Personal armor

Personal armor

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Personal armor is the whole of protecting clothing, designed to absorb and/or deflect slashing, bludgeoning, and penetrating attacks. They were historically used to protect soldier
Soldier
A soldier is a member of the land component of national armed forces; whereas a soldier hired for service in a foreign army would be termed a mercenary...

s, whereas today, they are also used to protect police
Police
The police is a personification of the state designated to put in practice the enforced law, protect property and reduce civil disorder in civilian matters. Their powers include the legitimized use of force...

 forces, private citizens and private security guard
Security guard
A security guard is a person who is paid to protect property, assets, or people. Security guards are usually privately and formally employed personnel...

s or bodyguards. Two types exist: regular non-plated personal armor (used by the people mentioned above, except combat soldiers) and hard-plate reinforced personal armor, which is used by combat soldiers, police tactical units and hostage rescue teams.

History



Many factors have affected the development of personal armor throughout human history. Significant factors in the development of armor include the economic and technological necessities of armor production. For instance plate armor first appeared in Medieval Europe when water-powered trip hammer
Trip hammer
A trip hammer, also known as a helve hammer, is a massive powered hammer used in:* agriculture to facilitate the labor of pounding, decorticating and polishing of grain;...

s made the formation of plates faster and cheaper. Also modern militaries usually do not provide the best armor to their forces since doing so would be prohibitively costly. At times the development of armor has run parallel to the development of increasingly effective weaponry on the battlefield, with armorers seeking to create better protection without sacrificing mobility.

Ancient


The oldest known western armor is the Dendra panoply
Dendra panoply
The Dendra panoply or Dendra armour is an example of Mycenean-era full-body armour made of bronze plates uncovered in the village of Dendra in the Argolid, Greece.- Description :...

, dating from the Mycenaean Era
Mycenaean Greece
Mycenaean Greece was a cultural period of Bronze Age Greece taking its name from the archaeological site of Mycenae in northeastern Argolis, in the Peloponnese of southern Greece. Athens, Pylos, Thebes, and Tiryns are also important Mycenaean sites...

 around 1400.
Mail, also referred to as chainmail, is made of interlocking iron rings, which may be riveted or welded shut. It is believed to have been invented by the Celt
Celt
The Celts were a diverse group of tribal societies in Iron Age and Roman-era Europe who spoke Celtic languages.The earliest archaeological culture commonly accepted as Celtic, or rather Proto-Celtic, was the central European Hallstatt culture , named for the rich grave finds in Hallstatt, Austria....

ic people in Eastern Europe
Eastern Europe
Eastern Europe is the eastern part of Europe. The term has widely disparate geopolitical, geographical, cultural and socioeconomic readings, which makes it highly context-dependent and even volatile, and there are "almost as many definitions of Eastern Europe as there are scholars of the region"...

 about 500 BC. When these Celts moved West they took mail with them. Most cultures who used mail used the Celtic word Byrnne or a variant, suggesting the Celts as the originators.. The Romans adopted mail as the lorica hamata
Lorica hamata
The lorica hamata is a type of mail armour used by the Roman Republic and the Roman Empire. During the 1st century it was starting to be supplemented by lorica segmentata, but had been reintroduced as sole standard-issue armor by the 4th century. It was issued for both primary Legionary and...

], although they also made use of lorica segmentata
Lorica segmentata
The lōrīca segmentāta was a type of segmented armour almost exclusively used in the Roman Empire, but the Latin name was first used in the 16th century...

 and lorica segmentata
Lorica segmentata
The lōrīca segmentāta was a type of segmented armour almost exclusively used in the Roman Empire, but the Latin name was first used in the 16th century...

. While no non-metallic armor survives, a linen laminate known as linothorax
Linothorax
The linothorax was a type of upper body armor used by the Ancient Greeks, as well as other civilizations, from the Mycenaean Period through the Hellenistic Period. The earliest attested account of a linothorax used for battle is recorded in Book 2 of Homer's Iliad . It is worn by Ajax the lesser...

 is repeatedly mentioned in ancient greek sources.

In East Asian history laminated armor such as lamellar
Lamellar armour
Lamellar armour was one of three early body armour types made from armour plates. The other two types are scale armour and laminar armour.-Description:...

, and styles similar to the coat of plates
Coat of plates
A coat of plates is a form of torso armour consisting of metal plates sewn or riveted inside a cloth or leather garment. The coat of plates makes a fairly brief appearance in the history of European armour during the era of transitional armour, during a portion of the 14th century...

, and brigandine
Brigandine
A brigandine is a form of body armour from the Middle Ages. It is a cloth garment, generally canvas or leather, lined with small oblong steel plates riveted to the fabric....

 were commonly used. Later cuirasses and plates were also used. In pre-Qin dynasty times, leather armor was made out of rhinoceros. Chinese influence in Japan would result in the Japanese adopting Chinese styles, their samurai armor
Samurai
is the term for the military nobility of pre-industrial Japan. According to translator William Scott Wilson: "In Chinese, the character 侍 was originally a verb meaning to wait upon or accompany a person in the upper ranks of society, and this is also true of the original term in Japanese, saburau...

 being a result of this influence.

Middle Ages



In European history, well-known armor types include the mail
Mail (armour)
Mail is a type of armour consisting of small metal rings linked together in a pattern to form a mesh.-History:Mail was a highly successful type of armour and was used by nearly every metalworking culture....

 hauberk
Hauberk
A hauberk is a shirt of chainmail. The term is usually used to describe a shirt reaching at least to mid-thigh and including sleeves. Haubergeon generally refers to a shorter variant with partial sleeves, but the terms are often used interchangeably.- History :The word hauberk is derived from the...

 of the early medieval age, and the full steel plate harness
Plate armour
Plate armour is a historical type of personal armour made from iron or steel plates.While there are early predecessors such the Roman-era lorica segmentata, full plate armour developed in Europe during the Late Middle Ages, especially in the context of the Hundred Years' War, from the coat of...

 worn by later Medieval and Renaissance
Renaissance
The Renaissance was a cultural movement that spanned roughly the 14th to the 17th century, beginning in Italy in the Late Middle Ages and later spreading to the rest of Europe. The term is also used more loosely to refer to the historical era, but since the changes of the Renaissance were not...

 knight
Knight
A knight was a member of a class of lower nobility in the High Middle Ages.By the Late Middle Ages, the rank had become associated with the ideals of chivalry, a code of conduct for the perfect courtly Christian warrior....

s, and a few key components (breast and back plates) by heavy cavalry in several European countries until the first year of World War I (1914–15).

Plate


Gradually, small additional plates or discs of iron were added to the mail to protect vulnerable areas. By the late 13th century, the knees were capped, and two circular discs, called besagews
Besagews
Besagues are circular defences designed to protect the armpits, as part of a harness of plate armour. Armour without besagues might employ larger shoulder defenses, such as winged pauldrons or simply leave the mail beneath exposed.-References:...

 were fitted to protect the underarms. A variety of methods for improving the protection provided by mail were used as armorers seemingly experimented. Hardened leather and splinted
Splint armour
Splint armour, also referred to as splinted armour. Splint armour first appears in a Scythian grave from the 4th century BCE..-Splint Armor:...

 construction were used for arm and leg pieces. The coat of plates
Coat of plates
A coat of plates is a form of torso armour consisting of metal plates sewn or riveted inside a cloth or leather garment. The coat of plates makes a fairly brief appearance in the history of European armour during the era of transitional armour, during a portion of the 14th century...

 was developed, an armor made of large plates sewn inside a textile or leather coat.

Early plate in Italy, and elsewhere in the 13th–15th century were made of iron. Iron armor could be carburized or case hardened
Case hardening
Case hardening or surface hardening is the process of hardening the surface of a metal, often a low carbon steel, by infusing elements into the material's surface, forming a thin layer of a harder alloy...

 to give a surface of harder steel. Plate armor became cheaper than mail by the 15th century as it required much less labor and labor had become much more expensive after the Black Death
Black Death
The Black Death was one of the most devastating pandemics in human history, peaking in Europe between 1348 and 1350. Of several competing theories, the dominant explanation for the Black Death is the plague theory, which attributes the outbreak to the bacterium Yersinia pestis. Thought to have...

, though it did require larger furnaces to produce larger blooms. Mail continued to be used to protect those joints which could not be adequately protected by plate, such as the armpit, crook of the elbow and groin. Another advantage of plate was that a lance rest could be fitted to the breast plate.

The small skull cap evolved into a bigger true helmet, the bascinet
Bascinet
The bascinet was a Medieval European open-faced military helmet, typically fitted with an aventail and hinged visor. The term is also written as bassinet or basinet.-Early versions:...

, as it was lengthened downward to protect the back of the neck and the sides of the head. Additionally, several new forms of fully enclosed helmets were introduced in the late 14th century to replace the great helm
Great helm
The great helm or heaume, also called pot helm, bucket helm and barrel helm, of the High Middle Ages arose in the late twelfth century in the context of the crusades and remained in use until the fourteenth century...

, such as the sallet
Sallet
The sallet was a war helmet that replaced the bascinet in northern Europe and Hungary during the mid-15th century. Some sallets were close fitting except at the back of the head where they extended and formed a pointed tail. Some Italian ones followed the shape of the neck, and had an additional...

 and barbute
Barbute
A barbute is a visorless war helmet of 14th to 15th century Italian design, often with distinctive "T" shaped or "Y" shaped opening for the eyes and mouth...

 and later the armet
Armet
Armet is the name of a type of helmet developed in the 15th century, most likely in Italy, France, Spain and Hungary. It was distinguished by being the first helmet of its era to completely enclose the head while being compact and light enough to move with the wearer...

 and close helm
Close helm
In Medieval armor, the close helm was a military helmet worn by knights and other combatants in the late medieval and early renaissance era. It carried a visor that pivoted up and fully enclosed the head and neck area, unlike earlier helms such as the sallet and barbute, which sometimes may have...

.

Probably the most recognized style of armor in the world became the plate armor
Plate armour
Plate armour is a historical type of personal armour made from iron or steel plates.While there are early predecessors such the Roman-era lorica segmentata, full plate armour developed in Europe during the Late Middle Ages, especially in the context of the Hundred Years' War, from the coat of...

 associated with the knight
Knight
A knight was a member of a class of lower nobility in the High Middle Ages.By the Late Middle Ages, the rank had become associated with the ideals of chivalry, a code of conduct for the perfect courtly Christian warrior....

s of the European Late Middle Ages
Late Middle Ages
The Late Middle Ages was the period of European history generally comprising the 14th to the 16th century . The Late Middle Ages followed the High Middle Ages and preceded the onset of the early modern era ....

, but continuing to the early 17th century Age of Enlightenment
Age of Enlightenment
The Age of Enlightenment was an elite cultural movement of intellectuals in 18th century Europe that sought to mobilize the power of reason in order to reform society and advance knowledge. It promoted intellectual interchange and opposed intolerance and abuses in church and state...

 in all European countries.

By about 1400 the full harness of plate armor had been developed in armories of Lombardy Heavy cavalry dominated the battlefield for centuries in part because of their armor.

In the early 15th century, small "hand cannon" first began to be used, in the Hussite Wars
Hussite Wars
The Hussite Wars, also called the Bohemian Wars involved the military actions against and amongst the followers of Jan Hus in Bohemia in the period 1419 to circa 1434. The Hussite Wars were notable for the extensive use of early hand-held gunpowder weapons such as hand cannons...

, in combination with Wagenburg tactics, allowing infantry to defeat armored knights on the battlefield. At the same time crossbow
Crossbow
A crossbow is a weapon consisting of a bow mounted on a stock that shoots projectiles, often called bolts or quarrels. The medieval crossbow was called by many names, most of which derived from the word ballista, a torsion engine resembling a crossbow in appearance.Historically, crossbows played a...

s were made more powerful to pierce armor, and the development of the Swiss Pike square
Pike square
The pike square was a military tactic developed by the Swiss Confederacy during the 15th century for use by its infantry.- History :The pike square was used to devastating effect at the Battle of Nancy against Charles the Bold of Burgundy in 1477, when the Swiss defeated a smaller but more...

 formation also created substantial problems for heavy cavalry. Rather than dooming the use of body armor, the threat of small firearms intensified the use and further refinement of plate armor. There was a 150 year period in which better and more metallurgically advanced steel armor was being used, precisely because of the danger posed by the gun. Hence, guns and cavalry in plate armor were "threat and remedy" together on the battlefield for almost 400 years. By the 15th century Italian armor plates were almost always made of steel. In Southern Germany armorers began to harden their steel armor only in the late 15th century. They would continue to harden their steel for the next century because they quench
Quench
In materials science, quenching is the rapid cooling of a workpiece to obtain certain material properties. It prevents low-temperature processes, such as phase transformations, from occurring by only providing a narrow window of time in which the reaction is both thermodynamically favorable and...

ed and temper
Temper
Temperare is the Latin origin of words like "temperature" and "tempering"; it and "tempo" come, in turn, from tempus...

ed their product which allowed for the fire-gilding to be combined with tempering.Williams, p.331

The quality of the metal used in armor deteriorated as armies became bigger and armor was made thicker, necessitating breeding of larger cavalry horses. If during the 14–15th centuries armor seldom weighed more than 15 kg, then by the late 16th century it weighed 25 kg. The increasing weight and thickness of late-16th-century armor therefore gave substantial resistance.

In the early years of pistol and arquebuses, firearms were relatively low in velocity. The full suits of armor, or breast plates actually stopped bullets fired from a modest distance. The front breast plates were, in fact, commonly shot as a test. The impact point would often be encircled with engraving to point it out. This was called the "proof". Armor often also bore an insignia of the maker, especially if it was of good quality. Crossbow bolts, if still used, would seldom penetrate good plate, nor would any bullet unless fired from close range.

In effect, rather than making plate armor obsolete, the use of firearms stimulated the development of plate armor into its later stages. For most of that period, it allowed horsemen to fight while being the targets of defending arquebuseers without being easily killed. Full suits of armor were actually worn by generals and princely commanders right up to the second decade of the 18th century.While heavy, it permitted mounted commanders to survey a battlefield while providing safety from musket fire.

Horse Armor


The horse was afforded protection from lances and infantry weapons by steel plate barding
Barding
Barding is armour for horses. During the late Middle Ages as armour protection for knights became more effective, their mounts became targets...

. This gave the horse protection and enhanced the visual impression of a mounted knight. Late in the era, elaborate barding was used in parade armor.

Gunpower Era


As gunpowder weapons improved, plate armor was no longer sufficient protection, and was largely discarded. Cavalry units continued to use armor for longer. Example include the German Reiter
Reiter
Reiters were a type of cavalry, which appeared in the armies of Western Europe in the 16th century in place of the outmoded lance-armed knights, at the same time that cuirassiers and dragoons began to attain typological distinction from other kinds of cavalry...

, Polish heavy hussars and the back and breast worn by (heavy) cavalry units during the Napoleonic wars.

Anachronisms


Metal armor remained in limited use long after its general extinction. At the start of World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

, thousands of the French Cuirassier
Cuirassier
Cuirassiers were mounted cavalry soldiers equipped with armour and firearms, first appearing in late 15th-century Europe. They were the successors of the medieval armoured knights...

s rode out to engage the German Cavalry who likewise used helmets and armor. By that period, the shiny armor plate was covered in dark paint and a canvas wrap covered their elaborate Napoleonic-style helmets. Their armor was meant to protect only against saber
Sabre
The sabre or saber is a kind of backsword that usually has a curved, single-edged blade and a rather large hand guard, covering the knuckles of the hand as well as the thumb and forefinger...

s and light lance
Lance
A Lance is a pole weapon or spear designed to be used by a mounted warrior. The lance is longer, stout and heavier than an infantry spear, and unsuited for throwing, or for rapid thrusting. Lances did not have tips designed to intentionally break off or bend, unlike many throwing weapons of the...

s. The cavalry had to beware of high velocity rifle
Rifle
A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...

s and machine gun
Machine gun
A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....

s like the foot soldiers, who at least had a trench
Trench
A trench is a type of excavation or depression in the ground. Trenches are generally defined by being deeper than they are wide , and by being narrow compared to their length ....

 to protect them.
Soldiers in the American Civil War
American Civil War
The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

 bought iron and steel vests from peddlers (both sides had considered but rejected body armor for standard issue). The effectiveness of the vests varied widely—some successfully deflected bullets and saved lives but others were poorly made and resulted in tragedy for the soldiers. In any case the vests were abandoned by many soldiers due to their weight on long marches as well as the stigma they got for being cowards from their fellow troops.

Modern Armor


Metal or ceramic plates can be used with a soft vest, providing additional protection from rifle
Rifle
A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...

 rounds, and metallic components or tightly-woven fiber layers can give soft armor resistance to stab and slash attacks from a knife
Knife
A knife is a cutting tool with an exposed cutting edge or blade, hand-held or otherwise, with or without a handle. Knives were used at least two-and-a-half million years ago, as evidenced by the Oldowan tools...

. Mail
Mail
Mail, or post, is a system for transporting letters and other tangible objects: written documents, typically enclosed in envelopes, and also small packages are delivered to destinations around the world. Anything sent through the postal system is called mail or post.In principle, a postal service...

 armor continues to be used as protection against stab/slash attacks.

Fibers


Kevlar
Kevlar
Kevlar is the registered trademark for a para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed at DuPont in 1965, this high strength material was first commercially used in the early 1970s as a replacement for steel in racing tires...

 is well known as a component of some bullet resistant vests and bullet resistant face mask
Ballistic face mask
A ballistic face mask, also known as facial armor, is a type of personal armor designed to protect the wearer from ballistic threats. Ballistic face masks are usually made of kevlar or other bullet resistant materials and the inside of the mask may be padded for shock absorption, depending on the...

s. The PASGT helmet and vest
Personnel Armor System for Ground Troops
Personnel Armor System for Ground Troops, sometimes abbreviated to PASGT, was a combat helmet and ballistic vest used by the American military from the mid 1980s until 2005, when the system was succeeded by the Lightweight Helmet, Modular Integrated Communications Helmet, and Interceptor body...

 used by United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 military forces since the early 1980s both have Kevlar as a key component, as do their replacements. Other military uses include bullet resistant facemasks used by sentries. Civilian applications include Kevlar reinforced clothing for motorcycle riders to protect against abrasion injuries. Kevlar
Kevlar
Kevlar is the registered trademark for a para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed at DuPont in 1965, this high strength material was first commercially used in the early 1970s as a replacement for steel in racing tires...

 in non-woven long strand form is used inside an outer protective cover to form chaps that loggers use while operating a chainsaw. If the moving chain contacts and tears through the outer cover, the long fibers of Kevlar tangle, clog, and stop the chain from moving as they get drawn into the workings of the drive mechanism of the saw. Kevlar is used also in Emergency Service's protection gear if it involves high heat (e.g., tackling a fire), and Kevlar body armor such as vests for police officers, security, and SWAT
SWAT
A SWAT team is an elite tactical unit in various national law enforcement departments. They are trained to perform high-risk operations that fall outside of the abilities of regular officers...

.

General



A shield
Shield
A shield is a type of personal armor, meant to intercept attacks, either by stopping projectiles such as arrows or redirecting a hit from a sword, mace or battle axe to the side of the shield-bearer....

 is held in the hand or arm. Its purpose is to intercept attacks, either by stopping projectiles such as arrows or by glancing a blow to the side of the shield-user. Shields vary greatly in size, ranging from large shields that protect the user's entire body to small shields that are mostly for use in hand-to-hand combat. Shields also vary a great deal in thickness; whereas some shields were made of thick wooden planking, to protect soldiers from spears and crossbow bolts, other shields were thinner and designed mainly for glancing blows away (such as a sword blow). In prehistory, shields were made of wood, animal hide, or wicker. In antiquity and in the Middle Ages, shields were used by foot soldiers and mounted soldiers. Even after the invention of gunpowder and firearms, shields continued to be used. In the 18th century, Scottish clans continued to use small shields, and in the 19th century, some non-industrialized peoples continued to use shields. In the 20th and 21st century, shields are used by military and police units that specialize in anti-terrorist action, hostage rescue, and siege-breaching.

Torso


A ballistic vest helps absorb the impact from firearm
Firearm
A firearm is a weapon that launches one, or many, projectile at high velocity through confined burning of a propellant. This subsonic burning process is technically known as deflagration, as opposed to supersonic combustion known as a detonation. In older firearms, the propellant was typically...

-fired projectile
Projectile
A projectile is any object projected into space by the exertion of a force. Although a thrown baseball is technically a projectile too, the term more commonly refers to a weapon....

s and shrapnel
Fragmentation (weaponry)
Fragmentation is the process by which the casing of an artillery shell, bomb, grenade, etc. is shattered by the detonating high explosive filling. The correct technical terminology for these casing pieces is fragments , although shards or splinters can be used for non-preformed fragments...

 from explosions, and is worn on the torso
Torso
Trunk or torso is an anatomical term for the central part of the many animal bodies from which extend the neck and limbs. The trunk includes the thorax and abdomen.-Major organs:...

. Soft vests are made from many layers of woven or laminated fibers and can be capable of protecting the wearer from small caliber handgun
Handgun
A handgun is a firearm designed to be held and operated by one hand. This characteristic differentiates handguns as a general class of firearms from long guns such as rifles and shotguns ....

 and shotgun
Shotgun
A shotgun is a firearm that is usually designed to be fired from the shoulder, which uses the energy of a fixed shell to fire a number of small spherical pellets called shot, or a solid projectile called a slug...

 projectiles, and small fragments from explosives such as hand grenade
Hand grenade
A hand grenade is any small bomb that can be thrown by hand. Hand grenades are classified into three categories, explosive grenades, chemical and gas grenades. Explosive grenades are the most commonly used in modern warfare, and are designed to detonate after impact or after a set amount of time...

s.

Metal or ceramic plates can be used with a soft vest, providing additional protection from rifle
Rifle
A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...

 rounds, and metallic components or tightly-woven fiber layers can give soft armor resistance to stab and slash attacks from a knife
Knife
A knife is a cutting tool with an exposed cutting edge or blade, hand-held or otherwise, with or without a handle. Knives were used at least two-and-a-half million years ago, as evidenced by the Oldowan tools...

. Soft vests are commonly worn by police
Police
The police is a personification of the state designated to put in practice the enforced law, protect property and reduce civil disorder in civilian matters. Their powers include the legitimized use of force...

 forces, private citizens and private security guard
Security guard
A security guard is a person who is paid to protect property, assets, or people. Security guards are usually privately and formally employed personnel...

s or bodyguard
Bodyguard
A bodyguard is a type of security operative or government agent who protects a person—usually a famous, wealthy, or politically important figure—from assault, kidnapping, assassination, stalking, loss of confidential information, terrorist attack or other threats.Most important public figures such...

s, whereas hard-plate reinforced vests are mainly worn by combat soldiers, police tactical units and hostage rescue teams.

Modern body armor may combine a ballistic vest with other items of protective clothing, such as a combat helmet
Combat helmet
A combat helmet or battle helmet is a type of personal armor designed specifically to protect the head during combat. Helmets are among the oldest forms of personal protective equipment and are known to have been worn by the Akkadians/Sumerians in the 23rd century BC, Mycenaean Greeks since 17th...

. Vests intended for police and military use may also include ballistic shoulder and side protection armor components, and bomb disposal
Bomb disposal
Bomb disposal is the process by which hazardous explosive devices are rendered safe. Bomb disposal is an all encompassing term to describe the separate, but interrelated functions in the following fields:*Military:...

 officers wear heavy armor and helmets with face visors and spine protection.

Head



A combat helmet
Combat helmet
A combat helmet or battle helmet is a type of personal armor designed specifically to protect the head during combat. Helmets are among the oldest forms of personal protective equipment and are known to have been worn by the Akkadians/Sumerians in the 23rd century BC, Mycenaean Greeks since 17th...

 is among the oldest forms of personal protective equipment
Personal protective equipment
Personal protective equipment refers to protective clothing, helmets, goggles, or other garment or equipment designed to protect the wearer's body from injury by blunt impacts, electrical hazards, heat, chemicals, and infection, for job-related occupational safety and health purposes, and in...

, and are known to have been worn by the Assyrians around 900BC, followed by the ancient Greeks and Romans
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....

, throughout the Middle Ages
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

, and up to the end of the 17th century by many combatants. Their materials and construction became more advanced as weapons became more and more powerful. Initially constructed from leather
Leather
Leather is a durable and flexible material created via the tanning of putrescible animal rawhide and skin, primarily cattlehide. It can be produced through different manufacturing processes, ranging from cottage industry to heavy industry.-Forms:...

 and brass
Brass
Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.In comparison, bronze is principally an alloy of copper and tin...

, and then bronze
Bronze
Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal...

 and iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...

 during the Bronze
Bronze Age
The Bronze Age is a period characterized by the use of copper and its alloy bronze as the chief hard materials in the manufacture of some implements and weapons. Chronologically, it stands between the Stone Age and Iron Age...

 and Iron
Iron Age
The Iron Age is the archaeological period generally occurring after the Bronze Age, marked by the prevalent use of iron. The early period of the age is characterized by the widespread use of iron or steel. The adoption of such material coincided with other changes in society, including differing...

 Ages, they soon came to be made entirely from forged steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 in many societies after about 950AD. At that time, they were purely military equipment, protecting the head from cutting blows with sword
Sword
A sword is a bladed weapon used primarily for cutting or thrusting. The precise definition of the term varies with the historical epoch or the geographical region under consideration...

s, flying arrow
Arrow
An arrow is a shafted projectile that is shot with a bow. It predates recorded history and is common to most cultures.An arrow usually consists of a shaft with an arrowhead attached to the front end, with fletchings and a nock at the other.- History:...

s, and low-velocity musket
Musket
A musket is a muzzle-loaded, smooth bore long gun, fired from the shoulder. Muskets were designed for use by infantry. A soldier armed with a musket had the designation musketman or musketeer....

ry. Many medieval helmets rested on the shoulders and prevented the wearer from turning his or her head, greatly restricting mobility. During the 18th and 19th centuries, helmets were not widely used in warfare, instead many armies used non-armored hats that offered no protection against blade or bullet. The arrival of World War I, with its trench warfare and wide use of artillery, led to mass adoption of metal helmets once again, this time with a shape that offered mobility, a low profile, and compatibility with gas masks. Today's militaries often use high-quality helmets made of ballistic materials such as Kevlar
Kevlar
Kevlar is the registered trademark for a para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed at DuPont in 1965, this high strength material was first commercially used in the early 1970s as a replacement for steel in racing tires...

 and Aramid
Aramid
Aramid fibers are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications, for ballistic rated body armor fabric and ballistic composites, in bicycle tires, and as an asbestos substitute. The name is a portmanteau of "aromatic polyamide"...

, which have excellent bullet and fragmentation stopping power. Some helmets also have good non-ballistic protective qualities, though many do not. Non-ballistic injuries may be caused by many things, such as concussive shockwaves
Shock wave
A shock wave is a type of propagating disturbance. Like an ordinary wave, it carries energy and can propagate through a medium or in some cases in the absence of a material medium, through a field such as the electromagnetic field...

 from explosion
Explosion
An explosion is a rapid increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases. An explosion creates a shock wave. If the shock wave is a supersonic detonation, then the source of the blast is called a "high explosive"...

s, physical attacks, motor vehicle accidents, or falls.

A ballistic face mask
Ballistic face mask
A ballistic face mask, also known as facial armor, is a type of personal armor designed to protect the wearer from ballistic threats. Ballistic face masks are usually made of kevlar or other bullet resistant materials and the inside of the mask may be padded for shock absorption, depending on the...

 is designed to protect the wearer from ballistic threats. Ballistic face masks are usually made of kevlar
Kevlar
Kevlar is the registered trademark for a para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed at DuPont in 1965, this high strength material was first commercially used in the early 1970s as a replacement for steel in racing tires...

 or other bullet resistant materials and the inside of the mask may be padded for shock absorption, depending on the design. Due to weight restrictions, protection levels range only up to NIJ
National Institute of Justice
The National Institute of Justice is the research, development and evaluation agency of the United States Department of Justice. NIJ, along with the Bureau of Justice Statistics , Bureau of Justice Assistance , Office of Juvenile Justice and Delinquency Prevention , Office for Victims of Crime ,...

 Level IIIA.

Limbs


Medieval armor often offered protection for all of the limbs, including metal boots for the lower legs, gauntlets for the hands and wrists, and greaves for the legs. Today, protection of limbs
Limb (anatomy)
A limb is a jointed, or prehensile , appendage of the human or other animal body....

 from bombs is provided by a bombsuit
Bombsuit
A bomb suit or a blast suit is a heavy suit of body armor designed to withstand the pressure released from a bomb and any projectiles the bomb may produce. It is usually worn by trained personnel attempting bomb disposal...

. Most modern soldiers sacrifice limb protection for mobility, since armor thick enough to stop bullets would greatly inhibit movement of the arms and legs.

Performance standards


Due to the various different types of projectile, it is often inaccurate to refer to a particular product as "bulletproof" because this implies that it will protect against any and all threats. Instead, the term bullet resistant is generally preferred.

Body armor standards are regional. Around the world ammunition varies and as a result the armor testing must reflect the threats found locally. Law enforcement statistics show that many shootings where officers are injured or killed involve the officer's weapon. As a result each law enforcement agency or para-military organizations will have their own standard for armor performance if only to ensure that their armor protects them from their own weapon. While many standards exist a few standards are widely used as models. The US National Institute of Justice
National Institute of Justice
The National Institute of Justice is the research, development and evaluation agency of the United States Department of Justice. NIJ, along with the Bureau of Justice Statistics , Bureau of Justice Assistance , Office of Juvenile Justice and Delinquency Prevention , Office for Victims of Crime ,...

 ballistic and stab documents are examples of broadly accepted standards. In addition to the NIJ, the UK Home Office Scientific Development Branch (HOSDB—formerly the Police Scientific Development Branch (PSDB)) standards are used by a number of other countries and organizations. These "model" standards are usually adapted by other countries by incorporation of the basic test methodologies with modification of the bullets that are required for test.
NIJ Standard-0101.06 has specific performance standards
Standardization
Standardization is the process of developing and implementing technical standards.The goals of standardization can be to help with independence of single suppliers , compatibility, interoperability, safety, repeatability, or quality....

 for bullet resistant vests used by law enforcement. This rates vests on the following scale against penetration and also blunt trauma protection (deformation):
Armor Level (Higher is better) Protection
Type I
(.22 LR
.22 Long Rifle
The .22 Long Rifle rimfire cartridge is a long established variety of ammunition, and in terms of units sold is still by far the most common in the world today. The cartridge is often referred to simply as .22 LR and various rifles, pistols, revolvers, and even some smoothbore shotguns have...

; .380 ACP
.380 ACP
The .380 ACP pistol cartridge is a rimless, straight-walled pistol cartridge developed by firearms designer John Browning. The cartridge headspaces on the mouth of the case. It was introduced in 1908 by Colt, and has been a popular self-defense cartridge ever since...

)
This armor would protect against:
  • 2.6 g
    Gram
    The gram is a metric system unit of mass....

     (40 gr
    Grain (measure)
    A grain is a unit of measurement of mass that is nominally based upon the mass of a single seed of a cereal. From the Bronze Age into the Renaissance the average masses of wheat and barley grains were part of the legal definition of units of mass. However, there is no evidence of any country ever...

    ) .22 Long Rifle
    .22 Long Rifle
    The .22 Long Rifle rimfire cartridge is a long established variety of ammunition, and in terms of units sold is still by far the most common in the world today. The cartridge is often referred to simply as .22 LR and various rifles, pistols, revolvers, and even some smoothbore shotguns have...

     Lead Round Nose (LR LRN) bullets at a velocity of 329 m/s (1080 ft/s ± 30 ft/s); and
  • 6.2 g (95 gr) .380 ACP
    .380 ACP
    The .380 ACP pistol cartridge is a rimless, straight-walled pistol cartridge developed by firearms designer John Browning. The cartridge headspaces on the mouth of the case. It was introduced in 1908 by Colt, and has been a popular self-defense cartridge ever since...

     Full Metal Jacketed Round Nose (FMJ RN) bullets at a velocity of 322 m/s (1055 ft/s ± 30 ft/s).

It is no longer part of the standard.
Type IIA
(9 mm; .40 S&W
.40 S&W
The .40 S&W is a rimless pistol cartridge developed jointly by major American firearms manufacturers Winchester and Smith & Wesson. The .40 S&W was developed from the ground up as a law enforcement cartridge designed to duplicate performance of the FBI's reduced velocity 10mm cartridge which could...

; .45 ACP
.45 ACP
The .45 ACP , also known as the .45 Auto by C.I.P., is a cartridge designed by John Browning in 1904, for use in his prototype Colt semi-automatic .45 pistol and eventually the M1911 pistol adopted by the United States Army in 1911.-Design and history:The U.S...

)
New armor protects against:
  • 8 g (124 gr) 9×19mm Parabellum Full Metal Jacketed Round Nose (FMJ RN) bullets at a velocity of 373 m/s ± 9.1 m/s (1225 ft/s ± 30 ft/s);
  • 11.7 g (180 gr) .40 S&W
    .40 S&W
    The .40 S&W is a rimless pistol cartridge developed jointly by major American firearms manufacturers Winchester and Smith & Wesson. The .40 S&W was developed from the ground up as a law enforcement cartridge designed to duplicate performance of the FBI's reduced velocity 10mm cartridge which could...

     Full Metal Jacketed (FMJ) bullets at a velocity of 352 m/s ± 9.1 m/s (1155 ft/s ± 30 ft/s); and
  • 14.9 g (230 gr) .45 ACP
    .45 ACP
    The .45 ACP , also known as the .45 Auto by C.I.P., is a cartridge designed by John Browning in 1904, for use in his prototype Colt semi-automatic .45 pistol and eventually the M1911 pistol adopted by the United States Army in 1911.-Design and history:The U.S...

     Full Metal Jacketed (FMJ) bullets at a velocity of 275 m/s ± 9.1 m/s (900 ft/s ± 30 ft/s).

Conditioned armor protects against:
  • 8 g (124 gr) 9 mm FMJ RN bullets at a velocity of 355 m/s ± 9.1 m/s (1165 ft/s ± 30 ft/s); 11.7 g (180 gr) .40 S&W FMJ bullets at a velocity of 325 m/s ± 9.1 m/s (1065 ft/s ± 30 ft/s); and
  • 14.9 g (230 gr) .45 ACP Full Metal Jacketed (FMJ) bullets at a velocity of 259 m/s ± 9.1 m/s (850 ft/s ± 30 ft/s).

It also provides protection against the threats mentioned in [Type I].
Type II
(9 mm; .357 Magnum
.357 Magnum
The .357 S&W Magnum , or simply .357 Magnum, is a revolver cartridge created by Elmer Keith, Phillip B. Sharpe, Colonel D. B. Wesson of firearms manufacturer Smith & Wesson, and Winchester. It is based upon Smith & Wesson's earlier .38 Special cartridge. The .357 Magnum cartridge was introduced in...

)
New armor protects against:
  • 8 g (124 gr) 9 mm FMJ RN bullets at a velocity of 398 m/s ± 9.1 m/s (1305 ft/s ± 30 ft/s); and
  • 10.2 g (158 gr) .357 Magnum Jacketed Soft Point bullets at a velocity of 436 m/s ± 9.1 m/s (1430 ft/s ± 30 ft/s).

Conditioned armor protects against:
  • 8 g (124 gr) 9 mm FMJ RN bullets at a velocity of 379 m/s ±9.1 m/s (1245 ft/s ± 30 ft/s); and
  • 10.2 g (158 gr) .357 Magnum Jacketed Soft Point bullets at a velocity of 408 m/s ±9.1 m/s (1340 ft/s ± 30 ft/s).

It also provides protection against the threats mentioned in [Types I and IIA].
Type IIIA
(.357 SIG
.357 SIG
The .357 SIG pistol cartridge is the product of Swiss-German firearms manufacturer SIG-Sauer, in cooperation with the American ammunition manufacturer Federal Cartridge. While it is based on a .40 S&W case necked down to accept bullets, the .357 SIG brass is slightly longer...

; .44 Magnum
.44 Magnum
The .44 Remington Magnum, or simply .44 Magnum, is a large-bore cartridge originally designed for revolvers. After introduction, it was quickly adopted for carbines and rifles...

)
New armor protects against:
  • 8.1 g (125 gr) .357 SIG FMJ Flat Nose (FN) bullets at a velocity of 448 m/s ± 9.1 m/s (1470 ft/s ± 30 ft/s); and
  • 15.6 g (240 gr) .44 Magnum Semi Jacketed Hollow Point (SJHP) bullets at a velocity of 436 m/s (1430 ft/s ± 30 ft/s).

Conditioned armor protects against:
  • 8.1 g (125 gr) .357 SIG FMJ Flat Nose (FN) bullets at a velocity of 430 m/s ± 9.1 m/s (1410 ft/s ± 30 ft/s); and
  • 15.6 g (240 gr) .44 Magnum Semi Jacketed Hollow Point (SJHP) bullets at a velocity of 408 m/s ± 9.1 m/s (1340 ft/s ± 30 ft/s).

It also provides protection against most handgun threats, as well as the threats mentioned in [Types I, IIA, and II].
Type III
(Rifles)
Conditioned armor protects against:
  • 9.6 g (148 gr) 7.62×51mm NATO
    7.62×51mm NATO
    The 7.62×51mm NATO is a rifle cartridge developed in the 1950s as a standard for small arms among NATO countries...

     M80 ball bullets at a velocity of 847 m/s ± 9.1 m/s (2780 ft/s ± 30 ft/s).

It also provides protection against the threats mentioned in [Types I, IIA, II, and IIIA].
Type IV
(Armor Piercing Rifle)
Conditioned armor protects against:
  • 10.8 g (166 gr) .30-06 Springfield
    .30-06 Springfield
    The .30-06 Springfield cartridge or 7.62×63mm in metric notation, was introduced to the United States Army in 1906 and standardized, and was in use until the 1960s and early 1970s. It replaced the .30-03, 6 mm Lee Navy, and .30 US Army...

     M2 armor-piercing (AP) bullets at a velocity of 878 m/s ± 9.1 m/s (2880 ft/s ± 30 ft/s).

It also provides at least single hit protection against the threats mentioned in [Types I, IIA, II, IIIA, and III].

In addition to the NIJ and HOSDB standards, other important standards include: German Police TR-Technische Richtlinie, Draft ISO
International Organization for Standardization
The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...

 prEN ISO 14876, Underwriters Laboratories
Underwriters Laboratories
Underwriters Laboratories Inc. is an independent product safety certification organization. Established in 1894, the company has its headquarters in Northbrook, Illinois. UL develops standards and test procedures for products, materials, components, assemblies, tools and equipment, chiefly dealing...

 (UL Standard 752).

Textile armor is tested for both penetration resistance by bullets and for the impact energy transmitted to the wearer. The "backface signature" or transmitted impact energy is measured by shooting armor mounted in front of a backing material, typically oil-based modelling clay
Modelling clay
You can use modelling clay to create items with it. The material compositions and production processes vary considerably. -Ceramic clay:...

. The clay is used at a controlled temperature and verified for impact flow before testing. After the armor is impacted with the test bullet the vest is removed from the clay and the depth of the indentation in the clay is measured.

The backface signature allowed by different test standards can be difficult to compare. Both the clay materials and the bullets used for the test are not common. In general the British, German and other European standards allow 20–25 mm of backface signature, while the US-NIJ standards allow for 44 mm, which can potentially cause internal injury. The allowable backface signature for body armor has been controversial from its introduction in the first NIJ test standard and the debate as to the relative importance of penetration-resistance vs. backface signature continues in the medical and testing communities.

In general a vest's textile material temporarily degrades when wet. Neutral water at room temp does not affect para-aramid or UHMWPE
Ultra high molecular weight polyethylene
Ultra-high-molecular-weight polyethylene , also known as high-modulus polyethylene or high-performance polyethylene , is a subset of the thermoplastic polyethylene. It has extremely long chains, with molecular weight numbering in the millions, usually between 2 and 6 million...

 but acidic, basic and some other solutions can permanently reduce para-aramid fiber tensile strength. (As a result of this, the major test standards call for wet testing of textile armor.) Mechanisms for this wet loss of performance are not known. Vests that will be tested after ISO-type water immersion tend to have heat-sealed enclosures and those that are tested under NIJ-type water spray methods tend to have water-resistant enclosures.

From 2003 to 2005, a large study of the environmental degradation of Zylon armor was undertaken by the US-NIJ. This concluded that water, long-term use, and temperature exposure significantly affect tensile strength and the ballistic performance of PBO or Zylon fiber. This NIJ study on vests returned from the field demonstrated that environmental affects on Zylon resulted in ballistic failures under standard test conditions.

Ballistic testing V50 and V0


Measuring the ballistic performance of armor is based on determining the kinetic energy
Kinetic energy
The kinetic energy of an object is the energy which it possesses due to its motion.It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes...

 of a bullet at impact. Because the energy of a bullet is a key factor in its penetrating capacity, velocity is used as the primary independent variable in ballistic testing. For most users the key measurement is the velocity at which no bullets will penetrate the armor. Measuring this zero penetration velocity (V0) must take into account variability in armor performance and test variability. Ballistic testing has a number of sources of variability: the armor, test backing materials, bullet, casing, powder, primer and the gun barrel, to name a few.

Variability reduces the predictive power of a determination of V0. If for example, the V0 of an armor design is measured to be 1600 ft/s (487.7 m/s) with a 9 mm FMJ bullet based on 30 shots, the test is only an estimate of the real V0 of this armor. The problem is variability. If the V0 is tested again with a second group of 30 shots on the same vest design, the result will not be identical.

Only a single low velocity penetrating shot is required to reduce the V0 value. The more shots made the lower the V0 will go. In terms of statistics, the zero penetration velocity is the tail end of the distribution curve. If the variability is known and the standard deviation can be calculated, one can rigorously set the V0 at a confidence interval. Test Standards now define how many shots must be used to estimate a V0 for the armor certification. This procedure defines a confidence interval of an estimate of V0. (See "NIJ and HOSDB test methods".)

V0 is difficult to measure, so a second concept has been developed in ballistic testing called V50. This is the velocity at which 50 percent of the shots go through and 50 percent are stopped by the armor. US military standards define a commonly used procedure for this test. The goal is to get three shots that penetrate that are slower than a second group of three shots that are stopped by the armor. These three high stops and three low penetrations can then be used to calculate a V50 velocity.

In practice this measurement of V50 requires 1–2 vest panels and 10–20 shots. A very useful concept in armor testing is the offset velocity between the V0 and V50. If this offset has been measured for an armor design, then V50 data can be used to measure and estimate changes in V0. For vest manufacturing, field evaluation and life testing both V0 and V50 are used. However, as a result of the simplicity of making V50 measurements, this method is more important for control of armor after certification.

Military testing


After the Vietnam War, military planners developed a concept of “Casualty Reduction”. The large body of casualty data made clear that in a combat situation, fragments, not bullets, were the greatest threat to soldiers. After WWII vests were being developed and fragment testing was in its early stages. Artillery shells, mortar shells, aerial bombs, grenades, and antipersonnel mines are all fragmentation devices. They all contain a steel casing that is designed to burst into small steel fragments or shrapnel, when their explosive core detonates. After considerable effort measuring fragment size distribution from various NATO and Soviet bloc munitions, a fragment test was developed. Fragment simulators were designed and the most common shape is a Right Circular Cylinder or RCC simulator. This shape has a length equal to its diameter. These RCC Fragment Simulation Projectiles (FSPs) are tested as a group. The test series most often includes 2 grain (0.13 g), 4 grain (0.263 g), 16 grain (1.0 g), and 64 grain (4.2 g) mass RCC FSP testing. The 2-4-16-64 series is based on the measured fragment size distributions.

The second part of “Casualty Reduction” strategy is a study of velocity distributions of fragments from munitions. Warhead explosives have blast speeds of 20000 ft/s (6,096 m/s) to 30000 ft/s (9,144 m/s). As a result they are capable of ejecting fragments at very high speeds of over 1000 m/s (3330 ft/s), implying very high energy (where the energy of a fragment is ½ mass × velocity2, neglecting rotational energy). The military engineering data showed that like the fragment size the fragment velocities had characteristic distributions. It is possible to segment the fragment output from a warhead into velocity groups. For example 95% of all fragments from a bomb blast under 4 gr have a velocity of 3000 ft/s (914.4 m/s) or less. This established a set of goals for military ballistic vest design.

The random nature of fragmentation required the military vest specification to trade off mass vs. ballistic-benefit. Hard vehicle armor is capable of stopping all fragments, but military personnel can only carry a limited amount of gear and equipment, so the weight of the vest is a limiting factor in vest fragment protection. The 2-4-16-64 grain series at limited velocity can be stopped by an all-textile vest of approximately 5.4 kg/m2 (1.1 lb/ft2). In contrast to the design of vest for deformable lead bullets, fragments do not change shape; they are steel and can not be deformed by textile materials. The 2 gr FSP (the smallest fragment projectile commonly used in testing) is about the size of a grain of rice; such small fast moving fragments can potentially slip through the vest, moving between yarns. As a result fabrics optimized for fragment protection are tightly woven, although these fabrics are not as effective at stopping lead bullets.

Practice


In December 2009, a British soldier deployed in southern Helmand, Afghanistan, survived a shot to the back during an operation to clear insurgents from a village, protected by the body armor he was wearing.

External links