Originally published at: Real Engineering's deep dive on the "questionable engineering" of Oceangate's Titan | Boing Boing
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It still seems so incredibly stupid to me that rich dweebs go through so much trouble for a chance to glimpse the Titanic wreckage through a tiny porthole when the HMHS Britannic, which is basically the same ship except in much better condition, is sitting just 300 feet beneath the Aegean sea. A rich tourist could get a full tour in a sub outfitted with panoramic windows and be back in time for a sunset cocktail at a five-star resort in Santorini.
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Yup. There are some similarities: You can’t evacuate a plane in-flight either–the crew is simply going to have to deal with any issues using the resources on hand until they reach the surface. And wings are long levers with aerodynamic constraints on the depth of the beam so the forces involved will be fairly large too.
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I suspect that’s exactly the problem. The comparatively mild conditions that would allow a sub that’s actually luxurious would also allow an adequate implementation that would be affordable on an upper middle class vacation budget(possibly a save-up-for-special-occasion one; not a ‘we try to book a cruise every winter’ one; but still).
How are you going to preen about being an ‘explorer’ at a location you could practically take the bus to?
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Gods, reading the emails, etc. from the ex-CEO talking about how they didn’t need safety regulations because they had their innovative (patented?) sensor system that would let them know that the carbon-fiber hull was failing. Their test of that system was, insanely, in practice. In a sense, it worked, in that it let them know there was a problem with the hull. In the more meaningful sense, it didn’t work, in that the hull shortly thereafter imploded, giving them no time at all to rise to a safe depth. Which seems like it was pretty predictable, from an engineering standpoint…
A pretty major difference being that, with the sub, most issues simply aren’t survivable. You have any sort of hull problem, it implodes. An aircraft can have some pretty major issues - the hull can be coming apart - and still reach the surface, because the environment in which it operates is relatively so forgiving. Planes don’t usually just explode mid-air on their own. Which of course just means you need orders of magnitude more regulatory scrutiny of subs…
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Yeah, but it’s not THE titanic! that one got a movie and everything (or, several?), and it’s hard to reach, so it MUST be more important! /s
It’s all about percpetions, I think, and something that’s over-hyped that not everyone gets a chance to see. Since the Britannic is so much more accessible, it’s easier for more people to have seen it. However, getting to see the titanic is more rare, and people will pay to be “rarer” than the rest of us…
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I wonder how many tourists actually have seen it though. You always hear about rich nerds bragging about visiting the Titanic but I can’t recall hearing anyone bragging about that one…
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Yeah, because as you note, it’s not hard to see, so no need to brag about it… But I have no idea how popular it is to visit. Might be common enough? 
But I think for most people, it’s not an actual interest in the type of boat, etc. It’s more about proximity to fame and showing off one’s status via experiences.
Come to think of it, going up Mt. Everest is becoming far more common and accessible, so I wonder what mountain rich dudes wanting to be rarer than the rest of us are looking to climb now? 
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It’s also in territorial waters rather than international ones, so there are actually regulations, and it’s not a free for all.
The wreck was discovered in Greek waters by explorer Jacques Cousteau in 1975 and then bought by British maritime historian Simon Mills in 1996. The reason the filmmaker/historian gave for purchasing the wreck was that he did not want it to be looted.
Now, if you would like to dive the wreck, you need to get special permission from the owner. Once that is achieved, permits need to be acquired from the Greek government to take the dive.
The Greek government does not readily give out these permits as the wreck has been classified as a British war grave. Getting these permissions and permits from the Greek government can take many months, even up to a year, so plan accordingly!
That doesn’t sound like the kind of process billionaires like to be subjected to!
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I am one of the furthest from being a qualified engineer, but that video puts into words the hunch I had when I heard it was carbon fiber instead of steel. That is carbon fibers resist stretching very well but have much lower compression strength. It was basically a reinforced plastic hull.
Very unscientifically this video shows the relative compressive strength and failure of similarly shaped (pipe section) materials.
Another for bending force.
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As far as I remember the discussion regarding the “real time hull monitoring” was that they just miked the fucking thing when they were testing a scale model. The hull made a lot of noise right before it failed, and supposedly they developed a pattern of what it sounded like right before that. I have a suspicion that their model may not have been very robust (did not have a lot of data because more data= more trials and who the fuck needs that).
The “titan” looks very much like the original submersible Rush bought at the outset, when he began his interest. That sub was for MUCH more shallow depths (and was designed accordingly). The first one the they “made”, which was a refit of an existing submersible, also is the capsule shape with a dome. It appears very much that all his efforts were to make one just like the one he had, but that could go to the depth he wanted.
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Put another way it’s a bit like how a balloon is pretty good at holding its shape as long as the higher pressure is on the inside.
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Also lost in a lot of these “but they use carbon fiber in airplanes!” discussions is that the pressure differential between the inside of the pressurized cabin and the ambient environment is generally no greater than 1 bar, and usually much less. Whereas the compressive pressure in the case of Titan was 400 bar.
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The saying goes, “the best place for an engineer when their bridge collapses is under it”
Stockton Rush saved himself from being sued to death by becoming algae fertilizer.
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It is the bit in the video where a materials expert on a previous trip pointed out that the sounds coming from the pressure hull was stress building up to a future catastrophic failure; but, hey, poindexters, am I right, what do they know? 
I think I’m somewhere between well-done and burnt to a crisp.
For real bragging rights, they should dive the SS Richard Montgomery; it is barely submerged, but exclusive as fuck.
“A billionaire walks in to 400 bar.”
Ronald Hamburger might need to reserve a parking space beside Millennium Tower.
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This is a great video because it focuses on the right problem. It’s not so much that carbon fibre isn’t good in compression. While that’s true, if you use enough of it, it’s still okay (and OceanGate did use enough of it). It is used in underwater pipelines, for example.
The problem is that complex composite materials fail unpredictably. You can’t model them effectively in software because of their complexity, and these clowns didn’t do any physical testing. Literally nobody knows how many pressure cycles you can safely get from a given quantity of carbon fibre because it’s too complex to simulate. These idiots did it anyway, based on nothing but hubris.
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I don’t even think the (ex) CEO was denying this was the case - I mean, it is kind of hard to deny, as carbon fiber is pretty famous for exactly that, building up stress and then failing catastrophically. He just, weirdly, put all his faith in the untested sensor system giving sufficient warning, despite the fact that carbon fiber is also famous for going from “it’s fine” to “it exploded” without a lot of warning too.
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Just curious, is this the deepest at which someone died? There have been submarine disasters before but they would have failed around 1000 meters. The Titanic victims who were trapped in the vessel would have died within the first few hundred meters after the boat sank.
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