Hull Ballet Tanks Engines Conning Tower Hydroplanes Navigation

Submarine Design

Submarines are underwater self-propelled crafts that are designed and built to perform underwater operations for a stipulated amount of time. This module will focus on the basic components of a naval submarine.


The hull is the outer shell or the metal skin of the submarine. Most designs of submarines have two hulls. The hull that houses all the accommodation spaces, weapons, weapon control systems, communications and control room, battery banks, main and auxiliary machinery, is the pressure hull. The other hull, called the pressure hull is housed inside the outer hull, which is not pressure tight.

Ballast Tanks

A ballast tank is a tank or compartment either at the bottom of a ship or on the sides, which is filled with liquids for stability of the ship. Ballast tanks are located between the inner and outer hull of a submarine. When a submarine needs to submerge it fills these tanks with sea water. This changes the buoyancy of the submarine.


Most submarines except nuclear ones have diesel-electric engines. The diesel engine operates normally when the sub is near the surface but it doesn't drive the sub's propellers directly. Instead, it powers an electricity generator that charges up huge batteries. These drive an electric motor that, in turn, powers the propellers. Once the diesel engine has fully charged the batteries, the sub can switch off its engine and go underwater, where it relies entirely on battery power.

Conning Tower

Conning tower is the control center of the submarine. A periscope is located in the conning tower so the submarine can remain completely submerged and still visually see what is on the surface. All submarine operating systems are controlled and monitored from the conning tower.


Hydroplanes are located on the bow and stern of a submarine. These work like the flaps on an airplane. As the submarine is propelled through the water the hydroplanes can be adjusted to make the submarine dive or surface. The vertical fin is the rudder, which turns the submarine right or left


Submarines cannot visually see where they are going while submerged. They depend upon a lot of electronic equipment to accomplish this task.