Comments by "" (@EbenBransome) on "Who Engineered the OceanGate Titan V2 Hull? Maybe Nobody Did?" video.

@ Scoring the titanium shouldn't be necessary as that could cause sites for crack propagation. A light chemical etch would normally do the job, having checked chemical compatibility. Ha, what am I saying? I think I've already exceeded the capacity of the late Stockton Rush to understand the technology.
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@solareclipsetimer Very big vacuum chamber. Many years ago our project group tried to design self supporting coils for a military project that were held together with epoxy. We managed it in the end with a rather complex and expensive fixture so we could actually wind the coils and add epoxy during the winding - in vacuum. It was a bit expensive but, you know, military budgets. The thought of a vacuum chamber and fibre winding machine big enough for a Titan hull is interesting, I suspect it would have cost more than the entire project.
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The problem for them with 45 degree winding would be the extra length needed at each end of the tube so that the thinner parts could be cut off. It would make the tube a lot more expensive.
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Needs more upvotes.
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@ Ultrasonic testing in a medium like carbon loaded epoxy is more than challenging. At that thickness it's almost impossible. To get the penetration you would need longer wavelengths which makes small flaws hard to detect. The scatter is tremendous.
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@ During the pandemic I amused myself building a carbon fibre/aramid kayak and paddle, using real 45 degree wound carbon fibre tubing, not the fake patterned stuff with a glass interior. The tube was 1mm thick and quite astonishingly strong, the hull was 2mm thick and survived bashing into rocks. There's no doubt, I think, that you could design and build a submersible with a hull that thick to survive a practical number of dives, using very carefully selected materials, proper construction and design. However, this one met none of the criteria (and you wouldn't get me in one, I get claustrophobia in the Blackwall Tunnel under the Thames.)
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I once found myself in a big confrontation between myself, as technical director responsible for standards and QA, and the production director who had taken shortcuts but wanted to release product which I knew would be nonconforming. I said no. He actually ranted and raved. But I was able to take the issue to the group engineering VP, and I won. The local CEO didn't like it, but a VP outranked him. The point here is that final engineering decisions to go ahead should never be with the CEO, whereas it is their responsibility to stop something that could adversely impact the company. I think the Cybertruck is the same thing: Musk should never have had the power finally to approve his pet project. The decision should have been made by a committee of engineering, production and marketing.
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The earlier equivalent was the jointing of the internal flues of steam boilers, which was a limiting factor on steam pressure for well over a century.
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@ But then the problem becomes one of buoyancy. Your submersible needs to come back up. Metal submersibles need large buoyancy tanks and these have to be filled with a light substance that can withstand the pressure. The 5 inch hull seems to have been on the limit and going to 7 would mean a complete redesign with added buoyancy, since carbon (or glass) epoxy is denser than water.
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@ You remind me of trying to set up strain gauges on aluminium where we didn't have an air conditioned lab (45 years ago) and the moment the last ether evaporated, the aluminium would instantly become damp. The test pieces had to be warmed very cautiously to about 40C. Even so there were failures.
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