Mines can be used at sea or on land and differ from most other weapons of war in that they are not directed against specific targets. Once laid they can remain active for many years, and modern types are very difficult to detect and destroy.
The term mine is derived from the medieval practice of digging, or mining, tunnels under enemy fortifications and filling them with explosive, which was then detonated to destroy or breach the fortifications. This type of mining still finds occasional application in modern warfare.
The modern land mine, however, is generally an explosive device used on, or just below, the ground surface and of two main types—antipersonnel and antiarmor. Antipersonnel mines are related to the older trip-wire guns while the first antitank mines, used by the Germans in World War I following the introduction of tanks by the British, consisted of artillery shells buried fuse uppermost. Subsequent development has resulted in a variety of modern mines of both types.
Antipersonnel mines
Antipersonnel mines, which may be of either fragmentation or blast type, are small devices mainly intended to injure or disable rather than kill outright. Subsequent care of wounded soldiers uses up enemy resources (such as other troops and transportation) that would otherwise be used in attack. Generally, nonmagnetic and nonconducting materials are used for these mines to make them difficult to detect. They can be fired by pressure fuses, trip-wires, and tilting rods or under direct control by a hidden operator.
Blast designs have a limited range, and their effect is limited to the enemy who sets them off; typically, such a mine would be no more than 3 to 4 in. (7.5–10 cm) in diameter and simply scattered on the surface. When stepped on, they explode with sufficient force to blow a foot off.
Fragmentation mines produce a large number of high-velocity fragments, which are spread over a comparatively large target area. Mines of this type can be placed on the ground or buried just below the surface, and when fired, they project the fragments upward and outward in all directions. In bounding mines, the fragmentation projectile is thrown up from the ground and exploded in the air at a height of around 6 ft. (2 m) to spread the fragments horizontally in all directions. Another type is the fixed directional mine, such as the Claymore, which is mounted on legs just above the ground and aligned to cover the desired target area. The Claymore has a curved-plate explosive charge covered with some 700 steel ball projectiles, and when fired, the casualty area covers a 60 degree arc for a range of 150 ft. (50 m) at a height of 3 ft. (1 m).
Antiarmor mines
Conventional antiarmor mines contain a large explosive charge, up to 20 lbs. (9 kg) or more in some cases, and are laid below ground level. They are triggered by the force, typically 300 to 400 lbs. (136–180 kg), of the tank passing over them and destroy the vehicle by the blast effect. Other designs use charges shaped to give an incan-descent jet of gases that have an armor-piercing effect. A small uncovering charge may be used to clear the earth covering before the main charge is exploded to penetrate the armor, while another variant is designed to be installed above ground at the side of a road to fire horizontally at the target.
An increasing trend with antiarmor mines is the use of microelectronics to create an intelligent mine, which can, for example, use acoustic sensors to sense the approach of a tank and then fire an armor-piercing warhead when the target is in range. A related trend is toward the use of smaller antiarmor mines or minelets, with the increasing sophistication of the firing system making the best use of the smaller charge. To increase the difficulty of detection, antiarmor mines make extensive use of plastics and even wood, while metal parts are restricted to a minimum or even totally eliminated.
Another type of mine is the chemical mine, which is designed to disperse both gaseous and liquid agents. Such mines are considered to be most effective when laid in antiarmor minefields, which slow down the progress of the enemy and so result in greater exposure to the chemical.
