Submarine

Submarine

Ever wonder what is submarine? Let's get to know a little background about submarine. A submarine is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability

                                     
     

Modern submarines are cigar-shaped. This design, visible in early submarines is sometimes called a "teardrop hull". It reduces the hydrodynamic drag when submerged, but decreases the sea-keeping capabilities and increases drag while surfaced.

A Submarine can float on water because the weight of the water displaced is equal to the weight of the craft. The upward force that the water has on the vessel is known as they buoyant force. The key to controlling a submarine’s diving and resurfacing, is to control the buoyancy.

Submarines are equipped with ballast tanks and trip tanks that can be filled with either water or air. To have the submarine sitting on the surface, the ballast tanks must be empty; to descend, the air in the tanks is replaced with water. The density of a submarine then becomes greater than the water and it will submerge. There is a supply of compressed air on board that is used for both life support and to fill the ballast tanks.