Submarine

A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. It 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. Two Greeks submerged and surfaced in the river Tagus near the City of Toledo several times in the presence of The Holy Roman Emperor Charles V, without getting wet and with the flame they carried in their hands still alight.Model of the Mésoscaphe Auguste PiccardInterior of the tourist submarine Atlantis whilst submergedTourist submarine Atlantis1900/Russo-Japanese War 1904–1905 A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. It 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. Although experimental submarines had been built before, submarine design took off during the 19th century, and they were adopted by several navies. Submarines were first widely used during World War I (1914–1918), and are now used in many navies large and small. Military uses include attacking enemy surface ships (merchant and military), or other submarines, aircraft carrier protection, blockade running, ballistic missile submarines as part of a nuclear strike force, reconnaissance, conventional land attack (for example using a cruise missile), and covert insertion of special forces. Civilian uses for submarines include marine science, salvage, exploration and facility inspection and maintenance. Submarines can also be modified to perform more specialized functions such as search-and-rescue missions or undersea cable repair. Submarines are also used in tourism and undersea archaeology. Most large submarines consist of a cylindrical body with hemispherical (or conical) ends and a vertical structure, usually located amidships, which houses communications and sensing devices as well as periscopes. In modern submarines, this structure is the 'sail' in American usage and 'fin' in European usage. 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 (or pump jet) at the rear, and various hydrodynamic control fins. Smaller, deep-diving and specialty submarines may deviate significantly from this traditional layout. Submarines use diving planes and also change the amount of water and air in ballast tanks to change buoyancy for submerging and surfacing. Submarines have one of the widest ranges of types and capabilities of any vessel. They range from small autonomous examples and one- or two-person subs that operate for a few hours to vessels that can remain submerged for six months—such as the Russian Typhoon class, the biggest submarines ever built. Submarines can work at greater depths than are survivable or practical for human divers. Modern deep-diving submarines derive from the bathyscaphe, which in turn evolved from the diving bell. Whereas the principal meaning of 'submarine' is an armed, submersible warship, the more general meaning is for any type of submersible craft. The definition as of 1899 was for any type of 'submarine boat'. By naval tradition, submarines are still usually referred to as 'boats' rather than as 'ships', regardless of their size. In other navies with a history of large submarine fleets they are also 'boats'; in German it is an Unterseeboot or U-Boot (under-sea boat) and in Russian it is a подводная лодка (underwater boat). According to a report in Opusculum Taisnieri published in 1562: In 1578, the English mathematician William Bourne recorded in his book Inventions or Devises one of the first plans for an underwater navigation vehicle. A few years later the Scottish mathematician and theologian John Napier wrote in his Secret Inventions (1596) the following: 'These inventions besides devises of sayling under water with divers, other devises and strategems for harming of the enemyes by the Grace of God and worke of expert Craftsmen I hope to perform.' It's unclear whether he ever carried out his idea. The first submersible of whose construction there exists reliable information was designed and built in 1620 by Cornelis Drebbel, a Dutchman in the service of James I of England. It was propelled by means of oars. By the mid-18th century, over a dozen patents for submarines/submersible boats had been granted in England. In 1747, Nathaniel Symons patented and built the first known working example of the use of a ballast tank for submersion. His design used leather bags that could fill with water to submerge the craft. A mechanism was used to twist the water out of the bags and cause the boat to resurface. In 1749, the Gentlemen's Magazine reported that a similar design had initially been proposed by Giovanni Borelli in 1680. Further design improvement stagnated for over a century, until application of new technologies for propulsion and stability.