What s working principle of a submarine?

Question

What s working principle of a submarine?

Answer 1

ITS NOT THAT SIMPLE TO EXPLAIN. IF YOU WANT TO KNOW JUST GO ON TO THIS SITE.

Answer 2

A submarine is submerged by allowing water into the main ballast tanks so that its total weight is equal to the weight of the water displaced, hence it attains neutral buoyancy. To bring back the submarine to the surface, the water in the main ballast tanks is blown out by air and the submarine gains positive buoyancy. The main ballast tanks however are either full (when submerged) or empty (when the vessel is on the water surface).

Variations in the loading of the submarine are compensated by means of smaller tanks called the trim tanks. There are normally three of these; one at the forward part of the sub, one at the midships, and one aft. These tanks are designed to compensate the changes in the loading of the vessel and the longitudinal moment of the variation in loading. The contents of these tanks are preset before the submarine goes on a dive so that when the main ballast tanks are filled, the submarine will submerge and still remain on even trim. Other smaller tanks in the submarine are also used for the compensation of the variations in loading such as the periscope compensating tank, torpedo tube water compensating tank, etc. The capability of the submarine to operate at extreme load variations is determined by a plot of the compensating ballast weight variations and corresponding moment variation called the equilibrium polygon.

The depth to which the submarine is brought underwater is controlled by a small tank called the depth control tank. For a 3800 ton submarine, the depth control tank is only about 5 tons capacity and this is filled at 50% capacity before the dive. Thus it provides the necessary increase or decrease in displacement to bring the vessel to a desired depth.

Supervision of the ballasting of compensating tanks is done by a special submarine officer designated as the ballast officer.

Answer 3

It's all about bouyancy.  When the tanks on a sub are full of air, the sub floats.  When they add enough water to them, it sinks.  They can control the depth by how much water is in the tanks.

Air is less dense and weighs less than water.  If a sub, even a huge one weighing sever tons, is in deep enough water, the air filled sub will float since it weighs less than the water around it.  If you put a huge sub in a shallow and small enough tank of water, it would sink to the bottom since it would weigh more than the water and displace it.