Shrapnel, named after its inventor Henry Shrapnel, is the name for "bullet shell".
The term "shrapnel" is often misused to designate small fragments projected by an explosion whatever their origin.
In 1784, Lieutenant Henry Shrapnel (1761-1842) of the British Royal Artillery Corps (Royal Artillery) began the development of an anti-personnel weapon.
At that time, the artillery used canisters to defend against infantry or cavalry attacks. Instead of a cannonball, the barrel was loaded with a metal case filled with iron or lead balls. When fired, the case tore inside the barrel, producing an effect similar to a huge loaded buckshot rifle. The canister still had a lethal effect at 300 yards, though at that range the projectile density had dropped to the point of making an impact on a human target unlikely. For longer ranges, the solid ball or the ordinary shell was used. The latter, a hollow cast iron sphere filled with black powder, had more of a blast effect than a fragmentation effect because the pieces of metal were few and large.
Shrapnel's innovation consisted of combining the multi-projectile effect of grapeshot with the delay effect of the fuse to bring the effect of the grapeshot box to a distance. Its shell consisted of a hollow cast iron ball filled with a mixture of balls and powder supplemented by a rudimentary fuse-detonator. If the fuze was properly tuned, the shell opened up, either in front of or above the target, and released its contents of rifle bullets which continued their course with the residual velocity of the shell. The explosive charge of the shell was just enough to fracture it but not to scatter the projectiles in all directions. In this form, his invention increased the effective range of the canister from 300 to 1100 meters. He called his machine "spherical case shot", but it was eventually called after his surname, which was approved in 1852 by the British government.
The first models had a catastrophic defect:during the very strong acceleration, at the start of the shot, the friction between the grapeshot and the black powder sometimes caused the premature explosion of the powder. The problem was solved by placing the powder in a central metal tube or in a separate compartment inside the shell. To prevent the lead shot from deforming, it was embedded in resin, the combustion of which had the positive effect of indicating the place of bursting of the shell.
The British artillery waited until 1803 to adopt the invention, but then did so with enthusiasm. Shrapnel was promoted to Major the same year. The Duke of Wellington used shrapnel against Napoleon from 1808 until Waterloo and wrote admiringly of its effectiveness.
The design was improved by Captain E M Boxer, Royal Corps Artillery, and evolved with the advent of rifled cannons.
Subsequent changes
Taking a cylindrical shape, the shell was slightly modified:it received at the tip a fuse-detonator in time, a central firing pipe around which were arranged the balls embedded in the resin and, at the rear, a housing containing black powder closed by a lid crimped onto the tube. During the course of the shell, after a pre-determined amount of time, the fuze would ignite the powder charge that was just enough to break the clips or pins securing it and expel the grapeshot. Most of the ball velocity came from the residual velocity of the shell. Once released, the shrapnel balls formed a hail of round bullets following the trajectory of the shot and hitting the ground in an oval area. Although very effective against troops in the open, this grapeshot was ineffective against personnel in cover, such as in trenches.
During the First World War
At the beginning of the First World War, the ball shell was used on a large scale by all belligerents to strike troops advancing en masse and in the open. Then it was abandoned in favor of the high explosive power shell due to the transition to trench warfare:shrapnel was unable to destroy the barbed wire networks in front of the lines, smash the ground or overcome of buried troops, all things necessary before launching an attack.
With the development of high shattering explosives stable enough to be loaded into the shells, it was found that a shell of Properly designed shell fragmented so effectively that the addition of grapeshot was not necessary. For example, the detonation of an ordinary 105 mm shell produces several hundred high-velocity (1000-1500 m/s) shrapnel, a deadly overpressure wave within a short radius and, in the event of a ground explosion or underground, disrupts soil and effectively destroys material - all with ammunition much easier to manufacture than later versions of shrapnel.
One notable model was the "universal shell" ( Universal Shell) developed by the German Krupp at the beginning of the twentieth century. This shell functioned either as a bullet shell or as a smashing shell. Its rocket was modified and the resin replaced by TNT to coat the balls. If the fuze-detonator was activated, it functioned normally, projecting the balls and igniting the TNT which burned but did not explode, emitting a conspicuous plume of black smoke. In impact mode, the TNT detonated transforming the shell into shattering producing a large amount of low velocity shrapnel and a moderate blast. Again, due to its complexity, it was dropped for the simple high-impact shell.
During World War II
During the Second World War, bullet shells in the strict sense were abandoned, the last shrapnel to be used by the British army being 60-pound shells fired in Burma in 1943.
The Imperial Japanese Navy developed an anti-aircraft ammunition combining shrapnel and incendiary shell under the name "Sanshiki".
During the Vietnam War
An American project of the 1960s led to the “beehive” shell (Beehive shell) which is not strictly speaking a bullet shell because it contains darts. The result was the 105 mm M546 APERS-T shell, first used in Viet-Nam in 1966.
The shell has approximately 8,000 half-gram darts grouped in five packs, a time fuze, detonators intended to tear the casing, a central tube, a smokeless propelling charge, a colored marker contained in the rear. The operation of the shell is as follows:the fuse fires, transmitting the explosion through the tube and igniting the detonators which separate the front of the casing into four pieces. The casing and the first four packets of darts squirt under the action of the rotation of the projectile, the last packet and the visual marker under the action of the propellant charge. The darts disperse from the point of explosion in a cone which is always growing in the extension of the trajectory of the projectile before its explosion.
This shell has a high anti-personnel effectiveness, in particularly under the forest canopy, but is tricky to manufacture. It is said that the name hive comes from the noise the darts make, resembling the buzzing of an enraged swarm.
Currently
Although used quite rarely, there are still ammunition of various calibers, based on the principle of shrapnel, using darts or tungtene bodies as grapeshot:balls, cylinders or rods. Some anti-missile missiles can be equipped with warheads that drop a swarm of sub-projectiles at a predetermined distance in the trajectory of the re-entrant missile. This process does not require as much precision in the pursuit and the approach trajectory as with an ordinary explosive warhead, and the use of rods provides better penetration into the adversary's walls and increases the chances of the attack. damage.
Shrapnel means loose change and is the equivalent of scrap metal in this sense.