I'm a 43 year retired Boeing guy. I'm not an engineer, but I managed engineers for about 12 years. There is a graphite fabric called Prepreg. Prepreg has the epoxy pre-impregnated into the fibers when it is being made. This type of graphite material must be cured in an autoclave. Pretty much all aerospace grade graphite parts are made this way. I've never seen Boeing parts being fabricated with a wet graphite layup like is seen in the KZitem custom motor sports world. I worked on the first five 787 program airplanes including the static and fatigue test articles. That airplane's primary structure is full of Titanium/graphic structural members. These members are electrically isolated by the use of sealing material and then bolted together. The seal is to prevent the carbon and Titanium from acting like a battery and degrading over time. In the video clip, the end rings being attached to the graphite tube looks more like a sealing material to me and that is a very sloppy process. All of this is just short of a wild ass guess and speculation about how the Titan was constructed is just that, a wild ass guess. Maybe someday the details will come out, but I'm holding on for the real data, because I want to know what happened.
@tonywilson4713
Жыл бұрын
I'm an aerospace engineer and agree 100% with all that you have said in this. If there is one thing I'd add is that *MOST* CF for pressure vessels like rocket fuel tanks is woven on. So late the fibres in some layers is at different angles. That forms that checker patter you often see with CF. The reason its done is you always want some of the fibres under TENSION (being stretched) and that weaving does that by translating the stresses via the resin. In all the vidoes I have seen of Oceangate they are just winding the pre-preg strip onto the casing. maybe they did weave other layers but so far I haven't seen it. This is the point I think you have dead right - there are unanswered questions which wont be answered until the reports are released. PLUS we really do need to know how & why this happened.
@FredsRandomFinds
Жыл бұрын
@@tonywilson4713 Pretty sure the fibres were only laid in one direction, Also wondering did they even vacuum bag the tube at the end of construction? Going by videos others had uploaded I've seen no mention of going in to a clave? Also a number of websites claim that the CEO stated the carbon used was old Boeing stock "That was past it's shelf life"
@zombieregime
Жыл бұрын
Is there something special about Prepreg that calla for a pressurized curing process? Ive working in molding and fabrication before, and I recall sometimes using vacuum to pull bubbles out of fiber glass and carbon fiber layups, so the use of a pressure vessel sounds interesting. the heat totally makes sense though, on cold and humid mornings we couldn't do layups since we couldn't kick the resin hard enough and still have decent working time before it hardened (and tried to light the paper cups we'd mix batches in on fire. Shop rule was to put resin cups in the deep sink until fully kicked with a splash of water on top just to be sure a hot batch didn't find something that didnt like getting hot in the trash bins).
@zombieregime
Жыл бұрын
@@tonywilson4713 That tension bit has been bothering me this whole time. Sure, a cylinder of carbon fiber will hold back a force pushing out (up to the failure point of course). But I STILL have yet to see anyone recommending it for a force pushing IN! Like, putting something high pressure in a composite tank and going into space, thats easy, its only a change of about 14psi. In a sub you want to keep elephants, hell city buses worth of pressure per square inch out.....and again Ive yet to see a carbon fiber vacuum chamber....at the bottom of the ocean what wants to get in is way more energetic than that....
@piotrd.4850
Жыл бұрын
Such comments are ONE THING that keeps YT worth visiting!
@kellik5453
Жыл бұрын
The descent rate is significant as it signifies that they were overweight or had another buoyancy issue since they could not ascend. The more we find out about this, the more shocked I am that it ever successfully ascended previously.
@ricktbdgc
Жыл бұрын
Would be nice to know ascent rate of previous dive, did they have trouble ascending i wonder..
@russellhltn1396
Жыл бұрын
That was my first thought as well, that they were too heavy.
@thunkjunk
Жыл бұрын
What about malfunctioning or improperly set vertical thrusters which went unnoticed? I imagine the thrusters pulling the craft down at a low but constant rate. That would explain the higher rate of descent which I believe they do a low power descent (basically just sink using ballasts) and then when dropping extra weight they still could not make progress...faulty vertical thrusters.
@dare-er7sw
Жыл бұрын
@@thunkjunkThruster issues?
@the_forbinproject2777
Жыл бұрын
@@thunkjunk we already know they had reported a thruster malfunction in a previous dive , they did not abort then but reconfigured the thruster by software on board. The thruster was operationing in reverse btw . Make me wonder it the same thing happened and was pushing the Titan downwards
@rawbebaba
Жыл бұрын
2:56 Cameron said it best "it's insidious because each dive brings you closer to death, and makes you more comfortable about diving'
@JoeLinux2000
Жыл бұрын
Interesting point.
@DreadPyke
Жыл бұрын
@SuperNostalgia. Thanks grandad, now back to the hospice...
@bagelbagelwah5047
Жыл бұрын
@@DreadPyke Lol.
@stephenfortin9485
Жыл бұрын
@@DreadPyke lmao, thank you
@kennethng8346
Жыл бұрын
Unfortunately that sounds like the Space Shuttle Challenger report. They got away with it several times so they convinced themselves it really wasn't a problem. In fairness to the shuttle, there were probably a million issues and you have to use your judgement on where to spend limited resources to fix things.
@bill6590
Жыл бұрын
Jeff, In 1972 I was a new products development Engineer for Shakespeare, Inc. At that time, the world's leader in Carbon Fiber and Fiberglass product design. In developing the 1st Carbon Fiber Golf shafts, etc. We did lots of destructive testing on carbon fiber over removable central rods & cylinder layup methods. The method used in the subs design is a simple one, that always failed in our tests. It has zero longitudinal or flex ability. You have to lay up carbon fiber in 2 or more simultaneous procedures, criss crossing from opposite directions. Between each other, going back and forth the length of the core. There are massive amounts of engineering that goes into laying up carbon fiber, layup designs, angle of fiber placements, speeds, and much more. As soon as I saw the technique used on the sub. I knew it would fail. Just like the hundreds of similar layups we tested to failure at Shakespeare Products, decades ago. It had zero chance of success. A completely stupid way of doing carbon fiber cylinders.
@desfletc
Жыл бұрын
Hi Bill, yeh your right with the criss cross laying of CF, his method was destined to fail, but also a bigger problem was the bonding of the titanium rings to the CF, I think he broke every correct way of manufacturing in the rule book, what àn arrogant individual
@culbyj3665
Жыл бұрын
could u compare those methods of criss cross to that of the SCBA breathing cylinders we use in the fire service because i was looking at them since they first came out to us after we stopped using steel cylinders. We gained so Much more as fireman in terms of light weight cylinders and the psi we could put into them we went from 2216 psi to nowadays as much as 4500 psi for 45 min to an hr long on our breathing appararrtus cylinders, Our SCBA cylinders are now carbon fiber wrapped and u can even tell at looking at them they seem to have a criss cross type of wrap. I know nothing of this except what NFPA standards teach us. But I would love to hear your opinion in comparison from titans fiber wrap to our breathing apparatus. U seem so very well educated and I appreciate your work In keeping Us safe. Thatnk You .
@alexsouthpb55
Жыл бұрын
Having worked in software projects, cutting costs by bypassing the Quality Assurance process only leads to certain failure. Combine that with a fanatical leader who refuses to acknowledge reality and unwillingness to build on existing expertise, led to these unfortunate avoidable deaths.
@Thepc425
Жыл бұрын
Your job sounds really cool !
@AnthonyOMulligan-yv9cg
Жыл бұрын
I remember buying a Shakespeare Carbon Fibre Fishing Rod, and having it in a rod holder by a lake when it was struck by lightning, I remember that there was a warning tag on the Rod. Didn't the Titan get struck by lightning?
@bwktlcn
Жыл бұрын
The discussion with PH was troubling. I have had many depressed patients over the years, and while some are actively suicidal, I think the percentage of older, widowed men who are passively suicidal is under reported - the “single car accidents,” the house fires where the battery is missing from the smoke detectors, the medication “mistakes” that weren’t accidental. PH had lost his wife, we don’t know his health history, but he’s getting older. He tells his friend it would be a “quick” way to go. The first trips to Titanic probably happened at the high point of his career, and when he sees it again, he can remember back to when he was young and his wife was alive. I’m not saying he actively killed himself, but he could have just had a “who cares” attitude where he would be okay with going if they’d told him the next trip was going to implode. So we have a complete mismatch between what was built and the requirements of the working environment, dozens of letters, calls, etc to Rush telling him the Titan was a death trap, which he responded to with nothing but anger. Egotistical idiot CEO with money who’s not as good an engineer as he thinks he is, an older sad, possibly depressed, possibly depressed to the point of passive suicide pilot, and 3 “mission specialists” that couldn’t have added any real help when things went sideways. The question isn’t why did Titan implode, the question is how did it function as long as it did. I feel nothing but pity for PH, and condolences to the families of the 3 others, but that CEO should have never had control over so much as a golf cart.
@lukewalker1051
Жыл бұрын
Well said. I was hoping a psychologist would weigh in. I also believe it quite possible Rush was suicidal as well. Would love to have an in depth conversation with you on the subject of 'subconscious suicidal ideation'. I will say this to you as a scientist and engineer. So many warning cues were given these men. Both were bright and experienced. This vessel is a veritable check list of 'what not to do' from a design standpoint. Beyond grievous oversight and irresponsible engineering judgment on 'every level.' A list of 20 things. I have to believe 'on some unquantifiable level' neither man cared about living and maybe even fantasied about joining the crew of the Titanic at the bottom of the ocean. Each man knew any failure of this vessel at 3800 meters and even above, would be immediate death. And of course, they were bolted in.
@jhoughjr1
Жыл бұрын
reading a hell of a lot into things based on unformed data and speculation.
@bernicebaker2596
Жыл бұрын
Yes for PH there was nothing else to live for after he lost his wife ..and he probably felt comfortable going down with Russ and if he died he died cause he knew about all the problems with Titan .no way could he help fix the problem at the depth they were at .like if it needed to be repaired at that moment in time..Titan would have to be brought up to the surface....they said if they were to have a problem..they were dead anyways..so yes..PH didn't care one way or the other..like all strew it..if it happens it happens..not thinking about the other innocent passengers..unaware of him and Russ true thoughts and feelings..as for Russ he had to be depressed and tired of people telling him what to do..and putting down his childhood dream mini vessel...but what I found interesting was that after he fired the whistleblower..he ask his Accountant to navigate take over and do the trips..😲.. without any prior training he told everyone that anyone can operate it with the XBOX Controller..and don't worry they keep plenty on hand..trying to convince her an future riders..dude was depressed didn't give a damn no more..if it can't ascend too bad..wonder if he was paying PH for his time and clout??
@Whyusemyname
Жыл бұрын
I agree that he was suicidal and I think it was more than passively. I disagree that he deserves pity though. He’s partially responsible for lulling people into a sense of security, who may not have taken the trip otherwise. I think he chose a selfish way to go because it was a romantic way to go in his mind and he didn’t have to do anything on his own to make it happen. Kind of like someone who just takes their hands off of the steering wheel around a bend in the road and smashes head on into a family or suicide by cop. It’s not noble if you create victims in the process.
@lukewalker1051
Жыл бұрын
@@jhoughjr1if you are a thoughtful man or woman, one has to. What occurred violates every tenant Rush was taught in engineering school and admonished by a veritable chorus of scientists in the industry. All on his deaf ears. He was literally barraged with science principles why what he was pursuing was fatal. And yet he and the French explorer continued. No degree engineered of sound mind understanding the track record of OceanGate would set foot on that vessel. A ship of fools.
@rickylandry9979
Жыл бұрын
Another thing I noticed was when they put the titanium rings on there was no squish out of the epoxy. When those rings were pressed on, you should have seen the epoxy ooze out (squish out) letting you know there was enough epoxy applied. Very disturbing not seeing any squish out when those rings were installed.
@AerialPhotogGuy
Жыл бұрын
Hi Jeff, I'm not a licensed or certified engineer but I do have an extensive background in mechanical engineering. I was very alarmed by the rate of decent that you outlined in one of your previous videos, part of the concern was about exerting too much external pressure too fast but what struck me more was "Why" they were descending so fast. They did the normal weight check of each so called crew member (passenger) including their food and other items they took with them. They already knew the amount of weight they can safely carry and they knew the amount of weight they needed to be able to eject to slow the rate of decent when nearing the ocean floor, as well as knowing how much weight they needed to eject for neutral buoyancy and a normal ascent. The decent should be at about the same rate as the ascent and according to their previous dives, the amount of time was close to 2.5 hours both ways. IMHO, the only reason for such a fast decent was because the submersible weighed a lot more than they thought. Maybe the voids in the carbon fiber tube (from separation of the fibers) on the previous dive was enough to allow water logging? I wonder if they even bothered to weigh the submersible after the previous dive? Personally, I would have weighed the submersible after each dive to see if it weighed more, but then again, I would never have attempted to dive in such a non-conventional design!! The rate they were descending on the last dive would have been enough to "Crash" into the ocean floor rather than hover as they had calculated (even after they ejected all of the weights required for a neutral buoyancy). And even after the frame was ejected, the submersible was ascending extremely slow, much slower than they expected. There had to be water in the carbon fiber tube IMHO, especially considering the fact that they were ascending so slow (even without the frame and ALL external weights).
@leer5858
Жыл бұрын
I thought maybe water leaked into the nose cone area as it was separate from the carbon hull. Is it true they heard noises coming from this section on the way down?
@kittenisageek
Жыл бұрын
My first guess when Jeff showed the rate of descent being too fast was that perhaps a cavity for boyancy had filled with water. Either way, the rapid rate of descent should have been a red flag at the first call-in and they should have started recovery procedures immediately. This isn't like a car where you simply press on the gas to go faster. Submarines are a balancing act where you adjust boyancy to either ascend or descend. There's going to be a limit to how fast you descend, because if the craft is too heavy, then you won't be able to reduce the weight enough to ascend back up.
@GrueTurtle
Жыл бұрын
does the rate of descent now slow naturally as the density of the water increases nearer the floor? or is the effect negligible?
@kittenisageek
Жыл бұрын
@@GrueTurtle There's an experiment I remember doing when I was a kid, using a jar, a balloon, and some other items. Once you had your "sub" at equilibrium in the jar, it would float just below the surface. Then you would put the balloon on the jar and blow it up just a bit, until the sub was near the middle of the jar. After that, you could squeeze the balloon to add pressure and the sub would sink to the bottom, or let out air and it works rise to the top. So, yes, the increasing density of the water due to pressure as you descend should slow the sub's descent.
@ccurrivan
Жыл бұрын
@@GrueTurtle Water isn't compressible enough for it to make a difference.
@budlanctot3060
Жыл бұрын
I have had a little experience wrapping relatively large(8" to 24"dia) marine propeller shafts with fiberglass tape & epoxy resin cladding between the raised bearing surfaces. To prepare the surface of the shaft for better adhesion, we would warm the surface with a rosebud torch while the shaft is slowly turning in the lathe. This would draw out whatever moisture is in the metal surface & help to accelerate the epoxy cure. We would follow with using a big abrasive flapper wheel to remove the slight flash rust which would form from the moisture/torch action. This would roughen the shaft surface & enhance adhesion, too. We would also machine a "landing ramp" on the ends of the bearings. This was a longish taper, with a rough machine finish and a few "O-ring like" grooves to also assist in adhesion and sealing. While the resin & tape is applied, the shaft is constantly being slowly turned in the lathe to assist in achieving a uniform application. The f/g tape is applied in layers with wraps in opposing directions. We kept spinning the shaft for 5 or 6 hrs until fully cured. The finished wrap would be spark tested electrically, per ABS stds.
@craigsowers8456
Жыл бұрын
Doomed from the get go ... no Clean Room, no Auto-Clave, no gloves/dirty shop rag and no AS9102 certification to keep it all on the straight and narrow. But hey, that's just what my 40 years in Aerospace Composite Engineering tells me. Just imagine if Rush had invested in a "Thread laying machine" (TOWS) like we use on our F-35 Program ... much stronger (offset ply orientation) ... and Rush wouldn't have been able to buy that expired (and obviously "re-tested" once) CF Tape from Boeing ! BTW, the steel cylinder is called a "Mandrel" ... wet or dry, an Auto-Clave would have done it's job. And THAT folks is why we call it "HALT" ... highly accelerated lifetime testing ... "bend it until it breaks" so you have a baseline; they did HALT but unfortunately with Humans on-board and killed them all in the process. IMHO, the Hull imploded and had NOTHING to do with the Titanium flanges/dome; the acrylic view port and domes blew off like Champagne corks (Water cannot be compressed and it had to go somewhere) ... studs smooth as a shiny new whistle ~ zero threads left nor CF tear away on the mounting flanges (there are ZERO “Adhesives” on the professional/FMS market that don’t call for application of a “Primer” prior to the actual Adhesive). His "Design Engineers" sucked ... the hull was in "hoop" yet zero internal stringer supports nor sleeve to help keep it equalized; hull thickness would have needed to be approximately 17.6 inches thick without said support structure. All the "popping noise" on previous dives was the CF delaminating, transitioning from "Elastic" to "Plastic" state ... the fibers ripped out of the resin matrix bed and never able to re-seat; Rush would have known this had he bothered to perform NDI (ultrasonic or X-Ray) after each dive. Pity his hubris got in the way ... and ended up taking PH and the rest.
@JoeLinux2000
Жыл бұрын
I'm not buying the need for a highly specialized Clean Room, but you seem to have significant experience.
@pollystyrene99
Жыл бұрын
why 50 year old engineers have value. experience and knowledge matters. that level of innovation (experimentation) has no place where client life is included and ignoring previous popping crackling noises? why wouldnt he ask a pro in that carbon fibre technique for input??
@CheeryRhymes
Жыл бұрын
@@JoeLinux2000you're kidding right? One of the major informed criticisms about the entire thing is how the carbon fibre was applied. Carbon fibre is incredibly strong but imperfections, even a tiny air bubble or a bit of hair will cause a significant weak point. In the perfect world it would always be laid in a clean room and vacuum cured... considering this was an untested experimental craft that's exactly what should have been done. That's what they do on aircraft.
@cyphi474
Жыл бұрын
@@JoeLinux2000 Any contamination is weakness.
@craigsowers8456
Жыл бұрын
@@JoeLinux2000 as is your right ... just stating what I've seen over the years doing it the correct method/process and having to scrap so many composite structures due to porosity and/or FOD even in Clean Rooms. Composites are "Science" based to achieve repeatability but approaching an "Art Form" as well. Would you believe it if I told you I've seen solid steel bond forms "leak" @24 psi of vacuum ... most think there's no "porosity" in Steel ... but most assuredly there is.
@hailstevemcqueen
Жыл бұрын
This footage of the gluing process, as mind-boggling as it is, shows the first iteration of the pressure hull that was presumably scrapped in 2020. There's only limited footage from the construction of the new hull (briefly shown in SR's 2022 Mind Geek presentation), apparently they did use a different layup - radial and axial orientation - and we dont have any new footage from the gluing of the end rings. So presumably there were *some* improvements but it looks like no one bothered to look into possible failure modes too deeply. "It'll be fine, trust me bro"
@thatshottaye
Жыл бұрын
And the sections being glued into the frame isn't that big/deep either. That's what baffled me more than anything else.
@stever2583
Жыл бұрын
If Rush was an engineer then why was the process changed? What type of engineer was Rush?
@torben777
Жыл бұрын
@@thatshottayeunder water the end caps are pressed towards the titanium at thousands of tons of pressure. They will never be pulled apart. Its not the overlap that should take the strain. Its the edge itself.
@uacnix
Жыл бұрын
@@torben777 But also along with these end caps and rings, there is some (unknown?) epoxy between them, that holds them together and that's not bolted and/or in any way (other than the force of the glue itself) secured and thus can give way to water. For me (besides the issues with the CF hull itself), its like trying to plug a hole in a pool, using a glue stick.
@torben777
Жыл бұрын
@@uacnix You are getting it wrong. The pressure on a sub is from the outside in. As long as the carbon fibre ring stays intact there could be absolutely nothing holding the endcaps there, and the water pressure would still hold them together with a force so great that they would be impossible to pull apart even if you tried. If the glue is a factor then it is likely because you have two different materials glue together, which to not react exactly identical to pressure and heat/cold. But lets see. I know I am also doing it myself, but we should really wait for the official findings. We are talking about accusing someone of having caused the death of multiple people after all, so waiting for an official finding would bevthevright thing to do. My guess is certainly a problem with the carbon fibre hull, but imagine if it turns out to be something none of us has thought off.
@ronaldcumpsty5605
Жыл бұрын
Your video's on this subject are very logical, so much that even a basic engineer as I can follow and understand. The method and concern for complete cleanliness just boggles the mind. I worked in hydraulics for most of my life and we took more precautions repairing valves and pumps than what appears to have been taken here.
@Patricia94227
Жыл бұрын
I am not even a "basic engineer", I am an Economist and I also understand and follow each of the videos Jeffostroff has been doing to explain this sad and regrettable accident. Regards from Cuernavaca, Mexico.
@ryelor123
Жыл бұрын
Don't take videos or pictures companies publish as being 100% honest. Companies have design secrets that they don't want to give out. We don't actually know how it was built. In fact, we don't even know if the things in those videos were part of the sub.
@joshdoe7288
Жыл бұрын
The most intriguing thing in this video was the though that P.H most likely knee this would happen eventually, and because he felt he was old/ grieving from the loss of his wife was almost using it as an unpredictable yet quick suicide method. That’s both extremely sad and frustrating all at once.
@thatcityboy73
Жыл бұрын
just so happened he didn't care about the other 4 people that would die with him
@Tank50us
Жыл бұрын
For those asking about the descent rate, think of it like G Forces on a fighter jet. If you make a very hard 7G pull in an F-14 Tomcat for example, just yank the stick back, at 7Gs, the wings snap off. But if you're more gradual, you can pull until about 11Gs before the wings break (or you stall). The rate at which pressure on the hull of a sub increases is factored into the design, If you descend too quickly, the hull will give, and you pop like a zit. Descend below that rate, and odds are you'll be fine.
@DKFX1
Жыл бұрын
The difference between descending 25 meters a minute and 35 meters a minute is not likely to be the cause of implosion. There's simply no force that could easily explain why a slightly faster descent rate would cause any damage like this.
@andyrbush
Жыл бұрын
I do not think there is any comparison.
@bentorres-betgaming
Жыл бұрын
@DKFX1 38.8 meters per minute. We're talking per min, that's 13 more meters per minute than what it was supposed to. Think about the difference between going 80 and 100 mph. Only 20 mile per hour difference, yet most cars start getting really uncontrollable at 100 mph. Not a perfect analogy but the vehicle was tested and meant to go a certain speed. If the transcript is true the crew on the support vessel asked if they should lower their decent speed multiple times. No engineer but simple imagination connects the dots as to how that speed affected this dive. I do think the implosion was bound to happen eventually regardless of the speed of decent though.
@tomatosoupwoo
Жыл бұрын
@@DKFX1it’s an extra bar per minute. Put that into psi and you’ll see why that could cause damage to the already damaged design
@zzaacchh
Жыл бұрын
@SuperNostalgia. cuckoo
@kingfishca30
Жыл бұрын
Spot on @Jeff. Rapid descent is a major red flag. Anyone who's experienced scuba diving will always tell you about controlled descent so your body can equalize to pressure depths.
@cluelessbeekeeping1322
Жыл бұрын
The pressure inside the sub isn't high. As in, descent rate does not matter.
@ClumsyCars
Жыл бұрын
@@cluelessbeekeeping1322 could matter. A fishing line will hold a lot more weight if you slowly load the line vs a sudden application.
@jomomma624
Жыл бұрын
@@cluelessbeekeeping1322yeah I’m sure the pressure of the ocean depths just disappear 🤣🤣🤣
@wedontlikenoneofyou
Жыл бұрын
@@cluelessbeekeeping1322I believe the descent rate is what caused this
@devn2190
Жыл бұрын
@@jomomma624 yeah, I’m thinking instantly adding a massive amount of pressure opposed to gradually allowing the carbon fiber to “flex” like a muscle ; had a lot to do with the implosion.
@ShootingStar_JB
Жыл бұрын
Good God, this just gets more sad and vile by the day / discovery of additional details. Great analysis and really appreciate you putting these discussion videos together!
@89TStefan
Жыл бұрын
I am a software engineer working also on PLCs (Programmable Logic Controllers). And I find it fascinating that only a very few people question using a wireless controller in a potentially radioactive environment. The ocean also has some sort of natural radiation too. This interferes with signals and may cause signal loss. The problem about those wireless controllers are that once they lose the connection, they still keep to the last command being issued, e.g. if someone said "down", it goes down until receiving another signal. If the connection is lost here it would explain why the submersible decended too fast. Maybe they lost the connection downways, not paid attention, and then it was already too late?
@uacnix
Жыл бұрын
I've crashed far too many cars and planes in games, when I used some cheapass wireless keyboard that dropped the connection randomly, but it would be tragically hilarious to lose a sub cause your controller did the same. But on the other hand couldn't they just unplug the receiver? If it was running on some common OS (and I believe it was some linux for steering and windoze for that bigger screen), it should just stop registering the button push/joystick position and level itself at "zero"?
@wiewioragaming5726
Жыл бұрын
If the thrusters where pushing them down, that would explain why they didn't ascend faster after dropping ballast (assuming the ballast drop was successfully completed). Also, as with many disasters, there might have been more than one thing that went wrong and thus multiple failures accumulated
@notean
Жыл бұрын
Generally, quality wireless (wifi) controllers should work fine at this short distance. It should be tightly packaged in high pressure containers. Bluetooth will probably be not good underwater. You likely want at least two hubs outside main vessel in different containers. Wireless has error correction built into protocol. Radioactivity will kill crew long before it causes any serious problem for wireless link. Although, I think it would be so much safer to bring fixed wire outside of main vessel and have wireless link as backup solution.
@89TStefan
Жыл бұрын
@@notean The problem is just, that we talk about a Logitech F710 controller here. Yes, they are good and also have implemented a function like that, however, there is still a certain risk for an accident like that to happen which is why I pointed it out above.
@IAM-iv1oz
Жыл бұрын
@@uacnix They were running Windows 10.
@dutchymon
Жыл бұрын
It was just a giant roll of carbon toilet paper.
@OofusTwillip
Жыл бұрын
And OceanGate's liability waiver is nothing more than bumfodder.
@JoeLaFon3
Жыл бұрын
"...just a giant roll of expired and unwanted carbon fiber toilet paper..."*
@car8820
Жыл бұрын
? Not really, it just want up to the job
@kathynj6479
Жыл бұрын
Thank you. Your explanations and visuals are informative and easy for this non-engineer to understand. I worked with engineers for decades, though, and also watched some things being manufactured, so pretty much know when something doesn't make sense and this submersible didn't make sense to me but I do know my limitations. Your videos explain why so much of this was bothering me. Thank you!
@keithpenny1119
Жыл бұрын
❤ (i've been obsessed trying to work out what happened... I just don't know why)
@nigelwilliams7920
Жыл бұрын
The descent rate was pretty constant down to their report at 09:17 (2960 m depth) at about 39 m/minute, then over the next 11 minutes from "no adjustment needed" the descent rate increased from 39 to 44 metres per minute, and the RTM alarms started as they approached 3433 metres depth. Something was causing them to loose buoyancy and sink faster over that last stage. They never reported water entering the pressure hull, so the buoyancy loss must have been caused by deformation of the hull resulting in lower displacement. IMHO.
@Jesse-qy6ur
Жыл бұрын
My first (mostly uninformed) thought would be water permeation of void spaces in the carbon fiber. CFRP doesn't really "do" plastic deformation.
@ryelor123
Жыл бұрын
I think there was an insidious short circuit that wasn't bad enough to flip a breaker until they got to that depth. Probably overheated the battery. The reduction in voltage to the thrusters would explain their slow ascent and rapid descent. Since salt water isn't a perfect conductor, this problem would go unnoticed since the resistance would've still been high enough to prevent a breaker from flipping. This is why complex machines have so many gauges that measure every single thing.
@nigelwilliams7920
Жыл бұрын
@@ryelor123 As I understand it the descent and ascent were primarily 'powered' by ballast on the way down and by dropping ballast on the way up. The surface-Titanic-surface trip was not done by using the thrusters - to do so would have used a lot of power that the craft did not have. The thrusters were used primarily for manoeuvre off and onto the launch sledge, and for touring the Titanic.
@wiewioragaming5726
Жыл бұрын
would turning on thrusters account for the speed increase to 44?
@jasonlinton9902
Жыл бұрын
Do you think it was possible for water to get in between the metal hull and the carbon fiber and the deeper they went the pressure made the leak worse and thats what was weighing them down? Their decent rate was way to fast and their accent rate was way to slow the only thing i can think of that was weighing them down had to be water somewhere in the hull maybe in the aft tail and thats why the batterys were burning out
@grunthostheflatulent9649
Жыл бұрын
The pressure hull is made of two completely different materials that perform completely differently. The bond between them is always going to be the weakest area.
@2RBYT
Жыл бұрын
Yeah I think worrying about how it was initially glued or prepared in that sense is like worrying about how the lipstick was applied to the pig. It's still a pig and no amount or application of lipstick is going to make much difference. Those rigid titanium pieces may have intruduced enough local strain to break the carbon fibre as it alone attempted to compress under the pressure. If that didn't happen, then at least it would have done a number on that glue connection. And weren't those recovered titanium pieces conspicuously free of carbon fibre remnants?
@MikeBurns-bi5xj
Жыл бұрын
In my opinion they didn't use touqe wrenches
@owenswabi
Жыл бұрын
@@MikeBurns-bi5xj would it really matter either way?
@KenjiMapes
Жыл бұрын
Yeah, and therein lies the problem: it wasn’t one but 3 disparate materials with different strengths & weaknesses. We all know US Navy subs which don’t even descent to those depths is windowless & basically a uniform cylindrical structure. The Russian submersibles had portholes but had a relatively long diving record that created a precedent for their viability. The Titan was carbon fiber, titanium & some type of polycarbonate or something for the port hole. It was all joined by glue. No matter how tight the tolerances were & how thin the flue layer way, pressure always seeks the path of least resistance as you mentioned. Stockon Rush might have been a bold innovator & courageous. However like most pioneers & innovators there are always attendant elements of hubris & risk involved in pioneering endeavors & adventuring. As the Roman historian once stated to this effect “There has never been a genius without a level of madness.” I’m an ex-US Army tanker. The 120mm main gun is a forged smoothbore barrel made from super high quality metal alloys free of impurities that is lined with chromium. Anyway, it has a thermal shroud around it. As you fire the main gun, there is a thing called thermal droop. The true axis of the main gun deviates ever so slightly from heat, weather, etc This is a precision direct fire tank gun that requires exacting ballistics and aiming for efficacy & accuracy. So we constantly bore sight it & while the ballistic computer helps calculate things like cat, lead, etc sometimes you fire without the computer on your auxiliary sight without the computer to aid your aiming & other factors. So boresighting & dialing in everything is critical. One of those things is accounting for the minuscule mms the gun’s barrel may change which affects the ballistics. This is just the gun too & deals with the affects of firing & the heating & cooling of the barrel from firing, friction, etc. It deals with accuracy & not safety like the Titan. So the fact that it was 3 different materials that went through many cycles of diving, immense pressures & the cyclic contracting, etc obvious put a lot of wear & tear on the structural integrity of it. If a 2,000lb gun barrel that is 1” thick of the highest quality steel can warp or bend ever so slightly from some heat, rain, then an experimental submersible undergoing what? 400 atmosphere of pressure in fluctuating but mainly near freezing to freezing temperatures, it will more than marginally affect the molecular structure & structural integrity over the cycles. Maybe the dissenting voices should have been louder but Stockton Rush was his own man but I think his hubris clouded his risk assessment. The problem is that he might have oversold the Titan’s safety to the passengers who put their trust in him. As brilliant & bold as he apparently was he had some misguided disdain for safety. The waiver form to all clients should have screamed red flag. In fact famous Discovery adventure host Josh Gates was uncomfortable with the Titan & had the opportunity to go but decided it wasn’t for him. Smart men know or maybe prudent men know their limits. That’s not to pile onto Stockton who sadly perished. It’s just a tragedy that eerily mimics the fate of the Titanic & its captain. You can’t spell Titanic without Titan either. Bizarre. Maybe some more testing would have yielded some crucial data. If it could ascend without power maybe they should have tested an unmanned variant multiple times to test long term affects on this experimental submersible. $250K checks per person could be a poisonous impetus to rush (no pun intended) things, cut corners & push forward without more stringent testing. Anyway, RIP to the crew & passengers of the Titanic & Titan & condolences to the grieving families.
@ryelor123
Жыл бұрын
You're forgetting that pressure is going to be holding them together, not push them apart. Its kind of like doors on an airliner that are impossible to open while its flying due to pressure.
@TruckingShooter
Жыл бұрын
It honestly seems like PH had at least a bit of a death wish, even if he didn't want to admit it. He prolly felt that what's the worst that will happen? That he will go join his wife and he won't know what hit him? As someone who came close to losing someone a couple years ago if i lost my partner i can say that i honestly don't know that I'd still be here today.
@petergibson2318
Жыл бұрын
An old man with a death-wish had no right to bring an innocent 19 year-old down with him.
@K1OIK
Жыл бұрын
prolly?
@outdoor044
Жыл бұрын
@@petergibson2318Agreed. IF that was he was thinking, it's pretty selfish to knowingly bring others to their death because you're ready for your own.
@electrictroy2010
Жыл бұрын
@petergibson2318 HOLD UP the 70 year old man didn’t invite the teenager along. The CEO did that. Even if the old man said “We shouldn’t have a teen onboard,” the CEO would just tell him to get lost (like he did with his safety engineer).
@electrictroy2010
Жыл бұрын
@outdoor044 WHEN you only have ~10 years left to live, a sudden death is no big deal. You lost very little. As for the teenager, the 70-year-old probably said “We shouldn’t have teens onboard” and the CEO ignored him (just like he ignored his safety engineer & fired him) .
@westa1762
Жыл бұрын
This world is on a morbid curiosity kick with this sub.🙂
@franktaylor7617
Жыл бұрын
Definitely one of the more interesting subjects to learn about currently. It's definitely tragic but there's a lot of lessons to be learned from it.
@electrictroy2010
Жыл бұрын
Don’t be stupid like this CEO is the only lesson I see. All the other lessons were learned decades ago (but he chose to ignore them).
@ryelor123
Жыл бұрын
The problem is we don't actually know how the pressure hull was designed since obviously a company isn't going to make public how it made the most important part. I think it was a short circuit that led to a battery failure. It could have been a clever murder by someone close to one of the passengers.
@stevesurfaro
Жыл бұрын
Hi I'm a structural engineer. Regarding unidirectional carbon fiber weave, which appears what version was applied to the cylinder, one major drawback is its workability. UD tends to fall apart quite easily during the layup process since it has no interlaced fibers to hold it together. If the fibers are placed incorrectly it can be almost impossible to correctly reorient them all again. When the fibers are not placed in a uniform manner, the weave's unified strength is compromised, much the same way threads loosen in clothing when under repeated use. Moisture in the application process keeps each application set uniform as they're spun. It appears that there were no machine vision cameras to verify uniformity in the process. Today's computer vision can leverage multiple sensors, visible light, ToF, thermal to immediately detect uniformity errors or a deviation from the intended weave to achieve strength at the joints. This process is often used in carbon fiber bike frames, where the weave may create stiffness near the bottom bracket and seat lugs, but allowed to be more shock absorbing in the middle for a more comfortable ride. Jeff you are also correct about methods to increase the coefficients of static & dynamic friction of the adhesive bonding surfaces through longitudinal grooves or simple surface abrasion.
@stevesurfaro
Жыл бұрын
Sorry for being verbose, but structural design with CF, and other fiber types requires the process be part of the engineering. After Jeff's comments regarding lack of prep on the Ti cap's surface used for adhesive, and that there were NO CF Fragments now is stuck in my mind, excuse the pun! The epoxy slipped RIGHT OFF THE Ti Cap the same way ice or stiff rubber at low temperatures leaves a glass surface. The last shocker was the pilot's severe depression. He himself didn't realize he was suicidal.
@ryelor123
Жыл бұрын
Keep in mind that that was probably the inner hull that wasn't the one that resisted the pressure from the ocean. The inner hull just had to support the weight of the furniture, passengers, toilet, screens, etc. The pressure hull was probably never shown since that's where the design secretes laid. Also, don't trust videos that companies release since, for all we know, that could've been footage from another company. The actual pressure hull would've been done differently since the fiber would've had to been used in a way where it was in tension while under pressure. The thing in the video you saw was designed to counteract pressure from within. The actual pressure hull was likely made out of strong rings with carbon fiber woven between them much like power lines on utility poles.
@chuckger1625
Жыл бұрын
I believe that Oceangate used a wet epoxy ( normally a 2 part) that heats up as it cures and traps small air bubbles and the way around it is use that autoclave to cure it under pressure avoiding trapped bubbles. That is what all the airlines used when using carbon fiber in their wings now. I think they never sed the wet method. I also believe that Stockton said he used the Autoclave system when in fact he used a wet Epoxy to cure as you see in the videos.
@life_of_riley88
Жыл бұрын
I have heard that it was expired "pre-preg" but if it was in fact wet layup. . .🤦🤦👍
@jeffostroff
Жыл бұрын
yes heard the same thing. Why would Boeing sell expired fiver
@gbear1005
Жыл бұрын
I would do the winding under partial vacuum
@MrJC1
Жыл бұрын
@@jeffostroffwell if you are going to make something like a boat or something noncritical then it would be fine.
@ironbomb6753
Жыл бұрын
I didn't see a wet lay up. I saw pre-preg carbon fiber being used. IF an autoclave was used, there would have been a form inside the tube so the pressure and heat could have turned the lay-up into monolithic block of material. Autoclaves have been used as an oven only, missing the most important benefit of the autoclave.
@kaidzaack2520
Жыл бұрын
Thank you sir! I have no idea of submersible vehicles, but once put a carbon fiber „body kit“ on my car (carbon on metal). 90% glue and 10% screws/bolt joints. It is crucial to roughen up the areas where these components are glued together, otherwise pure wind and shear force would strip your kit off at 200 km/h…maybe a clumsy example but…just saying…
@alanaland1990
Жыл бұрын
I think the enormous pressure pushing the end hemispheres against the CF tube would mean the glue is more of a sealant.
@kaidzaack2520
Жыл бұрын
@@alanaland1990 Thank you! I also assume that pressure is a way to seal things - but the sealant itself undergoes stress of constant pressure/relief cycles. Not sure what maintenance intervals this vehicle had. As it was not a „maiden dive“ it surely worked for a limited time. In the end it was human failure - either from technical side or due to pure curiosity. Even if you would pay me 1 Million I would not aboard such a death trap…
@alanaland1990
Жыл бұрын
@@kaidzaack2520 I agree, blind Freddy would decline even tho he possesses heightened hearing to listen for that crackle.
@Kyle-sr6jm
Жыл бұрын
There is a reason O rings exist, and we don't use glue joints to withstand pressure cycles on the scale of Titanic depths.
@kaidzaack2520
Жыл бұрын
@@alanaland1990 If you hear a crackle it might be too late already…😝
@donwjaco
Жыл бұрын
I piloted a 2 man submersible during a salvage operation off the coast of maine. The only reason the Titan descended too fast was that it was too heavy, probably due to seawater beginning to enter the carbon fiber prior to the implosion.
@shaymcquaid
Жыл бұрын
Improbable.
@adamw.8579
Жыл бұрын
@@shaymcquaid So said the captain of the Titanic and former CEO Mr. Stockton ... Physics said: check.
@hillbillybeerdranker6678
Жыл бұрын
You might be right don. A guy on the internet showed pictures of large air bubbles or bulging pockets on the cylinder in the rhino lining coating where it separated from the Carbon fiber. He waterproofed the outside with this rhino lining that people put in their truck beds. His theory was that the rhino lining eventually got so much water in between itself and the hull that it created heavy water bags weighting it down. Like you said, it could have also entered the layers of carbon fiber and weighted it down.
@ryelor123
Жыл бұрын
There would've been no room for the water to enter. It was probably a high-resistance short circuit. That would've caused the thrusters to be weaker because the voltage to them would've been lower. However, the current to them might have been what the computer controlled and thus it didn't notice the low voltage. All was basically green until the battery overheated. Then he turned the thrusters onto full power and it did what lithium batteries do when they're not happy.
@wecanrebuildhim
Жыл бұрын
Your channel has ,by far, addressed the necessary issues raised form this event and asked the correct questions. Well done.
@kevinrice7635
Жыл бұрын
Agreed 💯
@billharris6886
Жыл бұрын
Thanks Jeff for bringing some more details on this submersible implosion. One thing that surprised me with is submersible design was the attachment of the end caps. The interface is such a small contact area and is totally dependent upon the adhesive. As a bare minimum using the adhesive only attachment, I assumed the end rings would have inside and outside shoulders, at least 1 inch thick and 1 foot long to give significantly more contact area for the adhesive bond for the titanium/carbon fiber. One thing I haven't seen but, would think mandatory for this experimental submersible is, something that actively measures the deformation of the carbon fiber cylinder. Since the cylinder was wound like fishing line on a fishing reel (obviously to simplify construction), I would think it would be very vulnerable to shearing.
@kevinfergerson7169
Жыл бұрын
Excellent analysis, Jeff! I am surprised that there wasn’t an Abort criteria for excessive descent rate. Even if structural integrity was of no concern, it seems at some point higher than expected descent bring buoyancy into question and the ability to safely abort the dive or even normally return to the surface.
@Jesse-qy6ur
Жыл бұрын
Knowing what we do about Stockton Rush, I don't think there's much cause for surprise. The idiot probably considered it a bonus as it'd save on oxygen supplies and let them extend the dive.
@ryelor123
Жыл бұрын
I'm guessing he just assumed it was a current or something. My guess is that there was an electrical or mechanical failure. That would explain why he had trouble releasing the landing gear. Something was probably arcing which was reducing the voltage that went to whatever solenoid detached the landing gear. I don't know if anyone knows how a lithium battery bursts at those depths so this could all have been caused by an electrical short.
@hamonryechinaski180
Жыл бұрын
It's mind boggling that it wouldn't immediately be flagged. Surely it makes transcripts fake? BUT James Cameron knew they'd dropped their ballast...If its dropping even 1% faster than the normal then its an instant abort AND it's one of key rates to be monitored. Bizarre.
@sperestillan
Жыл бұрын
Just finished the newspaper article you linked, and all I can say of Rush now is, what a conman he was, and the way he treated Lochridge and others who tried to warn him was despicable. Yes, Rush paid the price for his ego and vanity, but so did many others.
@kevinthomas5364
Жыл бұрын
I am a former USN submariner and commercially, I have an extensive engineering background in (metal) pressure vessels and their operation. The strength of a steel vessel is directly correlated to the materials (i.e., alloys) it is composed of, it's geometry, the various pressures imposed upon it, and the RATE that these forces are imposed upon it. The two main constituents of these forces are temperature and pressure. Total temperature and pressure changes over the range of operation, as well as the RATE of those changes have a significant effect on the strength and viability of the vessel. These two forces can be either additive or opposing on the vessel. For the Titan, these forces were additive for both descents and ascents. Cooler water encountered during descent compresses the titanium domes inward with the sea water pressure forces acting in the same manner (i.e., inward). Steel conducts heat faster than Carbon and steel will also contract under pressure as well. The Titanium rings therefore would be contracting onto the carbon hull where these two are joined together. I have no idea what this Carbon matrix's co-efficient of expansion/contraction is due to temperature or pressure changes but I'm willing to bet it lags steel by a significant amount. This unequal contraction/expansion of these two very different materials would result in very different stresses in those (junction) areas during dynamic operation versus sitting on the surface where the only change in stress would be due to the slow change in atmospheric ambient temperature. Steel is more susceptible to "Brittle Fracture" (i.e., sudden breakage) at low temperatures therefore temperature changes and pressure application need to be performed slowly (e.g., rate of ascent/descent). Brittle Fracture typically occurs without warning whereas structural failures at or near operating conditions (i.e., design temperatures and pressures) are more forgiving and may just result in a deformation of the geometry of the vessel (with a warning and without failure). Vessel breaches (i.e., failure) due to Brittle Failure can be minimized by adhering to strict operating procedures that (among other things) limit the RATE of temperature and pressure forces on the vessel. For a given composition and geometry of the metal, these parameters are already known to engineers. For new designs, these known quantities are a starting point in the design with additional testing required for certification. In conclusion, even if the Carbon-Titanium (and glue) pressure hull was certified to dive and operate at 4000 meters and 31 degrees F, the RATE of the descent (and ascents) would be part of the requirement for maintaining any certification. In addition, cyclic fatigue would have to be ascertained in order to facilitate periodic inspections and maintenance that is typically required to maintain any type of engineering certification for pressure vessels.
@jeffostroff
Жыл бұрын
Great analysis Kevin thanks!
@bagelbagelwah5047
Жыл бұрын
Awesome analysis as always! I'm still curious as to why the sub descended too quickly and made little progress in its attempt to surface. I've seen comments make suggestions as to why, though I'm still curious what your thoughts on the matter are. Regardless, thanks for providing us with detailed videos! They're really enjoyable.
@utube321piotr
Жыл бұрын
It was taking on water
@russellhltn1396
Жыл бұрын
Too heavy/wrong ballast.
@KinariCuzz
Жыл бұрын
@@utube321piotrjesus this again… it CANT take on water and reach those depths.
@gailcullinan349
Жыл бұрын
Read Tock Rush's texts to the ship ... it appears that he was struggling to ascend
@yourshadows
Жыл бұрын
@@russellhltn1396it wasn’t too heavy that was the point of carbon fibre and ballast wasn’t wrong because they successfully used it before it doesn’t matter if they were construction pipes if they worked before. They had trouble dropping weights and landing frame because of electrical failure according to the transcript
@teamidris
Жыл бұрын
The glue on the titanium rings is there to hold it together at the surface. During diving the pressure holds it together, like the O ring on the domes. It’s just a seal.
@R0swell5104
Жыл бұрын
Yes agreed, the adhesive and the video game controllers are just red herrings.
@bobgteen6496
Жыл бұрын
Yaa. No. Because the pressure woukd have been inconsistent in uts deforestation systems
@JoeLinux2000
Жыл бұрын
Good point. I thought of that too, but it's also a point of potential leaks. There a lot of forces at play. It may be impossible to determine exactly what happened without recordings from inside the craft. It could simply be sudden catastrophic failure.
@ivarhusa454
Жыл бұрын
I get that, but might differential thermal and/or elastic properties between titanium and graphite produce enough shear in each dive that it could fatigue to the point of a pinhole size leak? Is the bonding adhesive elastic enough to take the cyclic loads? Their elastic moduli differ (depending on alloy and such) by factors of no less than 2 and perhaps as high as 10. Five might be a good enough approximate for our speculation. Stiffness matters a great deal.
@teamidris
Жыл бұрын
@@JoeLinux2000 I believe the cylinder was failing because carbon fibre doesn’t work in compression, but we need to re-build Titan and put it in a test chamber to know for sure.
@bamadad53
Жыл бұрын
Sir your videos are some of the best information regarding this tragedy that I’ve seen. Thank you for sharing.
@DKFX1
Жыл бұрын
Hi Jeff. You have to remember that the Titan hull was actually 2 seperate hulls. The first one build in 2016-2018, and the second one build in 2020-2021. There are documents online from before the distaster that describe how the hull was wound. The inner layers were prepreg and the majority outer layers were wet wound perpendicular to the tube as shown in here. Also the first hull was designed by spencer composites while the second hull was constructed by electroimpact under more controlled circumstances, including autoclave. It was the second hull that failed obviously.
@exshenanigan2333
Жыл бұрын
Interesting information, are there any sources that you could share to verify this? I'm interested in checking it out. Thanks in advance!
@DKFX1
Жыл бұрын
@@exshenanigan2333 Stockton held a talk at geekwire where he mentions the two different hulls. There's also a bit of info on the titan wiki page, as well as some older articles on geekwire.
@exshenanigan2333
Жыл бұрын
@@DKFX1 thank you, I'll check them out!
@mikefochtman7164
Жыл бұрын
Well the now infamous video showing the winding of CF includes a shot of the CF being wound onto a bare metal mandrel, not a layer of preprag. That may have been the first, or second hull, don't know. But at least one was started with winding onto a bare mandrel.
@matchesburn
Жыл бұрын
@@mikefochtman7164 You guys keep going over the gluing, material and curing process as if that matters... I have news for you: a multiple dive deep sea submersible with a carbon fiber pressure hull is going to malfunction if you dive it it enough. Not if. When. Because carbon fiber is one of the worst materials to put compression/decompression cycling on with loads this extreme. It doesn't matter how it's manufactured. It's going to malfunction, eventually. There's a reason why carbon fiber deep sea submersibles are a "one-and-done" thing. They don't have the structural strength to do dive after dive. And each time after the first is on borrowed time.
@alecb8509
Жыл бұрын
I am more careful not touching bare metal parts when doing a simple head gasket replacement. The lack of awareness of these assemblers is astonishing!
@WahrheitMachtFrei.
Жыл бұрын
I wonder if the guy with the dirty rag and bare hands is watching these videos and sucking a thoughtful tooth... 🤔
@coleuk8817
Жыл бұрын
The excessive descent speed has surely got to be a contributory factor to what subsequently occurred. If the transcript is authentic, what is really striking to me is the apparent lack of concern expressed about this issue from either Titan or its mother ship within the messages exchanged.
@it_sundae
Жыл бұрын
The problem is Rush acted like an asshole every time someone had any kind of concerns. He spent an insane amount of money hushing ex-engineers who tried to tell Rush that his submarine needs to be refactored. So he either replaced the mothership full of "yes men" or threatened them with their jobs if they told him he was wrong or had concerns.
@kisstune
Жыл бұрын
I wonder if the descent speed was because or partly because it had already sprung a leak and was taking on water.
@mrdan2898
Жыл бұрын
The mother ship did show some concern. I'm guessing that the mother ship knowing that Rush was the pilot, was knowing they would not need to express the fast decent. And even when the mother ship mentioned the increased decent speed, Rush did nothing but dismissed the concerns.
@soleiltounsi6754
Жыл бұрын
They expressed their concerns only when it was too late.
@tarasingh1584
Жыл бұрын
Maybe the guys on the main ship didn't know how to do math so they didn't understand it was going to fast none of them.seem very smart.
@justincaldarella
Жыл бұрын
The carbon fiber you are referring to is called prepreg carbon fiber, where the strands are pre-impregnated with resin and cured to a green state (partially cured) Once in place, the new carbon fiber part is placed in an autoclave under vacuum, not pressure, along with heat to cure the part.
@thedoctor16
Жыл бұрын
People are getting confused because a CF pressure vessel is cured this way however the vessel itself is pressurized during the cure.
@additudeobx
Жыл бұрын
Jeff, think about this also with your decent rate theory. The decent reached the Titanic in 90 minutes. When they realized they had alarms, they jettisoned ballast to start the assent. However, the assent rate was extremely slow. I think they were probably taking on extra ballast during the decent. Edit for spelling.
@Inkling777
Жыл бұрын
Quite right. And floating in the ocean, that extra ballast during descent could only come as seawater filling spaces that were lighter than seawater, perhaps the battery compartments. The latter would explain the electrical problems.
@BurnerJones
Жыл бұрын
I work in a shop that builds custom carbon fiber parts daily. I want more information before drawing any conclusions. I'm sure they are using some kind of prepreg (Carbon that already has resin applied, requires cold storage) and then after the layup curing it with a large oven (Very specific ramp and soak parameters here) under vacuum or an autoclave. Applying thickened epoxy or other two-part glue by hand is pretty normal, you just always want to apply more than necessary so you have good squeeze out on the edges of the glue joint. It's easy to clean up excess glue that squishes out, it's extremely difficult to take everything back apart because you didn't put enough glue in. I'd love to look at the datasheet of whatever glue they were using and see how appropriate its use was for this application. As for bonding to titanium, I have no idea how well that would work. We do use titanium reinforcement in some of our parts but it is completely encapsulated by the carbon. Think a skeleton of titanium with several inches of prepreg carbon surrounding it on all sides. If the part isn't completely encapsulated by carbon we use nuts and bolts, never glue. I'd be too worried about the carbon and glue delaminating from the metal to even try it.
@trebushett2079
Жыл бұрын
If they were descending too fast, implies not enough buoyancy, which explains why they couldn't ascend at any decent rate when they dropped ballast.
@kathypriest95
Жыл бұрын
But if you have no power to release the weights....😢
@larky368
Жыл бұрын
But Rush stated that buoyancy doesn't matter. Nor does communication or life support or steering or propulsion. Nothing matters except hull integrity. He was an egomaniac.
@electrictroy2010
Жыл бұрын
@kathypriest95 THEY did release the weights and the frame. And still had power thanks to a backup battery .
@Thepc425
Жыл бұрын
@@larky368hull integrity which he didn’t have to begin with💀 man you must watch the videos of him selling it so cooly with his silver tongue
@stargazer7644
Жыл бұрын
@@kathypriest95 First, why wouldn't they have power? Second, they had multiple ballast release mechanisms. Only one required power.
@silentpoet75
Жыл бұрын
I've been working on teaching myself to weld titanium. The precautions I took for my first weld was to clean with acetone while wearing vinyl gloves(the white cotton gloves I ordered had not arrived yet). Let the acetone dry for a bit. Then only handle the metal while gloved. While welding I used a new stainless steel wire brush to clean in between welds. I also used new tungstens to make sure no other metal would contaminate the weld. The weld turned out a perfect silver color once I got the amperage right. In so many aspects I do not see that level of care from Ocean Gate. The domes were not torqued to specific specs that I can see. The one clip I saw they were using a ratchet on one end and a wrench on the nut side. I have not seen anything that indicates the bolts were examined between dives. A drag race team will measure every bolt in the engine between runs. I suspect one problem, and Joe mentioned it in one of his videos, is how titanium would react differently to the compression/decompression cycles. I don't think their engineers accounted for that.
@DanielJohnson-ec8rk
Жыл бұрын
Torquing the bolts would be unnecessary. The equal pressure underwater would be natural and complete the seal. A human could not apply anywhere near the torque that diving to those depths achieves naturally
@amyc9155
Жыл бұрын
That New Yorker article is SO well written and researched.
@jasonharrison4816
Жыл бұрын
Are there transcripts available from previous dives? Would be interesting to check the descent rate of those vs this last one.
@JoeLinux2000
Жыл бұрын
It would also be valuable as a way to check the language of the recent one, that I suspect is fake.
@undeadarmy19
Жыл бұрын
You are a very wise man. No, this guy didn't check the previous dives, otherwise he'd know that the descent rate wasn't the issue. He keeps comparing the descent rate to when James Cameron made dives, which was a completely different fckin vessel, and, that also doesn't mean that faster descent rates arent ok. Oceangate performed hundreds of dives, including 13 dives to the Titanic, and all of those dives were done in around 90min, so the descent rate isn't an issue.
@qarnos
Жыл бұрын
@@undeadarmy19fake news gets views
@Bdiorio526
Жыл бұрын
@@undeadarmy19 But Oceangate advertised on their website that the dive time to the Titanic was 2.5 hours. That is his basis to say they were going too fast.
@electrictroy2010
Жыл бұрын
Undeadarmy needs to unalive himself before he procreates & spreads his “stupidity genes” to the next generation
@sethaldrich6902
Жыл бұрын
Yes descending too fast is absolutely a big problem, thank you for pointing that out.
@R0swell5104
Жыл бұрын
Well possibly but what rate of pressure increase over the hull is too rapid. With the best will in the world the craft could not plummit to the bottom like stone because of it's near neutral buoyancy, it took over an hour. In my view this is a bit of a red herring.
@undeadarmy19
Жыл бұрын
They were never descending too fast. He keeps comparing the descent rate of James Cameron's sub to this sub, which is fundamentally wrong. Doing 5min of research will show you that this company made 13 other trips to Titanic, and every one of them had a descent rate that got them there in 90min or so. The descent rate wasn't an issue. This topic keeps generating a lot of clicks though, so ignorant speculation keeps winning the day.
@kumak2591
Жыл бұрын
@@undeadarmy19transcript says so, so it is faster than anticipated speed.
@undeadarmy19
Жыл бұрын
@@kumak2591 Transcript isnt verified whatsoever, and shouldnt be used as any form of evidence until it is. This is a MAJOR issue with modern media practices, especially here on KZitem. Info either being presented as fact, when it isn't, or people being TOLD that its not verified, and still taking it to heart. The FACTS of the case, as they stand, show that the rate of descent was not an issue.
@mikefochtman7164
Жыл бұрын
@@undeadarmy19 Totally agree. So many people making a lot about the descent rate. Look at the numbers closer and put it in terms people are used to. For it to be 2.5 hours, they would descend at a rate of 0.944 miles per hour. Sure, that's pretty slow. And if they got to the bottom at 1 hr 45 min, that's a rate of 1.35 miles per hour. Hardly 'hurtling towards doom'. The rate is solely a function of net bouyancy and hydrodynamic drag. With a somewhat streamline hull, the difference in those two rates could be something like 50 kg difference. Between loading passengers (i'm sorry, they were NOT 'mission specialists'), their personal effects, some food, drink, a spare video controller, some O2 supplies, CO2 cartridges and give or take a couple of the pipes/ sandbags, etc... I don't see the difference as being all that unreasonable. Dive-to-dive variation, probably not that big a concern (until the hull monitor system maybe started alarming)
@truthtalker3498
Жыл бұрын
Thank you. I've really enjoyed your videos on the Titan implosion. They are some of the best info out there! I really enjoyed The New Yorker article, too. Thanks for the link!
@blessings2you435
Жыл бұрын
You're ALWAYS SO GOOD.l!! That voice too - you'll soothe us thru the very Apocalypse with your calming, dignified, thoughtful, experienced demeanor. Thank you, Jeff. 🙏
@jeffostroff
Жыл бұрын
Wow, thank you!
@tjpowers88
Жыл бұрын
I have been enjoying the content brother, especially the descent rate video as my father and I were talking about how it is a 2.5 hour descent yet their accident happened 105 mins (+/- some mins) at 3500 meters? Also I did see a talk he did at the explorers club a couple years ago and he mentioned the “sub” or hull was “being cured in the hothouse” now I am not sure if that means an autoclave but anyway thought I’d share that part at least.Again, great job 👏
@jeffostroff
Жыл бұрын
YEs I would like to see more video of manufacturing.
@wilhelm391
Жыл бұрын
they did i watched a video last week when the glued the first endcap to the hull.
@undeadarmy19
Жыл бұрын
Idk why he keeps comparing the descent rate to the James Cameron descent rate, seeing as how they're 2 completely different subs, and, seeing as how they purposely made the descent rate at 90 min, which is the time they descended at. This info is right on their website! They made 13 dives with a 90min descent rate, and no issues. It seems like he's caught up in the clicks and views this topic is getting, so just keeps putting sensationalized assumptions out there.
@electrictroy2010
Жыл бұрын
@undeadarmy19 AS ALREADY EXPLAINED several times, the Oceangate website says the descent time is 2.5 hours. It’s frakking obvious to people who are not dumbasess .
@electrictroy2010
Жыл бұрын
@undeadarmy19 seriously I suspect you’re IQ is below average (below 100)
@greggrusnak6094
Жыл бұрын
P H Nargeolet was 77y/o. He has said on TV and in Documentary's When asked if he was afraid of his life ending on a Dive " No I have done what most will never Do and if it happened it would be Instantaneous and I would be at Peace". So I think he knew he wasn't coming back.
@toomanyaccounts
Жыл бұрын
he obviously didn't care he was going to be the death of others.
@user-zp9br7jk9k
Жыл бұрын
i don't think anyone would say - give me a slow cruel death over quick and painless.
@thylabyrinth
Жыл бұрын
Imagine all the alarms going off in the sub and everyone losing their mind to panic except PH, who instead sat back, closed his eyes and smiled as he waited for the inevitable.
@SixStringflyboy
Жыл бұрын
For those who insist on claiming previous dives were all 90 minutes from the surface to the site, this is straight from OceanGate's faq page, in the event it disappears: How long is a Titanic dive? A Titanic dive takes approximately 10 hours from start to finish: - Mission Specialists board the submersible. Dome closes. - Sub launches from the Launch and Recovery Platform (LARS). - Descent begins. It takes about 2.5 hours to reach the bottom. - Dive team explores for up to 4 hours depending on conditions. - Ascent begins. It takes about 2.5 hours to reach the surface. - Submersible recovered to the expedition vessel. Dome opens and Mission Specialists exit the sub.
@kathleendolphin7993
Жыл бұрын
Another great video, as always, Jeff. You are the go-to guy for explanation of tragedies.
@MTechn1k
Жыл бұрын
My very amateur speculation is that it had a leak and was taking on water as it was going down. This would add to the weight of the craft and accelerate the descent. This would also lead to the overly heavy craft that can't rise quickly even after jettisoning every possible part. It should have been rising quickly without the jets after ditching the undertray/skid. The only extra weight I can easily add is water.
@mqb3gofjzkko7nzx38
Жыл бұрын
If the craft buckled and reduced in volume that could also have reduced its buoyancy.
@utube321piotr
Жыл бұрын
Spot on
@fauxpinkytoo
Жыл бұрын
Any water that would leak into the vehicle under that pressure would slash the contents to atoms as the it buckled and imploded. In milliseconds. The pressure is insane.
@Mglue3
Жыл бұрын
@@fauxpinkytoo yeah but if the leak started further up, like way further up, it might not have been immediatly catastrophic.
@OompaPompano
Жыл бұрын
A leak is instantaneously catastrophic.
@germsws
Жыл бұрын
I still have yet to hear anyone talk about thermal contraction of 2 different materials and how that glue/sealing material was able to compensate for that.
@night_owl365
Жыл бұрын
I was thinking about that as well. Especially if the carbon fiber is getting weaker each dive.
@MrJC1
Жыл бұрын
It wasnt able to. Lol.
@monstrositylabs
Жыл бұрын
good point
@musaran2
Жыл бұрын
I have heard around a 1% difference. Note that another manufacturer did reliable dives with same construction plan, just not manned.
@DKFX1
Жыл бұрын
I think the thermal expansion is not relevant here because the temperature are very stable in the oceans. Difference between surface temp and bottom temp is only about 15 degree celcius.
@spirg
Жыл бұрын
Fabulous channel, Smart guy, speaks perfect tone , no loud music, every video we learn something new ... Keep it up , Jeff , dont change a thing ....
@forrestgumpv9049
Жыл бұрын
The sub was leaking after it first entered the water and stopped after descending a short distance when there was enough pressure to seal the leak. This is why the decent speed was high from the beginning. Water was not noticed under the floor they were sitting on.
@karenmurray351
Жыл бұрын
#Jeffostroff another great episode again. Love that many questions are being answered with you. Keep up the great work, I'm sure that your channel must be growing 😊🏴
@monkeywrench-garage
Жыл бұрын
Lots of things you aren't thinking about here. The rings didn't require much glue to seal. The outside pressure would seal them as the pressure kept building during the dive. Remember they are being pushed tighter to the carbon as the outside pressure builds.They just needed to be held in place and reasonably water tight at the initial dive. Second the end caps you are discussing are in compression against the carbon fiber. Once the carbon fiber explodes, it would explode into millions of pieces. The glss pieces wouldn't have had a chance after the explosion to stick to anything. Also the fibers were prepreg carbon. They are previously wetted and applied with the epoxy already built in. Thats why you need the autoclave to heat it and cure the prepreg. Now the question I have is the prepreg has a shelf life and was it observed? Also it is supposed to be stored very cool in like a freezer to keep it from initially curing before assembly. I just did a show on this talking about the very topic of some of these facts and questions.
@JoeLinux2000
Жыл бұрын
All this is true. What we know is that for some reason the design of the craft failed.
@ryanwatterson4038
Жыл бұрын
The carbon fibre didnt seem to have cross weave, and also it couldve began to flex ever so slightly in the centre of the tube, which couldve forced the titanium ends right off
@IrLosin
Жыл бұрын
Rush told Weissmann that "he had gotten the carbon fiber used to make the Titan at a big discount from Boeing because it was past its shelf life for use in airplanes," Weissmann wrote. So no the shelf life was not observed, and he did it to save money..really sad.
@TeemarkConvair
Жыл бұрын
@SuperNostalgia. 👎
@kumak2591
Жыл бұрын
Once the hull cracked and opened water fills the hull instantaneously and won’t break hull into millions of pieces, but reasonable sizes - yes. Other fact is, more than end caps getting pressure from outside, hull get higher pressure which does not balance out since entire body is not spherical shape. And There is no theory to break glass of the end cap, if the hull broke first. If the glass broke first, the water splash and the shock could dismantle the glued from the end caps. I am not an engineer, but happy to discuss physics behind it. 😊
@goatbaaad3711
Жыл бұрын
Congratulations!!!! You’re the 1 millionth KZitem video with this title!
@poptartmcjelly7054
Жыл бұрын
The big issue i noticed right away is that, when the titanium ring was lowered onto the CF hull, it formed an air-lock. The air had to get pushed out and the only way for it to get out would be through the glue joint. So inevitably the air would either get trapped or push the glue out to release. What i would have done is to lay a bead of the glue on the edge of the CF hull and lower the ring on top, so that the glue would get pushed out from the center of the joint outward, pushing the air out as it propagates through the interface of the CF hull and titanium ring. Then there was the mixing of the epoxy by hand and this method is notorious of introducing air bubbles. The whole process was flawed.
@petergibson2318
Жыл бұрын
I'm surprised that it wasn't tethered to the mother-ship as 4000 meters is not a particularly long cable in the world of ships. A cable just might have hauled them back up fast enough to get to a safer less-pressurised depth before the implosion. A "controlled spin-out" cable could also have limited the maximum rate of descent as an extra safety measure.
@ivarhusa454
Жыл бұрын
A cable would make managing the descent rate essentially impossible. It is too technically difficult to find a sweet spot with just the right tension to give the vessel any real control over depth. The vessel is too light relative to the cable, and then their is unpredictable and ever changing water currents. Just not possible in my opinion.
@JoeLinux2000
Жыл бұрын
I don't think the particular ship had such a cable. The towed it out. At what point did the occupants board? probably in port, not out on the bouncing ocean. When as that hatch bolted closed?
@ArcFixer
Жыл бұрын
@@JoeLinux2000They did not board the Titan in port. The Titanic dive site is 370 miles from port. Transit to the dive site would have taken at least 24 hours, probably more depending on the sea state. Obviously the occupants were not sealed in the Titan battered by waves this long before they even commenced the dive.
@TheBobelly628
Жыл бұрын
I read somewhere that a tether would increase weight and drag so it’s not used.
@JSu2.
Жыл бұрын
... but what about a cable that can hold 10+ tons of vehicle weight plus tension?
@Mike-Bell
Жыл бұрын
Hey Jeff You are doing a fantastic job reporting on this story. Very well done and as always your voice is a pleasure to listen to. This information about PH Nargolet is just stunning... Did you know Ocean Gate deleted all their video in the last 12 hours.
@electrictroy2010
Жыл бұрын
Hiding the evidence so the courts have nothing to look at.
@sharonbland9061
Жыл бұрын
Thank you, Jeff, I am learning so much listening to your channel. Very intersting to a lay person who has zero knowledge in engineering.
@MrAmunai
Жыл бұрын
so i didn't really care too much about the rich kids with a broken toy that sadly involved themselves, but for the past few days whenever i got home after work i got recommended your videos and i'm not gonna lie, it's mega refreshing to just get presented facts by someone who has actual proven knowledge. keep it up!
@michaelelliott3627
Жыл бұрын
Good analyses on the glue "bonding" process, lots of different ways it was bad practice. 1) no temperature or environment controls. 2) no clamp or pressure applied, during cure time. 3) no run-out of excess glue to allow for void fill. 4) no twist or rotation of mating parts during application. 5) no NDI/NDT of glue post application/cycle usage. 6) no apparent surface preparation/approved application method. 7) no way to bleed air from glue area. 8) cycling of CF to Ti, at temperatures cause "working" of glue to surface. anyone think of any other failures?
@jeffostroff
Жыл бұрын
YEs a lot of nos!
@GeoStreber
Жыл бұрын
I mean, we don't even know if they used the correct type of glue.
@matchesburn
Жыл бұрын
It doesn't matter what glue they used, if they manufactured it "correctly" or not. A cylindrical deep sea submersible that's being used on dozens of dives and is made of a carbon fiber pressure hull is going to fail. Not a question of IF, *_BUT WHEN._* This glue stuff? It doesn't matter. It would have failed regardless. There's a reason we don't use designs like this on legitimate submersibles for deep sea diving and we surely don't use CF.
@putnamehereholdmadoodle
Жыл бұрын
Thubderfoot did a good experiment, with how glass bonds to metal. And the small change in size due to pressure is enough to break that titanium and plastic bond.
@changent
Жыл бұрын
A water jet table can cut thru steel around 10,000 psi. A pinhole leak only a few molecules wide thru the carbon fiber or adhesive joint would have done massive damage in a few seconds. This was a flawed design.
@edwardlafferty8796
Жыл бұрын
I was thinking the quick descent - if it happened - was indicating a major problem. While there are other factors involved, it is important to maintain a known dive profile to allow the hull time to adapt to the growing stresses. But, more importantly, the quick descent and - later, the slow ascent - point to one major problem. The submersible was too heavy. Much heavier than expected. That, in turn, suggests that water was seeping into the craft dragging it down. Eventually, this would have leaked into the battery compartment and compromised the power (it may even have interfered with the ability to jettison the frame) and it implies that the problems with the dive started a long time before the implosion. Of course, the reason it would have been seeping - as opposed to a leak - would have been a compromised hull. Not so much a hole as broken fibres which compromised the waterproofing. Of course, this assumes the leaked transcript is real.
@sophieh9387
Жыл бұрын
Thank you for your videos! The subs / comments are incredibly intelligent and respectful.
@gramps9838
Жыл бұрын
I find it simply mind numbing why anyone would have risked this journey in the first place. I worked composites for 16 years, When I saw them building the carbon fiber tube and attaching the titanium ring I can see why the sub imploded. Condolences to the families.
@patreilly6826
Жыл бұрын
Rate of descent should be standard for the calculation of the weight carried. It should be controlled by the amount of dive weights attached to compensate for the combined weight of the passengers. If they added too much dive weights then the rate of descent will be faster. Other wise there could have been other problems with some of the auxiliary systems in the tail. A reported “A” buss failure switching to “B” buss. Did a battery on “A” buss take on water? Was one of the thrusters running unknowingly to cause the “A” buss battery to deplete to fast on descent? Was one of the up and down thrusters setup backwards? So even though the controls were set for an emergency assent the sub was not rising as it should have. One of the biggest faults of this sub was the reliance of the lap top for control and the screens for monitoring. Emergency systems should be hard wired to a Go To Hell panel where to drop weights lift switch cover and activate switch. Remove landing frame same thing or activate a mechanical lever and linkage to drop. If the lap top froze up during an emergency then valuable time is lost to get it up and running again. Same with communication to the surface there should have been a backup system independent of the lap top.
@undeadarmy19
Жыл бұрын
They were never descending too fast. He keeps comparing the descent rate of James Cameron's sub to this sub, which is fundamentally wrong. Doing 5min of research will show you that this company made 13 other trips to Titanic, and every one of them had a descent rate that got them there in 90min or so. The descent rate wasn't an issue. This topic keeps generating a lot of clicks though, so ignorant speculation keeps winning the day.
@cherp7522
Жыл бұрын
@@undeadarmy19 Then why did the surface ship question the descent rate at all...several times I believe? And was the ascent rate also not too slow. Aren't those two sides of the same coin?
@undeadarmy19
Жыл бұрын
@@cherp7522Well, seeing as how this transcript hasn't been verified in any way, we have no way of knowing this. Again, all speculation, not fact.
@cherp7522
Жыл бұрын
@@undeadarmy19 It also hasn't been rejected by them either... That transcript smells accurate...if you know what I mean. But we will all stay tuned.
@posplayr
Жыл бұрын
I put together a spreadsheet to compute the descent rate at each reported depth. The salient data points are at each reported depth where I compute the average descent over the interval since the last reported depth. The start time is when the sub reported starting the descent. The reference descent rate is 25.3 m/min and the average over the descent is 36.34 close to that reported by the sub. The average descent intervals each show a progression in the descent rate from 27.6 to 44 m/min indicating that the sub was taking on water. I don't see any inconsistencies to indicate a falsified log file. Video Time Time Stamp depth DeltaT DeltaD Rate Description M:S H:M:S meters Sec meters m/min 1:33 7:54:07 0.00 Start Descent 1:50 8:21:28 756.00 27.35 756.00 27.64 First Depth Report (nominal 15 minutes ) 3:50 8:51:30 1934.00 30.03 1178.00 39.22 Second Depth Report 5:16 9:17:50 2960.00 26.33 1026.00 38.96 Third Depth Report 5:42 9:28:35 3433.00 10.75 473.00 44.00 Fourth Depth Report 7:37 9:35:48 3433.00 7.22 0.00 0.00 Attemped Ascent 7:37 9:35:48 3433.00 94.47 3433.00 36.34 Average Descent 3:02 150.00 3800 25.33 Reference Descent
@Jesse-qy6ur
Жыл бұрын
What's interesting is the third depth report shows a slight decrease in the depth rate. I would expect a forgery not to include a detail like that, which suggests a complicated physical process that slightly self-corrects with either depth or time, but then progresses afterwards.
@biosparkles9442
Жыл бұрын
How could the sub have possibly taken on water without imploding sooner?
@nigelwilliams7920
Жыл бұрын
Good analysis. From previous dives, the usual descent rate was about 25 m/min. It is unclear when they actually commenced their descent, as once released from the launch sledge, videos show the sub moving forwards and loitering for a bit. A delay of 8 minutes from the 07:54:07 'start of descent' report (perhaps getting everybody settled, adjusting trim etc), would see the actual descent rate for the first portion at 39 m/min, the same as the following ones. I would expect that (perhaps inadvertently) the crew was following the aviation mantra of priortising effort, viz.; Aviate, Navigate, Communicate, in that order". Thus as their concern / workload increased they may have delayed communicating depth reports. Thus the report at 1934 m depth which calculates to a slightly reduced rate could have been sent a few seconds late, which would increase the apparent time for the interval, and hence reduce the reported rate below the actual. When you round your figures to the nearest whole number, then the rates for each interval become 39 m/min (allowing for a delayed start of actual descent), 39, 39, 44, thence the end. The data does not warrant higher precision in the analysis. Once the dive was underway, the sub could not gain mass, so the only way the rate of descent rate could increase was by loosing buoyancy. The crew did not report any water leak at any stage, and given the intimate surroundings of the interior of the pressure hull, one would imagine they would have noticed. But something must have been happening to reduce the displaced volume of the craft as they were passing 2960 m and the alarms started to sound. The final info on the state of the structure was the report that the frame had been jettisoned after several tries. This suggests that the frame supports on the titanium end rings were no longer in their correct alignment hence jamming the frame in its sockets. Were the end caps twisting and/or moving towards each other? Was the frame the only thing holding the end caps apart? Was the loss of buoyancy due to the end caps moving towards each other?
@Jesse-qy6ur
Жыл бұрын
@@nigelwilliams7920 The frame jettisoning difficulty definitely suggests misalignment, but the frame pretty clearly would not have been able to withstand the bending moments involved. Had it been the sole thing keeping the end caps apart, given the tremendous forces involved, it would bind and never been freed while the structure was intact. You'd expect to see fairly drastic deformation and clear gouging at the contact surfaces between the frame and the caps. As for the loss of their buoyancy reserve, there are two possibilities: increase of mass, and decrease of volume: - The first possibility has the difficulty that water incorporation into the vehicle has to be in a way that is subtle enough not to lead to an abort -- even with Stockton Rush's non-existent sense of self-preservation, there are either three of four other people who could mutiny and abort the descent, so it can't be at a rate to cause them to freak out. - The second possibility has the difficulty that carbon fiber shatters rather than undergoing plastic deformation. As I understand it, under the compressive loading of a dive the CFRP cylinder loses about 1cm in radius -- measurable, but not so drastic as to immediately suggest itself as the explanation for the out-of-whack buoyancy. Previous successful ascents also took place with a compressed CFRP structure.
@nigelwilliams7920
Жыл бұрын
@@Jesse-qy6ur I agree with you completely, however I am stumped as to what can explain the observed behaviour. As Sherlock Holmes is said to have quipped: “When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.” As you say, the sub cannot have gained mass, so it must have lost buoyancy. As far as I can see from the diagrams of the sub, there is no other part of the sub which could change shape to account for the buoyancy loss. Yes, it is utterly improbable that the hull could progressively deform through 2960 metres depth to cause a faster descent, but I cannot find any other 'truth'. Remember, we are dealing with a 'structure in the form of the carbon fiber wound cylinder (which was the second hull, apparently, which was autoclaved etc) which may be rather more resilient than the original one. Who knows. The hull deformation was reported by the RTM alarms starting around 09:17 (2960 m) and continued down to 09:35 (3500 m, "Starting ascent") and no doubt until breakup. So there was almost 20 minutes when the hull deformation was detected by the sensors., and by 3433 metres depth all of them were 'red'. All of them. There was a lot going on. Smart folk will do analysis on where those sensors were, and make sense of the sort of deformation which could cause them all to trigger. But hey I'm just an armchair analyst sitting here about as far away from these events as it is possible to get without falling off the edge of the Earth! Wot do I know! :)
@patsk8872
Жыл бұрын
The Titan is just the gift that keeps on giving. So much hilarity for me to laugh at every single video.
@Sheikh_Speare
Жыл бұрын
You sound like another youtuber I watch named "Islamic Critique". Almost confused you for him when I clicked the video. Became fascinated by submersibles due to the Titan. You have become my favorite person in learning about this specific topic.
@hanselmansell7555
Жыл бұрын
Mate your voice is so good you really don't need music in the background, just saying.. another great vid btw 👍
@jeffostroff
Жыл бұрын
Thanks for the tip
@hanselmansell7555
Жыл бұрын
@@jeffostroff thanks for the info 🇬🇧
@timstoffel4799
Жыл бұрын
I have been questioning the whole fast descent thing as well, enough to wonder if the implosion wouldn't have happened if it had descended at the usual rate. Are there cases of rapid descent on previous dives? In any case, the rapid descent was a HUGE red flag that the crew should have immediately recognized. Was it simply a case of too many people/too many heavy weight people aboard? Or did something flood with water early on (like a battery pack? Where are the batteries located?) that wouldn't have been immediately noticed and would have negatively affected bouyancy? (I am wondering battery pack or some power electronics system because they lost a power bus shortly before the implosion.) Also noted that the rate of ascent was still very slow even after they had jettisoned a lot more weight then normal. Was something somewhere (outside the pressure hull, or maybe in the pressure hull but outside the crew compartment) actively flooding? I suspect that if the rapid descent had caused an abort before they had descended 1000 meters (and they clearly knew by then that the descent was much faster then normal) that everyone would have been recovered alive and perhaps a serious flaw found in the sub's design. Was ego involved in a decision to ignore the rapid descent? Or did everyone want to commit passive suicide?
@kaohsi4173
Жыл бұрын
Descent quick , ascent slow, 50% power failure,……. U must ck the batt compartment ( it is located beneath the floor) flooded. No matter what jettison ed , like 2 eng power aircraft lose one eng .beside , any broken clothes , socks, shoes, …….
@katelittlewolfwelshrosesan3630
Жыл бұрын
You do an incredible, sensitive job on this topic. Teaching us.
@ue4770
Жыл бұрын
When you use Prepreg, you don’t have to wetten the fibers because the resin is already applied. Drawback: the layup becomes thinner during the curing when the resin that’s applied on top of each layer, is melted and drawn in between the fibers.at works for mostly flat parts, like wing skins, but in case of a tube, with the diameter also the circumference shrinks, leaving the fibers less straight, and therefore less strong. Concerning the bonding between the carbon fiber tube and the titanium rings: this connection is purely loaded in compression. I wouldn’t see the strength of the bond as a big threat as there is form closure provided. However, with that little bonding area (typically, you shear in loads with a bonding length to thickness ratio of 50 or greater), the surface pressure on the composite will be quite high, and can lead to structural failure there, similar to bearing loads.
@kevinmcgovern5110
Жыл бұрын
Enjoying your series; very reasoned. Could you do a chart on normal descent rates v. pressures, comparing the last dive’s reported descent rate and pressure? Might be very instructive on your speculations of the carbon fiber failure. Doesn’t necessarily apply but saw a DIY carbon fiber plane build a few years ago. Builder had to take an FAA-approved class and have critical components inspected before use. In that application, the fiber layers had to be thoroughly wetted with a specific resin to allow for flex as well as lateral stiffness to allow the components to successively cycle for hundreds of flights. If the resin used for Titan was primarily for pressure resistance, successive cycles would likely be a serious problem after a dive or two, so perhaps the fiber hull should have been considered an expendable component?
@utube321piotr
Жыл бұрын
Towing of the sub across stormy Atlantic for 600 miles likely disturbed the epixy joint between titanium rings and carbon fiber tube
@MrJC1
Жыл бұрын
It certainly wont have helped.
@utube321piotr
Жыл бұрын
The floating rig was a flat bottom aluminum device suitable for a lake or river. Big waves call for a V Hull. Absent of that the waves pounded the sub viciously with extreme vertical G 's
@getx1265
Жыл бұрын
Another good discussion, Jeff! Thank you again.
@healthy2202
Жыл бұрын
Jeff said " the repeated compression and expansion" well it is more than that. As they descended the temperature affects the different materials Titanium and Carbon Fiber differently. They expand and contract at different rates. So between all these changes it was cracking that seam every single time.
@bills6093
Жыл бұрын
Wouldn't they have noticed the fast descent pretty early, and made efforts to reduce it? Hard to believe they were descending too fast for that long, and did not notice it.
@LittleBeams
Жыл бұрын
Especially with the transcripts. Polar Prince knew they were descending too quickly and didn’t bother to say anything.
@edwardlafferty8796
Жыл бұрын
@@LittleBeams Assuming the transcript is real, it looks like they did notice it but were told to back off by Rush who insisted all was OK.
@Ragetiger1
Жыл бұрын
@@edwardlafferty8796 That's my train of thought too. Cause they did ask about adjusting velocity, so they were trying to say something without being critical.
@ryelor123
Жыл бұрын
Its hard to notice if you don't do the math. Also, they probably assumed the water around them was going down too due to currents or something. No alarms were going off until near the end. I still think it might've been a high-resistance short circuit. That would've taken a lot of voltage away from the thrusters but not caused a breaker to flip. It would've also heated up the batteries a lot.
@Ragetiger1
Жыл бұрын
@@ryelor123 The overall issue with the alarm is that it only alerts when it picks up a sound. By then it's too late. Odds are those banging that have been dismissed were the sounds of the vehicle as it was starting it's death throws. The possible transcript did also mention hearing sounds in the aft a couple times before all communication ended.
@Valkyrie9000
Жыл бұрын
My going theory is that there may have been a small gap or misalignment between one of the flanges and the interface (vertical) surface of the carbon cylinder. The adhesive we see them putting on there is likely only for sealing (I hope). If there was a gap, it puts most or all of the lateral force from the pressure dome against the shear strength of the adhesive instead of the carbon. After enough dives, if that adhesive fractures or delaminates, flooding would occur, and more importantly if there's inadequate "wet shim" -and there was poor mating- the titanium flange would've contacted the carbon extremely rapidly in a high shock point load, possibly causing a cascading fracture. Honestly though it's about as likely the supposedly expired, supposedly bagged prepreg CF just had voids galore in it and failed spontaneously. I cannot believe they didn't do NDT or full-scale destructive testing at depth. If Stockton did as he said he did then this was just short of manslaughter. The most interesting part of this whole thing has been listening to Stockton's reasoning for the cylindrical pressure vessel over a spherical design: interior photography considerations... He literally designed this thing to be a photo booth on the ocean floor, and that's why they even went with a novel COPV... That's why 5 people are dead.
@Valkyrie9000
Жыл бұрын
You'll notice in the video of the flange installation that there doesn't appear to be any preloading fixture, press fit, or jig. They appear to have just gooped it up and slid it down into the CF cylinder (liner?). Did they put weights on top to ensure good mating and contact during the cure or just rely on gravity? This thing is operating at almost 400atm and the ends were just glued on with a slip fit?
@thelongislandguy
Жыл бұрын
What is COPV?
@Valkyrie9000
Жыл бұрын
Composite Overwrapped Pressure Vessel. You can get away with a thinner walled metal tank and a lighter overall construction. Used in solid rocket motors for missiles alot but they have many many problems and are still quite rare even in high end aerospace. They are almost exclusively for single use or light duty. Nobody has ever used them for deep sea diving successfully before because of the limited compression strength of composites and the cyclic fatigue of repeated dives.
@TheOneWhoMightBe
Жыл бұрын
I am far from an engineer, but one thing about the Titan design really stands out to me: there is zero mechanical fixing between the CF cylinder and the titanium ends. Two vastly different materials with different expansion/contraction rates held together by glue. It's no wonder that the ends simply popped off when the cylinder collapsed.
@ksc743
Жыл бұрын
Same here. It boggles the mind.
@roykliffen9674
Жыл бұрын
@jamespfp Thank you; finally someone mentioning ballast/ trim tanks. These submersibles don't descend or ascend using thrusters. These are mostly for attitude control, forward/reverse movement and steering.The main method of vertical control is varying the buoyancy by letting in or pumping/blowing out water in the ballast tanks (trim tanks mostly shift water forward/aft or even side to side to control the attitude). The rate of descend can be controlled by letting in more or less water; the more water in the ballast tank, the higher the descend rate. If the tank sprang a leak on top, it's already game over, but say only the water inlet valve was stuck open. If you start to descend with 1000 liters of air left in those tanks, you have 1000 kilograms of additional positive buoyancy from those tanks right up to the bottom with the water valve closed. Now suppose the water valve is stuck open. The pressure in the tanks will climb with depth; at 3500 meter, that'll mean a pressure of 350 Bar. That means that the original 1000 liter @1 bar will be reduced to 2.86 liters @ 350 bar which means only an additional positive buoyancy of barely 3 kg in stead of 1000 kg so the sub lost 99.7% of its additional buoyancy. This loss is valid for any number used in stead of this example 1000 number. What's more, with a stuck open water valve the "weight" of the sub will increase with every meter descended, and thus the descending speed would have increased with every meter descended. If the tank sprung a leak on the bottom, the result would pretty much be the same, but if it sprung a leak on top, all the air would be rapidly lost - and thus all of the additional buoyancy - and the sub would be descending at a high rate from the moment all the air was gone. For me the ballast tanks may have been the initial problem and monitoring the descend speed should have provided a warning. Had the enclosure/cabin itself sprung a leak, the occupants would have known very rapidly. Pressure would have rapidly increased which can be very painful on your ears (anyone with SCUBA experience can tell you how it feels if you don't clear your ears correctly). When the Titan went into emergency mode and dropped the main ballast followed by the undergear, it barely rose 20 meters in three minutes which means that at that moment it had barely any buoyancy left. What's more, it may very well have been the instigator of the hull failing. With very little technical data but a lot of gut-feeling: The Carbon fiber tube with occupants itself has about 1000 kg of positive buoyancy but is pulled down on either end -by the Titanium domes (5500 kg) and frames - in affect bending it like a banana with the ends turned downwards. With the depth creating strong compression stresses in the hull, the "bending" will have reduced the compression stress on top and increased the compression stress on the bottom of the hull. Releasing all the weight of the ballast and frame at maximum depth will have suddenly increased the compression stress on the top and reduced the stress at the bottom. I think the - never encountered - higher compression stress at the top was more than this marginal design was capable of withstanding.
@curiouscat8457
Жыл бұрын
You post makes sense and matches to my general concept of a "leak". The problem I can see in your version: what you are describing is a "variable balance control" and yes, it is being used for the purpose you are describing. That's why the tank are quite small - you don't need much ballast to move the buoyancy around the neutral point. However, this incident involved a loss of buoyancy for which dropping ALL the emergency ballast (don't have an exact number, but it had to quite a few hundred kilos) and using the upwards thruster couldn't compensate for. So, my reasoning is, the leak was in the main pressure hull or, in the auxiliary sealed compartment containing the batteries, pumps etc. - if it was large enough, that is. The main pressure hull is winning by long haul in my eyes.
@creamshop
Жыл бұрын
Ive worked in the aerospace industrie and standard practice for having proper manufacturing glue gap was to use calibrated glass beads, applied at around 3 to 4 beads per square inch on one part of the of the adhesive, when mating the parts we always made sure to have the adhesive oooze out a little bit, we always used static adhesive mixers to be sure that the part A and B were homogenous
@passionworksbodyshop9738
Жыл бұрын
We have the same system in the shop when we glue on the quarter panels on cars. The beads are in the 2 part glue.
@creamshop
Жыл бұрын
@@passionworksbodyshop9738 Its the only way to control gap thickness when mating parts
@baskoning9896
Жыл бұрын
Also dont forget this issue; carbon fiber is strong: when pulled. Not when being pushed upon. For airplanes, thats fine, the carbon will inflate like a balloon, then tension up, and hold. The other way around: it just buckles. The fibers are being pushed together: the circular form is no longer in play as soon as the first fibres give in. There is no other way for the fibers to go: then 'out of the circle'. and when the circle is no longer intact: boom.
@themushroominside6540
Жыл бұрын
plus carbon fiber is meant to be brittle when breaking appear in order to absorb the energy though fracturing, why cars are made of carbon fiber because it releases the crash energy into the brittle parts rather than transferring all of the energy into the driver, it simply sucks as a material when pressure is applied all around it since it would simply shatter.
@yogamon
Жыл бұрын
There is a company that makes carbon fiber tubes for submersibles that go lower than titanic and no failures to date
@cardboardboxification
Жыл бұрын
@@themushroominside6540 my experience with carbon tubes , they just snap .. the only strength was the epoxy on his sub, laying the carbon parallel add no strength . like wrapping a rope around a paper tube .. that carbon shattered like glass,, just like this at 1:00 at 14.6 psi kzitem.info/news/bejne/sqxju5ZtpJmeY44
@laurentausfrankreich4184
Жыл бұрын
🙄🙄🙄🙄🙄🙄
@CheeryRhymes
Жыл бұрын
Apparently carbon fibre can be used in this manner and still be incredibly strong.
@Slamscape
Жыл бұрын
As someone who does resin art. That was the first think I picked up on seeing the video of the sun being manufactured. 1- touching it with bare hands. 2- not giving rough edges for adhering. 3- dusty open environment. 4 - applying with a tool with wiping motions and no degassing. Any one of those the immense pressure would take advantage of.
@davidimhoff2118
Жыл бұрын
I am no engineer but I am a fan of the history of Titanic. I came across OceanGates idea to bring passengers down and thought, oh I wish I could afford this and also why do I have to be claustrophobic. What concerns me is when you create something like this how can you check for stress fatigue? If they glued it down how can you do maintenance to make sure you have a tight seal? I don't think you can. You are right @jeffostroff about no glue being on the rim. I haven't seen the video of the submersible ring made but it only makes sense the CEO's design had a lot of problems. You would think you would listen to people likes James Cameron and others but Rush sounds like he took everyone's feedback as people crashing on his dream. Its just a shame to lose the people onboard because of Rush's actions.
@wizrom3046
Жыл бұрын
I want to know the descent rates for previous dives. Was this one very different? Or were they in the habit of descending quickly? Or were they increasing the rate a little bit with each new dive?
@ruckusrodkustom8140
Жыл бұрын
Thanks Jeff for bringing this to us. I trust your take on this especially after watching the Champlain Towers series!
@jeffostroff
Жыл бұрын
Glad to hear it!
@ruckusrodkustom8140
Жыл бұрын
@@jeffostroff oh ya, and Ryobi tools are traaash!😄
@perrywalton2464
Жыл бұрын
When this investigation is over and findings confirmed about this tragic incident, all students, engineers and others in the industry should be required to study this and never again make the same mistakes. What an absolute shame. Thank you for this presentation
@electrictroy2010
Жыл бұрын
I’m an engineer. We learned DECADES ago to avoid these mistakes. The problem is the CEO ignored all the lessons (including firing his safety engineer) .
@PastTime777
Жыл бұрын
There was a video posted by ThunderF00t where he heats a glass tube, attaches it to a metal ring, lets it cool, and the glass breaks away from the ring. That's because contraction of each surface is different. That backs up what you said about the different surfaces.
@raremage
Жыл бұрын
It’s extremely unlikely that this has anything to do with the lack of abrading on the shell while carbon fiber is being applied. Much more likely is the different expansion and compression rates of two different materials that eventually, over time, lead to stress fractures as the two materials would compress and expand at different rates over time.
@larky368
Жыл бұрын
Normally you would scuff something up so the glue has more grip but this thing is going into outer space.....I mean to the bottom of the ocean. I got them mixed up because both are equally dangerous and required ever nut and bolt and every drop of glue and every hand that touches the vessel needed to be under controlled conditions. This damn thing was assembled on newspapers on their mom's kitchen table.
@stever2583
Жыл бұрын
So the gluing of the bell caps to the Fibre with a polished titanium meeting the fibre had no issues with you. Have you ever seen fibre glued to metal using polished surfaces to hold the glue?
@raremage
Жыл бұрын
@@stever2583 of course it does. Everywhere they are trying to link two different materials is a potential area for degradation and eventual failure over time due to the differing material compression rates.
@ladybeavanerdventures
Жыл бұрын
I feel sorry for PH aka Paul-Henri Nargeolet barely anyone spoke of him when it disappeared just saying he was the 5th guy if that. But this is pretty heartbreaking as this is his map and I bet he would never would have guessed it would be used to make his potential resting place well he and the rest are dust due to the implosion but man this hit me in the gut
@electrictroy2010
Жыл бұрын
He only had a few years left to live. He didn’t lose much
@neuralmute
Жыл бұрын
I feel the loss of P.H. Nargeolet as well. I've had a strong interest in shipwrecks and undersea archaeology for decades, and he was one of the greats in the field. Unfortunately, it seems he may have been unhappy enough to play fast and loose with his own safety while doing what he loved most, which is a state of mind I can empathise with. He will be remembered fondly by the people who knew him and knew about him.
@huna1950
Жыл бұрын
That’s not true Many experts I listened to thought so highly of him
@jhoughjr1
Жыл бұрын
well thanks to this asshole ppl think he suicided it. Based on basically nothing. Saying yeah its a risk but its a fast way to go and im old and will die anyway does not mean he was suicidal at all.
@ksc743
Жыл бұрын
Initially it was the media reporting on the missing sub, so of course they went for sensationalism: ie Stockton Rush and the billionaires. It was only when the knowledgeable submersible community started commenting that we learnt how much PH was liked and respected. There is a link below this video to an article from the New Yorker which is very interesting and provides some insight into his state of mind. PH was 77 years old.
@brianniegemann4788
Жыл бұрын
Thanks for your low-key, just the facts videos on this topic.
@zarahofshiloh7537
Жыл бұрын
One old gentleman interviewed on the news that went down to see titanic in the titan, (can't remember the year, but remember his ride got pushed back 1-2 years from his previous date because of the testing not all done) and he said that he was hearing crackling noise. All the others that road since then were really blessed not to have died in that thing.
@cybervigilante
Жыл бұрын
The carbon fiber was being infiltrated with water, weighing the Titan down, and also causing the crackling noises and sonic alarms. That's why it sank fast and couldn't rise fast enough, despite shedding weight.
@NithinJune
Жыл бұрын
is this just speculation? or is this confirmed?
@mqb3gofjzkko7nzx38
Жыл бұрын
Carbon fiber composite is more dense than water. The only time soaking something makes it less buoyant is when the water replaces something less dense like trapped air.
@diceraww
Жыл бұрын
@@NithinJunesounds like a theory of what could have happened with the current information out
@lsimms2534
Жыл бұрын
It's a good theory. While the implosion would happen very fast one could imagine a slower cascade effect with intrusion into the carbon fibers, de-lamination etc. Certainly a theory explaining crackling noises and RTM alarms not evident in early dives.
@tomr6955
Жыл бұрын
@@NithinJune everything is speculation to some degree
@yambo59
Жыл бұрын
I SAID THE SAME THING ABOUT THAT SMOOTH RING AWHILE BACK-!! I also wondered what the low temp limit of the epoxy was, maybe it hardened in the low temp enough to shrink at a different rate than the CF, the whole dissimilar material thing is huge to me.
@K1OIK
Жыл бұрын
CF?
@mrbluesky2050
Жыл бұрын
A very good point about a, contamination of surfaces to be bonded and b, those same surfaces needing a key for said bonding materials.
@brandywell44
Жыл бұрын
One of the specifications for all plastics is its absorbtion rate of water over time. Given that the plastics used in the contruction were in sea water and at immense pressure then water absorbtion would have been at a much higher rate. Add to this the temperature differences under water and at sea level and on the deck of the Mother ship in the warmer Sunshine, the effects of sunlight and sea air.
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