Submarines are marine vessels that are designed to operate underwater. Submarines have been mainly developed and used for military purposes. Some submarines, however, are used for research, recreational and commercial reasons.
Modern submarines are typically cigar-shaped, with hulls that are designed to withstand the pressure of oceanic depths. In order to make the submarine dive, water is taken into ballast tanks. For the submarine to rise, compressed air is used to force water out of the ballast tanks. The depth that the submarine dives to is determined by the amount of water that is taken into, or forced out of, the ballast tanks.
Horizontal rudders called hydroplanes are located at the bow and stern of the submarine. These stabilize the vessel when it dives or moves towards the surface.
The main weapon of military submarines are torpedoes. The torpedoes are often fired from the front of the submarine, although some submarines also carry torpedoes at the back of the vessel. Some submarines are armed with missiles that can be fired out of the water at terrestrial targets. In some cases these may be can be intercontinental nuclear missiles.
Submarines have been powered in a variety of ways. The earliest submarines were powered by hand. One of the early American naval submarines used a gasoline engine on the surface and an electric engine underwater. In 1906, the Germans began to use an adapted diesel engine in their naval submarines. Diesel engines became the primary means of propulsion for most submarines during the First and Second World Wars. After the Second World War, navies began to experiment with new means of powering submarines. The British launched a submarine powered by hydrogen-peroxide fuel in 1954. That same year, the United States launched the world’s first nuclear-powered submarine, the USS Nautilus.
The development of submarines
The first successful underwater vessel may have been built in England by Dutch inventor Cornelius Drebbel (1572-1634). Drebbel’s vessel was a rowboat encased in leather. Air was supplied by tubes that rose above the surface. Drebbel’s vessel reportedly made an underwater trip in England’s Thames River.
The first submarine designed for military purposes was the Turtle. This vessel was invented in the 1770s by American engineer David Bushnell. The egg-shaped craft was powered by a hand-operated screw. The craft was submerged by allowing water into the ballast tank. It was returned to the surface when the ballast tank was emptied by hand pump. Lead ballast was used to keep the vessel upright.
Another early submarine was the Nautilus, built in 1800 by U.S. inventor Robert Fulton. The Nautilus was notable because it resembled modern submarines in shape. It was also the first submarine to use horizontal rudders for control and compressed air to supply air underwater.
Four submersible crafts were built by the Confederates during the American Civil War. By the late nineteenth modern submarines began to come into use. One of the first practical submarines was built by U.S. inventor Philip Holland in 1898. The boat was powered by a gasoline engine on the surface and an electric engine underwater. The vessel was brought by the U.S. government in 1900 and renamed the USS Holland.
Since the early twentieth century submarines have been developed into effective war machines. German u-boat submarines were used extensively in both World Wars. After the end of the Second World War, submarines became part of the arms race between the United States and USSR. Both powers built an arsenal of nuclear reactor-powered submarines that were armed with intercontinental ballistic missiles.
Today many of the world’s navies possess military submarines. Submarines are also used for civilian purposes. Some submarines are used for scientific research. Others are used for commercial and recreational purposes. For, example, privately-owned commercial submarines may be used to take paying tourists on underwater tours.
“Submarine”. Funk & Wagnalls New Encyclopedia. New York: Funk & Wagnalls, Inc., 1979., p. 269-272.