|
History Early grenades were usually made of paper, ceramics, or primitive glass and could contain any sort of dangerous or unpleasant substance, ranging from botanical or animal toxins, skin irritants, lye, acids, flammable naptha, petroleum and unstable gunpowder, diseased matter, or parasite eggs (such as locusts, lice, fleas). The first grenade was invented in China, when Chinese soldiers packed gunpowder into ceramic and/or metal containers. The use of the word 'grenade' in the English language apparently originated in the Glorious Revolution (1688), where cricket ball-sized iron spheres packed with gunpowder and fitted with slow-burning wicks were first used against the Jacobites in the battles of Killiecrankie and Glen Shiel.• These grenades were not very effective (probably because a direct hit would be necessary for the grenade to have any effect) and, as a result, they saw little use. However, trench warfare favored the grenade. In a letter to his sister, Colonel Hugh Robert Hibbert, described an improvised grenade employed during the Crimea War (1854-1856): We have a new invention to annoy our friends in their pits. It consists in filling empty soda water bottles full of powder, old twisted nails and any other sharp or cutting thing we can find at the time, sticking a bit of tow in for a fuse then lighting it and throwing it quickly into our neighbours pit where it bursts, to their great annoyance. You may imagine their rage at seeing a soda water bottle come tumbling into a hole full of men with a little fuse burning away as proud as a real shell exploding and burying itself into soft parts of the flesh.• In World War I (1914-1918) both sides only had small pre-war stocks of grenades so as an interim measure, the troops often improvised their own, such as the Jam Tin Grenade. These were replaced when manufactured versions such as the Mills bomb, the first modern fragmentation grenade, became available to British front-line troops. The Mills bomb was an explosive-filled steel canister with a triggering pin and a distinctive deeply notched surface. This segmentation was thought to aid fragmentation and therefore increase the grenade's deadliness. Later research showed that the segmentation did not improve fragmentation in any way at all. Improved-fragmentation designs would later be made with the notches on the inside, but at the time this would have been too expensive to produce. The external segmentation of the original Mills bomb was retained since it did provide a positive grip surface. This basic "pin-and-pineapple" design is still used in some modern grenades. On the other hand, the U.S. M67 fragmentation grenade has a smooth exterior, which is much more suitable for being rolled into a room or being thrown in a flat arc like a baseball. To throw grenades further, the rifle grenade was devised. This made use of a modified rifle with a blank cartridge to propel the grenade. These rifles would often be permanently fixed in wooden support frames and would not be used for firing bullets. Also, use was made of catapults, some manufactured, some improvised, although these were eventually replaced in the trenches by small mortars. Parallel to the Mills bomb and its similar counterparts, the Germans issued the Stielhandgranate, or stick grenade, which featured an explosive charge encased in a metal can and mounted on a wooden shaft for throwing. This simple design continued to evolve throughout the First and Second World Wars, with the Model 24 grenade (popularly known as the "potato masher") becoming one of the most easily recognized of all small arms, and synonymous with the German soldier. The Molotov cocktail is an improvised grenade prepared from a glass bottle filled with gasoline (petrol) ignited by a burning strip of cloth when the thrown bottle bursts against its target, very similar to the original grenades mentioned at the beginning of this section. The Molotov cocktail was first used by poorly-equipped Finnish Army soldiers against Soviet Union forces during their 1939 Winter War. Design
Characteristics
Using grenades A classic hand grenade has a safety handle (sometimes incorrectly called a "spoon") and a removable safety pin that prevents the handle from being released. In transit, some grenade types also have a safety clip to futher prevent the handle from coming off. Before removing the pin, the soldier grips the grenade to prevent the handle being released at the same time. With the pin removed, the grenade is thrown, the handle is released, and a spring-loaded striker ignites a pyrotechnic delay element in the fuse. The delay burns for a pre-set amount of time and then activates the detonator, exploding the grenade. When using an antipersonnel grenade, the objective is to have the grenade explode so that the target is within its effective radius. For the M67 fragmentation grenade used by several NATO nations, the effective kill zone has a five meter radius, while the casualty-inducing radius is approximately fifteen meters. "Cooking off" is a term referring to intentionally holding onto an armed grenade after the pin has been pulled and the handle released, to decrease the amount of time to detonation after throwing. This technique is used to reduce the ability of the enemy to take cover or throw the grenade back. It is also used to allow the grenade to burst in the air over defensive positions. This technique is inherently dangerous, since fuses may occasionally vary from grenade to grenade. A call is usually given upon deploying a grenade to warn friendly forces. Some yells, such as "grenade" are used when a grenade has been thrown in by an enemy; in any instance the purpose is to give notice to fellow soldiers to take cover. In the U.S. Military, when a grenade is dropped into an enclosed space like a tunnel, room, or trench, the person dropping the grenade should yell "fire in the hole" to warn that an explosion is about to occur. Other U.S. military procedures include calling "frag out" to indicate that a fragmentation grenade has been deployed. Other such calls include "white fire" if a flashbang has been deployed too close, and "bee sting" in a similar case for stingers. Grenades are often used in the field to construct booby-traps, using some action of the intended target (such as opening a door, or starting an auto) to trigger the grenade. These grenade-based booby-traps are simple to construct in the field using readily available materials. The most basic technique involves wedging a grenade in a tight spot so the spoon does not leave the grenade when the pin is pulled. A string is then tied from the head assembly to another stationary object. When a soldier steps on the string, the grenade is pulled out of the narrow passageway, the spoon flies, and the grenade soon detonates. Abandoned booby-traps contribute to the increasing problem of unexploded ordnance. The use of tripwire-triggered grenades (along with landmines in general) is banned under the Ottawa Treaty and may be treated as a war crime wherever it is ratified. However, the People's Republic of China, the United States and Russia have not signed the treaty despite large international pressures, citing self-defense needs. Design and operation The basic action is as follows: The igniter is contained within the grenade enough so that throwing the grenade into water will not stop an explosion. Although leaving a grenade in water for hours may hinder its exploding capabilities, priming a grenade and throwing it into water would still result in a detonation as water would not have enough time to percolate into the grenade and waterlog the ignition. Hand grenades are usually designed to make them easy to throw. They weigh around 500 g (1 lb) and have a diameter of 100 mm. Due to the design of grenades left-handed people hold them upside down when thrown. The average grenade can be thrown about 25 to 35 meters by the average soldier. They use a compound of RDX, composition B or TNT as their explosive. Classical "pineapple" grenades, such as the Mills bomb, used smokeless powder and cast-iron shells, which (in theory) would fragment along deliberately-cast weak points in the shell—although the pattern on the grenade body was actually intended to allow the user to have a firm grip on the grenade. In practice, external grooves in the grenade body turned out to have little or no effect on the size and shape of fragments formed. • Grenades have also been made to release smoke, tear gas ("CS"), and other gases, as well as illumination. Special forces often use "flash-bang" grenades to disorient people during an entry into a room, without the intent of causing lasting injury. Some grenade designs were made to be thrown longer distances. The German "potato-masher" grenade had a long wooden handle that extended its range by fifty percent. The "potato-masher" was fired by a friction igniter in the head, which was activated by a pull string threaded through the hollow stick. Immediately before throwing the grenade, the soldier pulled a small plastic ring attached to a string attached to the friction igniter. This started the time fuse which fired the detonator after a delay. The "potato-masher" is often incorrectly thought to have had an impact fuse. It did not, but the superficially similar British stick grenade design of 1908 did have such a fuse. Types of hand grenades
Fragmentation grenades The fragmentation grenade (commonly known as a "frag") is an antipersonnel device that is designed to damage or destroy its target with a burst of flying shrapnel. The body is made of hard plastic or steel. Flechettes, notched wire, or the case by itself provide the antipersonnel fragments. The filler may also include small metal balls to injure the target. When the word "grenade" is used without qualification and context does not suggest otherwise, it is generally assumed that a fragmentation grenade is referred to. These grenades are usually classed as defensive grenades because the effective casualty radius is greater than the distance it can be thrown; it is assumed that they will be thrown from behind cover at attackers. The hand-sized Mills bomb with a cast iron casing is an example of a defensive grenade. Concussion grenades The concussion or overpressure grenade is an antipersonnel device that is designed to damage its target with explosive power alone. Compared to fragmentation grenades, the explosive filler is usually of a greater weight and volume. The case is far thinner and is designed to fragment as little as possible. The shock waves overpressure produced by this grenade when used in enclosed areas is greater than those produced by the fragmentation grenade. Therefore, it is especially effective in enclosed areas. These grenades are usually classed as offensive weapons because the effective casualty radius is smaller than the distance it can be thrown. The hand-sized US MK3A2 concussion offensive hand grenade is an example of an offensive grenade. It is filled with TNT and has a body made of tarred cardboard. A more famous example of an offensive grenade is the German Model 24 "potato masher" grenade with a standard tin body. The term concussion is often erroneously applied to stun grenades. This is not descriptive of the effects caused by the grenade. The term concussion is used because the grenade relies only on its explosive power for its casualty-producing effect. Percussion grenades
Smoke grenades
Riot control
Incendiary grenades
Stun grenades Stun grenades, also known as flashbangs or flash grenades, were originally designed for the British Special Air Service. Stun grenades are used to confuse, disorient, or momentarily distract a potential threat for up to five seconds. A "flashbang" can seriously degrade the combat effectiveness of affected personnel for up to a minute. The best known is the M84 Stun Grenade, commonly known as the "Flashbang", so called because it produces a blinding (1 million Candela) flash and deafening (170-180 decibel) blast. This grenade can be used to incapacitate people, generally without causing serious injury. Standard operating procedure for LAPD SWAT has officers deploy flashbangs close to the point of entry. This is because all attention will be directed towards the door once it has been breached, and deploying the flashbang close to this point heightens the chances that a suspect will be affected by the device. The physiological processes through which this is made possible are quite simple. The flash of light momentarily activates all photosensitive cells in the retina, making vision impossible for approximately five seconds until the eye restores the retina to its original, unstimulated state. Subjects affected by flashbangs describe seeing a single frame for the five seconds (as if their vision was "paused") until it fades and normal sight returns. This is because the sensory cells which have been activated continue sending the same information to the brain until they are restored to their resting state, and the brain translates this continuous information into the same image. The incredibly loud blast emitted from the grenade contributes to its incapacitative properties by disturbing the fluid in the semicircular canals of the ear. The semicircular canals consist of three half circles of tubing, each oriented in one of the three planes of motion, that are filled with fluid. The walls of the tubes are lined with hair cells which use their small, hairlike cilia to detect the motion of the water. This establishes a person's sense of balance and movement through space. When a flashbang detonates, the fluid in the semicircular canals is disturbed, and with it the subject's sense of balance. The phenomenon is similar to spinning rapidly in one direction, and suddenly stopping. The sensation that the room is moving comes from the movement of the fluid in the inner ear. Upon detonation, the fuse/grenade body assembly remains intact and produces no fragmentation. The body is a steel hexagonal tube with holes along the sides which allow a blast of light and sound to be emitted. This is done to prevent injury from shrapnel. However, injuries resulting from the concussive properties of the detonation sometimes occur. The filler consists of about 4.5 grams of a pyrotechnic metal-oxidant mix of magnesium and ammonium perchlorate. Sting grenades Sting grenades, or Hornet's Nest grenades, are another less-lethal grenade that are based on the design of the fragmentation grenade. Instead of using a metal casing to produce shrapnel, however, they are made using two spheres of hard rubber. Inside the smaller sphere is the explosive charge, primer, and detonation pin. The space between the two spheres is then filled with many small, hard rubber balls about 20mm in diameter. Upon detonation, the subject is incapacitated by the blunt force of the projectiles. The advantage to using sting grenades comes from the fact that the subject is very often knocked out, winded, or at the very least dislodged from cover because of the shock. Vision is sometimes also impaired due to minor trauma of the visual cortex located in the back of the head. Some types have an additional payload of chemical agents like CS gas or pepper spray. The advantages compared to a flashbang are This makes sting grenades ideal for containing small groups of rowdy prisoners, providing a shooting opportunity when a suspect is hiding behind cover, or in allowing SWAT teams to clear small rooms. In many situations, it is preferable to a flashbang. A disadvantage of using sting grenades is that a sting grenade is not sure to lessen the lethality of a suspect, so it is dangerous to use if the subject is armed. This arises from the fact that sting grenades rely on the body's reaction to adversive stimuli (pain and blunt force trauma) rather than in denial of sensory input. A person with sufficient mental focus can concentrate enough to fire a few shots even after being hit by a sting grenade's payload, whereas a flashbang will physically affect vision and sense of orientation in space. Also, the effective range of a sting grenade is limited compared to a flashbang. Impact stun grenades - Blank Firing Impact Grenade or BFIG A more recent development is the Blank Firing Grenade (BFIG or Blank Firing Impact Grenade). Preferred in many situations, especially training, for two main reasons; they are re-usable - and therefore more economical - because the charge is a standard ammunition blank, and they are subject to very few transport restrictions when unloaded. The BFIG contains a mechanism to fire a blank cartridge when dropped at any angle onto a hard surface from a height of a metre or more. Firing will occur in any combination of positions only on impact. * Anti-tank grenades The first anti-tank grenades were improvised devices usually made by putting a number of fragmentation grenades into a sandbag or by tying them together. Due to their weight, these were normally thrown from very close range or directly placed in vulnerable spots onto an enemy vehicle. Purpose-designed anti-tank grenades invariably use the shaped charge principle to penetrate the tank's armor. This means that the grenade has to hit the vehicle at an exact right angle for the effect to work properly. This is achieved by the grenade deploying a small drogue parachute or fabric streamers after being thrown. The British put the first anti-tank grenade into the field during the Second World War with the rifle-fired No 68 AT Grenade. Also developed by the British during the Second World War, was the No 74 ST Grenade popularly known as a sticky bomb; the main charge was held in a sphere covered in adhesive. In anticipation of a German invasion, it was produced in substantial numbers. Inherently dangerous for the user it was relegated to Home Guard use. The most widely-distributed anti-tank grenades are the Russian designs of the 1950s and later, mainly the RKG-3. Due to improvements in modern tank armor, anti-tank grenades are nowadays generally considered obsolete. Grenades as ornamentation Stylized pictures of early grenades, with a flame coming out, are used as ornaments on military uniforms, particularly in France (esp. French Gendarmerie) and Italy (Carabinieri). The British Grenadier Guards took their name and cap badge of a burning grenade from repelling an attack of French Grenadiers at Waterloo. Etymology The word "grenade" originally meant the pomegranate fruit, and was transferred to early explosive grenades whose filling was gunpowder with many small pieces of metal embedded in it. See also | |||||||||||||||||||||||
|
| ||||||||||||||||||||||||
 |
|
| |