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Why isn't Titan classed? (2019)

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Re: Why isn't Titan classed? (2019)

#121

Post by arp242 »

DeRock wrote: post #56
dghlsakjg wrote: post #43

> They [inspections] do not ensure that operators adhere to proper operating procedures and decision-making processes – two areas that are much more important for mitigating risks at sea. As a former tall ship captain: No Shit. Ships stopped sinking when we started requiring inspections and design rules around stability and watertight compartments. We largely eliminated a common failure mode, designer error, through…

Their reasoning is fundamentally flawed. > The vast majority of marine (and aviation) accidents are a result of operator error, not mechanical failure. As a result, simply focusing on classing the vessel does not address the operational risks. Aka "classing doesn't mitigate all problems, so we're not going to do it at all"

Also: the reason most accidents are due to operator error and not mechanical failure is because the requirements exist in the first place.

"Why do we have laws against slavery? It's not like anyone actually owns slaves. Seems pretty superfluous, so let's just get rid of it!"

Re: Why isn't Titan classed? (2019)

#122

Post by TheCondor »

Alupis wrote: post #44
ARandomerDude wrote: post #34

Earlier quoted context omitted.

That’s pretty wild. The operator was able to tell when they were going deeper based on the sound of the carbon fibers cracking in the hull.

These sort of sounds occur even in metal (steel/titanium) submersibles.

True. Those metals have flex and recovery to them though, not nearly as rigid as carbon fiber

FWIW, archers tap or attempt to flex arrows and listen to them to tell if the carbon has cracked. An intact arrow will flex a little, silently where damaged ones will crackle and sometimes splinter or shatter.

Re: Why isn't Titan classed? (2019)

#123

Post by mrguyorama »

stefan_ wrote: post #67
AdamJacobMuller wrote: post #48

The truly scandalous thing here is this: > Depth Validating > As an interim step in the path to classification, we are working with a premier classing agency to validate Titan’s dive test plan. A licensed marine surveyor will witness a successful dive to 4000 meters, inspect the vessel before and after the dive, and provide a Statement of Fact attesting to the completion of the dive test plan. They clearly did not do…

Found what problem? You realize they literally took this thing to the Titanic and back multiple times?

I had the same false information. It either came from the Sub Brief guy himself, or whoever he used as a source. He explicitly stated that the sub had only been tested down to between 3000 and 4000 meters, not the full 4000 meters. As other links show, this seems to have been incorrect.

Re: Why isn't Titan classed? (2019)

#124

Post by pessimizer »

xupybd wrote: post #79
DeRock wrote: post #56

Earlier quoted context omitted.

Their reasoning is fundamentally flawed. > The vast majority of marine (and aviation) accidents are a result of operator error, not mechanical failure. As a result, simply focusing on classing the vessel does not address the operational risks. Aka "classing doesn't mitigate all problems, so we're not going to do it at all"

I've heard the same argument against unit testing and strong typing.

I've heard the same argument against not using heroin.

It's a generic pretend argument: You say doing(or not doing) this thing will be risky. So that means you're saying that people who don't do(or do) the thing have perfect lives with no risks and free ice cream?

You're strangling innovation/A coward!

Re: Why isn't Titan classed? (2019)

#125

Post by aleph_minus_one »

postalrat wrote: post #68
AdamJacobMuller wrote: post #48

The truly scandalous thing here is this: > Depth Validating > As an interim step in the path to classification, we are working with a premier classing agency to validate Titan’s dive test plan. A licensed marine surveyor will witness a successful dive to 4000 meters, inspect the vessel before and after the dive, and provide a Statement of Fact attesting to the completion of the dive test plan. They clearly did not do…

How would droppingb it to the bottom found the issue? The theory is that each dive reduced the integrity of the ship and eventually it would fail. Could be 10 or it could be 10,000 drops. And that number would be different if you built a second ship. How many tests do you do?

> The theory is that each dive reduced the integrity of the ship and eventually it would fail. Could be 10 or it could be 10,000 drops.

It is already of high value to know whether the number is more like 10 or 10,000.

> And that number would be different if you built a second ship.

That is why you build the second ship either as similar as possible to the first one or in a way for which there exists evidence that it will have an improved integrity over the first.

Re: Why isn't Titan classed? (2019)

#127

Post by anyfoo »

JohnMakin wrote: post #49

This is such a clear fallacy right from the get go. "This thing doesn't completely solve the problem, therefore, we will not do it." So many people fall for this or talk in such terms like it's perfectly reasonable and it always baffles me. You see it in political discussion a lot.

It's even worse. The "thing that doesn't completely solve the problem" might have actually solved the biggest problem for classed vessels, that's why they don't see it as a problem in the first place.

Re: Why isn't Titan classed? (2019)

#128

Post by _yb2s »

learn_more wrote: post #60
hn_throwaway_99 wrote: post #22

> OceanGate’s submersibles are the only known vessels to use real-time (RTM) hull health monitoring. With this RTM system, we can determine if the hull is compromised well before situations become life-threatening, and safely return to the surface. This innovative safety system is not currently covered by any classing agency. > No other submersible currently utilizes real-time monitoring to monitor hull health during…

I too am perplexed. Perhaps the compressive strength is all derived from the epoxy not from the carbon fiber.

Yes, this doesn't make sense to me either. I suppose it could help prevent bucking and crack propagation, because as the walls of the sub started to bend, one side would have to suddenly be in tension? Still, I wonder if a pure plastic/epoxy hull would have actually been stronger than composite in this situation.

Re: Why isn't Titan classed? (2019)

#129

Post by mrguyorama »

bmurray7jhu wrote: post #57
dpedu wrote: post #3

Patent for their hull monitoring system: https://patents.google.com/patent/US11119071B1/en

The acoustic signature predictive of a material compromise or potential failure may include a large magnitude, high frequency acoustic burst followed by a sustained interval of acoustic signals of slightly lower magnitude and high frequency, but still well above a predetermined healthy structure condition. The patent concedes that a structural failure may be presaged by a "large magnitude ... burst", but does contemp…

That makes no sense. Carbon fiber is not known to fail under max load gracefully.

Re: Why isn't Titan classed? (2019)

#130

Post by rossjudson »

spencerflem wrote: post #109
stickfigure wrote: post #73

Earlier quoted context omitted.

The first space shuttle launch was crewed. It ended up with a ~2% failure rate. The Titan made about 50 dives. So, from a reliability perspective, on par with the shuttle. I posit that half the people on HN would volunteer for a hypothetical next shuttle flight without thinking twice.

Its a big hackernews meme that NASA spends way too much on safety/beurocracy instead of innovation. Plenty of other submarines companies do the same (and get classed). I don't think this is a very insightful comparison.

I have rarely seen large groups of humans be accused of excessive consistency over time when it comes to matters of fact and science.
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