We all have heard the word submarines sincere ages in war chapters. These technologys are heart of any naval force.These play major role in protecting our country and sealine.
A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. Submarines are referred to as boats rather than ships irrespective of their size.
Submarines first became a major factor in naval warfare during World War I (1914–18), when Germany employed them to destroy surface merchant vessels. Submarines played a similar role on a larger scale in World War II (1939–45), in both the Atlantic (by Germany) and the Pacific (by the United States). In the 1960s the nuclear-powered submarine, capable of remaining underwater for months at a time and of firing long-range nuclear missiles without surfacing, became an important strategic weapon platform.
The first serious discussion of a “submarine”—a craft designed to be navigated underwater—appeared in 1578 from the pen of William Bourne, a British mathematician and writer on naval subjects. A number of submarine boats were conceived in the early years of the 18th century. By 1727 no fewer than 14 types had been patented in England alone.
Most large submarines consist of a cylindrical body with hemispherical (or conical) ends and a vertical structure, usually located amid ships, that houses communications and sensing devices as well as periscopes. A “conning tower” was a feature of earlier designs: a separate pressure hull above the main body of the boat that allowed the use of shorter periscopes. There is a propeller at the rear, and various hydrodynamic control fins.
To submerge hydrostatically, a ship must have negative buoyancy, either by increasing its own weight or decreasing its displacement of water. To control their displacement and weight, submarines have ballast tanks, which can hold varying amounts of water and air.
Submarines in a neutral buoyancy condition are not intrinsically trim-stable. To maintain desired longitudinal trim, submarines use forward and aft trim tanks. Pumps move water between the tanks, changing weight distribution and pitching the sub up or down. A similar system may be used to maintain transverse trim.
The other systems in an submarine includes:
Control surfaces
Hull
Propulsion
Diesel–electric transmission
Snorkel
Air-independent propulsion
Nuclear power
Armament
Sensors
Navigation
Communication
Life support systems