Submarine is a special kind of vessel that can go underwater easily. They are used for military purposes, research work, salvage, etc. Submarines can float as well as sink easily. A submarine has a huge ballast tank, the air in it makes the submarine float, and when it has to go underwater, the ballast tank is filled with sea water and when the submarine has to come at the surface the water in the ballast tanks is pumped out like exactly a mug behaves in a tub full of water.

Submarines ,y ou must have seen this thing in movies, cartoons, or in books. But I would like to show you one picture of a submarine; here below you can find a submarine image, how it looks like.

It’s so interesting that something so heavy like a submarine can float underwater… when I was a kid I always tried to find an answer to this question. Did you try to find out the answer like me?

Let’s make it more interesting by knowing some facts about submarines before going for the real reason behind floating and sinking.

What is a submarine exactly?

A submarine is a kind of special vessel or a large ship that can go underwater easily; these enormous vessels have a large no. of the crew on it. It is used for traveling under the deep ocean. Through submarines, one can explore underwater wonderfully and can see many sea creatures there. But submarines are made to do a lot more than just stare at water animals.

Where are submarines used or by whom?

Submarines play a very significant role in the country’s navy. Submarines are used for militaries, protecting aircraft carriers, and carrying out various other tasks + kinds weapons are placed inside it to save our nation at the times of war, for science and research works- marine research works, undersea exploration finding kind of species living in deep waters,  for tourists- it’s a kind of adventure too, for salvage. Salvage means when any ship sinks and gets lost underwater, submarines are used to recover lost items. Submarines can remain submerged under the sea for months at a time. It holds various equipment like radar, periscope, and many other systems to keep it functioning better.

Why do our military prefer submarines over surface ships?

Surface ships are large ships that float on the surface of the water, not underwater, which carry passengers and cargo. Submarines and surface ships are both large, big, and strong,g so why does our military insist on using submarines more than surface ships? Because there are two big advantages, such as submarines are harder to detect or search, and harder to sink in comparison to surface ships. Submarines cannot be easily caught by enemies, we can see and save our country in a much better way by using submarines because it’s underwater so no one can see it from far and we can pose a threat to our enemy.

A submarine is so interesting and much more fun to see than surface ships, it goes underneath the waves and can make you feel like you are also one of those creatures who are living under water. It’s so beautiful.

When was the submarine first built?

The first submarine was built in 1620 by Dutch Engineer Cornelis Jacobszoon Drebbel, under the support of James 1 of England.

Now come to the main question,

How do submarines float and sink?

Before going for the scientific explanation, I would like to illustrate an example that sets your mind in a better way to understand this whole process.

Activity: take an empty mug and turn it upside down; now push the mug inside a bucket which must be filled with water. There you have to apply some force to get it underwater, but once you leave the mug, it floats back to the top. The mug comes to the surface and floats like a ship because the air in it makes it lighter than water, that weight makes the mug float on the surface. See for yourself by doing the above given activity, you will understand 50% of the reason behind this sinking and floating thing immediately.

Now come back to the submarine,

The submarine has huge, big tanks which are called ballast tanks. The air in them makes a submarine float. And when a submarine has to go underwater, the ballast tanks are filled with seawater, which makes submarines heavy, so it’s easy for a submarine to sink below the surface. And when a submarine has to come to the surface again, the water in the ballast tanks is pumped out and the air is again forced in and it will be on the surface again, so it’s very easy for submarines to go underwater and come up like a whalefish up and down.

The submarine body is like a sleek cigar shape that helps it move underwater swiftly. In order for the submarine to dive, ballast tanks are flooded with seawater that makes it heavy to float anymore on the surface and results in sinking deep to the bottom due to the additional weight of the seawater in ballast.

You can understand it better with this activity: Make Your Own Submarine

Submarines are very useful for military, it floats as well as sinks as and when required, it has super tanks that help it in floating and sinking beside it can’t get collapse in the water and it has periscope that is used by captain to see above waters where they are going, what is in front? or for many things. Surface ships are so different from submarines. Submarines are designed in the manner to go up and down underneath the waves but surface ships are forced to keep at surface or above on waters.

Fun Facts:

  1. The first-ever submarine was built by a Dutch inventor named Cornelis Drebbel.
  2. Submarines have a great role in history, as they have been used from the time of the American Civil War.
  3. The underwater navigation of submarines is based on sonar technology.

Related Questions:

  1. Explain in detail the use of submarine ships in the military.
  2. What are the advantages of submarines over normal ships?
  3. What advanced navigation techniques are used by submarines?

True or False:

  1. A submarine is a type of aircraft vehicle.
  2. Normal ships are designed to sail on the surface of the water, whereas a submarine is designed to be submerged in the water.
  3. Submarine ships consist of four pressure hulls.
  4. The negative buoyancy leads to the rise of submarines from the water.
  5. Submarines have a normal engine like other ships.

Objective Quiz:

  1. Submarines consist of a _________ engine.
    1. Nuclear powered.
    2. Oil powered.
    3. CNG powered.
    4. None of the above.
  2. The spaces between two hulls is known as ________.
    1. Ballast tank.
    2. Pressure hulls.
    3. Engine.
    4. All of the above.
  3. __________ is the ability of something to rise, float or sink to a certain depth of water.
    1. Buoyancy.
    2. Pressure.
    3. Swimming.
    4. Lifting.
  4. The outer covering of the pressure hull is _______.
    1. Water-resistant.
    2. Colour resistant.
    3. Oil resistant.
    4. All of the above.
  5. The _______ of a submarine are similar to the fins of fishes.
    1. Planes.
    2. Pressure hulls.
    3. Engines.
    4. Navigation systems.

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Experiments & Activites, Primary Schoolers

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