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What we know so far from the CG:
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How would bonding of Titanium to CF even work in that application?
I would think that the expansion/contraction differences at those pressures and temperature differences would almost ensure structural failure. |
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Quoted: I'm pretty sure that anything done in the aircraft industry, as well as most high end motorsport applications is done with prepreg CF, rather than an infusion. Even then, there are tight controls on the process to ensure the desired result. I have a friend who works with a major aircraft manufacturer who stated something as simple as using a second clean rag to wipe the excess cleaner off where they had cleaned a piece for bonding made an incredible difference in the joint. That said, I was interested in the small clip I saw posted days ago which showed the CF being made with a pretty straight monodirectional setup. I'm not familiar enough with CF at that scale to judge if it was prepreg or not, but I had concerns about any torsion on the final product due to the way it looked like they were weaving the fabric in the short clip. Frankly, I've seen designs which I would trust much more for real world use in a vehicle applied to driveshaft tubes than what I saw in that brief clip. Even if they changed up the weave pattern at some point in the process, I would be highly concerned about delamination of the various internal layers. Here is a good video showing the construction of a driveshaft. A lot of good points for those who haven't looked into this very much. https://www.youtube.com/watch?v=wKYZYBX51hU View Quote View All Quotes View All Quotes Quoted: Quoted: Quoted: If you glued it, you'd want to machine a groove into the titanium wide and deep enough to slide the CF into it after gluing, then glue and wrap more CF outside of that area well into the TI overlapping quite a ways to try and prevent the two dis-similar material from separating from each other. Even a pinhole or tiny delamination at those pressures would be enough to cause a catastrophic event. I'd also X ray it like you would a weld on a pressure containing vessel [or pipe] to make sure there were NO voids whatsoever. When they build airplane CF sections, dont these also go into a big autoclave to help the resin cure and maybe even push out little bubbles in the CF? It wouldn't surprise me if they didnt do that. Not an inspired expense ? There was a clip of the joining of the ring. I thought I did see some sort of channel milled into the titanium ring? The whole thing driven by cost, surprised he sprung for the Commercially Pure titanium for the domes. It wouldn't have been that difficult for such a small submersible to have been 100% ti. There are lots of fab shops that specialize in Ti and make things like chemical reactor vessels (same shape), and there is at least one company I know of in eastern OH near Salem that has a pretty big vacuum chamber for doing electron beam welding on titanium assemblies. I'm pretty sure that anything done in the aircraft industry, as well as most high end motorsport applications is done with prepreg CF, rather than an infusion. Even then, there are tight controls on the process to ensure the desired result. I have a friend who works with a major aircraft manufacturer who stated something as simple as using a second clean rag to wipe the excess cleaner off where they had cleaned a piece for bonding made an incredible difference in the joint. That said, I was interested in the small clip I saw posted days ago which showed the CF being made with a pretty straight monodirectional setup. I'm not familiar enough with CF at that scale to judge if it was prepreg or not, but I had concerns about any torsion on the final product due to the way it looked like they were weaving the fabric in the short clip. Frankly, I've seen designs which I would trust much more for real world use in a vehicle applied to driveshaft tubes than what I saw in that brief clip. Even if they changed up the weave pattern at some point in the process, I would be highly concerned about delamination of the various internal layers. Here is a good video showing the construction of a driveshaft. A lot of good points for those who haven't looked into this very much. https://www.youtube.com/watch?v=wKYZYBX51hU |
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Quoted: While I understand not wanting to divulge the sensor, I don't understand the delay in reporting. It's not like Titan was on a mission to blow up the Nordstream II pipeline. Between the navy and Cameron's revelation that Titan had dropped ballast and was returning to the surface, it's pretty clear on Sunday people knew this was a recovery operation, not a rescue operation. Yet we spun everything up as if it was a rescue. No one wanted to make that call. View Quote You were in that world, of course they sat on the info from SURTASS or SOSUS or whatever system detected it. They probably knew it was catastrophic and time wasn't a real issue. Even if they were still alive the capabilities of those systems is worth some lives in the grand scheme. Plus who knows exactly what was shared and when. What is being made public is only part of the truth. |
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Quoted: Yes CF used on aircraft is placed in vacuum chambers for curing. There is very strict quality control standards because the CF used is kept at temperatures below zero degrees. The material has limited time exposure above the freeze temps for fabrication. View Quote View All Quotes View All Quotes Quoted: Quoted: Quoted: If you glued it, you'd want to machine a groove into the titanium wide and deep enough to slide the CF into it after gluing, then glue and wrap more CF outside of that area well into the TI overlapping quite a ways to try and prevent the two dis-similar material from separating from each other. Even a pinhole or tiny delamination at those pressures would be enough to cause a catastrophic event. I'd also X ray it like you would a weld on a pressure containing vessel [or pipe] to make sure there were NO voids whatsoever. When they build airplane CF sections, dont these also go into a big autoclave to help the resin cure and maybe even push out little bubbles in the CF? It wouldn't surprise me if they didnt do that. Not an inspired expense ? There was a clip of the joining of the ring. I thought I did see some sort of channel milled into the titanium ring? The whole thing driven by cost, surprised he sprung for the Commercially Pure titanium for the domes. It wouldn't have been that difficult for such a small submersible to have been 100% ti. There are lots of fab shops that specialize in Ti and make things like chemical reactor vessels (same shape), and there is at least one company I know of in eastern OH near Salem that has a pretty big vacuum chamber for doing electron beam welding on titanium assemblies. Yes CF used on aircraft is placed in vacuum chambers for curing. There is very strict quality control standards because the CF used is kept at temperatures below zero degrees. The material has limited time exposure above the freeze temps for fabrication. Edit: Instead of bagging in the autoclave sometimes they have fixtures that do the same thing. I've even seen custom bags and release film molded to shape. I was in a composite manufacturing design class a few years back were they had COOLING pads to control the temperature of some fancy curing parts. I thought that was cool because I was given hell for suggesting using heat blankets on some larger layups in addition to the heat the autoclave uses. |
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Quoted: That... can't be accurate. Something is getting lost in translation. It's been known that the mothership only reported a problem several hours after loss of communications. The implosion would have occurred WELL before any SAR efforts. View Quote At the moment of the implosion there were no on scene commanders at the scene, there was no scene. Lost in translation. |
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Quoted: In the case of Scorpion SOSUS detected the event, but it was not noticed until the sub went missing and they reviewed the recorded data. That’s probably what happened here. The primary purpose of the system is not to detect imploding pressure vessels, but they can go through the data and find it if they have reason to look for one. View Quote Maybe these days the Navy has an AI reviewing the raw data and when it spots something weird it gives a heads up. |
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Quoted: I think Cameron's statement was speculation, at least that was my impression when I watched the interview. You were in that world, of course they sat on the info from SURTASS or SOSUS or whatever system detected it. They probably knew it was catastrophic and time wasn't a real issue. Even if they were still alive the capabilities of those systems is worth some lives in the grand scheme. Plus who knows exactly what was shared and when. What is being made public is only part of the truth. View Quote View All Quotes View All Quotes Quoted: Quoted: While I understand not wanting to divulge the sensor, I don't understand the delay in reporting. It's not like Titan was on a mission to blow up the Nordstream II pipeline. Between the navy and Cameron's revelation that Titan had dropped ballast and was returning to the surface, it's pretty clear on Sunday people knew this was a recovery operation, not a rescue operation. Yet we spun everything up as if it was a rescue. No one wanted to make that call. You were in that world, of course they sat on the info from SURTASS or SOSUS or whatever system detected it. They probably knew it was catastrophic and time wasn't a real issue. Even if they were still alive the capabilities of those systems is worth some lives in the grand scheme. Plus who knows exactly what was shared and when. What is being made public is only part of the truth. Even if the implosion signature was identified the day of the event, a single source detection like that is not definitive. I wouldn’t want to be the guy who called off the SAR based on that only to have a sub full of bodies turn up later. |
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Quoted: What are deep sea subs made of usually? Stainless? I'm curious. View Quote All of the ones that James Cameron has used have a pressure hull of titanium or some other alloy containing titanium from what I have read. These submersibles cost in the 10’s of millions to build. I believe the new Triton one cost 48 million. Oceangate was trying the cheaper route. |
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Quoted: Quoted: WSJ articles: Sub passengers died in implosion The five men onboard the missing submersible in the North Atlantic died in a catastrophic implosion, the U.S. Coast Guard said, after searchers found debris from the craft near the Titanic shipwreck that ended a desperate search to find them alive. US Navy detected Titan sub implosion days ago WASHINGTON—A top secret U.S. Navy acoustic detection system designed to spot enemy submarines first heard the Titan sub implosion hours after the submersible began its mission, officials involved in the search said. The Navy began listening for the Titan almost as soon as the sub lost communications, according to a U.S. defense official. Shortly after its disappearance, the U.S. system detected what it suspected was the sound of an implosion near the debris site discovered Thursday and reported its findings to the commander on site, U.S. defense officials said. “The U.S. Navy conducted an analysis of acoustic data and detected an anomaly consistent with an implosion or explosion in the general vicinity of where the Titan submersible was operating when communications were lost,” a senior U.S. Navy official told The Wall Street Journal in a statement. “While not definitive, this information was immediately shared with the Incident Commander to assist with the ongoing search and rescue mission.” The Navy asked that the specific system used not be named, citing national security concerns. At least they went quickly. eta: this reminds me of a story I read from WW I. After depth charging a German U-boat, the Royal Navy destroyer was circling the site listening through sonar. They heard some attempts at restarting the engines, then sounds of gunshots. There was no SONAR in the 1st WW. Really? |
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When was the last time a submarine catastrophicly imploded?
In fact has it ever happened before? |
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Fires a 50 yeal-old white guy engineer for stating carbon fiber is a terrible material to use and will fail after several compression and decompression cycles to be "inspirational".
Sub with carbon fiber hull fails after after several compression and decompression cycles. |
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Quoted: While I understand not wanting to divulge the sensor, I don't understand the delay in reporting. It's not like Titan was on a mission to blow up the Nordstream II pipeline. Between the navy and Cameron's revelation that Titan had dropped ballast and was returning to the surface, it's pretty clear on Sunday people knew this was a recovery operation, not a rescue operation. Yet we spun everything up as if it was a rescue. No one wanted to make that call. View Quote View All Quotes View All Quotes Quoted: Quoted: Quoted: Subscription required. Scroll up. He quoted the article in the post. It’s a good read, would like to hear your thoughts. While I understand not wanting to divulge the sensor, I don't understand the delay in reporting. It's not like Titan was on a mission to blow up the Nordstream II pipeline. Between the navy and Cameron's revelation that Titan had dropped ballast and was returning to the surface, it's pretty clear on Sunday people knew this was a recovery operation, not a rescue operation. Yet we spun everything up as if it was a rescue. No one wanted to make that call. Imagine saying they heard an implosion and then the urgency is turned off. Rescue crews stand down. Time is no longer pressing. Then weeks or months later a ROV goes down to check the area out and find an intact sub. I can understand why they delayed, the likelihood of what they heard being the titan imploding was probably pretty high. On the other hand there is still plenty of uncertainty going off of audio in the ocean and I'd say getting visual confirmation was probably the right decision. |
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In all seriousness, are they going to collect the pile of shit on the ocean floor and bring it up?
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Quoted: They would have known what it was, and where it was. They've captured other submarines imploding below crush depth before. Catching it on multiple sensors and using time difference of arrival tells them the exact location. Kharn View Quote It's one of the more closely held secrets in that area of the military. |
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Quoted: Imagine saying they heard an implosion and then the urgency is turned off. Rescue crews stand down. Time is no longer pressing. Then weeks or months later a ROV goes down to check the area out and find an intact sub. I can understand why they delayed, the likelihood of what they heard being the titan imploding was probably pretty high. On the other hand there is still plenty of uncertainty going off of audio in the ocean and I'd say getting visual confirmation was probably the right decision. View Quote View All Quotes View All Quotes Quoted: Quoted: Quoted: Quoted: Subscription required. Scroll up. He quoted the article in the post. It’s a good read, would like to hear your thoughts. While I understand not wanting to divulge the sensor, I don't understand the delay in reporting. It's not like Titan was on a mission to blow up the Nordstream II pipeline. Between the navy and Cameron's revelation that Titan had dropped ballast and was returning to the surface, it's pretty clear on Sunday people knew this was a recovery operation, not a rescue operation. Yet we spun everything up as if it was a rescue. No one wanted to make that call. Imagine saying they heard an implosion and then the urgency is turned off. Rescue crews stand down. Time is no longer pressing. Then weeks or months later a ROV goes down to check the area out and find an intact sub. I can understand why they delayed, the likelihood of what they heard being the titan imploding was probably pretty high. On the other hand there is still plenty of uncertainty going off of audio in the ocean and I'd say getting visual confirmation was probably the right decision. I think that also assumes free flow of information. From the lawyer point of view, if you pretty well know what happened but don't share, the chances of someone finding evidence to show what happened are generally in your favor. So, let them look and hope for the best. And you know, you could seize Oceangate's entire IP and put its employees on the Wheel of Pain, and you'll never recover lost income from the non-employee dead - and the dead employees' have claims as well. |
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Quoted: There was no SONAR in the 1st WW. View Quote I beg to differ: "ASDIC was the primary underwater detection device used by Allied escorts throughout the war. The first versions, crude to say the least, were created near the end of World War One and further developed in the following years by the Royal Navy. How it works The ASDIC, known to the Americans as Sonar, was basically a transmitter-receiver sending out a highly directional sound wave through the water. If the sound wave struck a submerged object it was reflected back and picked up by the receiver. The length of the time from transmission until the echo was received was used to measure the range, which was shown as a flickering light on the range scale. By mounting the transmitter head so that it could be directed almost like a searchlight, the bearing of the target could be read from the compass receiver." source: https://www.uboat.net/allies/technical/asdic.htm |
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Quoted: /media/mediaFiles/sharedAlbum/capReference-550.jpg But the CEO wouldn't have listened to Scotty anyways. He was a 50 year old White guy. View Quote True. But Aluminium Oxynitride is a real thing now. |
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From your link: https://en.wikipedia.org/wiki/Sonar The British tested their ASDIC on HMS Antrim in 1920 and started production in 1922. |
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Quoted: Fucking Dan Crenshaw on now criticizing the response. Saying they could have been on site Wednesday morning to save the crew. Fuck that asshole. View Quote Dan is what common people refer to as a moron. We could have had the navy on site when they hit the water and it would be 100% they would still be dead. There was zero percent chance of saving these people. |
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Quoted: Not sure, but they did say the Titan debris isn't close to any of the Titanic wreck or debris field. View Quote View All Quotes View All Quotes Quoted: Quoted: In all seriousness, are they going to collect the pile of shit on the ocean floor and bring it up? Not sure, but they did say the Titan debris isn't close to any of the Titanic wreck or debris field. Who's going to offer submarine tours of the Titan debris? |
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Quoted: I’m not a material scientist, I’m sure someone here is, but the epoxy used to connect the CF to the TI ring would be suspect IMO. I’m not aware of any adhesive that could survive that type of pressure change over and over. The lack of testing that we know of tells me they took a lot of “on paper” specs and decided good enough. The TI domes were likely the best built components on that craft. View Quote Those domes better have been the best part. I was likely the product met that signed off on the order and the processing - I do recall the inquiry and being called by the sales group that got the order (its not something you see every day or every year), and I am pretty sure I annealed and flattened at least one if not both plates that got formed by a company that specializes in fabricating titanium stuff. Did that during a lockout in 2015. And I had mostly a good time running the furnace and flattening plates of all sorts of metals - various stainless steel grades, some nickel alloys, titanium CP and alloyed, fixing turned up plates off the mill, running overhead cranes with a remote box. All kinds of stuff - only regret was not rolling a plate or slab on the rolling mill. But myself and the current ti product engineer searched our archaic business system (it wasnt even state of the art when I started at USSteel in 1990! and couldn't find any record of it. I thought it was 4" plate, but maybe it was thicker like 6"? I might expand my search tomorrow if nothing super important comes up I wanted to see what specs were on the order. Probably astm B265 and maybe asme SB265, which are just mechanical properties and being free from alpha case, plus chemisty. Nothing in those two about microstructure or ultrasonic or any other type of surface or internal defect detection , like immersion ultrasonic inspection, dye penetrant, etc Those things the customer would have to ask specifically for. Ultrasonic is the most common used for stuff like plate for industrial uses. Tensile tests should have been good. Alpha case is easy - either grind or pickle enough off the surfaces. Hydrogen hardly ever a problem on The type of melt used. And I made it dead flat, better than the regular crew. I cant recall who made the dome. I thought it was a major titanium fabricator in baltimore. The plate would've been heated up to form Im sure. But there's nothing listed on the web for one there now. Maybe they bailed out of that shithole? |
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Quoted: True. But Aluminium Oxynitride is a real thing now. https://www.designingbuildings.co.uk/w/images/9/91/ALON_transparent_aluminium.jpg View Quote Transparent Aluminium |
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Quoted: Fires a 50 yeal-old white guy engineer for stating carbon fiber is a terrible material to use and will fail after several compression and decompression cycles to be "inspirational". Sub with carbon fiber hull fails after after several compression and decompression cycles. View Quote Yup. That was a stupid move. Even exotic titanium and steels will work harden and become brittle because of the pressure cycles. |
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Quoted: Precisely. The Navy might have gone back and listened to their tapes, but they didn't "immediately relay" jack shit. This is Public Affairs bullshit, meant to make the Navy look more competent than they are. View Quote You have what actually transpired, what the navy reported, and what the press said. I'm guessing all three are a little different. |
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James Cameron says he was told on MONDAY that the sound of the Titan sub imploding had been detected, and claims the carbon fiber hull of the doomed ship was known to be unsuitable
James Cameron was told within 24 hours of the Titanic sub disappearing that it had been heard to implode, and 'watched over the ensuing days this whole sort of everybody-running-around-with-their-hair-on-fire search, knowing full well that it was futile.' The film director and deep sea expert, who has made over 30 dives down to the Titanic wreckage, said he was told on Monday that the noise of a likely implosion had been registered by underwater acoustic devices. 'I tracked down some intel that was probably of a military origin, although it could have been research - because there are hydrophones all over the Atlantic - and got confirmation that there was loud noise consistent with an implosion,' he told CNN. He said it did not surprise him, because he felt the carbon fiber hull of OceanGate Expedition's sub, named Titan, was fundamentally unsuitable. Cameron told Anderson Cooper on Thursday night he was 'kind of heart sick from the outcome of this.' But, he said, he had had more time than most to come to terms with it. 'I've been living with it for a few days now, as have some of my colleagues in the deep submergence community,' he said. 'I was out on a ship myself when this happened on Sunday. 'The first I heard of it was on Monday morning. I immediately got on my network - because it's a very small community in the deep submergence group - and found out some information with about a half hour that they had lost comms and they had lost tracking simultaneously. 'The only scenario that I could come up with in my mind that could account for that was an implosion. A shockwave event so powerful it actually took out a secondary system that has its own pressure vessel and its own battery power supply, which is the transponder that the ship uses to track where the sub is.' Cameron, 68, said he began speaking to friends and colleagues in the deep sea industry, and swiftly learned that there was little doubt there had been a catastrophic implosion. 'I let all of my inner circle of people know that we had lost our comrades, and I encouraged everyone to raise a glass in their honor on Monday. 'Then I watched over the ensuing days this whole sort of everybody-running-around-with-their-hair-on-fire search, knowing full well that it was futile, hoping against hope that I was wrong but knowing in my bones that I wasn't.' Cameron said it 'certainly wasn't a surprise' when the U.S. Coast Guard and OceanGate confirmed on Thursday that all five onboard were dead, and debris from the imploded sub had been found on the sea bed. He said he felt terrible for the families, saying they had to 'go through these false hopes that kept getting dangled as it played out.' Link |
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Quoted: I'd love to know how that thing was built. I'd expect to see it tape laid on a plug type tool, bagged and cured in an autoclave. I've never dealt with anything close to approaching the thickness they were dealing with though. I would expect a shitload of porosity if it were built and cured using the methods I'm familiar with. View Quote SubBrief showed a short clip done by Ocean Gate on his show from earlier in the week. Showed them wrapping the CF tape (or tow I think is the correct term) around a mandrel. I couldnt see if there was something applying resin as it wrapped. It was pretty thick when done. Then showed them applying some sort of glue to the end of the tube, and slipping the titanium ring over it. The ring had like a c-channel machined on the end, so it was sort of like a male CF tube wall end, and the ti ring had the female channel that slipped over the end of the tube. Maybe 2" deep is all it sat on the tube! Not very much. And you can imaging that both surfaces should really be 100% co-planar to get a contact bond and not rely on a big gap filled by epoxy. That six foot diameter ring gets machined, you cant think its not going to move some from residual stresses during milling. No mention of the autoclave curing of the tube. No mention of any sort of xray or UT inspection of the tube. Probably not very inspiring . |
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Quoted: Those domes better have been the best part. I was likely the product met that signed off on the order and the processing - I do recall the inquiry and being called by the sales group that got the order (its not something you see every day or every year), and I am pretty sure I annealed and flattened at least one if not both plates that got formed by a company that specializes in fabricating titanium stuff. Did that during a lockout in 2015. And I had mostly a good time running the furnace and flattening plates of all sorts of metals - various stainless steel grades, some nickel alloys, titanium CP and alloyed, fixing turned up plates off the mill, running overhead cranes with a remote box. All kinds of stuff - only regret was not rolling a plate or slab on the rolling mill. But myself and the current ti product engineer searched our archaic business system (it wasnt even state of the art when I started at USSteel in 1990! and couldn't find any record of it. I thought it was 4" plate, but maybe it was thicker like 6"? I might expand my search tomorrow if nothing super important comes up I wanted to see what specs were on the order. Probably astm B265 and maybe asme SB265, which are just mechanical properties and being free from alpha case, plus chemisty. Nothing in those two about microstructure or ultrasonic or any other type of surface or internal defect detection , like immersion ultrasonic inspection, dye penetrant, etc Those things the customer would have to ask specifically for. Ultrasonic is the most common used for stuff like plate for industrial uses. Tensile tests should have been good. Alpha case is easy - either grind or pickle enough off the surfaces. Hydrogen hardly ever a problem on The type of melt used. And I made it dead flat, better than the regular crew. I cant recall who made the dome. I thought it was a major titanium fabricator in baltimore. The plate would've been heated up to form Im sure. But there's nothing listed on the web for one there now. Maybe they bailed out of that shithole? View Quote |
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Quoted: I beg to differ: "ASDIC was the primary underwater detection device used by Allied escorts throughout the war. The first versions, crude to say the least, were created near the end of World War One and further developed in the following years by the Royal Navy. How it works The ASDIC, known to the Americans as Sonar, was basically a transmitter-receiver sending out a highly directional sound wave through the water. If the sound wave struck a submerged object it was reflected back and picked up by the receiver. The length of the time from transmission until the echo was received was used to measure the range, which was shown as a flickering light on the range scale. By mounting the transmitter head so that it could be directed almost like a searchlight, the bearing of the target could be read from the compass receiver." source: https://www.uboat.net/allies/technical/asdic.htm View Quote View All Quotes View All Quotes Quoted: Quoted: There was no SONAR in the 1st WW. I beg to differ: "ASDIC was the primary underwater detection device used by Allied escorts throughout the war. The first versions, crude to say the least, were created near the end of World War One and further developed in the following years by the Royal Navy. How it works The ASDIC, known to the Americans as Sonar, was basically a transmitter-receiver sending out a highly directional sound wave through the water. If the sound wave struck a submerged object it was reflected back and picked up by the receiver. The length of the time from transmission until the echo was received was used to measure the range, which was shown as a flickering light on the range scale. By mounting the transmitter head so that it could be directed almost like a searchlight, the bearing of the target could be read from the compass receiver." source: https://www.uboat.net/allies/technical/asdic.htm |
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Quoted: They are not placed in vacuum chambers that would do nothing as the entire object would be at the same pressure and thus there would be no vacuum on the object. The items are bagged then lines attached to the bag, sometimes under vacuum but then you will make sure to pull a vacuum to check for leaks. Then the items are placed into the autoclave and the vacuum lines are connected to the outside. The door is closed and the chamber is pressurized not placed under a vacuum. Since the bagged parts are under pressure from the autoclave but vented to the outside a differential is formed and the part cures under pressure. You can also apply vacuum to the parts as well as the pressure to the autoclave. You have to be monitoring the cure as if one bag opens up the entire autoclave will vent out and you may end up scraping the item/parts. Edit: Instead of bagging in the autoclave sometimes they have fixtures that do the same thing. I've even seen custom bags and release film molded to shape. I was in a composite manufacturing design class a few years back were they had COOLING pads to control the temperature of some fancy curing parts. I thought that was cool because I was given hell for suggesting using heat blankets on some larger layups in addition to the heat the autoclave uses. View Quote heater blankets are commonly used but at my work we have found that the hotspots they produce are not ideal. I know they are for sure used on rotor blade cures. Other proprietary options for heating are what we are shifting too now for large parts at least, ours are mostly barrels (rockets) so there are nice ways to heat the inside of an enclosed space. |
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Underwater forensic investigator: Mapping of submersible pieces will tell story
Underwater forensic investigator: Mapping of submersible pieces will tell story | Elizabeth Vargas Maritime lawyer: There will be 'tremendous litigation' related to the submersible tragedy Maritime lawyer: There will be 'tremendous litigation' related to the submersible tragedy | On Balan |
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Scott Manley live chat:
Under pressure - A live rant about carbon fiber submarines. |
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Quoted: SubBrief showed a short clip done by Ocean Gate on his show from earlier in the week. Showed them wrapping the CF tape (or tow I think is the correct term) around a mandrel. I couldnt see if there was something applying resin as it wrapped. It was pretty thick when done. Then showed them applying some sort of glue to the end of the tube, and slipping the titanium ring over it. The ring had like a c-channel machined on the end, so it was sort of like a male CF tube wall end, and the ti ring had the female channel that slipped over the end of the tube. Maybe 2" deep is all it sat on the tube! Not very much. And you can imaging that both surfaces should really be 100% co-planar to get a contact bond and not rely on a big gap filled by epoxy. That six foot diameter ring gets machined, you cant think its not going to move some from residual stresses during milling. No mention of the autoclave curing of the tube. No mention of any sort of xray or UT inspection of the tube. Probably not very inspiring . View Quote Pre-preg has the resin already as a part of it. Which is why it is appealing to work with and produces more consistent results. I hadn't seen their vid of the process but I am assuming it was an AFP process of some kind. |
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Quoted: Those domes better have been the best part. I was likely the product met that signed off on the order and the processing - I do recall the inquiry and being called by the sales group that got the order (its not something you see every day or every year), and I am pretty sure I annealed and flattened at least one if not both plates that got formed by a company that specializes in fabricating titanium stuff. Did that during a lockout in 2015. And I had mostly a good time running the furnace and flattening plates of all sorts of metals - various stainless steel grades, some nickel alloys, titanium CP and alloyed, fixing turned up plates off the mill, running overhead cranes with a remote box. All kinds of stuff - only regret was not rolling a plate or slab on the rolling mill. But myself and the current ti product engineer searched our archaic business system (it wasnt even state of the art when I started at USSteel in 1990! and couldn't find any record of it. I thought it was 4" plate, but maybe it was thicker like 6"? I might expand my search tomorrow if nothing super important comes up I wanted to see what specs were on the order. Probably astm B265 and maybe asme SB265, which are just mechanical properties and being free from alpha case, plus chemisty. Nothing in those two about microstructure or ultrasonic or any other type of surface or internal defect detection , like immersion ultrasonic inspection, dye penetrant, etc Those things the customer would have to ask specifically for. Ultrasonic is the most common used for stuff like plate for industrial uses. Tensile tests should have been good. Alpha case is easy - either grind or pickle enough off the surfaces. Hydrogen hardly ever a problem on The type of melt used. And I made it dead flat, better than the regular crew. I cant recall who made the dome. I thought it was a major titanium fabricator in baltimore. The plate would've been heated up to form Im sure. But there's nothing listed on the web for one there now. Maybe they bailed out of that shithole? View Quote Seriously man, that’s cool. Thanks for the details. Any idea what adhesive was used? I watched the video of the assembly, that seemed to be legit but I’m curious. |
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Quoted: I’m not a material scientist, I’m sure someone here is, but the epoxy used to connect the CF to the TI ring would be suspect IMO. I’m not aware of any adhesive that could survive that type of pressure change over and over. The lack of testing that we know of tells me they took a lot of “on paper” specs and decided good enough. The TI domes were likely the best built components on that craft. View Quote There are plenty of adhesives which are used to bond domes into barrels for many, many cycles in order to meet qual, protoqual, and acceptance testing requirements for SMC-S-016 |
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Quoted: I dont think you realize the cost of titanium that it would take to make a sub of the size of Titan. View Quote A lot less than the lives of a couple billionaires. They're better than the rest of everyone else. But for CP4 plate, I will take a shot and say $30 a pound. And thats with some nice margins for the producer. If 6-4 plate, not much more really. Leave the math for later to make a tube the size the titan was, to figure out how much. Maybe need two plates to weld together for the tube, so maybe add in a couple bulkhead plates. Not many plate mills wide enough to roll something to make a 5' dia tube as a single plate. Then pay a company to roll it into a tube, weld it, and do some NDT on the welds But thats not very inspiring |
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Quoted: Fires a 50 yeal-old white guy engineer for stating carbon fiber is a terrible material to use and will fail after several compression and decompression cycles to be "inspirational". Sub with carbon fiber hull fails after after several compression and decompression cycles. View Quote You can replace your highly experienced 50 year old white dude critics with 19 year old inexperienced youthful cheerleaders, but the outcome of using substandard equipment , and processes won’t change, it will turn out as the critics warned. Adding inexperienced personnel makes it happen even faster. What’s the saying? You can ignore reality, but you can’t ignore the consequences of ignoring reality? Attached File |
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Quoted: Underwater forensic investigator: Mapping of submersible pieces will tell story https://www.youtube.com/watch?v=6-LdDFbzcxI Maritime lawyer: There will be 'tremendous litigation' related to the submersible tragedy https://www.youtube.com/watch?v=vQqyKR4k-vA View Quote Tremendous? The estates of the deceased sure have the money to send a Genghis Khan horde of lawyers down on those responsible. The company assets + insurance are likely bupkis. Unless you can drag in a peripheal player like Boeing or UW (see above), there's no tremendous litigation. You sue a broke-dick, wrong company and you become owner of all $500 of broke-dick, wrong company's assets AND liabilities. Congratulations. |
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