Why doesn't water enter a submarine from below when a hatch

>>8843833
in 2017, people will tell you a story about pressure

also, all militaries are cuckolds

>>8843841
Don't post just to demonstrate your sensibilities concerning any military.

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>>8843833
as >>8843838 said, pressure
but lets think about it for a second, if the water would enter the submarine from that hatch, the volume of water in the submarine would increase in the finite capacity of the submarine that is already filled with a fixed volume of air, so this would require the air volume to diminish, aka air leaving the sub, but the only opening in the sub is that hatch where water would be coming from, wich is at the bottom of the sub, but air is less dense than water so it cannot go down threw that hatch while water is coming threw it

Are submarines pressurized at 1 bar or do they take on the pressure of the water as you go deeper?

>>8843905
>take on the pressure of the water as you go deeper
That would be like having no submarine at all

>>8843833
It depends on the internal pressure of the submarine.

If it's non pressurised the water would rapidly flood in.

If it's pressurised the water stays out but you have to worry about other stuff e.g. decompressing people, gas mixes, etc.

see: https://physics.stackexchange.com/questions/127745/pool-in-a-submarine

>>8843898
Why even bother having a floor then?

Fun fact:

Military submarines (e.g. nuclear attack boomers) are designed so that if they are dangerously close to reaching their crush depths they will instead deliberately flood themselves.

It would destroy the machinery and fittings, and obviously the crew would be killed, but you'd be able to recover the hull later and get it back into service with some work.

>>8843976
Well the hatch cant be open all the time to all rooms because the water could be at a huge pressure, which would raise the pressure in the submarine and concentrate the air allowing water in.

However for shallow dives there is no issue - you can go "scuba walking" where you essentially have an open bottom box on your head with air being pumped into it.

>>8843986
Well if its getting to that depth anyway and leaving it would collapse the hull the crew are dead regardless.

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>>8843976

>>8843898
>threw

>>8843946
Not quite. But it would cause problems; nitrogen and oxygen are toxic at high partial pressures, so at high depths you'd have to use artificial air mixtures (just like divers do), but it's still an issue. Fast depressurizing will kill you as the gasses tend to dissolve in your blood and sudden reduction of body pressure is the exact same thing as opening a soda bottle - and helium, which would have to be used in place of surplus nitrogen and oxygen, is the worst - the quickest one to dissolve in your blood. So unnecessary pressurization of the crew limits your ability to move up and down (especially true for emergency resurfacing) and forces you to constantly alter the atmosphere inside. On the bright side, your submarine would have to handle less pressure and tension.

>>8843991
Saved.

>>8843986
>but you'd be able to recover the hull later
So would your enemies though.

>>8843986
Is the personnel aware of this feature?

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>>8843991
Good fucking show, haven't laughed that hard in a while

>>8844242
yes. its why submariners get extra pay.

>>8843898
But the air in the sub is compressible...

>>8843986
This is false. First off, the US and Russia have lost submarines which have exceeded crush depth. Second, destroying all the shit inside the submarine would total it, as seen in that guy torching an ohio to leave work early. Third, good luck recovering a flooded submarine from below crush depth. The Kursk was in shallow water, and still had to be cut in half to be recovered. The CIA had an incredibly hard time recovering a russian sub in deep water, and it was a relatively small diesel.

Stop lying.

>>8843898
its through, threw is past of throwing

>>8844291
Yes, the water will rise upwards and the air will compress, depending on your dive depth. You can't do this if you get too deep.

Propeller shaft seals, how do they work?

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>>8843991

>>8843833
Uhh, because the hatch is the only point of entry for the water? Are you retarded?

>>8843833
>Why doesn't water enter a submarine from below when a hatch like this is opened under water?
It does. Who the fuck told you a submarine can open an underwater hatch without taking on water?

The only way to open an exterior hatch on a submarine is if that compartment is flooded to equalize the pressure, which is the operating principle of an escape hatch. Water still comes in.
https://en.wikipedia.org/wiki/Escape_trunk

>>8844380
>as seen in that guy torching an ohio to leave work early.
Wait, what? Story?

>>8843991
>have a cruiser
>flip it over
>submarine
GENIUS

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>>8843991

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>>8843991
this is the quality content I come to /sci/ to see

>>8843991
cute

>>8844380
>as seen in that guy torching an ohio to leave work early.
seconding >>8845272
pls elaborate

>>8845272
What does it even mean to torch an ohio?

>>8845272
Whoops, it was a 688i.
https://www.usatoday.com/story/news/nation/2013/03/15/nuclear-submarine-fire/1990663/

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>>8846960
holy shit

>>8843898
You probably would have sounded smart if you had proof read that goddamn paragraph of a sentence.

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>>8843991
I've gone ahead and made some propietary improvements.

>>8846772
Torch: Set fire to
Ohio: US missile sub class

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>>8843991
Never change /sci/

>>8843991
But wouldn't their legs get torn apart as the submarine moves?
The air will push them while the water will not

>>8847767
No because the pressure in the water is greater than in the submarine - so the water will push them out into the submarine, where gravity will push them back down and the wind keep them moving forward.

>>8844438
ye, sorry about that, im french

>>8847838
>the pressure in the water is greater than in the submarine

>>8843833

That hatch would NEVER be open underwater.

>>8843841

Submariners are super cuckolds because they get paid a pitiful amount in proportion to the amount of work they do and the amount of technical know-how they possess.

At least the US Navy. Never join submarines. Never join submarines. Never join submarines.

Do you like eating food from a crate marked "Not fit for California Penal System"? Don't join submarines.

>>8843898
Congratulations you have invented the diving bell.

https://en.wikipedia.org/wiki/Diving_bell

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>>8847681
My sides are in orbit (the EM drive brought me there)

>>8843898
The fuck are you talking about? The volume can and will diminish, air isn't imcompressible.

The volume does not diminish because the pressure of the air is equal to the pressure of water at it's interface.

>>8848839
>the pressure of the air is equal to the pressure of water at it's interface.
Not in a submarine.

>>8843991
Loooooooooool

>>8848871
Are you memeing? If the bottom hatch is open, and water is not flowing in, then yeah, it has to be equal.

>>8848299
rofl

>>8848882
So you're assuming water isn't flowing in to prove that air won't flow in?

>>8848882
>If the bottom hatch is open, and water is not flowing in, then yeah, it has to be equal.
I may have misunderstood what you were trying to say.

Obviously yes, once the pressure inside the sub is the same as outside, water will stop flowing in. However, initially (at the moment the hatch opens) the pressure inside will be much lower than outside, and a significant amount of water will need to flow in before it equalises.