Tuesday, March 15, 2011

Submarine

Introduction

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.
Following is a history of the development of submarines from the 17th century to the present. For a history of other warships, see naval ship. For the weaponry of modern attack and strategic submarines, see rocket and missile system.
 

Early hand-powered submersibles

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. Bourne proposed a completely enclosed boat that could be submerged and rowed underwater. It consisted of a wooden frame covered with waterproof leather; it was to be submerged by reducing its volume by contracting the sides through the use of hand vises. Bourne did not actually construct his boat, and Cornelis Drebbel (or Cornelius van Drebel), a Dutch inventor, is usually credited with building the first submarine. Between 1620 and 1624 he successfully maneuvered his craft at depths of from 12 to 15 feet (four to five metres) beneath the surface during repeated trials in the Thames River, in England. King James I is said to have gone aboard the craft for a short ride. Drebbel's submarine resembled that proposed by Bourne in that its outer hull consisted of greased leather over a wooden frame; oars extended through the sides and, sealed with tight-fitting leather flaps, provided a means of propulsion both on the surface and underwater. Drebbel's first craft was followed by two larger ones built on the same principle.
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. In 1747 an unidentified inventor proposed an ingenious method of submerging and returning to the surface: his submarine design had goatskin bags attached to the hull with each skin connected to an aperture in the bottom of the craft. He planned to submerge the vessel by filling the skins with water and to surface by forcing the water out of the skins with a “twisting rod.” This arrangement was a forerunner of the modern submarine ballast tank.
 

First use in war

Photograph:Bushnell's submarine torpedo boat, 1776. Drawing of a cutaway view made by Lieutenant Commander …
 
  • Bushnell's submarine torpedo boat, 1776. Drawing of a cutaway view made by Lieutenant Commander …
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.Robert Fulton, famed U.S. inventor and artist, experimented with submarines several years before his steamboat Clermont steamed up the Hudson River. In 1800, while in France, Fulton built the submarine Nautilus under a grant from Napoleon Bonaparte. Completed in May 1801, this craft was made of copper sheets over iron ribs. A collapsing mast and sail were provided for surface propulsion, and a hand-turned propeller drove the boat when submerged. A precursor of a conning tower fitted with a glass-covered porthole permitted observation from within the craft. The Nautilus submerged by taking water into ballast tanks, and a horizontal “rudder”—a forerunner of the diving plane—helped keep the craft at the desired depth. The submarine contained enough air to keep four men alive and two candles burning for three hours underwater; later a tank of compressed air was added.
The Nautilus was intended to attach an explosive charge to the hull of an enemy ship in much the same manner as the Turtle. Fulton experimentally sank an old schooner moored at Brest but, setting out to destroy British warships, was unable to overtake those he sighted. France's interest in Fulton's submarine waned, and he left for England, offering his invention to his former enemy. In 1805 the Nautilus sank the brig Dorothy in a test, but the Royal Navy would not back his efforts. Fulton then came to the United States and succeeded in obtaining congressional backing for a more ambitious undersea craft. This new submarine was to carry 100 men and be powered by a steam engine. Fulton died before the craft was actually finished, however, and the submarine, named Mute, was left to rot, eventually sinking at its moorings.
During the War of 1812 between the United States and England, a copy of the Turtle was built, which attacked HMS Ramillies at anchor off New London, Conn. This time the craft's operator succeeded in boring a hole in the ship's copper sheathing, but the screw broke loose as the explosive was being attached to the ship's hull.

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