Grenades: Wikis

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18th century French grenade, to be used with a grenade launcher.
Russian F1 grenade
An M67 grenade, used primarily by the U.S. and Canadian military
DM61A1 and DM78A1 grenades

A hand grenade is an anti-personnel weapon that explodes a short time after release. The French military term grenade probably comes from the shape of the pomegranate fruit, which is also called grenade in French.

Grenadiers were originally soldiers who specialized in throwing grenades. Today, some grenades are fired from rifles or from purpose-designed grenade launchers.

Contents

History

Hand grenades filled with Greek fire; surrounded by caltrops. (10th-12th c. National Historical Museum, Athens, Greece.)
Earliest known representation of a fire lance and a grenade (upper right), Dunhuang, 10th century CE.[1]
German grenade muskets from the 16th century (wheellock) and 18th century (flintlock) in the Bayerisches Nationalmuseum, Munich
Production of Sidolówka hand grenades in an underground Armia Krajowa facility in Lwów during World War II

The first grenades appeared in the Byzantine Empire, not long after the reign of Leo III (717-741).[2] Byzantine soldiers learned that Greek fire, a Byzantine invention of the previous century, could not only be thrown by flamethrowers at the enemy, but also in stone and ceramic jars.[2] Later, glass containers were employed. Byzantine hand grenades with Greek fire in the 10th to 12th centuries are on display in the National Museum at Athens. The use of Greek fire, or rather variants thereof, spread to Muslim armies in the Near East, from where it reached China by the 10th century.[2]

Some medieval petards were small enough to be employed against enemy troops and be considered as primitive hand grenades.

In China during the Song Dynasty (960–1279AD), weapons known as Zhen Tian Lei were created when Chinese soldiers packed gunpowder into ceramic or metal containers. In 1044, a military book Wujing Zongyao ("Compilation of Military Classics") described various gunpowder recipes in which one can find, according to Joseph Needham, the prototype of the modern hand grenade.[3]

The first cast iron bombshells and grenades did not appear in Europe until 1467.[4] Within a couple centuries of this, the Chinese had discovered the explosive potential of packing hollowed cannonball shells with gunpowder. Written later by Jiao Yu in the mid 14th century book of the Huolongjing ("Fire Drake Manual"), this manuscript recorded an earlier Song-era cast iron cannon known as the "flying-cloud thunderclap eruptor" (fei yun pi-li pao). The manuscript stated that (Needham's modified Wade-Giles spelling):

The shells (phao) are made of cast iron, as large as a bowl and shaped like a ball. Inside they contain half a pound of 'divine fire' (shén huǒ, gunpowder). They are sent flying towards the enemy camp from an eruptor (mu phao); and when they get there a sound like a thunder-clap is heard, and flashes of light appear. If ten of these shells are fired successfully into the enemy camp, the whole place will be set ablaze...
[5]

This text of the Huolongjing was also important for the understanding of the Chinese hand grenade in the 14th century, as it provided much more detailed descriptions and even printed illustrations of the grenade bombs used.[6]

In 1643, it is possible that "Grenados" were thrown amongst the Welsh at Holt Bridge during the English Civil War. The word "grenade" 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.[7] These grenades were not very effective (probably because a direct hit would be necessary for the grenade to have effect) and, as a result, 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.
[8]
French troops using a catapult to throw hand grenades during World War I.

In the American Civil War, both sides used hand grenades equipped with a plunger that detonated the device upon impact. The North relied on experimental Ketchum Grenades, with a tail to ensure the nose would strike the target and start the fuse. The Confederacy used spherical hand grenades that weighed about six pounds, sometimes with a paper fuse. They also used Rains and Adams grenades, which were similar to the Ketchum in appearance and mechanism.

One of the first widely used percussion hand grenades was designed about 1903 by a colonel of Serbian army, Miloš Vasić. In 1912, Colonel Vasić further redesigned his hand grenade into "Vasić" M.12 model. They were adopted by Serbian army in 1912, just in time to be used in 1st and 2nd Balkan War (1912-1913) and extensively used by Serbian infantry in World War I.[9] That grenade was popular under name of "Vasićka" (by its designers name), or "Kragujevka" (by its place of manufacture, the military-technical works in Kragujevac, Serbia). The Vasić design was further developed into series of new hand grenades which lasted until far after the end of World War II.[10] The most infamous usage of the "Vasić" hand grenade was in the assassination of Archduke Franz Ferdinand in Sarajevo in 1914, when one of the involved threw one at the Archduke's car. The grenade bounced off and exploded under the following vehicle, wounding about 20 people. Franz Ferdinand and his wife were shot to death later that day. Austro-Hungarian authorities confiscated a couple of "Vasić" grenades from assassins, and used them to support their accusations to Serbia for the alleged participation in assassination plot, the act that led to the outbreak of WWI[citation needed].

Early in World War I, both sides only had small grenades of a pre-war design. For example, in Italy, the Besozzi grenade had a five-second fuse with a match-tip that was ignited by striking on a ring on the soldier's hand.[11] 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 developed at the Mills Munitions Factory in Birmingham, England and was described as the first "safe grenade". Approximately 75,000,000 grenades were made during World War I. They were explosive-filled steel canisters with a triggering pin and a distinctive deeply notched surface. This segmentation was thought to aid fragmentation and increase the grenade's deadliness. Later research showed that the segmentation did not improve fragmentation. 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 more suitable for being rolled or for throwing in a flat arc.

To propel grenades farther, the rifle grenade was devised. This made use of a modified rifle with a blank cartridge to propel the grenade. These rifles may be permanently fixed in wooden support frames and would not be used for firing bullets. Use was also made of catapults, both manufactured and improvised, although these were eventually replaced in the trenches by small mortars.

Section of the Stielhandgranate Modell 24

Parallel to the Mills bomb and its similar counterparts, the Germans issued the "stick hand grenade" (Stielhandgranate Modell 24) 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 alcohol (ethanol) or gasoline (petrol) ignited by a burning strip of cloth when the thrown bottle bursts against its target. The Molotov cocktail received its name during the Soviet invasion of Finland in 1939 Winter War, but had been in use earlier in the decade when used by Franco's troops during the Spanish Civil War. The name originated from Finnish troops during the Winter War. It was named after former Soviet foreign minister Vyacheslav Molotov whom they deemed responsible for the war, and a humorous reference to the Soviet bombs known as "Molotov bread baskets" in Finland.

Design

Unused and used M69 training grenades.
American soldier throwing grenade, 1944

Most grenades explode, projecting shrapnel, i.e. pieces of the casing, serrated wire, or an incendiary material. Some, such as smoke grenades, merely burn, releasing smoke for masking, marking, or signaling. Grenades are filled with explosive or chemical filler and have a hole into which a fuse is inserted. In modern hand grenades, the fuse is lit by an internal device rather than an external flame.

Characteristics

Hand grenades have five characteristics:

  • Their employment range is short.
  • Their effective kill radius is small, roughly 5 meters.
  • Their effective casualty radius is large. Approximately 15 meters.
  • Their delay element permits safe throwing;
  • Their hard shell enables grenades to ricochet off hard surfaces, like walls, before detonating.

Hand grenades have:

  • A body containing filler.
  • A filler, the chemical or explosive for fragmentation.
  • A fuse causing the grenade to explode by ignition or detonation.
U.S. Army grenade training during initial entry training includes throwing both dummy and live hand grenades. A hand grenade range instructor, right, observes an M67 grenade in flight.

Using grenades

A classic hand grenade has a safety handle or lever (known colloquially as the spoon, due to its size and shape) and a removable safety pin that prevents the handle from being released. Some grenade types also have a safety clip to further prevent the handle from coming off in transit.

To use a grenade the soldier grips it firmly with the throwing hand, ensuring that the safety lever is firmly held in place with the thumb. This is called the death grip, because letting the lever go could (and probably will) cause the grenade to detonate, killing the thrower. Left-handed soldiers are advised to invert the grenade, ensuring that the thumb is still the digit holding the safety lever in place. The pull ring of the safety pin is then grasped with the index or middle finger of the non-throwing hand and the safety pin is removed using a pulling and twisting motion. The grenade is then thrown towards the target, an over-arm throw is recommended but may not be suitable for an actual combat situation. Soldiers are trained to throw grenades in standing, prone-to-standing, kneeling, prone-to-kneeling, and alternate prone positions and in under- or side-arm throws. If the grenade is thrown from a standing position the thrower must then immediately seek cover or lie prone if no cover is nearby.

Once the grenade is thrown the safety lever is released and the striker throws the safety lever away from the grenade body as it rotates to detonate the primer. The primer explodes and ignites the fuse (sometimes called the delay element), the fuse burns down and activates the detonator which explodes the main charge.

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.[12] Fragments can fly as far as 230 meters. Usually people in a 15 m radius are injured enough to effectively render them harmless enough to not have to worry about them and deal with the immediate threat then deal with the injured people.

Cooking off is a term referring to intentionally holding onto an armed grenade after the pin has been pulled and the handle released; allowing the fuse to burn partially to decrease the 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.[13] This technique is inherently dangerous, since fuses may vary from grenade to grenade. Because of this the U.S. Marines (MCWP 3-35) describe cooking-off as the "least preferred technique", recommending a "hard throw, skip/bounce technique" to prevent an enemy returning a grenade.

A call is usually given upon deploying a grenade, to warn friendly forces. Some yells, such as frag out or fire in the hole, are used when a grenade has been thrown in by an enemy; in any instance the purpose is to warn 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. Standard U.S. military procedure includes calling frag out to indicate that a fragmentation grenade has been deployed.

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 a car) 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 safety lever 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 safety lever is released, and the grenade detonates.

Abandoned booby traps and discarded grenades contribute to the problem of unexploded ordnance. The use of trip wire-triggered grenades (along with land mines in general) is banned under the Ottawa Treaty and may be treated as a war crime wherever it is ratified.

Discarded RGD-5 hand grenade (live but unfuzed) in Northern Kuwait.

India, the People's Republic of China, Russia, and the United States have not signed the treaty despite international pressure, citing self-defense needs.

36M Mills bomb dating from 1942

Grenades have also been made to release smoke, tear gas and other gases, as well as illumination. Special forces often use stun grenades to disorient people during entry into a room.

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.[citation needed] The potato-masher was fired by a friction igniter in the head, which was activated by a pull string threaded through the hollow handle. Immediately before throwing the grenade, the soldier pulled a small porcelain ball 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.

Variants

Two U.S. Marines take cover during M67 grenade training during Exercise Foal Eagle in 2004.
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Fragmentation

The fragmentation grenade (commonly known as a frag) is an anti-personnel weapon that is designed to disperse shrapnel upon exploding. The body is made of hard plastic or steel. Flechettes, notched wire, ball bearings or the case itself provide the fragments. When the word grenade is used without specification, and context does not suggest otherwise, it is generally assumed to refer to a fragmentation grenade.

These grenades were sometimes classed as defensive grenades because the effective casualty radius of some matched or exceeded the distance they could be thrown, thus necessitating them being thrown from behind cover. The Mills bomb or F1 grenade are examples of defensive grenades where the 30–45 m casualty radius[14] matched or exceeded the 30 m that a grenade could reasonably be thrown.

Modern fragmentation grenades such as the United States M67 grenade have a wounding radius of 15 m (half that of older style grenades which may still be encountered) and can be thrown about 40 m. Fragments may travel more than 200 m.[15]

Concussion

The concussion grenade is an anti-personnel 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 overpressure produced by this grenade when used in enclosed areas is greater than that 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 concussion effect is more lethal than fragmentation, but its power drops more rapidly with range as well.

The US MK3A2 concussion grenade is filled with TNT and has a body made of tarred cardboard.

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 on its explosive power to create casualties.

Percussion

A percussion grenade detonates upon impact with the target. Classic examples of percussion grenades are the British Gammon bomb and No 69 grenade. Timed fuse grenades are generally preferred to hand-thrown percussion grenades because their fuzing mechanisms are safer and more robust than those used in percussion grenades. Some percussion grenades have a conventional pyrotechnic fuse fitted as a backup detonation device.

Smoke

Smoke grenade

Smoke grenades are used as ground-to-ground or ground-to-air signaling devices, target or landing zone marking devices, and screening devices for unit movement. The body is a sheet-steel cylinder with emission holes in the top and bottom. These allow the smoke to be released when the grenade is ignited. Two main types exist, colored smoke (for signaling) and screening smoke. In colored smoke grenades, the filler consists of 250 to 350 grams of colored smoke mixture (mostly potassium chlorate, lactose and a dye). Screening smoke grenades usually contain HC (hexachloroethane/zinc) smoke mixture or TA (terephthalic acid) smoke mixture. HC smoke is harmful to breathe, since it contains hydrochloric acid. Whilst not intended as a primary effect, these grenades can generate enough heat to scald or burn unprotected skin and the spent casing should not be touched until it has cooled.

Riot control

CS gas grenade

Tear gas grenades are similar to smoke grenades in terms of shape and operation. In tear gas grenades the filler is generally 80 to 120 grams of CS gas combined with a pyrotechnic composition which burns to generate an aerosol of CS-laden smoke. This causes extreme irritation to the eyes and, if inhaled, to the nose and throat. (See also the Waco Siege). Occasionally CR gas is used instead of CS.

Incendiary

Incendiary grenade

Incendiary grenades (or thermite grenades) produce intense heat by means of a chemical reaction. The body is practically the same as that of a smoke grenade. The filler is 600 to 800 grams of thermate, which is an improved version of World War II-era thermite. The chemical reaction that produces the heat is called a thermite reaction. In this reaction, powdered aluminium metal and iron oxide react to produce a stream of molten iron and aluminium oxide. This reaction produces a tremendous amount of heat, burning at 2,200 °C (3,992 °F). This makes incendiary grenades useful for destroying weapons caches, artillery, and vehicles. Other advantages include its ability to function without an external oxygen source, allowing it to burn underwater. Because they are not intended to be thrown, thermate incendiary grenades generally have a shorter delay fuse than other grenades (e.g. two seconds).

White phosphorus (also used in smoke grenades; see above) can also be used as an incendiary agent. It burns at a temperature of 2,800 °C (5,070 °F). White phosphorus was notably used in the No 76 Special Incendiary Grenade by the British Home Guard during World War II.

Thermite and white phosphorus cause some of the worst and most painful burn injuries because they burn so quickly and at such a high temperature. In addition, white phosphorus is very poisonous: a dose of 50-100 milligrams is lethal to the average human.

A common improvised incendiary grenade is the Molotov cocktail.

Stun

A stun grenade, also known as a flashbang, is a nonlethal weapon. The first devices like this were created in the 1960s at the order of the British Special Air Service as an incapacitant.

These grenades are used to temporally neutralize the combat effectiveness of enemies by usually disorienting their senses.

IDF stun grenade

The flash of light momentarily activates all light sensitive cells in the eye, making vision impossible for approximately five seconds until the eye restores itself to its normal, unstimulated state. The incredibly loud blast produced by the grenade adds to its incapacitating properties by disturbing the fluid in the ear.

When detonated, the fuse/grenade body assembly remains intact. The body is a tube with holes along the sides which allow an explosion of light and sound to be produced. This is done to avoid injury from shrapnel but it is still possible to be burned, and injuries resulting from the concussive blast of the detonation can occur, the heat created can ignite flammable materials such as fuel. The fires that occurred during the Iranian Embassy Siege in London were caused by stun grenades. The filler consists of about 4.5 grams of a pyrotechnic metal-oxidant mix of magnesium or aluminium and an oxidizer such as ammonium perchlorate or potassium perchlorate.

Sting

Sting grenades (also called rubber ball grenades) are based on the design of the fragmentation grenade. Instead of using a metal casing to produce shrapnel, they are made using two spheres of hard rubber. Inside the smaller sphere is the explosive charge, primer, and detonator. The space between the two spheres is then filled with many small, hard rubber balls. Upon detonation, the subject is incapacitated, winded, or at the very least dislodged from cover, by the blunt force of the projectiles.

Some types, such as the ALSG101CS from ALS Technologies, have an additional payload of chemical agents like CS gas.[16]

The advantages compared to a flashbang are:

  • The subject does not need to be looking at the grenade for it to take full effect in outdoor areas.
  • Sting grenades are much more likely to cause a subject to either fall or lower himself in pain, thus providing good sight lines to unaffected targets in the area.

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.

A disadvantage of using sting grenades is that they are not sure to incapacitate a subject, so they are dangerous to use with armed subjects. This is because sting grenades rely on the body's reaction to adverse stimuli (pain and blunt force trauma) rather than denial of sensory input. A person with sufficient mental focus can concentrate enough to ignore being hit by a sting grenade's payload, whereas a stun grenade will physically affect vision and sense of orientation. The effective range of a sting grenade is limited compared to a stun grenade. In addition, there is the risk of serious physical injury as the target is being pelted with actual objects capable of inflicting harm, and not just being deafened/blinded.

Sting grenades are sometimes called "stinger grenades", which is a genericized trademark as "Stinger" is trademarked by Defense Technology for its own line of sting grenades.

Impact stun

Blank Firing Grenade

A more recent development is the blank-firing impact grenade (BFIG). 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.[17]

Anti-tank

Soviet RPG-43 antitank grenade

The first anti-tank grenades were improvised devices. The Germans were the first during World War One to come up with an improvised anti-tank grenade, taking their stick (potato masher) grenade and taping three to two of the explosive tops, (minus the stick) to one complete grenade. In combat, after arming, the grenade was thrown on top of the slowly advancing tank where the armor was thin.

During World War Two, various nations made improvised antitank grenades by putting a number of defensive high explosive grenades into a sandbag. Due to their weight, these were normally thrown from very close range or directly placed in vulnerable spots onto an enemy vehicle. Another method used by the British Home Guard in 1940 was to place dynamite or some other high explosive in a thick sock and cover the lower part with axle grease and then place the grease covered part in a suitable size tin can. The antitank sock was pulled out, the fuse lit and the sock thrown against the side of the tank turret, which it was hoped would stick and on explosion cause internal spalling of the armor plate, killing or injuring the tank crew inside. [18] It is not known if this type of improvised anti-tank grenade was ever successfully employed in combat. The British later took this crude concept and developed the No 74 ST grenade. [19]

During World War II, when tanks overran entrenchments, hand grenades could be and were used by infantry as improvised anti-tank mines by placing or throwing them in the path of a tank in the hope of disabling a track. While this method was used in desperation, it usually proved more dangerous to the soldier on the ground than to the crew of the tank. During the Italian-Ethiopian War, according to the Italians, the Ethiopians used sections of railroad rail pushed between the tank's tracks and running wheels. [20]

Purpose-designed anti-tank grenades invariably use the shaped charge principle to penetrate tank armor. In military terminology, warheads employing shape charges are referred to as HEAT warheads, meaning high explosive anti-tank. Because of the manner in which shaped charges function, the grenade has to hit the vehicle at an exact right angle for the effect to work most efficiently. This is achieved by the grenade deploying a small drogue parachute or fabric streamers after being thrown.

Britain put the first anti-tank grenade into the field during the Second World War in late 1940 with the No 68 AT Grenade which was one of the first "any" type anti-tank weapons of the shape charge or HEAT type. The No 68 was fired from a rifle using the Mills grenade cup launcher. The Type 68 had a penetration of 50mm of armor plating, which was astonishing for 1940. Also developed by the UK during the war was the No 74 ST Grenade, popularly known as a sticky bomb, in which the main charge was held in a sphere covered in adhesive. In anticipation of a German invasion, the British Army asked for ideas for a simple, easy to use, ready for production and cheap close-in antitank weapon. The ST Grenade was a private development, but seeing how it was operated, the British Army rejected it for the Home Guard much less their regular forces.

The ST Grenade, though, attracted the attention of MD1, a group tasked with developing weapons for use in German and Italian occupied territory, and they placed the ST Grenade into mass production. In a full circle, the No 74 Grenade was later issued to troops as an emergency stop-gap measure against Italian tanks in North Africa, where it proved to the surprise of many highly effective. Later in the war, the No 74 also proved itself with French partisans in sabotage work against German installations. [21]

Shortly after the German invasion of Russia in 1941, the Germans introduced the Panzerwurfmine(L), an extremely lethal close-quarter HEAT anti-tank grenade which could destroy the heaviest armored tanks of the war. The grenade was tossed overhand giving a trajectory where it landed on the top of the tank. After release by the thrower, three spring-out canvas fins stabilized it during its' short flight. The Panzerwurfmine(L), while extremely lethal and inexpensive to manufacture, but required considerable skill to throw with accuracy and was issued only to specially trained infantry tank-killer teams. [22]

It did not take long after the Russians captured the German Panzerwurfmine(L) to come out with their own hand thrown antitank grenade that used a HEAT warhead. In 1940, they had developed a crude antitank grenade that used the simple blast effect of a large high explosive charge, designated RPG-40 which was stabilized in flight by a ribbon that was released after it was thrown. [23] The RPG-43 (developed in late 1943) was a modified RPG-40 with a cone liner and a large number of fabric ribbons for flight stabilization after release. In the last year of the war, they introduced the RPG-6, a total redesign of the RPG-43 with an improved kite-tail drogue in the handle and a standoff for the HEAT warhead, drastically increasing both accuracy and penetration was reported to be over 100mm, more than adequate to cause catastrophic damage to any tank if it impacted the top. Unlike the German Panzerwurfmine(L), the Russian RPG-43 and RPG-6 were far simpler to use in combat and did not require extensive training.

After the end of World War Two, many eastern European nations engineered their own versions of the RPG-6, such as the East German AZ-58-K-100. These were manufactured in the tens of thousands and given to "armies of national liberation", seeing combat worldwide, including with the Egyptian Army during 1967 and 1973. [24] [25]

In the final two years of World War Two, the Japanese developed a crude HEAT hand thrown antitank grenade and a suicide-weapon HEAT-warhead anti-tank grenade, which was neither launched nor thrown, but rammed home like a bayonet. The first was a hand thrown hand grenade which had a simple 100mm diameter cone HEAT warhead fitted with an ultra simple "all the way" fuse system in the base of the warhead (and if it was dropped accidentally after the safety pin was removed, it would explode) with what looked like the end of an old fashion mop head on the tail end of the warhead. The antitank grenade was removed from its sack, the safety pin pulled, and thrown by operator gripping the mop-head as the handle. This was a dangerous system as there was no arming safety after release and the thrower could strike something in his back swing before release. Penetration was reported to be only approximately 50mm.

The second Japanese antitank grenade -- a suicide weapon -- was nicknamed the lunge mine. This weapon was a very large HEAT warhead on a five foot stick, which when rammed forward a sheer wire would break allowing a strike pin to impact a primer and detonate the large HEAT warhead, destroying both the tank and the soldiers using the "lunge mine". While crude, the Japanese "lunge mine" had six inches of penetration, the greatest penetration of any antitank grenades of World War Two. The hand thrown antitank grenade was first encountered by the US Army in 1944 in the Philippines (some believe they were locally manufactured), while the later suicide "lunge mine" first saw combat during the U.S. invasion of Saipan and then the subsequent invasion of Okinawa. Tens of thousands of these crude "lunge mines" had been produced and issued to both regular units and home-guard units on the home islands of Japan before the war ended. [26]

External images
US Army Early 1980s HAG Concept
Details of HAG concept (US Army)
Details of Combat Use of HAG (US Army)

In the late 1970's, the U.S. Army was worried about the lack of emergency antitank weapons for issue to its rear area units, to counter isolated enemy armored vehicles infiltrating or being air dropped. When the US Army asked for ideas, engineers at U.S. Army laboratories suggested the reverse-engineered and additional safety improvements of the East German AZ-58-K-100 HEAT antitank grenade that had been obtained from various classified sources. This concept was called "HAG" for High-explosive Antiarmor Grenade. While the civilian engineers working for the US Army thought it was a great idea, it was rejected out of hand by almost all senior US Army officers who had in the past commanded troops in the field as being of more dangerous to the troops who used them than the enemy vehicles that would be targeted. The idea was quietly shelved by 1985. [27][28]

The most widely-distributed anti-tank grenades today are the post World War Two Russian designs of the 1950s and 1960s, mainly the RKG-3.

Due to improvements in modern tank armor, anti-tank hand grenades are generally considered obsolete. However, in the recent Iraq War, the RKG-3 anti-tank hand grenade has made a reappearance with Iraqi insurgents who use them primarily against U.S. Humvees, Stykers and MRAPs, which lack the heavier armor of tanks. This has in turn led the U.S. to adopt countermeasures such as modifications to the MRAP vehicles by the fitting of "slate" armor or "bird cage" armor which causes the antitank grenade to detonate too early.[29]

Grenades as ornamentation

Grenade on a kepi of the French Army.
The pomegranate's (grenade in French) shape probably gave its name to the hand grenade.

Stylized pictures of early grenades, emitting a flame, are used as ornaments on military uniforms, particularly in France (esp. French Gendarmerie and the French Foreign Legion), and Italy (Carabinieri). Fusilier regiments in the British and Commonwealth tradition (e.g., the Princess Louise Fusiliers, Canadian Army) wear a cap-badge depicting flaming grenade, reflecting their historic use of grenades in the assault. The British Grenadier Guards took their name and cap badge of a burning grenade from repelling an attack of French Grenadiers at Waterloo. The Spanish artillery arm uses a flaming grenade as its badge. The flag of the Russian Ground Forces also bears a flaming grenade device. The branch insignia of the U.S. Army Ordnance Corps also uses this symbol, the grenade being symbolic of explosive ordnance in general. The United States Marine Corps also uses the grenade on their uniforms: the rank insignia for master gunnery sergeant has three chevrons pointing up, with four rockers on the bottom. In the middle of this is a bursting bomb, or grenade. U.S. Navy Aviation Ordnanceman's rating badge features a winged device of similar design. Ukrainian mechanized infantry and engineers use a flaming grenade in their branch insignia.

See also

References

  1. ^ "The Genius of China", Robert Temple
  2. ^ a b c Robert James Forbes: "Studies in Ancient Technology", Leiden 1993, ISBN 978-90-04-00621-8, p.107
  3. ^ Joseph Needham: Science and civilization in China: Vol. 5; Part 6: Chemistry and chemical technology; Military technology: missiles and sieges, Cambridge University Press 1994, ISBN 0-521-32727-X
  4. ^ Needham, Volume 5, Part 7, 179.
  5. ^ Needham, Volume 5, 264.
  6. ^ Needham, Volume 5, Part 7, 179-180.
  7. ^ Cramb, Auslan (23 Feb 2004). "Battlefield gives up 1689 hand grenade". Scotland Correspondent. http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2004/02/23/ngren23.xml&sSheet=/news/2004/02/23/ixhome.html. 
  8. ^ "The National Archives, records of the UK government". Letters of Hibbert, Hugh Robert, 1828-1895, Colonel, ref. DHB/57 - date: 14 June 1855. http://www.a2a.org.uk/search/records.asp?cat=017-dhb&cid=3-1-3#3-1-3. Retrieved 2006-08-09. 
  9. ^ "Istorijat". Zastava-arms.co.yu. http://www.zastava-arms.co.rs/english/zastava.htm. Retrieved 2008-12-26. 
  10. ^ LEXPEV. "Yugoslavian hand- and riflegrenades". Lexpev.nl. http://www.lexpev.nl/grenades/sovietbalkan/yugoslavia/index.html. Retrieved 2008-12-26. 
  11. ^ How the Modern Grenadier is Armed: an ancient practice that was revived by the trench fighting of the great war, Popular Science monthly, January 1919, page 14, Scanned by Google Books: http://books.google.com/books?id=HykDAAAAMBAJ&pg=PA14
  12. ^ United States Army Field Manual 3-23.30, Grenades and Pyrotechnic Signals (2005 revision), page 1-6
  13. ^ United States Army Field Manual 3-23.30, Grenades and Pyrotechnic Signals (2005 revision), pages 3-11 to 3-12
  14. ^ (Ukrainian) [1]
  15. ^ Federation of American Scientists. M67 FRAGMENTATION HAND GRENADE
  16. ^ "ALS Technologies, Inc. - ALSG101CS". Alstechnologies.com. http://www.alstechnologies.com/index.php?page=ALSG101CS. Retrieved 2009-03-31. 
  17. ^ "Impact Stun Grenade from HFM Pyrotechnics:". Hfmgroup.com. http://www.hfmgroup.com/professionalsupplies/product-specs/impact-grenade.html. Retrieved 2008-12-26. 
  18. ^ a 1941 issue of LIFE magazine showed a series of photo on how to make such antitank grenades along with X shaped slit trenches to protect the grenade thrower
  19. ^ Ian Hogg "Grenades & Mortars" page 38 Ballantine Books 1974
  20. ^ A.J. Barker "The Rape of Ethiopia 1936" page 49 Ballantine Books/1971
  21. ^ Ian Hogg "Grenades & Mortars" page 39 Ballantine Books 1974
  22. ^ Chris Bishop "Weapons of World War II" page 207-208 Barnes and Nobles Books 1998
  23. ^ Denis H.R. Archer "Jane's Infantry Weapons" page 462
  24. ^ Chris Bishop "Weapons of World War II" page 214 Barnes and Nobles Books 1998
  25. ^ Denis H.R. Archer "Jane's Infantry Weapons" page 464-465
  26. ^ edited by W.H. Tantum and E.J. Hoffschmidt "Second World War COMBAT WEAPONS - JAPANESE" page 174 and 184
  27. ^ Eric C. Ludvigsen "Association of the United States Army GREEN BOOK 1984-85" page 348
  28. ^ As this type of antitank grenade had been successfully employed by other armies in the Second World War, one can only conclude that cultural factors influenced the decision of the senior officers. As it was, the decision left many rear-area U.S. units with no heavier "antitank weapon" than the M2 heavy machine gun.
  29. ^ stripes.com
  • Needham, Joseph (1986). Science and Civilization in China: Volume 5, Part 7. Taipei: Caves Books, Ltd.

External links


Redirecting to Hand grenade


1911 encyclopedia

Up to date as of January 14, 2010

From LoveToKnow 1911

"GRENADES 12.578). - The revival of the hand grenade in the Russo-Japanese War of 1904-5 resulted in new designs for weapons of this class being worked out in several countries, not only for hand grenades with a time fuze, but also for percussion grenades and for grenades fired from a rifle. In the World War the advent of trench warfare on the largest possible scale produced a sudden demand for grenades in enormous quantities and as pre-war and war-time designs were successively exposed to the test of active service conditions, while at the same time the needs of quantity production constantly imposed checks of another kind, grenade design passed through a rapid evolution from 1914 up to 1917 after which warfare became more open and the rifle and light machine-gun asserted themselves as the prime infantry weapons. It is proposed here to indicate the course of this evolution by describing representative patterns of grenade employed successively in the British and other armies.

During the course of the war, both hand and rifle grenades (especially the latter) were used as containers for gas and smoke compositions, as well as for illuminating and light-signalling purposes. These special grenades, as grenades, presented fewer problems of design than the explosive grenade, and the safety and ignition devices employed with them were simple adaptations of those used with the explosive grenade. They do not, therefore, require special treatment in the present connexion, and the following account will deal with the explosive grenade only.

Hand Grenades. - Perhaps the dominating characteristic of trench warfare as practised in 1914 and 1915 was the inability of the deeply entrenched infantry on each side to inflict damage upon the other otherwise than by high angle fire. Within the infantry arm itself, this high angle fire could at first be provided only by hand grenades. But as no one had foreseen the use of this weapon by infantry on a large scale, the available patterns in Great Britain and elsewhere (designed for use by skilled sappers in siege warfare) were of a somewhat complicated design. Thus, at the outbreak of the World War, the only grenade available in the British service was the" No. 1,"evolved after the Russo-Japanese War, and the only immediate means of supplementing it was a stock of" Hale's grenades which had been manufactured for the Mexican Government. These two, in very small quantities, formed the only armoury of the bomber in the early days of 1915, and soon the troops in the field began to improvise grenades out of jam tins and other receptacles, using any explosive and any form of igniter which was at hand. At the same time other types were worked out by the engineer branch of the War Office, and both then and afterwards countless inventors set to work to produce weapons of this class and submitted them to the military authorities, who sifted them, tested the more promising both on the experimental ground and in the trenches, and finally, where the advantages of a proposed new design outweighed the very serious drawbacks attendant upon manufacturing a new type and training the army to its use - considerations which ruled out many designs that were intrinsically very good - it was adopted as a service store. So far as concerns British grenades, only service stores will be dealt with in this article.

Thus, towards the end of 1915 or the spring of 1916 the types in use and in prospect were very numerous, and most of them were open to objections, either in point of safety to the user, or of trustworthiness in trench conditions, or of manufacture.

Considering them collectively, these grenades may be classified in two ways: according to their effect and according to their method of explosion. As regards the former, a distinction arose between those designed for concussion effect and those designed for fragmentation. From the same dual need of localized effect and of distributed effect which produced the two main classes of artillery shell, came "concussion" grenades which contained a maximum of explosive, contained in the thinnest possible case, and "fragmentation" grenades with heavy iron cases, provided only with the explosive necessary to impart wounding energy to the fragments, and having the iron prepared for the desired fragmentation by criss-cross weakening grooves. Each of these had the defects of its qualities; thus, the concussion grenade was only effective within a narrow radius from the point of burst, and the fragmentation grenade was liable when used in the open to kill the thrower himself with splinters coming back. Examples of each class will be found below, and it should be added that special grenades such as those used for smoke, for light and for gas, were in the intermediate position, having thin walls, so as to contain a maximum of composition and a small explosive charge sufficient merely to open the casing.

The second basis of classification, which from the designer's point of view was the more important, was the method of bursting the charge. In all grenades filled with H.E.' as in all shell so filled, a small charge of sensitive explosive is required to detonate the relatively inert main charge. This element is contained in a copper tube called a detonator and it is in the means of igniting this detonator and the safeties provided against its premature action that the whole art of grenade design resides. Many of the risks, indeed, only became evident as the result of active service experience - for instance, the risk that a man would be shot after putting the safety device out of action but before he could throw the grenade.

At the outset, the standard patterns of hand grenade had percussion ignition - that is, they were arranged to explode on contact 1 Certain German grenades were filled wholly or in part with black powder and needed no detonator.

with the ground or the target. Such grenades were "armed" and dangerous as they lay in the bomber's hand ready for throwing, since, whereas in an artillery shell or a rifle grenade the shock of discharge is available as a force for arming the ignition, in a hand grenade this has to be done by the bomber himself. They were, further, intrinsically more sensitive than artillery fuzes in that they had to act at very low striking velocities and even on soft ground. A very little experience of existing types, therefore, sufficed to turn the current of opinion in favour of time grenades, not because of any special utility and function such as those possessed by the time fuze of artillery but purely because a delay between ignition and explosion was the best practical form of safety. Five seconds was as a rule adopted as a standard interval, and this gave time in case of accident to throw the grenade to a safe distance, or to take cover or lie down. Later, in perfected designs, the percussion grenades came to the fore again, but only towards the end of the war, and these new types were never actually used by the British army in the field.

Apart from the question of safety, the percussion grenade - at least in all patterns previous to those embodying an all-ways fuze - had to be designed so as to fall on its nose. The usual method of ensuring this was by an air-drag in the form of streamers, attached to the tail or handle. Time grenades would of course act whatever the position in which they fell.

With percussion grenades the ignition device was simply armed by, or before, the act of throwing, but in all time grenades of course positive ignition was necessary. Many ignition devices were used and many others proposed; in general, they may be classified as friction lighters and striker-and-cap combinations. In either case, the actual ignition was done by the bomber. In many designs he ignited the grenade before throwing it. In some a cord, attached to his wrist and to the grenade, suddenly tightens when the grenade has travelled to the end of its tether (a few feet) and the parting jerk fires the ignition device. In others, which are the best known and most successful, ignition takes place automatically as (or shortly after) the grenade leaves his hand.

The charge employed in grenades naturally varies according to the intention of the design. In fragmentation grenades, as above mentioned, it is kept small (in the Mills grenade described below it is 21-3 oz. only, in a total weight of 1 lb. 8 oz.), whereas in concussion grenades - notably in the heavy tin-cased concussion grenades used in the earlier days of the war for wire cutting and demolition effect - it is at a maximum (3 lb. 9 oz. out of a total weight of 5 lb. in the Russian "obstacle" grenade). The permitted weights of hand grenades have also varied considerably. In 1915 heavy grenades intended to be thrown by trench engines (see Bomb Throwers) were in frequent use, but these were superseded by trench mortar bombs, just as their throwing engines were displaced by light trench mortars. The special grenades used with certain explosive-propellant throwers were also frequently of this heavy class. But for the hand grenade an upper limit was fixed when the ranges required on service and the throwing powers of the average bomber had been ascertained by experience. This limit was about 2 lb. in Germany and II lb. in Great Britain and France. To qualify as a bomber, a British soldier was required to pitch half of his (II lb.) bombs into a trench target measuring Io ft. longitudinally and 4 ft. laterally at a range of 30 yd., but specially expert men were capable of much longer throws. Another consideration limiting the size of hand grenades was that of ammunition supply in the very difficult conditions of trench fighting.

These two requirements, range and supply in the trenches, combined from 1916 onward to bring into use a much lighter form of grenade, colloquially called the "egg," which weighed only 11-12 oz. and could be thrown 50 yd. by an average bomber. At the same time the grenade of the I i lb. class began to be adapted for firing from a rifle, and thus to take the place of the rifle grenade, though it also remained in use as a hand grenade to the close of the war.

FIG.1 F!

A representative percussison grenade of the earlier type is the British "No. 2" or Mexican Hale (figs. i and ia). Though light (i lb.) it is of the fragmenting class, for while the casing itself is thin, it is surrounded by a heavy iron collar prepared by grooves for fragmentation. The streamers and the presence of this collar well up on the head ensure a nose-first fall. In the interior is a central tube, the upper portion of which takes the detonator, the middle a creepspring and the lower a pellet with pointed striker. The pellet is held firmly by a safety-pin which is only Nvithdrawn at the last moment. When thrown, the parts retain their relative positions, but on impact inertia causes the striker pellet to fly forward, overcoming the creepspring, and its needle pierces the detonator and the grenade is exploded. It will be noted that, once the safety-pin is removed, the only safety device operating consists of a creepspring which is necessarily kept very weak.

An ingeniously designed French grenade which was much used in 1915, but later shared the fate of all percussion grenades, is shown in figs. 2 and 2a. It is pear-shaped and fragmenting but weighs hardly more than i lb. complete. Essentially its ignition arrangements consist in a lever with a weighted cord, a striker and a creepspring. Until the moment before throwing, the lever 7 is held in place by a string, which the bomber breaks with his left hand while firmly gripping the lever with his right. When the grenade is thrown, the lever flies up under the impulse of the spring 9 and the striker 5 is now held off the cap only by the creepspring 6. The lever 7 with the weighted cord it act as an air-drag to ensure nose-first impact. The head of the lever mo is pivoted eccentrically and its underside is formed to a curve which gives an initial leverage against the action of the spring 9, and therefore acts as a safety device.

'FIG.2 ' Cap Safety Pin Cap Detonator. FIG.3 The German "disc" percussion grenade (fig. 3) is designed so as to act in any position of fall. Ii has internally six radial channels, of which four are provided with striker pellets carrying caps, one contains the detonator, and the sixth has a safety pellet. In the centre is a fixed star, offering four striker points to the four striker pellets. These points are masked by arms or prongs on the safety pellet until the latter falls out of the grenade during flight and leaves them exposed. Then, whichever portion of the disc edge strikes the ground, the opposite striker pellet sets forward, dashing its cap on to the corresponding point of the star and so firing the detonator. A disc percussion grenade was also used with the Minucciani bombthrower described under Bombthrowers.

It will be noted that in both these cases the ignition arrangements constitute what is called in artillery language a "graze fuze," that is, the active element (the striker pellet) sets forward when the motion of the body of the grenade is checked on impact or graze. In other patterns, on the contrary, the ignition is of the "direct action" class, the pellet projecting from the head of the grenade Screwed Plug Safety Striker Pellet - Shell --- Ch arge 4 Pointed Star Brass Tub Detonator- Screwed Plug; and being forced back on to the detonator when the object is struck. To ensure this action, in the case of grenades, the outer end of the pellet is usually formed with a large disc or mushroom head which augments the surface of impact and therefore the resistance which tends to drive in the pellet.

10.

A simple grenade of this kind is the "Japanese" grenade as employed by the Russian army in the World War (fig. 4). This is a heavy-bodied fragmentation grenade with a hood bound on by cord wrapping instead of streamers. It will be seen from the drawing that when the safety ring 6 is removed nothing holds the striker 5 away from the detonator cap except the tightness of fit of the striker rod in the india-rubber block 8. On impact the mushroom head 9 forces the striker in and the grenade is fired. This was a rather light grenade weighing about i lb. 4 oz. and ranged, in expert hands, to about 45 yards. It could not be used in the open, as fragments came back as far as 200 yards. It had no handle, being grasped by the body.

Time grenades, as already explained, possess the advantages of intrinsic safety and of being able to act in any position of fall, though in other respects inferior to percussion. The types described below have been selected (a) to show the variety of ignition devices employed and (b) to indicate the evolution of design generally during the war period.

The type of grenade shown in figs. 5 and 5a is a Russian pre-war design, based no doubt on Port Arthur experience. The model shown was brought out in 1914 to replace an earlier and heavier engine of similar design.

Between the detonator and the cap is a column of slow-burning composition 21 connected to the cap 19 by strands of quickmatch 25. As in almost all patterns of grenade, the detonator element is transported separately. In this case the parts which render the grenade "live" are assembled in a U-shaped body 18 which is dropped into position with the cap over the striker 6 and the detonator 22 in a cavity in the exploder 23, and clipped there by the fastener 20. The action is as follows: the bomber grips the handle, pressing on the lever 12, and thus by means of the sear a cocking the striker-spring 8 and striker 6. His fingers encircle the safetyring 15 (which has hitherto held the lever) in such a way that in throwing the grenade the ring will remain in his hand. He then withdraws the safety-pin 11 which limits the forward movement of the striker. When he throws the grenade, the spring 14 forces out the lever 12 and the striker 6, released from the sear a, flies forward under the influence of its spring and fires the cap. This, through a flash along the quickmatch 25, starts the slow-burning composition which in due course fires the detonator, exploder, and main charge. Though primarily a thin-walled "concussion" grenade, this pattern has the casing lined with metal rings 17 prepared for fragmenta tion.1 It will be noticed that the handle portion as well as the body proper is filled with explosive. Carrying nearly i lb. of H.E., this was a very formidable concussion grenade, serviceable and not too difficult to manufacture (in spite of its apparent complexity), and could safely be used in fighting in_the open.

In marked contrast to this grenade are the more or less improvised time grenades of 1915 of which the British "cricket ball," the French "Fi" and some German specimens may be taken as representatives. The British "cricket ball" (fig. 6) and its variant the "lemon" was a plain iron, spherical or ovoid shell into which was screwed a plate carrying a detonator sleeve. In preparing for action the detonator was placed in the sleeve and secured by wire. Crimped into the mouth of the detonator was a 5-seconds length of Bickford safety fuze, the other end of which was prepared with a patch of composition such as is used for safety matches. The protective cap 8 being pulled off, the grenade was ignited by rubbing the head against a strip of matchbox composition (tied on the bomber's sleeve), and thrown. The weight of this grenade in its cricket-ball form was 12 lb.

The French "defensive" (i.e. fragmenting) grenade "F1" weighed 1 lb. As shown in fig. 7 it was ignited by a blow. The cover io being removed, a sharp blow on the cardboard inner tube 4 (carrying the cap) forced the cap down on the striker, igniting the timefuze length 8.

The German 2-lb. ball grenade (fig. 8), unlike most, was powderfilled and, as it could therefore be fired by a flash, needed no sensi 1 The earlier (22-lb.) pattern had a large amount of "langridge" (i.e. small pieces of metal) packed round the explosive charge.

HG. 4 attached to the bomber's wrist, tightening when the bomb reached the end of its tether, jerked out this roughened bar and so effected ignition.

The German H.E. cylindrical grenade (fig. 9) had also a frictiontube igniter, but the bomber fired this by a pull on the attached wire before throwing. This was essentially a concussion or "offensive" grenade and remained in use throughout the war. It was provided with a handle and with a hook whereby to attach it to the waistbelt. In another type of cylindrical handled grenade, part of the H.E. charge was replaced by langridge 1 and the ignition was by a spring striker as in the "hairbrush" described below.

Another form of handled time grenade used by the Germans and then copied by the British was the "hairbrush." The German FIG 10a Section r --- ?.

' o -- ? o + d?

FIG. 10 pattern (figs. 10 and ioa) had a spring igniter of a simple character. In a tube (fig. ioa) inserted in the rear end of the detonator and time-fuze tube was a striker, striker spring and cap. A collar on the striker rod kept the spring in compression so long as the tail end of the rod was held by the safety-pin. As soon as this was withdrawn the spring reasserted itself and the striker flew forward, firing the cap and igniting the time fuze.

Neater in design, more trustworthy in action, and far more popular with the troops than other British types, the Mills grenade requires a more extended description (fig. II). If the number supplied, and the steadiness with which the type maintained its hold on opinion be a test, this grenade was the most important of all those used in the World War.

As its name implies, it was patented by Mr. William Mills, of Birmingham, but the idea was of Belgian origin; although it is fair to add that the original Belgian design differed very considerably from that which is now so familiar as the "Mills" grenade.

The No. 5 grenade, which was the first of several British service patterns of the Mills type, consisted of a barrel-shaped iron casting, fitted internally with an aluminium tube known as the "centre piece." Adjoining the centre tube, and communicating with it at the bottom end of the grenade was a cylindrical chamber for the reception of the detonator to which was attached a 5-second fuze, terminating in a rim-fire percussion cap, which was inserted in the end of the central tube. The lower end of the grenade was closed with a screwed plug, known as the "base plug," made in aluminium, 1 Some of the grenades improvised in the field by the British army were also partly filled with langridge or so-called "shrapnel." 2 tive detonator. Its ignition arrangement was somewhat similar to the familiar friction tube of artillery, viz. a roughened bar which was inserted in a tube coated with match composition. A cord ?, ?>

?  ? screwed into base plug.

FIG. 11a EI v i brass, or a soft alloy, and which secured in position the detonating apparatus, and also formed a firm base to receive the shock of the striker when released from the lever. The high-explosive filling was introduced through an opening situated near the top of the grenade, closed with a brass screw, which, after filling, was carefully cemented into position. The cap was fired by means of a steel plunger, known as the "striker" which was operated by a powerful spring. The striker was held off the plug by means of an external lever provided close to one end, with small trunnions which rested in seatings formed on the head of the grenade. The shorter end of the lever was forked, the prongs of the fork engaging the projecting head of the striker. Thus, while the long end of the lever (which was bent to conform to the outer shape of the grenade) continued to be held in the thrower's hand or to be pinned down by the safety-pin the spring remained compressed and unable to drive the striker down on to the cap, but as soon as the lever was freed, the spring asserted itself, forcing the lever up (and out of its seatings) and the striker fired the cap. Modifications of the No. 5 were made later from time to time with the object of increasing its safety and efficiency, but its main features remained unaltered.

Originally the "Mills" grenade was intended purely and simply as a hand grenade, but it was found that its usefulness could be materially increased if means were adopted for projecting it from a rifle. This idea was considered and ultimately accomplished by substituting for the aluminium base plug one of steel, to the centre of which was attached a short steel rod 51 in. long. The rod, when inserted in the barrel of a rifle, enabled the grenade to be projected by the firing of a 35 gr. cordite blank cartridge, later replaced by the 43 gr. blank cartridge used for firing all rodded grenades.

In order to hold the lever in its correct position in relation to the grenade, and secure the striker until the moment of discharge from the rifle, a special appliance, known as a "rifle cup," was designed to fit on to the barrel of the rifle, and was secured to the barrel by the bayonet. The rifle cup consisted substantially of a flat steel ring slightly larger in diameter than the grenade, and projecting beyond the barrel of the rifle about 22 in., the ring being fixed concentrically with the rifle barrel. It will thus be seen that at whatever angle in relation to the horizontal plane, the grenade was inserted in the rifle cup, the lever was prevented from rising and thus releasing the striker until the grenade had been discharged, although the safety-pin had been previously withdrawn, leaving the lever otherwise free to act (fig. i ra).

This device had the effect of increasing the range of the grenade by about 50 yards. In this form the grenade was known by the description of "No. 23 Mark I" and perhaps attained its maximum of usefulness. Later developments of the Mills as a rifle grenade are dealt with below.

The "egg" class of hand grenades, alluded to earlier in this article, embody no novel technical devices and, therefore, need not be further described here. (C. F. A.) Rifle Grenades. - The desire to obtain increased range in a convenient way had already before the World War broke out led to the design of rifle grenades, which were, essentially, percussion grenades fitted with a steel tail-rod that was inserted in the bore of the service rifle and propelled by the force of a blank cartridge. In these rifle grenades, two forces became available to the designer which were not so in the case of hand grenades, viz. high velocity and therefore the possibility of causing and utilizing rotation, and the shock of discharge. Both these forces greatly facilitated the design of percussion grenades, as also did the fact that (given a suitable charge and conditions of firing) the tail rod ensured a nosefirst fall. The development of the rodded rifle grenade in the war period was therefore steadier and more consistent than that of hand grenades.

For most of the patterns used by the British army in the war, the original "No. 3" or "Hale's rifle grenade" (fig. 12) may be taken as representative in point of principle. It was a fragmentation grenade, as were all explosive rifle grenades, since the range eliminated danger from blowing back of fragments.

To the lower end of the body was fitted a base-piece of brass, which was bored out to receive a striker-rod and its needle. The outside of this base-piece was machined to receive a wind-vane, the boss of which held in position two safety bolts situated in the basepiece and preventing forward movement of the striker rod. Below the boss of the vane was a sleeve-like safety socket securing the boss above mentioned against premature rotation, so machined and slit that it clipped over the lower portion of the base-piece, this also being suitably machined. Into the lower end of the base-piece was screwed a steel rod, 10 in. long and of the calibre of the rifle, viz. .303 in. (In this and certain of the patterns which succeeded it a clip was fitted to the base-piece which was sprung over the muzzle of the rifle in order to secure the grenade in position.) The grenade body itself was traversed by a central tube, in the forward portion of which was secured the detonator in its sleeve, the middle portion containing a creepspring and the lower the point of the striker rod.

When the rifle was fired (a special 43 gr. blank cartridge was used) the safety socket set back, releasing the wind-vane which presently, under the action of the air, began to revolve and so to unscrew itself; in turn, this released the safety bolts which flew out, and thenceforward nothing but a light creepspring kept the detonator off the needle, which flew forward on graze and exploded the detonator and the bursting charge.

Steel Body ..Detonator 'FIG. 12 ' While the general principle of this grenade was maintained without change, certain defects of detail and other reasons for modification soon appeared. Thus, the difficulty of so much machining in a store which was required urgently and in enormous numbers, and the difficulty of keeping the wind-vane and its screw clean in trench conditions, led to the design of the vaneless "No. 20" in which the safety socket alone controlled the safety bolts, and considerations of manufacture, especially of filling conditions, led to further modifications in the types No. 24 and No. 35. These need not be dealt with in detail here. It should be mentioned, however, that the substitution of a service-rifle cartridge case (with its cap) for special detonator holders brought about a marked improvement in the direction of simplicity of manufacture.

Another British rifle grenade, known as the "Newton Pippin" or No. 22, was an improvised design by Capt. H. Newton, which was manufactured in the workshops of the army in the field. Its ignition arrangements were of the direct-action type, the mushroomheaded striker being forced back on impact. Other features of the grenade were the use of the service cartridge case as a detonator holder (a practice which, as has just been remarked, became general); the length of the rod (15 in.); and the provision of a gas-check on the end of the rod, a device used fairly frequently in other armies but not accepted in regulation British grenades. Ordinarily, the rod of the grenade does not seal the bore of the rifle, as it does not enter the grooves, and a proportion of the propellant force of the gas is therefore lost by escape round the rod. A gas-check, expanding into the grooves and then sealing them, obviates this, though of course the higher efficiency is obtained at the cost of an increased strain on the rifle.

Two other British types of rodded rifle grenade may be mentioned - the Sangster and the Steuart, distinguished by the numbers 25 and 39. In the former, which was of the direct-action class, a wind-vane attached to the striker screwed it down in flight until it left the screw thread and became sensitive. Owing to the careful design of the body and the use of a 15-in. rod, very long ranges were obtained with this grenade, but it was never adopted as a standard pattern owing to the same considerations of difficulty in manufacture and of service rough usage as those which had militated against earlier vaned patterns. The characteristic of the Steuart pattern was a safety device consisting in a sleeve which was slit across in manufacture so as to leave only a narrow web of metal; this sleeve was placed on the striker rod in such a way as to hold it firmly till the shock of discharge occurred, when the rod set back and a shearing blade fixed to it cut through the remaining metal of the sleeve. The striker rod was thus freed. The Steuart was a direct-action grenade. Experience had proved that, in spite of the relatively low velocity of rifle grenades, the conditions of grenade practice were similar to those of artillery in that graze fuzes, having a slight delay inherent in their design, were liable to act only after the projectile had more or less buried itself. It is preferable, therefore, that the ignition arrangements of a rifle - -- -Detonator Holder Fxplosive? Charge Firing Needle Brass Bose__ Piece II.

Safety Pin Base Plug.____ Sprin,Clip 10 Rod.-- - Detonator. Cap -Creep Spring -- - Neddie Pellet. - -Retaining Bolts ---Wind Vane Releasing Socket grenade should resemble in principle the artillery "instantaneous" fuze so as to ensure a burst above ground.

In the rodded rifle grenades used by foreign armies, the same general arrangements are, as a rule, found, and a catalogue of the minor variations which are found would be of no interest to the non-technical reader. As France (and America) did not employ rodded rifle grenades at all in the World War, interest centres practically on German and Russian designs. These are not numerous. Both directaction and graze types are found, and a gas-check is almost invariably fitted to the rod. A tin saucer is sometimes fitted to graze types to prevent the grenade from burying itself in soft ground. Both German types, model 1913 and model 1914, are complicated, especially the latter, which is organized with all the elaboration characteristic of German artillery fuzes of the period. Russian types are usually simpler, and reflect the lessons of active service experience in demanding little or no expertness in the user. Whereas elsewhere it is the almost invariable practice to keep the detonator element separate in transport, and to assemble it in the field, Russian rifle grenades have the detonators (which are rather explodergaines than detonators in the British sense of the word) buried in the interior of the body. The usual length of rod was 152 in., which in a long rifle gives the same length of propellant chamber as a 10-in. rod in the short rifle.

One Russian type, however, merits a'full description as it has several unique features. This is the Mgebrov, illustrated in fig. 13.

Against its complexity and evident difficulty of manufacture must be set the positive and "fool-proof" character of its safeties which are such that the bomber is not even called upon to withdraw a safety-pin.

The outer casing I is thick (for fragmentation) and inside this outer casing is a separate thin-walled explosive container 2 which is capable of a slight forward movement. The bottom of this container is formed with an incurving lip 14, and it is traversed from end to end by a central tube 13, longer than itself. In this central tube are an extended spring and the pellet containing cap and detonator 12, 15, 17. The spring is attached to the top socket of the tube and to the cap-holder of the pellet. The striker-rod with its needle 16 (which is fixed to the outer shell and not to the container) projects into this central tube. The tendency of the spring therefore is to pull the cap on to the needle. The premature occurrence of this is prevented by two sets of safety devices in which reside, as usual, the ingenuity and the complication of the design.

Under the base of the detonator pellet is formed a detent a consisting of a short stem with a barbed end. This end is buried in a block of fusible alloy, which is itself in a cup that is nearly surrounded by thermit 18. The thermit chamber has holes to provide air for combustion and communicates by a channel with the hollow tail-rod 3, which is filled with powder composition 19. All these elements are rigidly attached to the outer case and tail-rod and the detonator pellet is therefore solidly fixed both during transport and when fired. Moreover, the spring in the central tube tends to bind the unattached explosive container to its supporting platform 6, thus avoiding any shock due to set-back on discharge.

On firing, the flash ignites the powder in the tail-rod which burns through to the thermit chamber and ignites the thermit. This instantly develops so high a temperature that the fusible alloy in its cup melts away, freeing the barb of the detent a and therefore the detonator pellet. This takes place after four seconds, and the detonator pellet is now gently pulled forward by the spring. Thereupon the second set of safeties comes into play. This consists in two pivoted catches 7, the lower ends of which bear (through slots in the central tube) on the sides of the detonator pellet, and are held there by small springs 8. The pivots of these catches lie in the rigid platform 6 which supports the explosive container, and their upper ends engage in the annular lip 14 formed on its underside.

On graze, the explosive container sets forward, and its under-lip actuates the two catches so that their lower ends no longer bite on the detonator pellet; this latter is then quite free and, under the combined influence of inertia and of its contracting spring, moves violently forward in the central tube, dashes its cap on to the needle and explodes the grenade.

To complete this. survey of rodded rifle grenades it remains to mention the British Nos. 44 and 45 anti-tank grenades. These, having often to be fired almost at point blank, had short rods (8 in.) and a calico vane to ensure front contact. Unlike all the types above described, they were designed purely for concussion, having tin bodies and a maximum explosive content. The ignition was of the graze-fuze type. These engines gave a very efficient shattering effect on the hard steel of British tanks and seriously bulged the mild steel of German tanks, besides producing marked shock effects.

(C. E. W. B.; C. F. A.) Discharger-Cup Grenades. - It has already been mentioned that the French army never adopted the rodded rifle grenade. The objections to the rod are indeed serious, quite apart from the fact that it is awkward to handle and requires careful treatment. The rifle tends to bulge and eventually to split in the barrel, especially with the shorter rods, since the propellant gases impinge upon the end of the rod at high velocity and set up wave pressure at the point of contact. This is true, however accurately straight the rods may be. If they are not so, they buckle in the bore and the barrel bursts, probably with fatal results to the firer; in this case it is obviously the longer rod which is the more dangerous. Further, the general strain of firing rodded grenades shakes the rifle to pieces after some time, especially with long-rodded grenades in which heavy recoil is accepted for the sake of obtaining high muzzle velocity and ranging power.

In the latter part of the World War, therefore, we find a general tendency to discard rodded grenades in favour of the discharger-cup or tromblon. In Great Britain this tendency began to show itself after the fitting of the muzzle attachment above described for the Mills grenade. This was not a true discharger-cup since the grenade was rodded and the cup was merely intended to hold down the Mills lever before firing, but its success established the principle that hand and rifle grenades should be as nearly as possible interchangeable, and this requirement was bound in the long run to lead to the discharger-cup in some form.

The pioneers in developing the discharger-cup were the French, whose Viven-Bessieres or "V.B." grenade (fig. 14) became as famous in war as the Mills hand grenade. This was a cylindrical fragmentation grenade with a hollow passage through its middle. The ignition arrangement was peculiar. The detonator and time composition were mounted in a tube parallel and adjacent to the central passage, and at the head of this tube, at right angles to its axis, was a small cap-cartridge. A flat spring called the palette, carrying a pointed striker, was mounted in such a way as to protrude into the central passage. The space in the grenade cylinder not taken up by the central passage and the detonator and fuze tube was of course filled with explosive. To the muzzle of the rifle was attached, by a sleeve, the "tromblon" (an old word for blunderbuss) or discharger-cup which was cylindrical for the greater part of its length and coned for the rest. When the grenade was placed in this, the axis of the central passage was in line with the axis of the bore of the rifle. An ordinary bulleted service cartridge was employed.

When the rifle was fired, the bullet, on leaving the muzzle, passed through the central passage of the grenade giving a sharp inward blow to the palette and thus firing the cap. At the same time the expanding gases from the bore filled the conical space in the cup and propelled the grenade.

This combination of cup and grenade proved very serviceable, its chief defect being shortness of range (180 metres) as compared with the rodded grenade. For longer ranges a different discharger was employed known as the D.R. In this, the cup (called a "mandrin") was externally cylindrical and internally coned (fig. 15), and the grenade had a sleeve with external vanes (cf. the grenades of the German Granatwerfer described under Bombthrowers. A blank cartridge was employed. The sleeve of the grenade was slid over the outside of the cup as far down as the regulating pin allowed it to go, the function of this pin being to regulate the volume of the gas expansion chamber and therefore the range. The body of the ? ^I?

. ^I grenade was arranged for fragmentation and it had a direct-action ignition system. The maximum range was nearly 400 yards.

Expansion Chamber The German discharger-cup grenade, introduced in 1918 to replace rodded grenades, was in all but details a copy of the French V.B. It ranged to 150 metres. The ignition arrangement was simpler than in the French archetype.

The Russians also used a discharger-cup grenade in addition to their rodded rifle grenades. The grenade for this fuze had an adjustable time ring. (C. F. A.) The Grenade of the Future. - In Great Britain, a reconsideration of grenade problems in the middle of 1917 led to several modifications in the Mills grenade as such (the new pattern being designated No. 36) and in particular to the design of a discharger-cup for it. The rod was abandoned, and replaced by a steel disc 22 in. in diameter attached to the base plug. This fitted accurately into the cylindrical portion of the cup, and the whole of the escaping propellant gas was therefore usefully employed. This cup was used on active service in the last months of the war.

Meantime, research had again been directed to the percussion hand grenade. Various types had been tried but, owing chiefly to the fact that the Mills had become thoroughly familiar and was trusted by the army, none was actually adopted.

The fusion of hand and rifle grenades, however, was not imminent, and amongst the conditions laid down for the "grenade of the future" were that it was to be (I) a percussion grenade, but one that would act in any position of impact or fall without the necessity of any form of air-drag; (2) capable of use either as a hand grenade or as a rifle grenade; (3) safe (a) during the first To yd. of flight and (b) if dropped or accidentally knocked prior to throwing, but sensitive beyond ,o yd., even should it fall in soft mud; capable also of being picked up and thrown away when lying on the ground with all safeties removed; (4) weatherproof and mudproof; (5) simple to manufacture, to assemble in the field, and to use.

The last two conditions are obvious necessities in a service grenade required in vast quantities. The other three, however, involve technical questions of design and are largely interdependent. Thus, requirement (I) might be met by rotating the grenade by grooves in the discharger-cup and ridges on the grenade or vice versa (thus ensuring nose-first impact) were it not for requirement (2), and in requirement (3) the significance to the designer of the to-yd. frontier between "safe" and "sensitive" is different according as a hand-throw or an explosive propulsion is in prospect. A discussion of these requirements in detail, the technical elements available for meeting them, and the experimental patterns which have been evolved in accordance with this schedule of conditions lies outside the scope of this article. It must suffice to say that the problem thus set is one of great difficulty, but that, with the harvest of experience gained in grenade design during the war period, it is by no means insoluble. One or two questions of a general character should, however, be mentioned in conclusion.

The range and weight of the grenade of the future will depend undoubtedly on the final interpretation of the lessons of the war. The tendency to increase range will be checked at some upper limit fixed by the capacity of the infantr y man's standard weapon to endure the strain. Beyond that limit a special weapon will be required, and this will either compete with or fuze with the light trench mortar, but in either case its projectile will cease to be a grenade in the ordinary acceptation of the term. On the other hand the lower limit of weight of projectile remains fixed by the necessity of producing adequate effect on explosion. Under existing conditions it may be stated, as a rough indication, that the lower limit of weight compatible with effect is hardly, if at all, below i lb., and that 300-350 yd. represents the upper limit of weight for 1 - 12lb. bombs fired from a discharger-cup fitted to the ordinary rifle.

Another question of importance is the means used for varying the range. As a hand-thrown weapon of course the grenade is brought on to its target by the skilled eye and hand of the thrower, but as a rifle grenade it requires mechanical adjustment. During the war, special rifle-grenade stands were designed, into which the rifle was clamped, but such devices may be considered as proper to trench warfare only, and the problem of the present day is to find a means of varying the trajectory of the grenade which is adaptable to the individual rifle. Two solutions have offered themselves. One is varying the pressure of the propellant gas by varying the position of the grenade in the cup, as in the French D.R. grenade and mandrill, the discharger-cup used in the last months of the war for the Mills grenade, and other types. Opinion is divided on the merits of this method, which, though attractive in other respects, is open to criticism because it does not legislate for wind - a specially important factor in shooting with a large object of low velocity such as the grenade, and also because such an adjustment may easily be forgotten or mis-set in battle conditions. The alternative is to provide a simple form of clinometer or elevation indicator on the rifle. (C. E. W. B.)


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