Torpedo

A 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.

Etymology

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.