How Nuclear Submarines Work

Nuclear Submarine Parts

Let's take a look at some of the basic parts of a nuclear submarine.

  • A submarine has an inner hull, which protects the crew from the water pressure bearing down on the submarine, and an outer hull, which provides a streamlined shape to the submarine. The hulls of nuclear submarines are made of HY-80, an alloy made from nickel, molybdenum and chromium that protects the submarine from the incredible pressures exerted upon it at great depths.



  • ­The sail is the streamlined portion that rises above the main body of the sub. It consists of several components, such as the horizontal diving planes, the radar masts, communications antennas and periscopes.
  • ­Ballast tanks are located between the two hulls. They help control the depth of the submarine by taking on or releasing water. Trim tanks -- located in the front and aft (rearward) sections of the sub -- are also able to take on or release water in order to keep the submarine's weight equally­ distributed.
  • The rudder is vertically aligned, and by moving it, the ship can be directed side-to-side. Stern planes are horizontally aligned, so that moving them will guide the submarine's movement upward or ­downward.
  • The propeller is powered by the steam-driven turbine and generators. The steam is creat­ed by the nuclear reactor.
  • A nuclear reactor is essentially a glorified steam engine. It's usually located in the rear portion of the submarine. The reactor is protected by a thick metal casing that weighs around 100 tons. A specially designed alloy inside this shielding further protects the radioactive fuel rods.­
  • The sonar sphere is located in the nose (or front) of the submarine. Sonar helps a submarine detect other objects in the water. It works by sending out a sound wave. If this sound wave strikes an object, a portion of the sound will be echoed back to the sub.
  • Atmosphere control equipment decontaminates the crew's breathing air by ridding it of carbon dioxide and impurities.
  • Distilling plants purify saltwater to be used for the engine or for drinking water.
  • The control room/attack center is the nerve center of the submarine. It contains the operational controls for all navigational, sonar, communications and weapons systems on the submarine. From here, the vessel's activities are directed.
  • The torpedo room is where all torpedoes are stored and loaded into torpedo tubes to prepare them for launching.
  • The submarine's crew is housed and fed in very tight, efficient quarters called the berthing and mess deck. Usually, this area is located in the middle level of the ship's forward compartment.
Nitty-gritty Nuclear

Within the nuclear reactor, a neutron is used to split an atom of uranium, producing energy in the form of gamma radiation and heat. A coil filled with circulating water is superheated as it's routed past the reactor. This water is under extremely high pressure, which prevents it from boiling. Inside self-contained piping, the water is directed through a secondary source of water, where it's heated again. Here, the water is converted to steam and is piped toward the turbine that generates power for the submarine. The steam is condensed again in special cooling tubes, and the resulting water flows back into the steam generator. Inside the generator, it's reheated and the process repeats. This method requires no oxygen, so the submarine doesn't need to maintain or refresh a supply of air from above the surface.

Continue reading to find out why you should never bring a knife to a ballistic-missile fight.