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>> "I think it was General MacArthur who said: 'You're remembered for the rules you break,'" Rush told the Mexican YouTuber alanxelmundo. The problem with this

by toss1 3y ago

>> "I think it was General MacArthur who said: 'You're remembered for the rules you break,'" Rush told the Mexican YouTuber alanxelmundo. The problem with this approach is that the CEO failed to distinguish between human rules (to which MacArthur was referring) vs. laws of physics. Laws of physics do not know about, care about, or yield to any human action or intention. They are absolute, and will kill you if you get on the wrong side of them. If he wanted to go himself on this device, that is fine, but the way he was actively selling this as safe is just fraud. He got what he deserved, his passengers were fooled to their deaths. Owning a carbon fiber composites design & fabrication business which builds both aerospace and subsea components, nearly everything I've read and viewed about this CEO's practices ranges from creep-me-out to 'looks criminal'. Compiling just references to the bad practices and failings would fill many pages, but perhaps the worst is the assumption that "hey, it went down there once, so it's good to go as many times as we want.", and refusal to even get any kind of ultrasonic or radiological testing of the carbon fiber hull. Plus, to think that you can with acoustics, outrun the cascading failure at those kinds of pressures is nothing less than hard stupidity. The core function of carbon fiber composites is to spread the loads through the matrix with the extremely light and high-tensile-strength carbon fiber. This works great until it doesn't, so the failures are well known to be nearly explosive in rate and catastrophic, unlike metals which tend to deform first. When the load is exceeding the maximum — especially in a well-designed & well-fabricated part — it is spread throughout the material. When it exceeds the maximum, either by fracturing the matrix between layers, or by fracturing some fibers, the load is now borne by proportionally less material, so is more focused, that material breaks, etc.. Even at normal pressures, this happens in microseconds. See the standard open hole compression test at about 1:46+ [0]. The pressures at that depth, would only increase the failure speed. The tech guy got fired from the Titan project (w/10min to clean out his desk) for pointing out that the acoustic flaw-detection method the CEO wanted to use would not work, and would give them only milliseconds of warning. He was right. What I do find a bit surprising is that James Cameron (himself a very accomplished depth explorer) says he heard from his sources that the Titan had dropped its weights and was ascending trying to manage an emergency, which indicates they actually had seconds or maybe even minutes of warning. Could mean that it just took longer with the 5in thick hull. So, it'll be really interesting to see the final reports... [0] https://www.youtube.com/watch?v=u1gHxCt-qv0 https://www.youtube.com/watch?v=u1gHxCt-qv0

jacquesm 3y ago
The idea that you can outrun a cascading failure has me completely baffled. What is your view on the liability of Spencer Composites?
- toss1 3y ago
  >>What is your view on the liability of Spencer Composites? Yikes! (good question) I read elsewhere that they were given six weeks to design and build the cylindrical hull. And that he OceanGate CEO had sourced a bunch of out-of-date prepreg carbon fiber from Boeing, getting a great deal, and said that 'those aerospace guys may need those dates but we don't'. The right answer to both of those is: "Those ideas are too insane or too stupid to work with us. Either let us help you with a better idea, or come back when you have one". Six weeks is an insanely short time to even make a few test coupons and a single full-thickness panel and maybe a 50% scale short tube section to test things like curing rates, production methods, compaction/void rates, actual yielded properties, and so forth, plus, whether the epoxy in that out-of-date material was even still any good. At least if you want to have a clue of what you are doing. Six months is an insanely short time to do development on the titanium endcaps, the surface on the composite tube to which they will mate, the adhesive, the process, etc. The few snippets of video I saw and the CompositesWorld article [0] indicate that they likely did a decent job with the resources they had. But, damn, there was a LOT missing. They said that they worked with NASA, but listening to Sarah Cox, the director of composites at NASA[1], she talks at length about the need for extensive testing at every stage from test coupons (small panels), sub-assemblies, full parts, and in and after operation. Just the video of the bonding process gave me the creeps. It would be fine for something like an art show piece, or maybe even on a test mule automobile. But there was nothing but a person using a manual straight-edge Bondo applicator (flexible plastic rectangle) trying to spread an even thickness. There was zero protection from any warehouse/shop debris, no evidence that pressure would be applied after the mating, and no vacuum to eliminate entrapped air. I guarantee there were voids, air pockets, unbonded sections under that titanium ring. The key thing is that undersea does not require less caution than space flight, it requires MORE, a lot more, because the pressures are insane. As for Spencer Composites' liability, I'm no lawyer, but I'd be worried even if they made the Oceangate CEO sign in blood that the craft was experimental, not their design, only a best effort, and definitely not fit for the intended purpose. The only thing that might save them is that there were a few dozen dives on the hull before it imploded, so they could say "it worked when we gave it to them, how they abused it, maintained it, monitored it, etc. is not in our control, so not our problem.". But those sorts of issues are for the lawyers, judges, and juries to sort out. I expect they'll all have more fun than they wanted. [0] https://www.compositesworld.com/articles/composite-submersibles-under-pressure-in-deep-deep-waters https://www.compositesworld.com/articles/composite-submersib... [1] https://www.compositesworld.com/podcast/episode/episode-40-sarah-cox-nasa https://www.compositesworld.com/podcast/episode/episode-40-s...

by toss1 3y ago

jacquesm 3y ago

The idea that you can outrun a cascading failure has me completely baffled. What is your view on the liability of Spencer Composites?

toss1 3y ago
>>What is your view on the liability of Spencer Composites? Yikes! (good question) I read elsewhere that they were given six weeks to design and build the cylindrical hull. And that he OceanGate CEO had sourced a bunch of out-of-date prepreg carbon fiber from Boeing, getting a great deal, and said that 'those aerospace guys may need those dates but we don't'. The right answer to both of those is: "Those ideas are too insane or too stupid to work with us. Either let us help you with a better idea, or come back when you have one". Six weeks is an insanely short time to even make a few test coupons and a single full-thickness panel and maybe a 50% scale short tube section to test things like curing rates, production methods, compaction/void rates, actual yielded properties, and so forth, plus, whether the epoxy in that out-of-date material was even still any good. At least if you want to have a clue of what you are doing. Six months is an insanely short time to do development on the titanium endcaps, the surface on the composite tube to which they will mate, the adhesive, the process, etc. The few snippets of video I saw and the CompositesWorld article [0] indicate that they likely did a decent job with the resources they had. But, damn, there was a LOT missing. They said that they worked with NASA, but listening to Sarah Cox, the director of composites at NASA[1], she talks at length about the need for extensive testing at every stage from test coupons (small panels), sub-assemblies, full parts, and in and after operation. Just the video of the bonding process gave me the creeps. It would be fine for something like an art show piece, or maybe even on a test mule automobile. But there was nothing but a person using a manual straight-edge Bondo applicator (flexible plastic rectangle) trying to spread an even thickness. There was zero protection from any warehouse/shop debris, no evidence that pressure would be applied after the mating, and no vacuum to eliminate entrapped air. I guarantee there were voids, air pockets, unbonded sections under that titanium ring. The key thing is that undersea does not require less caution than space flight, it requires MORE, a lot more, because the pressures are insane. As for Spencer Composites' liability, I'm no lawyer, but I'd be worried even if they made the Oceangate CEO sign in blood that the craft was experimental, not their design, only a best effort, and definitely not fit for the intended purpose. The only thing that might save them is that there were a few dozen dives on the hull before it imploded, so they could say "it worked when we gave it to them, how they abused it, maintained it, monitored it, etc. is not in our control, so not our problem.". But those sorts of issues are for the lawyers, judges, and juries to sort out. I expect they'll all have more fun than they wanted. [0] https://www.compositesworld.com/articles/composite-submersibles-under-pressure-in-deep-deep-waters https://www.compositesworld.com/articles/composite-submersib... [1] https://www.compositesworld.com/podcast/episode/episode-40-sarah-cox-nasa https://www.compositesworld.com/podcast/episode/episode-40-s...