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submarine

Underwater warship. The first underwater boat was constructed in 1620 for James I of England by the Dutch scientist Cornelius van Drebbel (1572-1633). A naval submarine, or submersible torpedo boat, the Gymnote, was launched by France in 1888. The conventional submarine of World War I was driven by diesel engine on the surface and by battery-powered electric motors underwater. The diesel engine also drove a generator that produced electricity to charge the batteries.

History

In the 1760s the American David Bushnell (1742-1824) designed a submarine called Turtle for attacking British ships, and in 1800 Robert Fulton designed a submarine called Nautilus for Napoleon for the same purpose. John P Holland, an Irish emigrant to the USA, designed a submarine in about 1875, which was used by both the US and the British navies at the turn of the century. Submarine warfare was established as a distinct form of naval tactics during World War I and submarines, from the ocean-going vessels to the midget type, played a vital role in both world wars. In particular, German U-boats caused great difficulty to Allied merchant shipping, until the radio codes were broken in 1942.

Nuclear submarines

In 1954 the USA launched the first nuclear-powered submarine, the Nautilus. The US nuclear submarine Ohio, in service from 1981, is 170 m/560 ft long and carries 24 Trident missiles, each with 12 independently targetable nuclear warheads. The nuclear warheads on US submarines have a range that is being extended to 11,000 km/6,750 mi. Four Vanguard-class Trident missile-carrying submarines, which will each wield more firepower than was used in the whole of World War II, were built in the 1990s in the UK. Operating depth is usually up to 300 m/1,000 ft, and nuclear-powered speeds of 30 knots (55 kph/34 mph) are reached. As in all nuclear submarines, propulsion is by steam turbine driving a propeller. The steam is raised using the heat given off by the nuclear reactor (see nuclear energy).

In oceanography, salvage, and pipe-laying, smaller submarines called submersibles are used. They are also being developed for tourism.

Aboukir, HMS anti-submarine warfare Bushwell, David E-Class submarines Lake, Simon

Lockwood, Charles A(ndrews) periscope schnorkel Trident warship