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Debris found came from missing Titan sub, says friend of passengers

bbc.com

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Re: Debris found came from missing Titan sub, says friend of passengers

#661

Post by bumby »

seabird wrote: post #328
seattle_anon wrote: post #166

Stockton Rush (OceanGate's CEO) was known in the Seattle tech community [0] My understanding (very much not first hand) is that he was seen as an expert in the specific engineering disciplines necessary to safely build and operate deep sea submersibles like Titan. He was also apparently a father to members of the Seattle tech community, who are no doubt grieving at the moment. Please remember that, for some members o…

It's sad that they're dead, but all parties had time to brace for this inevitability. I can't imagine any engineer (save a software engineer) seeing this guy's attitude and not seeing this coming from a mile away.

You’d be surprised. I used to work at a hazardous test site and there was a lot of complacency. Sometimes it was just bad engineering, sometimes it was arrogance about their ability, or something else. It taught me we’re all humans first, and all susceptible to human biases regardless of credentials or prestige.

Re: Debris found came from missing Titan sub, says friend of passengers

#662

Post by maverwa »

pests wrote: post #629
dvt wrote: post #431

Earlier quoted context omitted.

Gas-filled cavities in the body instantly compress. So this means that your lungs, stomach, etc. instantly get crushed, rupturing in the process. Depending on circumference, depth, etc., the hull itself moves at speeds of ~1000+ mph towards itself, crushing everything inside in less than 100 milliseconds. Someone linked a great safety video of what happens under a pressure column (not gore)[1]. Though as some people…

> turning all organic matter to ash Is this actually true? I see it being repeated everywhere but there is a lot of mass in a human body. Can 100 milliseconds of "ignition" (as you put it) really burn off all of that?

I am no expert on any of this but was curious. So I entered some guesstimates in online calculators. Assuming they were at 12,500 ft / 3810m we get a pressure down there of 5546 PSI / 382 Bar. Compressing the air in the cabin from roughly atmospheric pressure to 382 Bar would heat it to above 1300°C, or 1600°F. As far as I understand, in milliseconds. That’s a lot of heat energy. The water around them will absorb some of that, but they‘d be toast.

Re: Debris found came from missing Titan sub, says friend of passengers

#663

Post by krisoft »

nicce wrote: post #620
krisoft wrote: post #586

Earlier quoted context omitted.

> Submarines cannot communicate more hundred meters in the bottom of sea. Sorry if I am misunderstanding you. It sounds like you are saying that it is impossible to design a system which would be able to keep in contact with the submarine/submersible all the way down to the bottom? Because if that is what you are saying that is simply false. We have the technology to keep in contact with a submarine all the way to th…

If you read the article, you know that the context was extremely specific and not suitable for general use. The noise is too big problem. In ”normal” context such signal is not currently known to be really possible. You know that submarines are not equipped with these. The ship on the surface had to drop cable 100 meters below the ship to combat noise. Which means that for communication to be possible, ship cannot re…

> If you read the article

Rest assure that I have read the article i have linked.

> the context was extremely specific and not suitable for general use

What does general use mean? The context is the same. We are talking about an expeditionary submersible having constant and reliable communication with its support ship all the way to the bottom. This was the setup of Cameron’s dive and this was the setup of the ill-faited Titan mission.

Are you claiming that this is not possible?

Re: Debris found came from missing Titan sub, says friend of passengers

#664

Post by mc32 »

perihelions wrote: post #617
mc32 wrote: post #547

Earlier quoted context omitted.

The question are: Why use novel vessels when tried and true work. Why did they have to try a carbon-fiber wrapped vessel? The bathysphere went all the way down to the Marianas trench --many decades ago. Why try something new in unforgiving environments? Why fire an engineer after he started raising questions about safety? It seems like there was a bit of a cavalier attitude that cost five people their lives.

I don't believe that one was particularly safe in its design either? Just quoting the most colorful parts of Wikipedia's history: - "Oxygen was supplied from high-pressure cylinders carried inside the sphere, while pans of soda lime [hn: sodium hydroxide?] and calcium chloride were mounted inside the sphere's walls to absorb exhaled CO2 and moisture.[6] Air was to be circulated past these trays by the Bathysphere's o…

I grant you that; but that was decades ago and it went down to the Marianne’s trench. People have developed safe vessels. Why did this guy think he needed to reinvent it with experimental of unproven materials. Dunk it dozens of times into 2x depths see if it remains intact. No, the Navy or someone deemed a vessel a 3,000 meter rating. And they were like ooops, I guess it’s not good enough. Damned right you don’t just meet the minimum rating. You should have a healthy margin of safety.

Re: Debris found came from missing Titan sub, says friend of passengers

#665

Post by phire »

invalidator wrote: post #634
scotty79 wrote: post #416

Earlier quoted context omitted.

I don't understand why they didn't just drop it to the bottom of the ocean without people hundred times to see if it still holds. Who experiments with a crew in the age of remote control sensors and computers?

The carbon fiber hull has a limited cycle life. It's designed for a single-digits number of dives, and it becomes weaker on each cycle.

If it's a consumable, they should have tested at least one hull to destruction, just so they could be sure of it's failure modes.

Based on what I've seen, it doesn't sound like OceanGate had decided on a fixed number of dives. Instead they were planning to continually monitor it (x-ray scans after every dive and real-time acoustic monitoring during the dive) with the assumption that they would get some warning before it failed.

Re: Debris found came from missing Titan sub, says friend of passengers

#666

Post by stickfigure »

jacquesm wrote: post #356
seattle_anon wrote: post #166

Stockton Rush (OceanGate's CEO) was known in the Seattle tech community [0] My understanding (very much not first hand) is that he was seen as an expert in the specific engineering disciplines necessary to safely build and operate deep sea submersibles like Titan. He was also apparently a father to members of the Seattle tech community, who are no doubt grieving at the moment. Please remember that, for some members o…

I really couldn't care less. As far as I can see he was exactly what's wrong with people chasing money and forgetting about the possible consequences of their attitude towards other people's lives. I'm sure his relatives are grieving, but my sympathy goes to the family of the passengers first. As for the CEO's credentials: nature can't be fooled.

I don't know the guy, but this seems off the mark. If he wanted to get rich, spending 11 years on a money losing operation seems an unlikely choice. My take is that it was a passion project, a passion he shares with apparently a substantial number of well-to-do people.

I don't judge.

Re: Debris found came from missing Titan sub, says friend of passengers

#667

Post by ghaff »

stronglikedan wrote: post #377
hawk_ wrote: post #358

Earlier quoted context omitted.

Yes I get the training aspect. My point was around charging them for this. There are other such rescue missions where our brave men and women risk their lives because of reckless behavior of some. We should at least have such reckless actors take a bigger burden where possible.

It's my understanding that in rescue missions where the targets don't pay with their lives, they end up paying monetarily afterwards.

In general, certainly at smaller scale (e.g. hikers who get lost/injured in winter), they're not charged in many places unless there was clear negligence. Which is mostly how you want it to be. You don't really want people to avoid search and rescue and just hope things work out because they're afraid of a big bill.

Re: Debris found came from missing Titan sub, says friend of passengers

#668

Post by [deleted] »

mcguire wrote: post #209
seattle_anon wrote: post #166

Stockton Rush (OceanGate's CEO) was known in the Seattle tech community [0] My understanding (very much not first hand) is that he was seen as an expert in the specific engineering disciplines necessary to safely build and operate deep sea submersibles like Titan. He was also apparently a father to members of the Seattle tech community, who are no doubt grieving at the moment. Please remember that, for some members o…

He's also on record as saying things like, " It's obscenely safe because they have all these regulations. But it also hasn't innovated or grown — because they have all these regulations. " ( https://www.insider.com/titan-submarine-ceo-complained-about... )

[deleted]

Re: Debris found came from missing Titan sub, says friend of passengers

#669

Post by kubectl_h »

aurizon wrote: post #115

The most likely first failure is the window. At that instant a rapid turbulent fill event would occur. The outside pressure and the hole diameter will provide a calculable interval for the internal volume to fill. At 12,000 feet = 800 atmospheres, this would be on the order of 1/20th of a second, with intense crush/shear forces = instant death as perceived. That interval can be related to the speed of sound and wavel…

This is a very interesting comment. You seem to have a firm grasp on the physics of this situation. Out of curiosity, beyond common sense, does adding pressure internally on something with a significant load of external pressure create a compounding/exponential amount of force/pressure on the material overall?

Re: Debris found came from missing Titan sub, says friend of passengers

#670

Post by somat »

nicce wrote: post #481
crazygringo wrote: post #394

Earlier quoted context omitted.

Can you expand? To a layman like myself, tracking is part of communications and it seemed clear there was no tracking because they didn't know where the sub was. What is the specific type of tracking device you're referring to? What signals does it emit? And if overall power was lost, for example, why wouldn't the tracking stop just like communications stopped?

Both will be lost at the same time. We don't really know such signal. Submarines cannot communicate more hundred meters in the bottom of sea. Sea water absorbs the signal quite well. When the signal is lost, the expectation is that the submarine is under the water. https://en.wikipedia.org/wiki/Communication_with_submarines

To clarify EM waves which are used for most(all?) tracking in the atmosphere, are attenuated very quickly in water. Underwater sound waves work better. I don't know what this submarine used but I would expect at minimum an acoustic transponder to aid in underwater tracking. with a acoustic telephone as a comm channel. However reading about some of their other engineering decisions this is probably too optimistic of me.

Data recorders(airplane black boxes) have a sound pinging unit for this exact case. being lost under water.

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