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Oceangate Statement, “We now believe that [all crew] have sadly been lost.”

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Re: Oceangate Statement, “We now believe that [all crew] have sadly been lost.”

#191

Post by masklinn »

toofy wrote: post #178
ilyt wrote: post #105

Earlier quoted context omitted.

And weird focus on that fucking gamepad that they were using, which was probably the least of engineering problems

i didn’t see the game pad as the cause, but an indicator of where they would cut corners. it’s strange on its face to use a game controller when we’ve all spilled soda or water on one and watched it become useless and they’re taking this into… the ocean… and just to add insult to injury, playing on offbrand controllers always irritated me so to see them cut even further was super strange. more than anything it is tha…

In a sense, the game pad was a canary (if unintentionally so).

Re: Oceangate Statement, “We now believe that [all crew] have sadly been lost.”

#192

Post by ilyt »

toofy wrote: post #178
ilyt wrote: post #105

Earlier quoted context omitted.

And weird focus on that fucking gamepad that they were using, which was probably the least of engineering problems

i didn’t see the game pad as the cause, but an indicator of where they would cut corners. it’s strange on its face to use a game controller when we’ve all spilled soda or water on one and watched it become useless and they’re taking this into… the ocean… and just to add insult to injury, playing on offbrand controllers always irritated me so to see them cut even further was super strange. more than anything it is tha…

> it’s strange on its face to use a game controller when we’ve all spilled soda or water on one and watched it become useless and they’re taking this into… the ocean… and just to add insult to injury,

I mean the buttons got sticky but that's the worst I saw, nothing a bit of IPA wouldn't fix.

But yeah, definitely red flag, especially that they used wireless one. Industrial (and so protected from dust and at least humidity) ones are not that expensive compared to the price of massive carbon tube at least

> playing on offbrand controllers always irritated me so to see them cut even further was super strange.

Lmao "offbrand" Logitech is one of biggest makes of accessories. They have both good and cheap stuff, this one is some midrange one so I doubt quality is a problem.

Also it's a PC controller, what "brand" would they be offing ?

Re: Oceangate Statement, “We now believe that [all crew] have sadly been lost.”

#193

Post by ilyt »

guax wrote: post #185
civilitty wrote: post #143

Earlier quoted context omitted.

If the rumors about the window being certified to a maximum safe depth of 1300m are true, we’re well in “crazy negligent” territory. It’d be a surprise the sub survived so long.

I wonder if the issue was the certification or the construction. As in, the window was mad for 4k but was not tested and certified for that.

From what I gather they didn't really want to bother with same due dilligence similar other vehicles went thru

Re: Oceangate Statement, “We now believe that [all crew] have sadly been lost.”

#194

Post by ilyt »

Solvency wrote: post #122
ilyt wrote: post #85

Earlier quoted context omitted.

It's carbon fiber. It doesn't break like soda can, it breaks like eggshells or hard plastic. It would probably look like something exploded on side of it, when any small hole/crack started it would just isntantly make rest of it rip till the pressure equalizes

Empty eggshells implode into thousands of increasingly smaller little shards. Is that what happened here?

At some fraction of milliseconds, maybe ? We're talking about pressure difference comparable to big explosion so any break would most likely, on top of near-immediately expanding the hole, compress everything into the sub and possibly heat it enough to combust.

400 atm is only one order of magnitude of a difference from what water cutters use. It's insane amount of force, there is no "small leak" nor "small leak expanding", just "boom"

Re: Oceangate Statement, “We now believe that [all crew] have sadly been lost.”

#195

Post by ilyt »

jacquesm wrote: post #169
Solvency wrote: post #122

Earlier quoted context omitted.

Empty eggshells implode into thousands of increasingly smaller little shards. Is that what happened here?

Depends on the speed of the change. The pressure differential is what causes the material to fracture, the longer the differential exists the more fracturing you will get. Carbon fiber fails much like wood, you'll end up with a couple of larger fragments and a much larger number of smaller fragments, some too small to even see with the unaided eye. Unlike say a metal vessel during an implosion which would remain most…

> Shows nicely how a fault propagates through carbon fiber.

That's tensile fault, in sub it would be compressed, for which carbon fiber is much worse for. But yeah, it would be equally if not more violent

Edit: https://www.youtube.com/watch?v=QYqOMjoz_i8

https://youtu.be/PlvyZ1r1DCM?t=266

https://youtu.be/Iedj9OZlEfI?t=330

not explosive because hydraulic press doesn't move as much but still shows it will instantly lose strength the second it is breaking

Re: Oceangate Statement, “We now believe that [all crew] have sadly been lost.”

#196

Post by throwanem »

voisin wrote: post #182
toomuchtodo wrote: post #175

Earlier quoted context omitted.

> Is it an icon of human hubris or simply a tragedy that they didn’t think could happen? https://www.bbc.com/future/article/20120402-the-myth-of-the-... (Titanic anniversary: The myth of the unsinkable ship) "There is no danger that Titanic will sink. The boat is unsinkable and nothing but inconvenience will be suffered by the passengers." Phillip Franklin, White Star Line vice-president, 1912

I don’t deny that this was the prevailing wisdom but did it lead to them taking any extra risk (relative to what other ships did at the time) as a result?

It's been argued both ways for a hundred and eleven years now, but my understanding of the current historical consensus is that they weren't doing anything especially unusual for ocean liners of the day, either in design or in operation, and indeed had altered course further south in response to iceberg warnings received by radio on the 14th.

It's considered to be true that the prioritization of on-time arrival and the belief that the ships of the day were too well designed to founder contributed to the disaster, but rather than representing unique hubris on the part of Titanic's builders and captain, these are understood to have been common throughout the passenger shipping industry of the day.

Re: Oceangate Statement, “We now believe that [all crew] have sadly been lost.”

#197

Post by HPsquared »

ansible wrote: post #165
jacquesm wrote: post #118

Earlier quoted context omitted.

Not really. I work with a company that does this kind of stuff (deep see exploration vehicle design), materials science is a tricky but very interesting subject. When someone seemingly does 'the impossible', subjects paying passengers to extreme risks and throws the rulebook on safe design out of the porthole you can bet there will be an entry in 'Risks Digest' at some point or another. Carbon fiber is a great materi…

> Carbon fiber is a great material, if used where it shines. For this application I don't think it is a good choice, even if it worked a few times. What I didn't understand is the focus on the electronics and the control system, those are irrelevant if the hull isn't going to work out. That's all true, but the use of the Logitech game controller and and other consumer-grade electronics rightfully drew scorn of its ow…

It really depends on the environmental conditions. In the case of a deep sea submersible you might expect that the controller will always be in controlled indoor conditions, depending on when/where they open the hatch. In normal operation it's going to be dry, and if there's a leak the controller probably isn't going to be of much use anyway. (same goes with the rest of the electronics).

A car is of course much different, most components have to operate for years without maintenance in a very uncontrolled, varied set of environments.

Re: Oceangate Statement, “We now believe that [all crew] have sadly been lost.”

#198

Post by HPsquared »

ilyt wrote: post #192
toofy wrote: post #178

Earlier quoted context omitted.

i didn’t see the game pad as the cause, but an indicator of where they would cut corners. it’s strange on its face to use a game controller when we’ve all spilled soda or water on one and watched it become useless and they’re taking this into… the ocean… and just to add insult to injury, playing on offbrand controllers always irritated me so to see them cut even further was super strange. more than anything it is tha…

> it’s strange on its face to use a game controller when we’ve all spilled soda or water on one and watched it become useless and they’re taking this into… the ocean… and just to add insult to injury, I mean the buttons got sticky but that's the worst I saw, nothing a bit of IPA wouldn't fix. But yeah, definitely red flag, especially that they used wireless one. Industrial (and so protected from dust and at least hum…

Even wireless doesn't seem that much of an issue. There isn't going to be any external interference down there, so as long as they've tested all the systems it should be OK. Also it's not going to be dusty, and it's not humid (if anything the humidity is going to be very low as the water outside is cold, any moisture in the air will condense on the hull)

Re: Oceangate Statement, “We now believe that [all crew] have sadly been lost.”

#199

Post by f38zf5vdt »

amluto wrote: post #180
pfdietz wrote: post #142

Earlier quoted context omitted.

Adiabatic compression of air to 400 bar increases the absolute temperature by about a factor of 5.5, which would be the temperature of a flame.

Water, fat, etc are not nearly as compressible as air, and the thermal mass of the air involved would be a couple orders of magnitude lower than everything else. 400 bar is (from some quick searching) fairly mild for industrial hydraulic systems, and hydraulic fluid doesn’t get especially hot while in use. On the other hand, a leak in a pressurized hydraulic system is extremely dangerous if you’re around it due to th…

Hydraulics don't get hot while in use unless you introduce air into the system, in which case they do get hot and explosive. This is called hydraulic dieseling and microdieseling. The passengers would have been surrounded by oxygen and CO2 gas, and the oxygen tank would rupture as soon as the capsule imploded.

Re: Oceangate Statement, “We now believe that [all crew] have sadly been lost.”

#200

Post by ansible »

guax wrote: post #190
ansible wrote: post #165

Earlier quoted context omitted.

> Carbon fiber is a great material, if used where it shines. For this application I don't think it is a good choice, even if it worked a few times. What I didn't understand is the focus on the electronics and the control system, those are irrelevant if the hull isn't going to work out. That's all true, but the use of the Logitech game controller and and other consumer-grade electronics rightfully drew scorn of its ow…

I think you're under estimating the controller and over estimating your understanding of the conditions it would live on the vessel. Why it's non redundant? There were likely spares around, if it misbehaves you can get a new one in seconds.

> Why it's non redundant? There were likely spares around, if it misbehaves you can get a new one in seconds.

So you are saying they were carrying around a spare controller, and a spare everything else inside the sub? At all times?

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