How A Submarine Moves

An explanation on how submarines work and move


“Beret March of IDF’s Submarine Combat Soldiers” by Israel Defense Forces is licensed under CC BY-NC 2.0

By: Rakat Haque, Journalist

There have been quite a few deep sea explorations into the ocean, and it is very difficult to reach those depths.  To do so, they have to make use of submarines. Submarines are very useful as they allow researchers to go hundreds of meters underwater to make observations and gather materials for researching from the deep, and they are also useful for the military. You might be wondering though, how does a submarine actually work? Well, you’ll learn here. First of all, what is a submarine? A submarine is a vessel that is able to completely submerge underwater for long periods of time and is able to reemerge back to the surface of the water, they are also called subs for short.

The way a submarine dives and resurfaces is because of buoyancy. Buoyancy is sort of like an upward force that things of many sizes afloat, it can be anything from something small like a barrel to a gigantic ship. If the weight of the water being displaced by the object is equal to the weight of the object itself, it will float. If it is not equal, it will sink. This is how huge ships are able to float on water despite their size. Though submarines actually control buoyancy and manipulate it to control the diving and rising of the submarine.

The way they control buoyancy is by using ballast tanks. When surfaced, the ballast tanks have no water in them and only have air so that the submarine’s density is less than the water around it. But when it dives, the ballast tanks are filled with water and the air gets pumped out of the submarine until the submarine’s density is greater than the water around it. Also, in the submarine, they have a maintained supply compressed air aboard it to use for the ballast tanks.


Related Stories: