lbs. It didn't destroy the plastic because it's water, likely filtered. If you were to use seawater, it would have more of an impact as a result of sediment and other particulate in the water. Like a water jet machine. They run around 20,000 psi. But they will not cut through steel and concrete and all the other things they use them for until you introduce an abrasive into the stream, then shit gets cut, which is why pressure washers contain filters, by the way, so that minerals and particles in the water won't just strip the paint off your home or car, or cut your foot off from an accidental blast.
@@philbert006 Pure water can easily cut soft materials, no need for an abrasive. It's actually common practice to cut plastics with water alone, because there's no reason to waste your relatively expensive abrasive on a soft material that has no need for it. The problem here is the nozzle, obviously you wouldn't design the nozzle for a pressure washer to be able to cut things. The orifice in a waterjet is very different from a pressure washer nozzle.
It is the best explanation I have seen on TH-cam so far. Great video as always. Thanks
Carbon fiber has high tensile strength which makes it good for building aircraft fuselages and scuba tanks (where you need to contain high pressure inside the vessel). A submarine is different because the pressure is pushing from the outside in. The carbon fiber can't easily resist getting pushed inwards, so all it can do is make the epoxy resin more rigid. The epoxy cracks under compressive stress (because it's not as strong as carbon fiber), and the carbon fiber layers start to peel off from one another. You get an effect similar to metal fatigue, where the vessel is initially strong but the cracks grow with each dive/surface cycle, until catastrophic failure occurs.
@@criticalevent Kinda doomed before he started. Especially cycling pressure states embrittling the polymers let alone the cold. Planes go through regular appraisals of their integrity after known hours of abuse.
Or simply put, you can't push a rope.
@@miinyoo Also according to the proposed transcript, the Titan was descending too fast and ascending too slow when the dumped their weights. They also lost power to Battery A (Indicating flooding in their electronics bay.) Anyway... Carbon fiber also does not like rapid increases in stress loads... it actually fails at a lower loads if the rate of increase is fast rather than slow. So Titan's rapid descent (nearly 2x faster than normal) might have been the straw that broke the camel's back.
Yes, composite overwrapped pressure vessels are common, but have a limited life at full pressure, and also a cycle life. I have one used as a water purifier, and while it is 10 years past it's life, it also is only used at 1bar of water pressure, not the rating of 10bar, and 20 bar test pressure. Should have a near indefinite life at that pressure, especially as it generally is not under pressure unless I need to draw water. I will probably wear out the threads changing the resin first.
That's my theory of the cause of the implosion, the carbon fibre started delaminating because the inner surface is under compression. But Thunderfoot raises a good point that the carbon fibre shell will be trying to shrink relative to the titanium rings, creating a shearing action at the join.
The fact that they used 2 materials that compress at vastly different rates, and GLUED them together in a device meant for the depths and PRESSURES of the deep ocean is absolutely insane to me...
If only they’d used Gorilla Glue…
It works, glue isn't that fixed joint as weld for example and glue can adapt to those changes.... once or twice, not multiple times in a row without any protection from the elemts, without maintance, etc.
You have to understand, safety regulations and regulatory body inspections only cause to hamper innovation...
@@LordHypnos4 what will chatGPT make of this comment? :D
Nearly every aspect of this situation is absolutely insane to me.
Thank you! I was imagining the junction of the composite to titanium hemisphere as stressing at the bond from different strain modulus. For some reason I never thought of bulk modulus, in hindsight this is very clear ! Aside from this grotesque design error I was thinking they didn’t model LCF well, as I have seen others making the mistake of assuming perfect properties, ignoring the normal defects that arise in building a composite structure.
A very informative video, thank you! I have just subscribed to your channel, and am looking forward to a lot more great content. 🥰
Being in a sub peacefully is scary enough. Being in a sub with hostile forces trying to MAKE the sub fail is another couple of orders of magnitudes even MORE scary. Holy shit!
Outside forces are always trying to make all subs fail at all times. That's just normal for subs.
You think russia is trying to make the sub fail what are you babbling about?
Deep water diving in a sub should be done by highly trained personnel only. Trying to make this into a money making tourist attraction is reckless and stupid.
@@feonor26 It wasn't the diver's fault this failed. It was the engineers fault who let that get into the water with people in it.
When you’re in a submarine the ocean is ALWAYS trying to kill you…
Its really amazing how you just document these incredibly insightful discoveries on various topics just casually time and time again, but none of your information becomes widely known to the public somehow
The media belong to the corporate class. Its their job to keep us all distracted and misinformed, not to reveal capitalism's dirty secrets.
because nobody likes being wrong and thunderfoot makes everyone wrong
@@s_low_s10people wanna read drama and see cool implosions they dont wanna actually learn the "boring" reality
Most people have no interest in the nitty-gritty of this.
Shame he has no engineering knowledge and often makes things up.
Example: 4:55 "You can pump out that water"
Errr what? How are you going to pump out the water? And replace it with what? A vacuum? Phil aint too bright.
The only way you clear ballast tanks below the water line is by blowing them with pressurised air.
What I've been thinking during time of my life after this incident, is that when you're in water oxygen wants to escape and water wants to break in, that alone to me is crazy physics, but i also think about how in space air wants to break out and nothing wants to take it away... And one is under the stress of gravity and the other is under no gravity.... And all the ships are essentially well sealed air metal boxes with mini air tanks, air filters, AC, video and audio... idk kinda trippy.
Excellent explanation. Weird how media just bought whatever one guy animated and did not even ask any scientists whether, "hey is this animation how it physically happened? Is it accurate?"
It‘s because the media will show anything that is presented in a spectacular fashion, regardless if it is correct or not
The animation was so bad, it actually made me laugh out. I don't know how anyone can take that seriously. Mainstream media is a joke.
@richardsejour7731 It would have started as a leak, but the water leaking in would also be cutting the hole larger, so the leak would speed up, so cutting the hole even larger. This whole process would last a fraction of a second, and the whole could get large enough to completely destroy the carbon fibre part. It's a similar process to a dam collapsing from an initial tiny crack.
You must have media confused with journalism, which officially ended in Britain, at least, when islamists targeted kuffar little girls for their love of noncery, on an industrial scale.
Why is it excellent? There are like 3-4 different sub-theories branched out in the vid. The animation may be basic or crude, however all the experts seem to agree that basically it happened like that.
If these experts where to jump into TF's area of expertise and start going of with theories on something he'd done a video on, I know I'd probably be more inclined to listen to TF as that is his area of expertise.
At 20:18 I sure hope that wasn't their official cleaning of the rings, wiping it down with a rag (presumably soaked with alcohol) before the glueing process with the other hand lagging behind depositing grease / oil back onto the surface.
Even with mountain bikes, it's stated hundreds of times to never touch the surface of the brake rotor as the natural oils / grease on your hands will ruin the brake pads.
You saw the guys hand as well ! I am glad someone else saw that, and I was also thinking the same thing. So careless if that was the final cleaning.
still amazes me the amount of people who touch these things... or even when builders apply silicone with a bare finger, i dont want mouldy grout!
The guy wiping the ring is probably just a friend of Stockton Rush that was brought in to save a few bucks on labor.
That explains a lot of why Titanium parts are still perfectly intact.
I feel like there's an oversight here in the idea that the water-jet would be contacting the material being cut at this distance. As you can see in the water-jet cutting videos, the water-jet nozzle is basically right up against the material being cut. Presumably in the sub, it would have been a few feet away from the other wall and the stream would be dispersed by the time it hits the other side. Water isn't a laser.
pinhole leak? Dude, at the depth they were going to... and given the wreckage found, they suffered an implosion, which happens instantly once the hull is compromised in any way. There is no 'getting filled with water', there is "crack" then "squish", almost instantly.
Yeah I think TF is incorrect here. Not wrong with the science stuff, but ignoring the fact that Naval vessels monitored a loud underwater sound that was consistent with an implosion, and also that the fragments recovered were basically end pieces and nothing from the carbon fiber body. The fact that they recovered "probable" human remains also suggests a violent event that rendered the bodies unrecognizable. So I gotta say I disagree with the analysis here, based on what we seen publicly reported.
You can have both. A pinhole leak is enough to create delamination that results in a big final implosion.
If the leaked communications log is real, then the sub was too heavy all the way down. And they had 10 minutes of strange sounds before the loss of communication.
Good video. I'm glad to see someone else point out that ridiculous glued-together butt-joint between two dissimilar materials under extreme stress.
I forget this channel for like 5 years. Glad you're still here🎉
I haven't seen your videos pop up in ages, not a super massive fan, but I loved your debunk videos when I came across them, just about to watch this video and for once out of all these titan videos I'm sure the experiments are going to be legitimate.
Delamination was the likely cause of the Sub implosion, the noises heard from witnesses as the sub went down and up very low depth is likely to have been caused by internal delamination of the Carbon Fiber / Composite hull overtime
This is correct and never considered by Thunderfoot, because he's making uninformed guesses.
@@SoldererOfFortune There is an excellent video on the subject I watch just the other day from someone who did a PhD on just that scenario! Will post the link if I can find it again
@@SoldererOfFortune Nothing of the guesses in the video is uninformed. It's just another failure mode. If there will ever be a public report about the incident, maybe we will learn which failure mode was the most likely in this case. Sure, delamination is a probable one, but the mating area between two completely different materials is defenitely another probable one. Heck, even the 1300 m rated window was a probable failure. This thing was a red flag carrier.
@@nikethunner2732 exactly. It could have been any number of things. This is a likely scenario but there are others.
Found it, video from "Real Engineering"
As a marine engineer i can say you nailed it on this one.
Let us know whom you work for so that we can save our life by avoiding that shithole.
This makes perfect since, the Titan was having problems surfacing, we all heard that part when they had only went up like 25 meters in 30 minutes after first dropping the ballast and doing everything they could to go up. They knew they were screwed there, they had already taken on water. This guy nailed it, the best explanation I've heard. I thought I had it figured out but I didn't. most of us probably knew it was in the joint between the carbon fiber and titanium... well I guess this was close to what I was thinking but this just clarified everything. This is the smartest guy I've seen on YT, I'm gonna check out his other content
The thing is, Oak Ridge were doing this exact same thing way back in 1988. CF hull with titanium ring pieces and titanium hemisphere end pieces. And *they* rated it for 100 dives on the full scale model. They used IM6 CF on a vessel with an interior diameter of just 2', and a hull thickness of 2.5". Astonishingly, they even used the same method of acoustic monitoring during pressure cycle testing as oceangate. These vessels were cycle tested to 9000 (yes, a nine) PSI and crushed at around 12000 PSI if i recall.
Now granted, 100 cycle rating isn't great, and I have no idea how many *deep* cycles Titans second hull had endured, but the whole concept isn't quite as bat shit insane as we all initially thought. They even used the same 'lip on each side' of the titanium rings idea, and yes - it was glued.
So why did Titan fail so catastrophically then? Honestly, I think (as pointed out by other commenters) its the construction process and a lack of thorough non-destructive testing. I also think that the way Oak Ridge hand-wave away acoustic events as NOT being evidence of progressive failure is dubious.
Ultimately though, Oak Ridge only rated the AUSS mod 2 for AUTONOMOUS work. There was talk of further research into the viability of human rated submersibles with CF hulls, but as far as i'm aware it went no further. Without massive amounts of EXPENSIVE testing, Stockton Rush had NO business conducting real-world testing on an experimental vessel with paying passengers.
Please take a look at the following report for more information: www.researchgate.net/publication/235179850_Graphite-Fiber-Reinforced_Plastic_Pressure_Hull_Mod_2_for_the_Advanced_Unmanned_Search_System_Vehicle
Are you on/off meds?
" They used IM6 CF on a vessel with an interior diameter of just 2'"
"Graphite-Fiber for Advanced UNMANNED Search System"
Glad people like you aren't on some Safety Standards body.
Wanted to take the time to say we all appreciate what you're doing
Agreed
Agreed x2
X3
Imagine if the yt alghoritm would actually push his videos to more people
Completely true
There's an unverified transcript of communications between the sub and surface vessel in which the pilot observes creaking noises. The sub was also diving quite fast relative to other operators on the Titanic. If correct, the crew knew there was trouble for about 19 minutes.
He shoulda known on that first half hour check. What an idiot!
Its fan fiction at best.
Yea.. any noise would have been followed by an imediate snap.. its too brittle to crack without failling immediatly.
It's super likely to be fake tbh. Lot's of stuff doesn't add up and no news agency covering it is a big red flag. Plus it was "leaked" on TikTok of all places. But most of all, if the transcript was true, that would be a massive story, because then the whole search and rescue operation should have never happened. OceanGate not giving the transcript to the rescue operation makes zero sense.
I think the carbon fiber went without any hint. I think that there was no pinhole at all, the entire (or at least huge part) carbon hill broke open with a bang. There are recorded audio verifying that bang.
Glueing rigid (titanium) material with more flexible (carbon fiber) material ought to create displacement between the materials, and either the glue or the carbon fiber has to take the damage.
Nice video. I like how you "glued" it all together 😮
For the pressure washer demonstration, you didn't have a tight enough jet, it may say professional on the box it came in, but there's a bunch of consumer saftey baked in as well. So if it were necked down to say 1mm it would cut the plastic palnter tray
Looked like one of those cheap ones. For a decent one you need a air compressor
Insane thing, the CEO of the company (who built and owned the Titan) was inside that ridiculous, unseaworthy, monstrosity, on that fateful final journey.
P.S - regarding your 'previous video'... 26 March 2012, Director James Cameron reached the bottom of the Challenger Deep, the deepest part of the Mariana Trench. The maximum depth recorded during this record-setting dive was 10,908 metres (35,787 ft).
He was a narcissist.
but most modern naval fatalities are due to user error, so they could just skip all the strict safety regulations and just throw random sciency crap (carbon fiber) together and call it a day
He was a crazy SOB! I give him credit. Maybe he really thought he was gonna get elon musk rich..dollar signs in his mind all day
I honestly think this was well beyond simply being brash or cavalier; I think he actually got off on the death-defying element - like those parkour rooftop jumpers or people who climb without ropes - you can clearly see it in the look on his face when he talks about getting the glue right (the eyebrow-raise says it all) at 20:20
Which is fine if he wants to go by himself, like the mouthbreather who was going to prove the earth was flat with his rocket that couldn't get high enough to see the curvature of the earth. This fckwit killed 3 people with his thrill-seeking fetish.
To be fair: 3D animators are pretty expensive. Nobody wants to pay a dude in the basement to make a real simulation of something the target audience doesn´t understand anyway and paying them 35$+/h for it.
Source: I´m one of these dudes in the basement.
Edit: Guys, chill. This is a guessed average based on what a good friend of mine living in a developing country makes, which usually is the kind of person getting hired for such a job.
I know the averages in US/EU are much higher than that.
Yeah was hoping someone would say this. If FOX commissioned me for an animation I'm not doing the best job possible that's for sure 🤣
35$/h sounds pretty cheap though
Sounds like what the channel Corridor Digital would do
@@bassmeo3937 It is. But like most things, it depends on where you are hiring. Usually such productions try to cheap out by hiring in countries like India.
Yeah they usually just pay Jerry's son to do them since he is pretty nifty with that adobe program.
"She's made of iron, sir. I assure you, she can."
Love this clip
I think one of the hydraulic press channels actually reproduced this - they increased pressure, nothing remarkable happened, but when they opened the container, they found that the sub model was full of water, without any significant signs of damage.
This story has a similar vibe to the "Mad" Mike Hughes flat earth rocket. Both were repeatedly told, "You're going to die" by people who knew what they were talking about. Both were cutting corners at the expense safety, while simultaneously claiming that safety was a #1 priority. Stockton Rush and Mike Hughes are two excellent examples of the Dunning Krueger effect in god-mode.
With stuff like that, the Hyperloop, Solar Freakin Roadways and Triton it sure feels like people are actively trying to invent new lines for the "dumb ways to die"-song.
This is by far the best explanation I have seen on the topic.
"It's not the pressure that kills you it's the water expanding" has the same vibe to it as "It's not the gravity that kills you it's the stopping suddenly after a fall". Yeah. Why is the water compressed at depth? Because it's under pressure.
The porthole being made of plexiglass and the whole thing being held together with normal epoxy resin is crazy. Im suprised catastrophic failure took as long as it did.
The glue is referred to as "peanut butter" which is a term we often use in boat building to discuss thickened epoxy. Could it be that they're just using thickened epoxy and not some specialist glue that can take the enormous shear forces that will be caused by the relative compression? Also, that's a planar joint. I was expecting some sort of rim or overlap so that e.g. the titanium was surrounded by the carbon fibre, which could then compress *under tension* around the titanium and support the shrinkage. That's the thing carbon fibre is good at after all. But no, they just butted the two together with glue. The more I find out about this the more astounded I am.
Not quite a butt joint but as you point out they built it backwards, with the ring slipped over a thinned end of the cylinder instead of having the cylinder over the ring.
THIS. No lip on that ring made this thing a death trap in your 30ft deep marina let alone deep ocean. I used to repair power plant water mains (2ft diameter often) with carbon fiber and epoxy. Nobody does high pressure CF flange butt connections for a reason. I promise you a flat sheer point with no teeth or keyway on the titanium was engineering suicide. It's like this thing was designed to put on a deep sea fireworks show. 😅
@@tactileslut I was just thinking this. "Oh, it would be really smart if they put the more compressible material over the non-compressive material--WAIT WHAT ARE THEY DOING"
There is no glue on earth that could bond those two materials.
@seanprice7645 sheering force is still acting on a flat plane surface (less surface area to hold connection than lipped or grooved socket connections) and still would have a catastrophic failure mode due to the difference in material compression. The way an internal pressure vs external would fail different but the point has more to do with the poor design choice of connection. Not meant for high pressure deep sea anything. It was a carbon fiber playground they had the audacity to repeatedly risk peoples lives in. A thin seam overlap of CF on the outside wasn't a "lip" to hold anything from shifting, it was the beginning of it's delamination points in the structure. A groove should have been in the ti cap for a socket connection in a better design but still. Carbon fiber ain't that material. Keep that shit on race cars and aircraft
nicely done, no screaming, no clickbait, just logic and analysis -- thank you!
You misspelled only, ignorance and drivel. It's only clickbait, ignorance and drivel.
What I find fascinating is that the CF tube is *inside* the titanium tube. It should be *outside* so that the compression does an interference fit. Although that would not solve the flexing of the CF tube itself at the transition seem.
True, but I'm with you on that. Maybe it would just prolong the inevitable, but then again it might have given more obvious signs that some fuckery was afoot.
IDK i don't think it was a pinhole leak. As someone else mentioned the hydraulic press channel did a pretty good experiment and the results looked a lot like the recovered wreckage.
He didn't think it was a pinhole leak. He said at the end he thinks it was a crack, and the mad rush of water was powerful enough to dissisemble the vessel.
this thing imploded. It may have been a pinhole for a few microseconds but that was about it. This implosion was so violent that it probably shredded a good portion of that cylinder. heated up the air to a 1000c and roasted everybody before shredding them as well.
If you watch a recent video from jeffostroff about what might be the leaked transcript, apparently there was a "crackling sound at aft", which is apparently a walled off section where some of the equipment is. So perhaps there was a pinhole leak in the aft section that caused the increased rate of descent, very slow ascent and equipment failure reported in the apparent transcript: "trying to run diagnostics, ascending now. but very slow.... global RTM alert active all red... reading red on the A power bus. I switched to B... more sounds aft...". So unbeknownst to them, water might have been slowly building up in the aft section as they were descending due to a pinhole leak causing increased descent rate, eventually frying some of the equipment and finally causing a catastrophic failure. Or maybe the transcript was made up, idk.
The black line in the paint on my carbon fibre bike tells me that sometimes,even joining carbon fibre to carbon fibre isn't that reliable a process.
That titanic hitting the iceberg, and the iceberg, just crumbling, and then falling through the world 😂 that really gets me 😂😂😂😂
That animation of titan blowing up looked like something someone on crack would have come up with!!!😂😂😂
If you imagine the titanium caps as concrete foundations for a tubular carbon fibre bridge, you can see how it would work for a while. Bridges hold significant compression/tension across multiple materials with differing bulk moduli. Essentially the carbon fibre was compressing but the titanium was anchoring it like a bridge support. I imagine a few load cycles worked the glue loose and bam.
I'm not well versed enough to give concrete(tish) reasons, however there is no need for such an analogy.
You have 2 end caps of basically incompressible metal being pushed together/compressed axially?
At the same time, that plastic toilet roll is being pressed from all 360' radially, as 5-6Kpsi.
It seems even more possible/likely that one of the end caps had a failure where it was glued to the tube, and with the 1 meter diameter(IIRC) end cap you're looking at 5000psi * 4071sqi = 20,355,000# of force on that cap end which experiences a failure which propogates.
Didn't the US navy confirm it was a sudden implosion because implosions have a very distinct audio signature that was picked up by acoustic monitors designed to detect enemy submarines.
Well yeah it was implosion nobodies denying it, it just didn't happen like those a animations suggest
@@AverageAlien Thunderf00t is saying there was no implosion and that it just sprung a leak and filled up with water over a few seconds or a minute.
It was very likely an implosion. But if the communications log that has spread on the net is legitimate, then there was issues before the implosion.
If the texts are true, then the sub descended 50% faster than normal alreadt from the start. Which indicates if was too heavy. Either waterlogged plastic (one of the issues with CF) or ot had a leak so there was water in the sub.
Next thing is the leaked (if real) communication mentioned sounds maybe 10 minutes before the loss. And loss of one power bank while they drived to ascend.
So a leak could have started the issue. Then the leak could finally have damaged the CF hull enough that instead of just getting a larger hole it totally imploded from loss of stiffness. A leak can delamination the CF bonding.
@@mikehawk5492 Did you not watch to the end of the video? He explained how a pinhole leak escalated into an implosion.
@@mikehawk5492 The point is a tiny leak would erode away at the material it's leaking through, combined with the fact that the material it's likely leaking through is glue thats constantly shifting throughout the dive it wouldn't be too long before it failed entirely and explosively.
However the glue is just one theory, another is the hull was damaged and leaking, which like the glue would be essentially waterjet cut by the leak until it grew large enough to catastrophically fail.
Hydrualic Press Channel already did a test (I think others have now as well) where they take a carbon fiber tube to depth and back in a pressure chamber 30-50 times and it suffered no noticeable loss in strength from the cyclic loading. However the timespan was so short that no leaks would have time to actually weaken the material by abrasion. It's unlikely the hull failed simply by cyclic loading but instead cumulative damage of some sort. Which brings us back to a sub millimeter leak that slowly ate away at something until it failed, similar to how hydraulic hoses or other hydraulic failures occur, they slowly seep and leak until they blowout without much visible progression.
I suppose the big difference between the pressure washer you used and the sub leak is when that leak expanded and the hole got bigger the pressure would remain pretty much the same irrespective of the jet size, it'd go from a tiny jet to a big jet to a sub breaking water hammer, all in a few seconds.
Dirty Garage Guy has a video with a simulation of the actual sub design and does a proper job explaining and showing what probably happened, if you have 2 hours to spend the whole video or 10-20 mins to watch the actual simulation at the end of the video.
If you want the TLDR of it, it's likely to be the housing unit (cilinder made of titanium and carbon fiber) that compressed to the point where the glue that attached the housing unit to the titanium rings got so fatigued from multiple dives that it just popped open. That also sort of goes hand in hand with the leaked transcript (if it's the real one) where the crew reported 20 minutes of on and off crackling from the back of the vessel, which is probably the indication of the glue they used losing it's grip. So, the housing unit probably got compressed way too much one too many times, and the glue coming apart is very likely to be the teller of that.
Just go watch the simulation he did, it makes things _very_ obvious.
How the hell did he simulate carbon fibre compression at a depth of 4000 metres?
There are special simulation software I saw one where the acrylic window gave way first. But the glue is a strong second contestor. The window was just rated for 1300 meters.
@@alexstanciu8598 Solidworks doesn't have the correct solvers to do a stack failure in these conditions.
It was obviously leaking water on the outside from the moment they put it in the water that's why it was dropping too fast and that's why it wasn't Rising fast enough when they dropped the ballast
I'd rather bet on carbon fiber collapsing due to accumulated buckling damage. They used expired carbon fibers, wrapped them without weave patterns and likely didn't even vacuum cure the thing but just bagged it. This thing started to crackle and then collapsed.
Also CF doesnt really have any useful properties for making a vessel for deep sea... For deep space its ideal because of tensile strength.
And, considering information on other channels, carbon fiber was not only less then optimal choice and not weaved as it should and could have been, but also cured improperly.