In warfare, high-explosive incendiary (HEI) is a type of

ammunition Ammunition (informally ammo) is the material fired, scattered, dropped, or detonated from any weapon or weapon system. Ammunition is both expendable weapons (e.g., bombs, missiles, grenades, land mines) and the component parts of other we ...

specially designed to impart energy and therefore damage to its target in one or both of two ways: via a high-explosive charge and/or via its incendiary (fire-causing) effects. Each round has both capabilities. HEI ammunition is

fuse Fuse or FUSE may refer to: Devices * Fuse (electrical), a device used in electrical systems to protect against excessive current ** Fuse (automotive), a class of fuses for vehicles * Fuse (hydraulic), a device used in hydraulic systems to protect ...

d either mechanically or chemically. The armor-piercing ability can vary widely, allowing for more focused fragmentation or larger scatter.

History

HEI ammunition was originally developed for use in large-

caliber In guns, particularly firearms, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel bore – regardless of how or where the bore is measured and whether the finished bore matc ...

cannon A cannon is a large- caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder ...

howitzer A howitzer () is a long- ranged weapon, falling between a cannon (also known as an artillery gun in the United States), which fires shells at flat trajectories, and a mortar, which fires at high angles of ascent and descent. Howitzers, like ot ...

and naval

artillery Artillery is a class of heavy military ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during si ...

. Currently, HEI rounds are most commonly made in medium-caliber sizes of 20, 25, and 30 mm. They are fired from various platforms, including aircraft, anti-aircraft cannons, and anti-missile systems, as well as common battlefield

s, though the latter has gone through a recent decline in use. HEI ammunition has also been used on the battlefield against tanks and other armoured vehicles, but this has become impractical due to the invention of modern armour systems such as

Chobham Chobham is a village and civil parish in the Borough of Surrey Heath in Surrey, England. The village has a small high street area, specialising in traditional trades and motor trades. The River Bourne and its northern tributary, the Hale, ...

and

reactive armour Reactive armour is a type of vehicle armour that reacts in some way to the impact of a weapon to reduce the damage done to the vehicle being protected. It is most effective in protecting against shaped charges and specially hardened kinetic ener ...

, which can absorb most high-explosive rounds currently used. Recently, API ( armour-piercing incendiary) shells have been used; these penetrate targets using the kinetic properties of the round before the incendiary round goes off, smothering the crew in flames,

cooking off Cooking off (or thermally induced firing) is unfired weapon ammunition exploding prematurely due to heat in the surrounding environment. The term is used both for detonation of ammunition not loaded into a weapon, and unintended firing of a loa ...

ammunition and igniting combustible materials, generally destroying the target.

Uses

The shells were first employed in naval batteries, but soon found their way to land-based howitzers as well. They caused fires, which on ships can be difficult to extinguish in the tight spaces. Also, fired at tanks and soft targets, they can cause fires that completely engulf the vehicle, killing anyone inside. Occasionally, HEIs were used against tanks (heavily armoured) and also lightly armoured vehicles, but, since the invention of modern battle armour, such as

and

, these shells have become less and less practical for anti-tank work and more useful for destroying "soft" targets such as

air base An air base (sometimes referred to as a military air base, military airfield, military airport, air station, naval air station, air force station, or air force base) is an aerodrome used as a military base by a military force for the operation ...

trench A trench is a type of excavation or in the ground that is generally deeper than it is wide (as opposed to a wider gully, or ditch), and narrow compared with its length (as opposed to a simple hole or pit). In geology, trenches result from ero ...

es, or bunkers, in which they can create fires of over 1000 degrees Celsius. Incendiary shells are no longer in use by many countries due to bans on the use of phosphorus weapons. Armour-piercing shot and shell penetrate the target using

kinetic energy In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acce ...

before the incendiary charge ignites, smothering the crew in flames, detonating ammunition, and destroying the target.

References

External links

{{commons, Ammunition
Live fire experiment of mechanically fuzed HEI roundsExample of NATO 35×228mm HEI round
from

Nammo Nammo, short for Nordic Ammunition Company, is a Norwegian/Finnish aerospace and defence group specialized in production of ammunition, rocket engines and space applications. The company has subsidiaries in Finland, Germany, Norway, Sweden, Switze ...

Fragmentation pattern of a German Round
Artillery ammunition Anti-tank rounds Explosive_weapons Incendiary weapons

History

Uses

See also

References

External links