torpedo

A torpedo is a self-propelled underwater weapon designed to detonate against ships, submarines, or other underwater targets. It is launched from surface ships, submarines, or aircraft and travels underwater to reach its target, using onboard guidance to improve accuracy.

Propulsion in modern torpedoes is usually electric, powered by batteries that drive a propeller or pump-jet, or it is provided by a small turbine engine in some designs. Earlier models used combustion engines or compressed air. Torpedoes are designed to operate at a range of depths and speeds, with steering fins and control surfaces enabling course correction during flight.

Guidance and targeting systems range from unguided to highly sophisticated. Early weapons ran straight to the target, while later models employ wire guidance, active or passive sonar homing, or a combination of inertial navigation and sonar-based guidance for terminal attack. Some versions use wake homing or other terminal guidance methods to acquire a target in the final approach.

Warheads are typically high-explosive and designed to create a damaging underwater shock or to puncture hulls. Most contemporary torpedoes carry conventional warheads, though some historical designs and specialized variants experimented with nuclear payloads. Modern safety and reliability standards emphasize secure arming, naval compatibility, and safe handling.

Deployment and platforms include submarines, surface combatants, aircraft, and helicopters, reflecting a wide range of naval doctrines. The standard 533-millimeter (21-inch) torpedo size is common among many navies. Since their 19th-century origins, torpedoes have evolved from simple self-propelled projectiles to versatile, guided weapons that remain central to anti-ship and anti-submarine warfare.