I assume the metal and materials the boats are made of are strong but surely not to withstand the pressure of being 12,000 feet underwater? At the end of the day it’s not like the engineers had to consider holding up to that much pressure in their design right?
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The material of sunken ships is indeed under immense pressure. But the pressure is on all sides, so it’s not going to pull everything flat as if you cranked up gravity. A lot of the materials in the wrecks can only be compressed a little if at all. Take a steel beam and apply pressure on it from all sides and you won’t see any significant change.
Because pressure acts in all directions.
In the current submarine issue, there is water pressure pushing in on the walls, but relatively little pushing back out.
The titanic is filled with water, so the same water pressure is pushing everything at the same time in all directions.
E: this has turned a bit popular. Thanks all!
What do you expect to happen by it getting crushed?
It is getting crushed, the metal is I’m sure a little denser than it would’ve been on the surface cause the atoms are being squeezed together. But thats just what getting crushed is.
Things only implode/explode if pressure is not evenly distributed. If it is evenly distributed, like it is on the titanic because this pressurized water has filled every nook and cranny, then its just the atoms getting squeezed more, there isn’t a structural crushing that can happen.
In simple terms, it’s because there is equal pressure all the way around the wreckage. Whatever water pressure is pushing against one side of the hull is equal to the water pressure pushing against the other side of the hull. When you see things like a film in which a submarine implodes at great depths, it’s because the air pressure inside is less than the water pressure on the outside. But the Titanic no longer has any pressurized compartments–it’s surrounded by equal water pressure on all sides.
You can do a little experiment.
Raise your arm out in front of you. Right now your arm is experiencing the pressure of the entire column of air from the surface of Earth all the way to the edge of the atmosphere. This will be approx. 1013 millibars or 14.7 pounds per square inch. If the air to the sides and under your arm weren’t present and exerting the same amount of pressure in various directions to counteract this column of air…you’d…well, you’d have a tough time moving around.
Same idea with water surrounding wreckage.
They do, but not the way you’re thinking.
As many other commenters pointed out, when the thing is full of water the pressure acts in all directions so it doesn’t want to collapse anything, which is what we usually think of when we mean “crushed”.
The metal *is* getting squeezed by all that pressure, and the atoms do move a little closer together and the object does get a little bit smaller due to the pressure. The amount things shrink or don’t under pressure is a value called “bulk modulus” and it’s *really* high for dense solids like metals. It takes hundreds of thousands of psi to noticeably crush metals (at which point other, weirder, more exotic physics start happening anyway).
You may have heard the expression “water is incompressible”…it’s not, but it has such a high bulk modulus that it might as well be for all practical purposes. The bulk modulus of steel is about 80 times higher than water…i.e. it shrinks 80 times *less* under the same pressure.
Things underwater get crushed when they are sealed and there is a pressure difference between the sealed interior and the exterior. Most (all) of the compartments and rooms and spaces on the titanic have been compromised and filled with sea water years ago so there are no pressure differentials anywhere.
In short, the problem that creates the crushing is the *pressure differential*, not the pressure itself. Longer explanations above; that’s the short version.
>How do sunken ships like the titanic not get crushed under the pressure?
By filling with water.
There is no pressure difference between the inside and the outside of the ship, so there’s nothing to crush.
What’s left is the pressure on one side of a metal hull plate being equal to the pressure on the other side of the same metal hull plate.
Imagine an inflated balloon on the floor. When you step on it, it pops. The balloon is a pressured submersible and your foot is the crushing sea pressure pushing on it.
The Titanic on the sea bed is like an uninflated balloon. It is not pressurised. Anything that was pressurised did explode/implode on the way down.
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