r/interestingasfuck • u/ThugLeeVoguee • 1d ago

The implosion of the Titan submarine (OceanGate) was so rapid that the pain wasn't even registered by the brain. They didn't feel anything at all. Utterly instantaneous.

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u/Gramage 1d ago

Absolutely insane. How about some actual clamps that can release the ballast? How about some sort of rapid-inflating emergency airbag things? So many options other than just… jiggling.

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u/Tomek_Hermsgavorden 1d ago

John Hammond levels of sparing no expense.

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u/marty4286 1d ago

The amount of money they spent on it could have probably built an actually good submarine, it's like they were ideologically committed to making the worst thing possible

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u/whogivesashirtdotca 22h ago

Ironically that company could've used some clever girls.

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u/Sauron_the_Deceiver 1d ago

"Move fast and break things"; I'm sure they thought they were being clever, radically innovative, and efficient.

Lol.

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u/candygram4mongo 1d ago

That only kind of works when the things you're breaking are just bits on a hard drive. When you have actual physical objects upon which people's lives depend, you do the fucking engineering review.

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u/splendidsplinter 1d ago

Not if everything I've ever read on LinkedIn is true.

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u/Big_Slope 1d ago

He was out of buttons on the Xbox controller.

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u/Both_Status_7842 1d ago

Proper release mechanism would have been better. Inflating anything at these depths would require 380 to 400 bars of pressure in reasonably sized air tanks. Which means added weight. That's also assuming you could deflate the balloons while ascending, otherwise they would just explode with the pressure dropping, and you would end up being stuck again.

Having proper water ballast would have taken too much space I suppose ? Dropping weights is overall the best course of action in this instance, but the execution was incredibly poor.

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u/Animostas 1d ago

I think the argument was that if you had something like a claw that released weights, it's just another point of failure. If the clamp locks or some plant gets tied around it or something then you're fucked. It makes sense how they arrived at jiggling free weights back and forth but the idea of doing it with a Logitech controller still sounds crazy

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u/DouchecraftCarrier 22h ago

Ideally you'd have something akin to air brakes in trucks where the actively powered mode is to hold the brakes open (or clamp down on the weights in this case). So in the case of a failure, the default state when the device is unpowered would be to drop the weights.

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u/Germanofthebored 1d ago

Considering the pressure at the bottom of the Atlantic (380 atm), there isn't really a chemical reaction that would produce a significant amount of gas. Depending on an active mechanism would mean that there is an additional failure point (The Triest actually had used electromagnets to hold on to its balast, so if the electric system failed, the craft would surface by default)

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u/dwkfym 1d ago

didnt the sub have compressed air to control bouyancy? thats how every sub does it. Which is basically 'rapid inflating emergency airbag things' you speak of, except I am not sure if you realize how much air pressure is needed to 'inflate a bag' (in this case, its actually displacing water in ballast tank)

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u/nascent_aviator 23h ago

I'm pretty sure most deep sea submersibles don't use air to control buoyancy. Under 400 atm of pressure, air gets too dense to be practical for it, and carrying weights and then dropping them is easy and cheap.

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u/nascent_aviator 23h ago

I don't think airbags would work basically at all. The pressure down there is way to high. At 3800m, 1 cubic foot of air would weigh like 14 kg. Just carrying the tanks to fill a balloon of appreciable size is going to be a serious load, to the point you'd probably just drop the tank rather than try to inflate a balloon with its contents lol.

Actual clamps for sure seem like a saner alternative though.

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u/Emotional-VroomVroom 17h ago

How about an electro magnet, so the craft would automatically drop ballast on power loss

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u/STEM-Travel 1d ago edited 1d ago

> How about some sort of rapid-inflating emergency airbag things?

Probably best to leave the engineering up to the engineers, lol… - What sort of mechanism do you imagine can rapidly inflate at that pressure?

Edit: OK, turns out most of you need a bit more handholding. Ask google, what is the pressure at the bottom of the ocean? Answer, 15000 PSI. Ask google, what pressure do we store nitrogen? Answer: 10000 PSI.

So, if the ocean is 15000 PSI, and the Gas is 10000 PSI, when you open the tank, water goes into the tank, the gas doesn’t come out. Feel free to actually do some googling and try to find a gas we store at higher PSI that Nitrogen. Most gas is stored FAR lower.

The pressure OUTSIDE is greater than the pressure INSIDE the gas cylinder.

So when you try to trigger the emergency inflate, water actually rushes INTO the gas cylinders because they’re stored at less pressure than ambient.

This is like, basic shit guys…

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u/never-fiftyone 1d ago

Speaking of engineers engineering things, there are specialized emergency buoyancy systems designed to operate in high-pressure environments. One such system was designed by Subsalve (a company that specializes in underwater inflatables and recovery systems) specifically for the Deepsea Challenger and its trip to the bottom of the Mariana's Trench. I'd probably not be so indignant of the idea given it actually exists.

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u/STEM-Travel 1d ago edited 23h ago

You are completely, 100% wrong. I suspect it would have taken far less time to discover you were wrong, than to waste my time with this comment.

Speaking of engineers engineering things, there are specialized emergency buoyancy systems designed to operate in high-pressure environments.

No, there aren’t.

One such system was designed by Subsalve (a company that specializes in underwater inflatables and recovery systems) specifically for the Deepsea Challenger and its trip to the bottom of the Mariana's Trench.

Nope. As I mentioned, from a fundamental physics standpoint, the pressure is too high, down there, to ‘inflate’ anything.

But also, there are no emergency inflation systems designed in the Deepsea Challenger. That’s sort of easy to verify by looking at the Wikipedia page?

I'd probably not be so indignant of the idea given it actually exists.

100% of the stuff you’ve posted is wrong. I’m not indignant so much as I am confident that a bachelors degree in physics means I understand how gas operates at pressure.

I truly cannot fathom being so confident and so wrong simultaneously.

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u/never-fiftyone 1d ago

lol because Wikipedia is so exhaustive and correct? Maybe you should have expanded your search beyond a single website.

https://subsalve.com/case-studies/james-camerons-deep-sea-challenger/

Subsalve provided standard products to aid in the launch and retrieval, and they developed together with the Challenger team a self contained emergency buoyancy system that included a custom pontoon and a specialized inflation source that was packaged in a confined space on the submersible.

In preparing for a record-breaking drive to the bottom of the Mariana Trench, James Cameron approached Subsalve to help with two key problems. The first was to maintain safe positioning of the submersible during launch and retrieval operation and the second was to develop a back-up system to return to the surface should primary systems fail.

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u/STEM-Travel 23h ago

lol because Wikipedia is so exhaustive and correct?

you are now angry because Wikipedia says you are wrong?

Maybe you should have expanded your search beyond a single website.

lol, can you find a source on the internet other than subsalve.com that suggests the Challenger had an emergency inflation return device?

I’ll make you a deal… I’ll find a second source that states the pressure at the bottom of the ocean when you find a second source that suggests ANYTHING you’ve said about the challenger is correct.

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u/nascent_aviator 22h ago

I'm very skeptical of the picture you're painting. We have a lot of details on the emergency ways for the sub to ascend from reliable sources:

The sub will descend because of more than 1,000 pounds (450 kilograms) of steel weights held on to either side by electromagnets. To rise to the surface, the pilot will flip a switch, the plates of steel will fall to the ocean floor, and the lighter-than-water foam will hurtle the sub skyward. This step is critical—if the weights don’t drop, the pilot will be stuck at the bottom of the ocean. To ensure they function properly, engineers incorporated several backup systems:

If there’s a power failure or the magnets’ batteries run out, the weights will drop automatically.

The support team at the surface can command the weights to drop via an acoustic command.

A special wire (galvanic timed release) helps connect the weights to the sub; it will corrode after about 11 to 13 hours in seawater.

Cameron can power up something called a “frangibolt,” which uses heat to break the bolts that keep the weight-drop mechanism in place, thus jettisoning the whole assembly.

Nothing about emergency inflation, which is, if not impossible, at least wildly impractical at such depths. Air is nearly as dense as water at those depths (only "nearly" instead of "denser" because the gas molecules are packed so tightly together they stop acting like an ideal gas).

Note that in your link it doesn't say that "a self contained emergency buoyancy system that included a custom pontoon and a specialized inflation source that was packaged in a confined space on the submersible" and "a back-up system to return to the surface should primary systems fail" are the same thing.

It seems likely that Subsalve helped develop one of the emergency systems mentioned above, and that the "self contained emergency buoyancy system" was for floatation on the surface, not for emergency. Far more likely than them making a marvel of engineering that nobody talks about for some reason.

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u/defaulticus 23h ago

Ask google, what pressure do we store nitrogen? Answer: 10000 PSI.

We can store it at any pressure. Google is presumably just giving you the standard pressure available in cylinders from the likes of Praxair, Airgas, etc. If you're building a submersible to conquer the Challenger Deep, you can build a custom pressure vessel that works at some other pressure. If it were my design, I'd use cryogenically liquefied helium and heat it up to vaporize it if the emergency ascent device were needed. That way, if you lost power, it'd eventually boil and inflate on its own causing the submersible to surface.

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u/STEM-Travel 21h ago

We can store it at any pressure.

lol

If it were my design, I'd use cryogenically liquefied helium and heat it up to vaporize it if the emergency ascent device were needed.

That won’t work. That’s literally what I’ve been saying repeatedly.

The pressure is so great, at the bottom of the ocean, that you CANNOT maintain a gas of ANY sort. It’s impossible.

You understand that a gas like helium is liquid under a huge pressure. That’s why you said cryogenic.

The pressure at the bottom of the ocean keeps the helium in a liquid state. No matter how warm you got it.

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u/defaulticus 20h ago

That's flat out incorrect. Helium is a gas at room temperature even at 110 MPa. It can't even be a liquid above like 5.2 kelvin. It becomes a supercritical fluid if you pressurize it enough (which, okay, is what it is at 273 kelvin and 1100 bars of pressure).

Anyway its got a density of like 15 or 20 kilograms per cubic meter at 110 MPa which is 2% of the density of water, and 10% of its own density in liquid phase, so whether you consider that to be a liquid or a gas or a supercritical fluid doesn't matter, it would displace 10x its original volume in water and be buoyant.

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u/STEM-Travel 19h ago edited 19h ago

That's flat out incorrect.

Lo fucking l.

Why are you wasting my time if you can’t even get pressure and temperature straight?

It becomes a supercritical fluid if you pressurize it enough (which, okay, is what it is at 273 kelvin and 1100 bars of pressure).

This is literally my point? No gasses at those pressures. Why are you wasting my time?

so whether you consider that to be a liquid or a gas or a supercritical fluid doesn't matter.

Only one of those words is accurate.

it would displace 10x its original volume in water and be buoyant.

Yes! Duh? Many things are more buoyant than water

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u/defaulticus 19h ago edited 19h ago

I guess this is the difference between a physicist and an engineer, because I don't actually care what phase it is. I care that 20 kg of liquid helium expands and displaces a cubic meter of water, which masses about a thousand kilograms for 20 kilograms of helium, resulting in 980 newtons 9600 N of buoyant force [ed. to correct: force = mg = 980*9.81]. Whether that helium is actually a gas or a supercritical fluid or just a somewhat-less-dense liquid doesn't really matter.

Also temperature and pressure are not the same thing. Are you familiar with a phase diagram? They each get their own axis. Now why do you think that is? (That's a rhetorical question. It's pretty clear from the diagram that the phase depends on both.)

Also note that for helium all the action is taking place between 0 and 6 kelvin. Above that its technically a supercritical fluid but for the most part its very gas-like. People don't normally say that a child's helium balloon is full of supercritical fluid even though technically it is.

And sure, at the bottom of the sea the pressure makes some difference, but its still much lower density than it was a liquid, which brings us back to the beginning. As long as it can displace water, we can use it to achieve buoyancy. Which, going from 2 kelvin and 1 bar to 270 kelvin and 110 bar, it can. So the device can work.

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u/STEM-Travel 19h ago edited 18h ago

I guess this is the difference between a physicist and an engineer, because I don't actually care what phase it is.

So you are neither a physicist nor an engineer?

I care that 20 kg of liquid helium expands and displaces a cubic meter of water

Are you just now understanding that water is fairly incompressible, while most elemental gasses are quite compressible?

which brings us back to the beginning. As long as it can displace water, we can use it to achieve buoyancy.

That is certainly not the beginning of this conversation? We were talking about emergency surface return mechanisms?

Also temperature and pressure are not the same thing. Are you familiar with a phase diagram? They each get their own axis. Now why do you think that is?

Temperature and pressure exist as two different axis on the phase diagram… do you think that means they are ‘different’? Can you find a place on the phase diagram where increasing temperature doesn’t increase pressure? You really haven’t studied any of this formally?

ChatGPT is probably your best resource, it will slowly explaining these concepts to you until you comprehend them. Arguing about concepts you don’t understand is probably not the most efficient route to an education in these concepts.

I would suggest you go back to all the areas where you say ‘I don’t care that I don’t know’ and ask the AI if it may be able to help you understand what you are missing.

It’s like arguing that 3.99999999999999 repeating isn’t 4.0 - it seems simple to argue about, but you really need a few years of math in college to understand.

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u/defaulticus 18h ago

I am an engineer and you are a troll who earlier claimed to have a bachelors in physics. You started out this conversation by belittling Gramage's suggestion of:

How about some sort of rapid-inflating emergency airbag things?

But as you can see from the change in density, using helium to displace water like this and achieve buoyancy is absolutely possible. Notably you said all gases are liquid at those pressures so you can't even pretend you were really just being pedantic about the difference between a supercritical fluid and a gas.

In reality, this device would probably be used to blow out the ballast tanks, not to inflate some kind of mylar balloon on the side of the submersible like Gramage suggested. (Or maybe not - but I can forsee other ways the bag concept could go wrong.) The point is, there are substances you can use to generate a 'gas' (lower-density supercritical fluid that is gas-like in properties) and use that to surface in an emergency. His idea isn't laughable.

As for T and P, they are of course separate properties. We have three things. Temperature, pressure, and the phase of the material in question. You can hold temperature constant, vary the pressure, and get one set of phase transitions. You can hold pressure constant, change the temperature, and get another. (Doing either of these to a real gas requires an input of work/heat - i.e. they are not adiabatic transitions.) Or you can just pick out the end states you want to work with (in this case, a surface pressure and cryogenic temperature liquid point, and a bottom-of-the-challenger-deep-emergency-pressure and temperature), and use them to obtain whatever property you are interested in. In this case, the change in density for a fixed mass of helium means an expansion would be produced, and that expansion is what you use to displace water, increase your buoyancy, and surface.

Changing temperature does not change pressure, or vice versa, on the phase diagram. In an enclosed adiabatic gas, changes in pressure produce changes in temperature and vice versa, but a tank in a submarine is not adiabatic. You add heat to the helium to change it from the liquid phase that its stored at, to the seawater-temperature phase its 'inflated' to. Nor is it fully enclosed, since the point is to expand and displace water.

Now I am done talking with you because I'm pretty sure you know this stuff, or at least don't care, and are only trolling. This is fairly stereotypical, being deliberately wrong and smarmy about it to get a reaction out of people.