Submarine

Ship built to sail under the water surface, although they also can do at the surface, the use of these vessels is reserved universally navies, they are essentially attacking unit. During the two guerrasmundiales occurred during the first half of the twentieth century submarines of the belligerent countries were actively involved in operations to disrupt maritime traffic. Many merchant ships were sunk, victims of torpedoes fired by submarines and even came to check sinking of large battleships.

The submarine has proved useful to carry out such operations varied. Thus, for example, has played a fleet vanguardiade services, minefields planted in strategic places in the seas, landed sabotage patrols, rescued downed airmen at sea and even made explorations under thick layers of ice in the polar regions.






In the early eighteenth century in England revived interest in submarines and for 1727 had already been patented at least 14, of different types. In an article published in 1747 in revistaGentleman's Magazine, an inventor anonymous suggested the use as ballast water contained in boots made pielde goat filling them with water, submerged underwater, and rose to the surface when it expelled the liquid by a valve at the bottom of the vessel. This idea is basically the same applies today in the construction of submarines that carry ballast tanks.

The difficulties to solve the many problems of hydraulics and mechanics, together with the rooted general conviction that the submarine would never be a practical means of navigation, were due to slow its adoption by the navy for at least another 100.