Submarine

Submarine _Designed by ProCoPrint3D ( http://www.thingiverse.com/ProCoPrint3D/about ) _Submarine, any naval vessel that is capable of propelling itself beneath the water as well as on the water’s surface. This is a unique capability among warships, and submarines are quite different in design and appearance from surface ships. Submarines first became a major factor in naval warfare during World War I (1914–18), when Germany employed them to destroy surface merchant vessels. In such attacks submarines used their primary weapon, a self-propelled underwater missile known as a torpedo. 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. Armed with torpedoes as well as antiship and antisubmarine missiles, the nuclear attack submarine has also become a key element of naval warfare. _The submarine was first used as an offensive weapon in naval warfare during the American Revolution (1775–83). The Turtle, a one-man craft invented by David Bushnell, a student at Yale, was built of wood in the shape of a walnut standing on end (see photograph). Submerged, the craft was powered by propellers cranked by the operator. The plan was to have the Turtle make an underwater approach to a British warship, attach a charge of gunpowder to the ship’s hull by a screw device operated from within the craft, and leave before the charge was exploded by a time fuse. In the actual attack, however, the Turtle was unable to force the screw through the copper sheathing on the warship’s hull.