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Reminds me of the story of the first crewed submersible to the bottom of the Mariana Trench. During the descent there was a loud boom, like some something massive broke. After recovering from the shock, they decided to continue the dive, because if it was something important, they would have already been dead.
Did they find out what it was?
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What better alternatives would they have in the middle of the ocean?
More traditional satellite networks, I guess? As I understand it, this is what sailors do / did before starlink. This had me curious if I could find coverage maps of satellite operators, and I found this: https://www.satphonestore.com/coveragemaps
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If your design breaks at less than the target then you really have to question the logic of continuing with that design. Making it slightly bigger won't fix the inherent issue with the materials. They're potentially opening themselves up to charges for killing these people. They knowingly or recklessly put them on a boat when it isn't capable of reaching the depth safely and now they are dead.
The fact they took it to some testing facility to test for cyclic fatigue shows that they understood that it was an unknown in the design, decided to test it at a facility designed for exactly that, it failed so they redesigned presumably with a design to mitigate the failures of design one. They probably took design two through the same testing process, and presumably it passed or they wouldn't have paying guests in…
Skimming the website, I assume this submersible is using electromagnetically attached drop-weights so that if anything goes wrong and power is lost, the weights drop off and the submersible floats up to the surface again? And 96 hours of life support sounds good, but unless there is another submersible nearby that can dive down, find them AND attach a line, the number of hours of life support will be irrelevant. Of c…
David Pogue went down with the same vessel last year for CBS: https://www.youtube.com/watch?v=29co_Hksk6o "I couldn't help noticing how many pieces of the sub seemed... improvised."
I'm hesitant to speculate but just sharing -- an earlier version of this submersible was scrapped: "OceanGate will take advantage of lessons learned during the construction of its carbon-hulled Titan submersible, which was originally built for Titanic journeys. Rush said tests that were conducted at the Deep Ocean Test Facility in Annapolis, Md., revealed that the Titan’s hull “showed signs of cyclic fatigue.” As a r…
If your design breaks at less than the target then you really have to question the logic of continuing with that design. Making it slightly bigger won't fix the inherent issue with the materials. They're potentially opening themselves up to charges for killing these people. They knowingly or recklessly put them on a boat when it isn't capable of reaching the depth safely and now they are dead.
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My first thought was that expanding foam from the hardware store is very cheap, but obviously that sort of foam would be crushed by the water pressure. > Syntactic foams are composite materials synthesized by filling a metal, polymer,[1] cementitious or ceramic matrix with hollow spheres called microballoons[2] or cenospheres or non-hollow spheres (e.g. perlite) as aggregates.[3] In this context, "syntactic" means "p…
I wonder how similar its properties are to air-entrained concrete.
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Carbon fiber is used because it is rigid. The failure mode for a member in compression is buckling, which is resisted by stiffness, not strength. It's also a lot easier to make a huge thick tube out of composites than out of titanium. That's why only the spherical ends are titanium, and the middle tube part is CF.
>The failure mode for a member in compression is buckling, which is resisted by stiffness Hmm, this is probably the right answer. When things start to buckle, you'd be putting part of the surface in tension, which would be resisted by the fiber. I would definitely be very interested to see the plots of strain gauges embedded throughout the thickness of the wall as it goes to depth (in all three axes, hoop, radial, an…
This appears to be the vessel in question: https://oceangate.com/our-subs/titan-submersible.html Pressure hull made from titanium and carbon fiber, capable of diving to 4000m (13,000 ft). I recall that one reason SpaceX switched from carbon fiber to stainless steel pressure vessels (fuel tanks) was the difficulty of detecting structural flaws. Can any engineers comment on whether that task is easier for a vessel expo…
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> no one thought a safety hatch the can be opened from the inside in emergencies could be useful? It’s quite possible that they considered it and felt that it would compromise the structural integrity and the risk would be higher than not having it.
Then that sub should not have been designed. Because if they do surface they should be able to open the hatch.
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David Pogue, who traveled to the Titanic with OceanGate last summer, has said that he was on the control ship when a previous sub was "lost for about 5 hours". Source: https://twitter.com/Pogue/status/1670835763536183297
Jesus. This sounds like this group is just taking billionaires' money while running a death trap. How the hell do you lose your sub for five hours? This should have stopped all trips until they fixed this problem through a combination of technical and procedural changes.
What if people pay for that exactly because it's risky and potentially fatal?