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Engineering assessment of the OceanGate Titan failure

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Re: Engineering assessment of the OceanGate Titan failure

#71

Post by toss1 »

SV_BubbleTime wrote: post #18
ramesh31 wrote: post #14

Earlier quoted context omitted.

My question is just... why? It's not like carbon fiber was any cheaper than just making the thing out of steel or titanium like literally every other submersible. It just doesn't make any sense. You have none of the weight penalties that exist in aviation, so the heavier and the thicker the better.

As I understood it, you do have a weight penalty for a sub. You need to get back up by powered movement, or down by it. You are limiting your dive time either way. They can’t use foam for flotation at that depth. There is a concrete like “synthetic foam” if you want unpowered rise to surface but it’s expensive. I read early on they wanted carbon to be light enough to get back up by releasing weights on powerloss. Fro…

>>there is a concrete like “synthetic foam”

The word you are looking for is "syntactic foam", which is an epoxy or other material typically with embedded hollow glass microspheres. This material is used for the buoyancy components of undersea vessels. It comes in a broad variety of densities and depth ratings. It is typically machined into shapes on the inside of the part fitting around the metallic components and on the outside the shape of the outer surface of the vessel. It is also somewhat expensive, more for higher depth ratings (on the scale of dozens to low thousands of dollars per cubic foot). Here's a product from one of the suppliers I worked with for more info [0]

Typically, the goal in designing the vessel is to account for the mass and buoyancy of the metal parts and design in the right final volume of syntactic foam so that the vessel is neutrally buoyant at the operating depths, and doesn't have to work to stay up or stay down.

For more moderate depths, there are also various structural foams, which use a variety of chemistries to achieve low densities and high compression strengths. These are also used in sandwich panel construction for composites (instead of honeycomb, and for the same effect), e.g., [1].

Source: I own & run a composites design & manufacturing shop which does work on, among other things aerospace and undersea projects.

[0] https://www.trelleborg.com/en/applied-technologies/products-...

[1] https://www.gurit.com/structural-core-materials/

Re: Engineering assessment of the OceanGate Titan failure

#72

Post by tivert »

throwway120385 wrote: post #31
JKCalhoun wrote: post #16

Earlier quoted context omitted.

And perhaps like the Tacoma Narrows bridge it will end up being a cautionary tale for future engineers.

The kinds of people who make these stupid decisions are never the same people who actually learn lessons the easy way like you're proposing.

> The kinds of people who make these stupid decisions are never the same people who actually learn lessons the easy way like you're proposing.

It's quite possible it could lead to new regulations that would make similar stupid decisions illegal.

It might be time, it sounds like the whole human-occupied submersible industry is entirely unregulated.

Re: Engineering assessment of the OceanGate Titan failure

#73

Post by anon_cow1111 »

kodah wrote: post #69
anon_cow1111 wrote: post #58

Earlier quoted context omitted.

>Edit: I looked it up. The human body almost instantly incinerates. It takes a matter of milliseconds. This is most likely BS- consider that a shotgun shell is made from a low melting-temp plastic and handles higher pressures and temperatures without issue (and repeatedly if you're reloading them). Probably your hair and light clothing would burn somewhat during an implosion, but would be extinguished as soon as the…

Feel free to give this a read, it has an answer for your assertion about waters role: https://mindofjp.medium.com/what-really-happens-to-a-human-b...

(Pay/login gated article, by the way)

Re: Engineering assessment of the OceanGate Titan failure

#74

Post by [deleted] »

gnfargbl wrote: post #66
MobileVet wrote: post #3

> From all available sources, it is apparent that the viewport was designed and certified down to a depth of 1300 meters, not 4000 meters. Wow. What kind of hubris could look past that huge red flag? Apparently the kind that thinks it is interesting that it deforms by several inches and not scary

> What kind of hubris could look past that huge red flag? I don't think it was outright hubris. I think it was commercial necessity, driven by the business model that OceanGate used: Rush needed rich tourists to fund the business, and he got rich tourists by offering them a close-up view of a famous shipwreck. To give his passengers a view that they were willing to pay for, he needed an oversized viewport. He had alr…

[deleted]

Re: Engineering assessment of the OceanGate Titan failure

#75

Post by oneTbrain23 »

hef19898 wrote: post #8

After an initial reluctance to follow this story, mostly due to the hysterical media coverage of a pointless rescue operation, my engineering half of my brain got interested. I am by no means a materials engineer nor a naval architect, but I was involved in some Design FMEAs and wrote thesis about the manufacturing of structural, pressurized aerospace carbon fiber parts. Some things I came across, which are in line w…

Those carbon fiber wrapping seems to be in single direction as well with no criss-cross diagonal wrappings from their Titan making vid.

Re: Engineering assessment of the OceanGate Titan failure

#76

Post by oneTbrain23 »

ChuckNorris89 wrote: post #12
MobileVet wrote: post #3

> From all available sources, it is apparent that the viewport was designed and certified down to a depth of 1300 meters, not 4000 meters. Wow. What kind of hubris could look past that huge red flag? Apparently the kind that thinks it is interesting that it deforms by several inches and not scary

>Wow. What kind of hubris could look past that huge red flag? The "bad-boy" disruptive innovator kind that doesn't play by the rules and that's worshiped in SV because he makes his wealth playing fast and loose around old stuffy bureaucratic regulations made by "evil old men" to gatekeep innovators like him from entering the naval market held by centuries year old corporations who actually know what they're doing. Th…

The billionaire dad should be shamed along too to drag his son along. He could easily call Cameron for professional opinion. Instead he thought savings of 150K warranted to risk his young son to play along his stupid game of death for a stupid prize of sudden permanent blackout. He won.

Re: Engineering assessment of the OceanGate Titan failure

#77

Post by SV_BubbleTime »

toss1 wrote: post #71
SV_BubbleTime wrote: post #18

Earlier quoted context omitted.

As I understood it, you do have a weight penalty for a sub. You need to get back up by powered movement, or down by it. You are limiting your dive time either way. They can’t use foam for flotation at that depth. There is a concrete like “synthetic foam” if you want unpowered rise to surface but it’s expensive. I read early on they wanted carbon to be light enough to get back up by releasing weights on powerloss. Fro…

>>there is a concrete like “synthetic foam” The word you are looking for is "syntactic foam", which is an epoxy or other material typically with embedded hollow glass microspheres. This material is used for the buoyancy components of undersea vessels. It comes in a broad variety of densities and depth ratings. It is typically machined into shapes on the inside of the part fitting around the metallic components and on…

I knew that, but either bonehead, fatfinger, or was autocorrected. Good links tho.

Re: Engineering assessment of the OceanGate Titan failure

#78

Post by [deleted] »

mrcwinn wrote: post #55
intelVISA wrote: post #26

Earlier quoted context omitted.

Wasted opportunity - could've been a top tier SaaS hustler with that perfect playbook.

This is a dead person who isn’t here to defend himself. I am certain that if he had a chance to reclaim life and correct a mistake, he would. As in airplane accidents, though it is sometimes hubris or poor communication, it is more often a chain of incorrect decisions that were at the time rationalized as safe. Nobody is trying to die.

[deleted]

Re: Engineering assessment of the OceanGate Titan failure

#79

Post by timbit42 »

anon_cow1111 wrote: post #73
kodah wrote: post #69

Earlier quoted context omitted.

Feel free to give this a read, it has an answer for your assertion about waters role: https://mindofjp.medium.com/what-really-happens-to-a-human-b...

(Pay/login gated article, by the way)

https://archive.ph/EoD4S

Re: Engineering assessment of the OceanGate Titan failure

#80

Post by carrolldunham »

hef19898 wrote: post #27
bboygravity wrote: post #17

Earlier quoted context omitted.

> Despite claiming otherwise on their homepage (archive.org still has it) they did attach equipmwnt directly to the carbon hull on the inside by screwing (!) to the hull. Result, all the fibers cut by the screws don't take any load whatsoever anymore, increased risk of delaminations (the hull is compressed, the screw on the inside isn't) This one is actually the most mind-blowing to me if true. That and the fact that…

The first thing I saw of Titan, while lookong for some footage of the infamous controller, was two screenholders, and that lightbar fr AliExpress or something, directly screwed into the inside of the hull... I honestely do not know what to say about all of this, which is actually pretty rare. I pitty the other four passengers, Rush got what asked for, and rightly so.

It was screwed into a floating inner liner cylinder which you can see in any video is separated from the hull. Get the facts straight before sounding off with gleeful incredulity.
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