Torpedo

A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such a device was called an automotive, automobile, locomotive, or fish torpedo; colloquially, a fish. The term torpedo originally applied to a variety of devices, most of which would today be called mines. From about 1900, torpedo has been used strictly to designate a self-propelled underwater explosive device.

While the 19th-century battleship had evolved primarily with a view to engagements between armored warships with large-caliber guns, the invention and refinement of torpedoes from the 1860s onwards allowed small torpedo boats and other lighter surface vessels, submarines/submersibles, even improvised fishing boats or frogmen, and later light aircraft, to destroy large ships without the need of large guns, though sometimes at the risk of being hit by longer-range artillery fire.

Modern torpedoes are classified variously as lightweight, heavyweight, straight-running, autonomous homers, and wire-guided types. They can be launched from a variety of platforms. In modern warfare, a submarine-launched torpedo is almost certain to hit its target; the best defense is a counterattack using another torpedo.

The word torpedo was first used as a name for electric rays (in the order Torpediniformes), which in turn comes from the Latin word torpēdō ("lethargy" or "sluggishness"). In naval usage, the American inventor David Bushnell was reported to have first used the term as the name of a submarine of his own design, the "American Turtle or Torpedo." This usage likely inspired Robert Fulton's use of the term to describe his stationary mines, and later Robert Whitehead's naming of the first self-propelled torpedo.

Torpedo-like weapons were first proposed many centuries before they were successfully developed. For example, in 1275, engineer Hasan al-Rammah – who worked as a military scientist for the Mamluk Sultanate of Egypt – wrote that it might be possible to create a projectile resembling "an egg", which propelled itself through water, whilst carrying "fire".

In modern language, a "torpedo" is an underwater self-propelled explosive, but historically, the term also applied to primitive naval mines and spar torpedoes. These were used on an ad-hoc basis during the early modern period up to the late 19th century.

In the early 17th century, the Dutchman Cornelius Drebbel, in the employ of King James I of England, invented the spar torpedo; he attached explosives to the end of a beam affixed to one of his submarines. These were used (to little effect) during the English expeditions to La Rochelle in 1626. The first use of a torpedo by a submarine was in 1775, by the American Turtle, which attempted to lay a bomb with a timed fuse on the hull of HMS Eagle during the American Revolutionary War, but failed in the attempt.

In the early 1800s, the American inventor Robert Fulton, while in France, "conceived the idea of destroying ships by introducing floating mines under their bottoms in submarine boats". He employed the term "torpedo" for the explosive charges with which he outfitted his submarine Nautilus. However, both the French and the Dutch governments were uninterested in the submarine. Fulton then concentrated on developing the torpedo-like weapon independent of a submarine deployment, and in 1804 succeeded in convincing the British government to employ his "catamaran" against the French. An April 1804 torpedo attack on French ships anchored at Boulogne, and a follow-up attack in October, produced several explosions but no significant damage, and the weapon was abandoned.