Naval Mine

A naval mine is a self-contained explosive weapon placed in water to damage or destroy ships and submarines, deposited in advance and left dormant until a passing vessel triggers it, unlike a depth charge, which is actively deployed against a specific target. Early mines relied on physical contact, and Chinese military texts from the 14th century document some of the earliest such devices, while in the West the American inventor David Bushnell built the first American naval mine in 1777, a watertight gunpowder-filled keg that detonated on impact, which he used in an attack on HMS Cerberus. Russia deployed more than 1,500 mines during the Crimean War of 1854 to 1856, and the American Civil War ironclad USS Cairo became the first ship sunk by a mine, in 1862. Modern naval mines have moved well beyond contact fuzes, using sensors that detect a passing vessel's magnetic field, acoustic signature or the pressure wave it creates in the water, a shift that began with the magnetic influence mines introduced in the Second World War.