Submarines
Imagine living underwater for months at a time. You could only stay underwater that long on a submarine.
A submarine is a ship that can move around underwater. Submarines can also move on top of the water. Submarines are called subs for short.
WHAT DOES A SUBMARINE LOOK LIKE?
A submarine does not look like other ships. A submarine looks like a long tube. The outside of the tube is called the hull. The front of the hull, called the bow, is rounded. The back of the hull, called the stern, comes to a point.
There is a tower on top of the hull. The tower is called the sail. The entrance to the submarine is in the sail.
WHAT MAKES A SUB GO?
Propellers on the back of a submarine make it go. The propellers turn and push the sub through the water.
In most big submarines, nuclear energy provides the power needed to turn the propellers. These subs are called nuclear-powered submarines. Nuclear energy also makes electricity for the sub.
Some submarines are diesel-electric submarines. Their get their power from diesel fuel and from batteries.
WHAT SUBS DO
Most submarines are warships. Navies use two main kinds of subs: attack subs and ballistic missile subs.
Attack submarines can go very fast. They hunt ships and other submarines. Attack submarines sink them with torpedoes. They fire missiles at targets on land as well. They can also lay mines that explode if a ship hits one.
Ballistic missile submarines can launch missiles that carry nuclear bombs. These submarines can be deep underwater when they launch a missile. The missile can travel thousands of miles.
Scientists use small submarines to study the depths of the ocean. Some small submarines can go down very deep.
HOW DO SUBS DIVE?
Submarines have big tanks on board. Sailors fill the tanks with seawater to make the sub heavy. The sub can dive once it is heavy enough.
Sailors empty the tanks to make the sub lighter. They push air into the tanks to push out the water. Then, the sub can float to the surface.
HOW SUBS MOVE AROUND UNDERWATER
Sailors turn on the propeller to make a sub go forward. They can make the sub go fast by speeding up the propeller.
A submarine has short wings called diving planes on the sail or along its sides. These planes allow a sub to angle up and down while it’s moving underwater. Diving planes look a bit like airplane wings. The planes can be tilted to make the sub go up or down. They help it dive and come back up to the surface.
A sub also has stubby wings in the stern that stick up and down. These wings are called the rudder. Turning the rudder makes the sub go left and right.
HOW DO YOU SEE OUT OF A SUB?
A military submarine does not have windows. You cannot look out from inside. Submarines use sound to look for things underwater. The sound comes from a sonar system. Sonar can hear noise from ships and other submarines.
The sonar system can also send out sounds. The sounds bounce back when they hit something. This makes a picture on a sonar screen. The picture might show a big rock on the bottom of the sea. It might show an enemy submarine.
Sailors use a periscope to see above the surface of the water. A periscope is a long tube. You look in one end from inside the sub, and the other end sticks up out of the water. Mirrors inside the periscope let you see what is on the surface.
WHAT IS IT LIKE TO LIVE ON A SUB?
There is not much room on a submarine. Submarines must carry sailors, missiles, torpedoes, food, and a lot of equipment. Every inch of space gets used.
Sailors sleep in small bunks. They eat in small dining rooms. They have places to exercise and watch videos. One big Russian submarine even has a small swimming pool!