Titanic submersible confirmed destroyed with loss of all five souls onboard.
- Thread starter danlightbulb
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Don
Would have been done for weight reasons I suspect making ballast and flotation smaller (cheaper).
Carbon fibre might have been cheaper than titanium as well.
Soldato
Bring different for the sake of being different…
That’s my view as someone who has worked on Airbus composite primary structures and nuclear submarine pressure vessels. Matrix dominate properties are no advantage in deep water when your CFRP vessel is essentially plastic.
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Soldato
Needed the equipment capable in place to confirm the outcome which takes time, in the meantime let the media circus commence, always the way in some situations.
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Soldato
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Where'd you hear/read this ? I'm surprised that info was held from the press if true
As evidenced, it had no advantages but plenty of flaws
To elaborate further, if Carbon Fiber was a viable alternative to Titanium/Stells hulls and it was as simple as just making a CF tube, other companies better than Oceangate in the sub business would have tried/done it first
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All the quotes that have surfaced recently show a man determined to "prove" that the established convention wisdom was wrong. And he knew better..
It appears there were some teething problems and a couple minor kinks in the design to work out.How'd that work out for him? Whoops.
Soldato
Carbon is amazing for a pressure vessel. This is maybe where they got their inspiration from. It is going to be considerably cheaper than a machined titanium hull. However and this maybe where the inexperience of the team shows they didn’t consider that it only works well when the pressure is on the inside. In this case it was on the outside so the fibres aren’t anywhere near as effective because it is being compressed.
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Associate
Carbon?
Carbon fibre succeeds in tensile strength rather than compressive strength. It's greatly more difficult to measure the fatigue of carbon fibre in a use such as this.
As far as I'm aware, PVHO-1 does not allow for carbon constructed pressure vessels for human occupancy because of the above fact.
Carbon should have never been used in my opinion.
Soldato
Carbon is what engineers refer to carbon fibre as.
Soldato
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It may well be but a sub isn't a pressure vessel, it's 1 atmosphere inside vs 387 atmosphere at 4,000m depth, all the pressure is on the outside, I'm not an engineer but it's obvious there's a difference between holding something inside a vessel at pressure vs trying to stop pressure getting into a vessel the 2 forces are opposite and I would imagine atomic structure plays into how one material may be great for expansive force but terrible for compressive force ?
Man of Honour
I'm made of carbon, just like everyone else, we are all limitless subs!
Anyone thinking otherwise is a cabron ;p
Anyone thinking otherwise is a cabron ;p
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I can't remember the details but the technical differences meant they could carry 5 passengers instead of being limited to 2 or 3 depending on conventional design - I guess due to being able to fit extra paying passengers in so compromising on safety to make money.
Soldato
Perhaps read past the first sentence.
exactly that from bbc expert interviews yesterday - their business model needed space for 5 -
and a tried&tested (forged - not machined - folks should watch mrk's video) sphere large enough could not be made from titanium
... how come their mothership is returning to port (just refuelling ?)
Only in mainstream media do you get a complete different version of reality
5 people decide to go into a questionable tube and get themselves killed on a tourism trip to bottom of the Atlantic - everyone else calls them idiots; media calls them heroes.
There has never been a time that such disparity in media and general consensus been so starkly different. And no wonder populism is one the rise everywhere and peole are not interested in mainstream news anymore.
5 people decide to go into a questionable tube and get themselves killed on a tourism trip to bottom of the Atlantic - everyone else calls them idiots; media calls them heroes.
There has never been a time that such disparity in media and general consensus been so starkly different. And no wonder populism is one the rise everywhere and peole are not interested in mainstream news anymore.
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Soldato
It's an interesting point, did the USCG know of the implosion from Sunday/Monday or did they just follow process and await for the ROVs to find it and then determine? The did the whole "banging sounds "investigation which kept up the hope after all - All whilst the experts in deep sea diving knew it was a gonner since Sunday. I think they knew, which explains why the USCG guy left the conference as the questions from the press got more and more troublesome.
Also, The Onion being The Onion:
I think it was pretty obvious, right from the start, that it was an implosion. The lack of signal from the sub, the lack of sub at the surface, the lack of constant banging, all meant it was a lost cause right from the start.
It was also obvious that rescue weren't really doing anything because they couldn't. Once the second sub arrived, then they looked right under where it was descending, and they found the debris right there.
Everything else was media hysteria.
Carbon fibre composite suffers brittle failure. That’s probably the main reason why it is not used for such application. Ie evident in this sub - it was ok for a few use then suddenly it goes pop without a warning.
Otherwise the composites has very high tensile as well as compressive capacity if cross weaved.
The fundamental flaw of the sub design I guess is a deviation from a spherical design to a tube design which means the stress build up in the materials will be highly concentrated around where the end bells connect to the tube and the likely failure point. The tube fiber hwould have been primarily weaved to deal with hoop stress but the longitudinal stress can be exceptionally high as well meaning the tube is prone to high end compression and if not dealt with the tube will just fail.
That’s probably where titanium composite excel ie it’s strength is not uni-directional and it is ductile so gives you plenty warning and ability to inspect and predict failure.
Otherwise the composites has very high tensile as well as compressive capacity if cross weaved.
The fundamental flaw of the sub design I guess is a deviation from a spherical design to a tube design which means the stress build up in the materials will be highly concentrated around where the end bells connect to the tube and the likely failure point. The tube fiber hwould have been primarily weaved to deal with hoop stress but the longitudinal stress can be exceptionally high as well meaning the tube is prone to high end compression and if not dealt with the tube will just fail.
That’s probably where titanium composite excel ie it’s strength is not uni-directional and it is ductile so gives you plenty warning and ability to inspect and predict failure.
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