The water would rush in and sink the sub. The pressure would equalise rapidly and when it does, the people inside would be crashed if they were too deep.
The hull is the outer shell or the metal skin of the submarine that protects the inner area from the outside water.
When a boat reaches its crush depth limit, the inner pressure hull succumbs to the extreme outer sea pressure, causing the hull to implode.
Yes, water exerts pressure on the hull of the submarine.
A casing deck is another term for a submarine's superstructure hull, which is the outer hull that protects the inner pressure hull. Using a thermos bottle as an analogy, the inner container where liquid goes would be the pressure hull, and the outer case which protects it the superstructure, or outer hull.
All modern submarines are "dual hull" constructed. What you see on the surface is the outer hull, or "superstructure". The inner hull, where the main systems and crew are, is protected by the outer hull. Damage severity of either the outer or inner hulls depends on the boat's depth at the time. If deep enough, it doesn't take much damage to the hull, as sea pressure will be virtually unstoppable, even with the quick-reaction damage control skills of a submarine crew. However, if sea pressure isn't a factor and the flooding can be controlled, then it's possible to survive such a casualty. Again, it depends on the severity of the hull breach, and the depth at the time. Several modern submarines (my old boat included) have survived underwater collisions which produced severe damage.
Submarine hulls are subject to sea pressure, and that pressure increases the deeper the submarine goes. There are design limits to the amount of pressure that a hull can take, and if that pressure is exceeded by diving too deep, the hull will fail and will be crushed.
because if a submarine goes under water to deep levels, it needs to hold against the air pressure. Yes the person said above.. They have to have a MUCH higher ability to withstand the pressure of the water pushing in against the hull of it.
Yes it can. Every submarine has a maximum depth at which it is safe to operate. If it goes lower than its safe limit, the pressure can crush the hull.
The pressure hull of a submarine must withstand the pressure of water at depth. Hundreds of pounds of pressure per square inch translates into many tons of pressure around a pressure hull. If that hull doesn't have the strength to stand up to this, the pressure hull will implode. Steel is a "known quantity" as far as metals. We've used it for a long time, and we have a good handle on its characteristics. Steel alloys are extremely strong, fairly easy to fabricate, and won't double the national debt if we use this metal to make a submarine pressure hull. Steel's weldability and its common availability make it a fine choice for submarine pressure hulls. It's really strong, too. That's a big plus. No one wants to be inside the pressure hull of a submarine when it fails.
All submarine screw shafts have seals around the full length of the shaft hull penetration area to prevent water coming in. Shaft seals can be mechanical, hydraulic, etc., but regardless they serve the same purpose.
Periscopes allow a submarine, when submerged at a shallow depth, to search visually for nearby targets and threats on the surface of the water and in the air. When not in use, a submarine's periscope retracts into the hull.
The pressure exerted on the hull of the sub will get too great and crush it.