Vehicle armour

{{Short description|Plating used to fortify against damage}} {{for multi|body protection|body armor|armoured forces|armoured warfare|other uses|armour (disambiguation)}} {{Use British English|date=August 2016}} [[File:Abrams-transparent.png|thumb|300px|The [[U.S. Army]]'s [[M1 Abrams]] [[Main battle tank|MBT]] with TUSK (Tank Urban Survival Kit) upgrade uses [[composite armour|composite]], [[reactive armor|reactive]] and [[slat armor|slat armour]]]] [[Military vehicle]]s are commonly [[armour]]ed to withstand the impact of [[Fragmentation (weaponry)|shrapnel]], [[bullet]]s, [[Shell (projectile)|shell]]s, [[Rocket (weapon)|rocket]]s, and [[missile]]s, protecting the personnel inside from enemy fire. Such vehicles include [[armoured fighting vehicle]]s like [[tank]]s, [[aircraft]], and [[ship]]s.

Civilian vehicles may also be armoured. These vehicles include cars used by [[official]]s (e.g., [[Official state car|presidential limousines]]), [[reporters]] and others in conflict zones or where violent crime is common. Civilian [[Armored car (valuables)|armoured car]]s are also routinely used by security firms to carry money or valuables to reduce the risk of [[highway]] [[robbery]] or the [[Carjacking|hijacking]] of the cargo.

Armour may also be used in vehicles to protect from threats other than a deliberate attack. Some [[spacecraft]] are equipped with specialised armour to protect them against impacts from [[micrometeoroid]]s or fragments of [[space debris]]. Modern aircraft powered by [[jet engine]]s usually have them fitted with a sort of armour in the form of an [[aramid]] [[Composite armour|composite]] [[kevlar]] bandage around the fan casing or debris containment walls built into the casing of their [[gas turbine]] engines to prevent injuries or [[airframe]] damage should the fan, compressor, or [[turbine blade]]s break free.<ref>{{cite web|url=http://www.pinnaclearmor.com/transport-armor/containment-device.php |title=Containment Device: Transport Armor: Pinnacle Armor – Body Armor and Armoring Products |publisher=Pinnacle Armor |access-date=2012-01-29 |url-status=dead |archive-url=https://web.archive.org/web/20110928094857/http://www.pinnaclearmor.com/transport-armor/containment-device.php |archive-date=September 28, 2011}}</ref>

The [[design]] and purpose of the vehicle determines the amount of armour plating carried, as the plating is often very heavy and excessive amounts of armour restrict mobility. In order to decrease this problem, some new materials ([[nanomaterials]]) and material compositions are being researched which include [[buckypaper]],<ref>{{cite web |url=http://www.slipperybrick.com/2008/10/future-vehicles-could-be-made-of-buckypaper/ |title=Buckypaper armour |publisher=Slipperybrick.com |date=2008-10-19 |access-date=2012-01-29 |archive-url=https://web.archive.org/web/20120217002852/http://www.slipperybrick.com/2008/10/future-vehicles-could-be-made-of-buckypaper/ |archive-date=2012-02-17 |url-status=live}}</ref> and [[aluminium foam]] armour plates.<ref>{{cite web |url=http://www.ntnu.no/gemini/2009_spring/10.htm |archive-url=https://archive.today/20120905122231/http://www.ntnu.no/gemini/2009_spring/10.htm |url-status=dead |archive-date=2012-09-05 |title=Lightweight aluminum foam armour plates |publisher=Ntnu.no |access-date=2012-01-29}}</ref>

==Materials== ===Metals===

====Steel==== ''[[Rolled homogeneous armour]]'' is strong, hard and tough (does not shatter when struck with a fast, hard blow). Steel with these characteristics is produced by processing [[cast steel]] billets of appropriate size and then rolling them into plates of required thickness.<ref name="Thomas2016">{{Cite journal|last=Thomas|first=Daniel J.|date=October 2016|title=Laser cut hole matrices in novel armour plate steel for appliqué battlefield vehicle protection|journal=Defence Technology|language=en|volume=12|issue=5|pages=351–359|doi=10.1016/j.dt.2016.07.002|issn=2214-9147|doi-access=free}}</ref> Rolling and forging (hammering the steel when it is red hot) irons out the grain structure in the steel, removing imperfections which would reduce the strength of the steel.<ref>{{Cite web|last=Administrator|first=System|date=2009-01-27|title=Advanced armour steel|url=https://www.theengineer.co.uk/advanced-armour-steel/|access-date=2020-09-16|website=The Engineer|language=en-US}}</ref> Rolling also elongates the [[grain structure]] in the steel to form long lines, which enables the stress the steel is placed under when loaded to flow throughout the metal, and not be concentrated in one area.<ref name="Thomas2016"/>

''Cast homogenous armour'' or ''cast steel armour'' is produced by directly [[casting]] steel into the desired shape.<ref>{{cite book |last1=Cimpoeru |first1=SJ |title=The Mechanical Metallurgy of Armour Steels |chapter-url=https://apps.dtic.mil/sti/pdfs/AD1027340.pdf |pages=28 |chapter=9. Armour Steel Specifications and Standards}}</ref> It tends to be softer as heat treatment is difficult or impossible. Nevertheless, the flexibility in shape has made it popular as the structural hull in modern tanks.<ref>{{cite web |title=[Tanks 101] Armor Protection 1920-1980 – Features and Characteristics – Military History Visualized – Offical{{sic |nolink=yes}} Homepage for the YouTube Channel |url=http://militaryhistoryvisualized.com/tanks-101-armor-protection-1920-1980/ |date=19 August 2016}}</ref>

====Aluminium==== [[File:Fox Scout Car (6553547749).jpg|thumb|The British [[Fox armoured reconnaissance vehicle|Fox CVR(W)]] was built largely of aluminium.]] ''[[Aluminium]]'' is used when light weight is a necessity. It is most commonly used on [[Armoured personnel carrier|APCs]] and [[Armoured car (military)|armoured cars]]. While certainly not the strongest metal, it is cheap, lightweight, and tough enough that it can serve as easy armour.

====Iron==== Wrought ''[[Iron armour|iron]]'' was used on [[ironclad warship]]s. Early European iron armour consisted of 10 to 12.5&nbsp;cm of wrought iron backed by up to one metre of solid [[wood]]. It has since been replaced by steel due to steel being significantly stronger.

====Titanium==== [[Titanium]] has almost twice the density of aluminium, but can have a [[Yield_(engineering)|yield strength]] similar to high strength steels, giving it a high [[specific strength]]. It also has a high specific resilience and specific toughness. So, despite being more expensive, it finds an application in areas where weight is a concern, such as [[personal armour]] and [[military aviation]]. Some notable examples of its use include the [[USAF]] [[A-10 Thunderbolt II]] and the Soviet/Russian-built [[Sukhoi Su-25]] ground-attack aircraft, utilising a bathtub-shaped titanium enclosure for the pilot, as well as the Soviet/Russian [[Mil Mi-24]] attack helicopter.

====Uranium==== Because of its high density, [[depleted uranium]] (DU) can also be used in tank armour, sandwiched between sheets of steel armour plate. For instance, some late-production [[M1 Abrams|M1A1HA and M1A2 Abrams]] tanks built after 1998 have DU reinforcement as part of the armour plating in the front of the hull and the front of the turret, and there is a program to upgrade the rest (see [[Chobham armour#Heavy metal modules|Chobham armour]]).

===Plastic=== {{Main|Plastic armour}} ''Plastic metal'' was a type of vehicle armour originally developed for [[merchant ship]]s by the [[British Admiralty]] in 1940. The original composition was described as 50% clean [[granite]] of half-inch size, 43% of [[limestone]] mineral, and 7% of [[bitumen]]. It was typically applied in a layer two inches thick and backed by half an inch of [[steel]].

Plastic armour was highly effective at stopping [[armour piercing bullet]]s because the hard granite particles would deflect the bullet, which would then lodge between plastic armour and the steel backing plate. Plastic armour could be applied by pouring it into a cavity formed by the steel backing plate and a temporary wooden form.

Some main battle tank armour utilises polymers, for example polyurethane as used in the "BDD" appliqué armour applied to modernized [[T-62]] and [[T-55]].

===Glass=== {{Main|Bulletproof glass}} [[File:IDET2007 bulletproof glass armor.jpg|thumb|Ballistic test of a bullet-resistant glass panel]] '''Bullet-resistant glass''' is a colloquial term for [[glass]] that is particularly resistant to being penetrated when struck by [[bullet]]s. The industry generally refers to it as ''bulletproof glass'' or ''transparent armour''.

Bullet-resistant glass is usually constructed using a strong but [[Transparency (optics)|transparent]] material such as [[polycarbonate]] [[thermoplastic]] or by using layers of [[laminated glass]]. The desired result is a material with the appearance and light-transmitting behaviour of standard glass, which offers varying degrees of protection from [[small arms]] fire.

The polycarbonate layer, usually consisting of products such as Armormax, [[Makroclear]], Cyrolon, [[Lexan]] or Tuffak, is often sandwiched between layers of regular glass. The use of plastic in the laminate provides impact-resistance, such as physical assault with a hammer, an axe, etc. The plastic provides little in the way of bullet-resistance. The glass, which is much harder than plastic, flattens the bullet and thereby prevents penetration. This type of bullet-resistant glass is usually 70–75&nbsp;mm (2.8–3.0&nbsp;in) thick.

Bullet-resistant glass constructed of laminated glass layers is built from glass sheets bonded together with [[polyvinyl butyral]], [[polyurethane]] or [[ethylene-vinyl acetate]]. This type of bullet-resistant glass has been in regular use on [[combat vehicle]]s since [[World War II]]; it is typically about 100–120&nbsp;mm (3.9–4.7&nbsp;in) thick and is usually extremely heavy.

Newer materials are being developed. One such, [[aluminium oxynitride]], is much lighter but at US$10–15 per square inch is much more costly.

===Ceramic=== {{Main|Ceramic plate}} [[Ceramic]]'s precise mechanism for defeating [[high-explosive anti-tank|HEAT]] was uncovered in the 1980s. High speed photography showed that the ceramic material shatters as the HEAT round penetrates, the highly energetic fragments destroying the geometry of the metal jet generated by the [[hollow charge]], greatly diminishing the penetration. Ceramic layers can also be used as part of composite armour solutions. The high hardness of some ceramic materials serves as a disruptor that shatters and spreads the [[kinetic energy]] of projectiles.

===Composite=== [[File:Plasan SandCat.jpg|thumb|right|[[Plasan Sand Cat]] light (5 ton) military vehicle featuring integrated composite armoured body]] {{Main|Composite armour}} Composite armour is armour consisting of layers of two or more materials with significantly different physical properties; [[steel]] and [[ceramic]]s are the most common types of material in composite armour. [[Composite material|Composite]] armour was initially developed in the 1940s, although it did not enter service until much later and the early examples are often ignored in the face of newer armour such as [[Chobham armour]]. Composite armour's effectiveness depends on its composition and may be effective against [[kinetic energy penetrator]]s as well as [[shaped charge]] [[munition]]s; [[heavy metals]] are sometimes included specifically for protection from kinetic energy penetrators.

Composite armour used on modern Western and Israeli main battle tanks largely consists of non-explosive reactive armour (NERA) elements - a type of [[reactive armour]]. These elements are often a laminate consisting of two hard plates (usually high hardness steel) with some low density interlayer material between them. Upon impact, the interlayer swells and moves the plates, disrupting heat 'jets' and possibly degrading kinetic energy projectiles. Behind these elements will be some backing element designed to stop the degraded jet or projectile element, which may be of high hardness steel, or some composite of steel and ceramic or possibly uranium.

Soviet main battle tanks from the [[T-64]] onward utilised composite armour which often consisted of some low density filler between relatively thick steel plates or castings, for example [[Combination K]].<ref>{{cite book |editor1-last=Foss |editor1-first=Christopher F. |editor1-link=Christopher F. Foss |title=Jane's Armour & Artillery, 2005-06 |date=15 August 2005 |publisher=Janes Information Group |isbn=978-0-7106-2686-8 |page=102 |edition=26th |language=English}}</ref> For example, the T-64 turret had a layer of ceramic balls and aluminium sandwiched between layers of cast steel armour,<ref>{{cite book |last1=Zaloga |first1=Steven J. |title=Tanks at the Iron Curtain 1960–75 |date=21 July 2022 |publisher=Bloomsbury Publishing |isbn=978-1-4728-4817-8 |page=44 |url=https://books.google.com/books?id=4nxtEAAAQBAJ |language=en}}</ref> whilst some models of the [[T-72]] features a glass filler called "Kvartz". The tank [[glacis]] was often a sandwich of steel and some low density filler, either textolite (a [[fibreglass]] reinforced polymer) or ceramic plates.<ref>{{cite journal |last1=Warford |first1=James M. |editor1-last=Blakely |editor1-first=LTC Terry A. |editor2-last=Clemens |editor2-first=Jon T. |title=Soviet-Russian Tank Turret Armor: The Cold War Shell-Game |journal=Armor: The Professional Bulletin of the Armor Branch |date=January–February 1998 |volume=CVII |issue=1 |pages=16–18 |url=https://books.google.com/books?id=7PVLAQAAMAAJ |access-date=1 October 2023 |publisher=U.S. Armor Association |location=U.S. Army Armor Center, 4401 Vine Grove, Fort Knox, KY 40121 |language=en |issn=0004-2420}}</ref> Later T-80 and T-72 turrets contained NERA elements, similar to those discussed above.<ref>{{cite web |title=T80 Tank Characteristics |url=https://man.fas.org/dod-101/sys/land/row/t80tank.htm |website=Military Analysis Network |publisher=Federation of American Scientists |access-date=1 October 2023}}</ref><ref>{{cite report |last1=United States Marine Corps |title=Soviet/Russian Armor and Artillery Design Practices: 1945-1995 |date=1995 |pages=I-92−I-93 |publisher=Marine Corps Intelligence Activity |location=Quantico, VA |url=https://books.google.com/books?id=XeM72t6oOZIC |access-date=1 October 2023 |language=en |author1-link=United States Marine Corps }}</ref>

==Ships== [[File:WWI style ship armor.svg|thumb|right|Diagram of common elements of warship armour. The belt armour is denoted by "A".]] [[Belt armor|Belt armour]] is a layer of armour-plating outside the [[hull (watercraft)|hull]] of warships, typically on [[battleship]]s, [[battlecruiser]]s, [[cruiser]]s and some [[aircraft carrier]]s.<ref>those converted from other warships</ref>

Typically, the belt covers from the deck down some way below the [[waterline]] of the ship. If built within the hull, rather than forming the outer hull, it can be fitted at an inclined angle to improve the protection.

When struck by a [[shell (projectile)|shell]] or [[torpedo]], the belt armour is designed to prevent penetration, by either being too thick for the warhead to penetrate, or sloped to a degree that would deflect either projectile. Often, the main belt armour was supplemented with a [[torpedo bulkhead]] spaced several metres behind the main belt, designed to maintain the ship's watertight integrity even if the main belt were penetrated.

The air-space between the belt and the hull also adds [[buoyancy]]. Several wartime vessels had belt armour that was thinner or shallower than was desirable, to speed production and conserve resources.

''Deck armour'' on aircraft carriers is usually at the [[flight deck]] level, but on some early carriers was at the [[hangar deck]]. (See [[armoured flight deck]].)

==Aircraft== {{unreferenced section|date=October 2020}} Only the vital parts of an aircraft, such as the [[ejection seat]] and engines, are usually armoured. In the American [[Fairchild Republic A-10 Thunderbolt II]] and the Soviet-built [[Sukhoi Su-25]] ground attack aircraft, as well as the [[Mil Mi-24]] Hind ground-attack helicopter, the pilot sits in a titanium enclosure known as the "bathtub" for its shape.

Windscreens of larger aircraft, including civilian craft, are generally made of impact-resistant, [[laminated material]]s, to prevent damage from [[bird strike]]s or [[debris]].

==Armoured fighting vehicles== {{Main|Armoured fighting vehicle}} The most heavily armoured vehicles today are the [[main battle tank]]s, which are the spearhead of the ground forces, and are designed to withstand [[anti-tank guided missile]]s, [[kinetic energy penetrator]]s, [[high-explosive anti-tank]] weapons, [[NBC (weapon)|NBC]] threats and in some tanks even steep-trajectory shells. The [[Israel]]i [[Merkava]] tanks were designed in a way that each tank component functions as added back-up armour to protect the crew. Outer armour is modular and enables quickly replacing damaged parts.

===Layout=== For efficiency, the heaviest armour on an [[armoured fighting vehicle]] (AFV) is placed on its front. Tank tactics require the vehicle to always face the likely direction of enemy fire as much as possible, even in [[Defence (military)|defence]] or [[Withdrawal (military)|withdrawal]] operations.

[[Sloped armour|Sloping]] and curving armour can both increase its protection. Given a fixed thickness of armour plate, a projectile striking at an [[angle]] must penetrate more armour than one impacting [[perpendicular]]ly. An angled surface also increases the chance of deflecting a projectile. This can be seen on [[v-hull]] designs, which direct the force of an [[improvised explosive device]] or [[landmine]] away from the crew compartment, increasing crew [[survivability]].<ref>{{cite web |last=Katzman |first=Joe |url=http://www.windsofchange.net/archives/in_praise_of_senator_biden_survivable_rides_for_the_troops-print.php |title=In Praise of Senator Biden: Survivable Rides for the Troops |publisher=Winds of Change.NET |date=2007-04-26 |access-date=2012-01-29 |archive-url=https://web.archive.org/web/20080518143036/http://www.windsofchange.net/archives/in_praise_of_senator_biden_survivable_rides_for_the_troops-print.php |archive-date=2008-05-18 |url-status=dead}}</ref>

===Spall liners=== Beginning during the [[Cold War]], many AFVs have ''spall liners'' inside of the armour, designed to protect crew and equipment inside from fragmentation (spalling) released from the impact of enemy shells, especially [[high-explosive squash head]] warheads. Spall liners are made of [[aramid]]s ([[Kevlar]], [[Twaron]]), [[UHMWPE]] ([[Dyneema]], [[Spectra Shield]]), or similar materials.

===Appliqué=== [[File:Add-on kit.png|thumb|Vehicle composite add-on armour kit]] Appliqué armour,<ref>[[Oxford English Dictionary]] "appliqué, ''n.'' and ''adj'': "Ornamental needlework in which small decorative pieces of fabric are sewn or stuck on to a fabric or garment to form a pattern or trim; the practice of this as a technique or activity; (also) (a piece of) decoration or trim made in this way. Also in extended use in metalwork, and ''fig''". ''adj.'' "Of fabric or a garment: decorated by sewing or sticking on small pieces of fabric to form a pattern or trim; (of decoration, trim, etc.) attached in this way".</ref> or add-on armour, consists of extra plates mounted onto the hull or turret of an AFV. The plates can be made of any material and are designed to be retrofitted to an AFV to withstand weapons that can penetrate the original armour of the vehicle.<ref>Gary W. Cooke [http://www.inetres.com/gp/military/cv/protect.html Combat Vehicle Protection] {{Webarchive|url=https://web.archive.org/web/20090204045942/http://inetres.com/gp/military/cv/protect.html |date=2009-02-04}} 1 August 2004. cites "FM 3-22.34 TOW Weapon System." and "FM 5-103 Survivability."</ref><ref>[http://www.patentstorm.us/patents/6962102/claims.html US Patent 6962102 - Armour constructions] {{Webarchive|url=https://web.archive.org/web/20110429100826/http://www.patentstorm.us/patents/6962102/claims.html |date=2011-04-29}} US Patent Issued on November 8, 2005. [http://www.patentstorm.us/ PatentStorm] {{Webarchive|url=https://web.archive.org/web/20090201184317/http://www.patentstorm.us/ |date=2009-02-01}}, Retrieved 2009-02-04</ref> An advantage of appliqué armour is the possibility to tailor a vehicle's protection level to a specific threat scenario.

===Improvised=== {{Main|Improvised vehicle armour}} Vehicle armour is sometimes improvised in the midst of an armed conflict by vehicle crews or individual units. In [[World War II]], British, Canadian and Polish tank crews welded spare strips of tank track to the hulls of their [[M4 Sherman|Sherman]] tanks.<ref name="Moran">Moran, Michael. [https://web.archive.org/web/20130226103349/http://www.nbcnews.com/id/4731185 "Frantically, the Army tries to armour Humvees: Soft-skinned workhorses turning into death traps,"] ''MSNBC'', April 15, 2004.</ref> U.S. tank crews often added sand bags in the hull and turrets on Sherman tanks, often in an elaborate cage made of girders. Some Sherman tanks were up-armoured in the field with glacis plates and other armour cut from knocked-out tanks to create ''Improvised Jumbos'', named after the heavily armoured [[M4A3E2]] assault tank. In the [[Vietnam War]], U.S. "[[gun truck]]s" were armoured with sandbags and locally fabricated steel armour plate.<ref name="Gardiner">Gardiner, Paul S. [http://www.almc.army.mil/alog/issues/JulAug03/gun_trucks.htm "Gun Trucks: Genuine Examples of American Ingenuity,"] {{webarchive|url=https://web.archive.org/web/20071102202739/http://www.almc.army.mil/alog/issues/JulAug03/gun_trucks.htm |date=2007-11-02}} ''Army Logistician'', PB 700-03-4, Vol. 35, No. 4, July–August 2003, Army Combined Arms Support Command, Fort Lee, Virginia. {{ISSN|0004-2528}}</ref> More recently, [[History of Iraq (2003–2011)|U.S. troops in Iraq]] armoured [[Humvee]]s and various military transport vehicles with scrap materials: this came to be known as "[[hillbilly armour]]" or "haji armour" by the Americans.<ref name="Moran"/> Moreover, there was the [[Marvin Heemeyer|Killdozer incident]], with the modified bulldozer being armoured with steel and concrete composite, which proved to be highly resistant to small arms.

===Spaced===<!-- This section is linked from [[T-34]] and [[Performated armour]]--> {{Main|Spaced armour}} [[File:Bundesarchiv Bild 101I-154-1986-05, Russland, Sturmgeschütz III mit Seitenschürzen.jpg|thumb|left|{{Lang|de|[[Sturmgeschütz III]]|italic=no}} with spaced armour plates]] Armour with two or more plates spaced a distance apart, called spaced armour, has been in use since the [[First World War]], where it was used on the [[Schneider CA1]] and [[Saint-Chamond (tank)|Saint-Chamond]] tanks. Spaced armour can be advantageous in several situations. For example, it can reduce the effectiveness of [[kinetic energy penetrator]]s because the interaction with each plate can cause the round to tumble, deflect, deform, or disintegrate. This effect can be enhanced when the armour is [[Sloped armour|sloped]]. Spaced armour can also offer increased protection against [[high-explosive anti-tank|HEAT]] projectiles. This occurs because the [[shaped charge]] warhead can detonate prematurely (at the first surface), so that the metal jet that is produced loses its coherence before reaching the main armour and impacting over a broader area. Sometimes the interior surfaces of these hollow cavities are sloped, presenting angles to the anticipated path of the shaped charge's jet in order to further dissipate its power. Taken to the extreme, relatively thin armour plates, metal mesh, or [[slat armor|slatted plates]], much lighter than fully protective armour, can be attached as side skirts or turret skirts to provide additional protection against such weapons. This can be seen in [[Panzer IV|middle and late-World War II German tanks]], as well as many modern [[Armoured fighting vehicle|AFVs]]. Taken as a whole, spaced armour can provide significantly increased protection while saving weight.

The analogous [[Whipple shield]] uses the principle of spaced armour to protect spacecraft from the impacts of very fast [[micrometeoroid]]s. The impact with the first wall melts or breaks up the incoming particle, causing fragments to be spread over a wider area when striking the subsequent walls.

===Sloped=== [[File:Merkava mk iv084.jpg|thumb|right|The [[Merkava]] features extreme sloped armour on the turret]] {{Main|Sloped armour}} Sloped armour is armour that is mounted at a non-vertical and non-horizontal angle, typically on tanks and other armoured fighting vehicles. For a given normal to the surface of the armour, its plate thickness, increasing armour slope improves the armour's level of protection by increasing the thickness measured on a horizontal plane, while for a given area density of the armour the protection can be either increased or reduced by other sloping effects, depending on the armour materials used and the qualities of the projectile hitting it. The increased protection caused by increasing the slope while keeping the plate thickness constant, is due to a proportional increase of area density and thus mass, and thus offers no weight benefit. Therefore, the other possible effects of sloping, such as deflection, deforming and ricochet of a projectile, have been the reasons to apply sloped armour in armoured vehicles design. Another motive is the fact that sloping armour is a more efficient way of covering the necessary equipment since it encloses less volume with less material. The sharpest angles are usually seen on the frontal glacis plate, both as it is the hull side most likely to be hit and because there is more room to slope in the longitudinal direction of a vehicle.

===Reactive=== [[File:M60A1-Patton-Blazer-latrun-2.jpg|right|thumb|[[M60 Patton|M60A1 Patton tank]] with Israeli [[Reactive armour|Blazer ERA]] ]] {{Main|Reactive armour}} ''Explosive reactive armour'', initially developed by German researcher Manfred Held while working in Israel, uses layers of [[high explosive]] sandwiched between steel plates. When a shaped-charge warhead hits, the explosive [[Detonation|detonates]] and pushes the steel plates into the warhead, disrupting the flow of the charge's liquid metal penetrator (usually [[copper]] at around 500 degrees Celsius;{{fact|date=January 2023}} it can be made to flow like water by sufficient pressure). Traditional "light" ERA is less effective against kinetic penetrators. "Heavy" reactive armour, however, offers better protection. The only example currently in widespread service is Russian [[Kontakt-5]]. Explosive reactive armour poses a threat to friendly troops near the vehicle.

''Non-explosive reactive armour'' is an advanced spaced armour which uses materials which change their geometry so as to increase protection under the stress of impact.

''[[Active protection system]]s'' use a sensor to detect an incoming projectile and explosively launch a counter-projectile into its path.

===Slat=== {{Main|Slat armour}} [[File:IDF-D9-Zachi-Evenor-001.jpg|thumb|[[IDF Caterpillar D9]] [[armored bulldozer|armoured bulldozer]] with slat armour (in addition to armour plates and bulletproof windows). The D9 armour deflected [[Rocket-propelled grenade|RPG]] rockets and even [[9K11 Malyutka|9K11 Malyutka (AT-3 Sagger)]] [[ATGM]]s.]] Slat armour is designed to protect against [[anti-tank]] rocket and missile attacks, where the warhead is a [[shaped charge]]. The slats are spaced so that the warhead is either partially deformed before detonating, or the fuzing mechanism is damaged, thereby preventing detonation entirely. As shaped charges rely on very specific structure to create a jet of hot metal, any disruption to this structure greatly reduces the effectiveness of the warhead.<ref name="DU_SS">{{cite web |url=http://www.defense-update.com/products/s/slat-stryker.htm |title=Slat Armour for Stryker |publisher=Defense-Update |date=2006 |access-date=2012-01-29 |archive-url=https://web.archive.org/web/20120130013026/http://www.defense-update.com/products/s/slat-stryker.htm |archive-date=2012-01-30 |url-status=dead}}</ref> Slat armour can be defeated by [[tandem-charge]] designs such as the [[RPG-27]] and [[RPG-29]].<ref>{{cite web |url=http://www.defenseindustrydaily.com/baes-lrod-cage-armor-03473 |title=BAE's LROD Cage Armor |publisher=Defense Industry Daily |date=2011-03-15 |access-date=2012-01-29 |archive-url=https://web.archive.org/web/20120129065912/http://www.defenseindustrydaily.com/baes-lrod-cage-armor-03473/ |archive-date=2012-01-29 |url-status=live}}</ref>

===Electric armour=== {{Main|Electric armour}} [[Electric armour]] is a recent development in the [[United Kingdom]] by the [[Defence Science and Technology Laboratory]].<ref>[https://www.wired.com/science/discoveries/news/2002/08/54641 U.S. Military Uses the Force] {{Webarchive|url=https://web.archive.org/web/20130409014129/http://www.wired.com/science/discoveries/news/2002/08/54641 |date=2013-04-09}} (Wired News)</ref><ref>[https://www.theguardian.com/science/2001/aug/19/weaponstechnology.internationalnews 'Star Trek' shields to protect supertanks] (The Guardian)</ref><ref>{{Cite web |url=https://www.telegraph.co.uk/news/main.jhtml?xml=%2Fnews%2F2002%2F08%2F19%2Fnmod19.xml |title='Electric armour' vaporises anti-tank grenades and shells |access-date=2018-11-18 |archive-url=https://web.archive.org/web/20080423153550/http://www.telegraph.co.uk/news/main.jhtml?xml=%2Fnews%2F2002%2F08%2F19%2Fnmod19.xml |archive-date=2008-04-23 |url-status=dead}}</ref><ref>[http://itvibe.com/news/2627/ MoD Develops 'Electric Armour'] {{webarchive |url=https://web.archive.org/web/20080217014613/http://itvibe.com/news/2627/ |date=February 17, 2008}}</ref><ref>{{cite web |url=http://www.armedforces-int.com/categories/electric-armour/new-age-electric-armour-tough-enough-to-face-modern-threats.asp |title=New Age Electric Armour&nbsp;– Tough enough to face modern threats |publisher=Armedforces-int.com |access-date=2012-01-29 |url-status=dead |archive-url=https://web.archive.org/web/20090502161846/http://www.armedforces-int.com/categories/electric-armour/new-age-electric-armour-tough-enough-to-face-modern-threats.asp |archive-date=2009-05-02}}</ref><ref>{{cite web |url=http://www.defense-update.com/features/du-1-04/reactive-armor.htm |title=Add-On&nbsp;– Reactive Armor Suits |publisher=Defense-Update |date=2006-04-25 |access-date=2012-01-29 |archive-url=https://web.archive.org/web/20120126053552/http://www.defense-update.com/features/du-1-04/reactive-armor.htm |archive-date=2012-01-26 |url-status=dead}}</ref><ref>{{cite web |url=http://www.defense-update.com/features/du-1-04/passive-armor.htm |title=Advanced Add-on Armor for Light Vehicles |publisher=Defense-Update |date=2006-04-25 |access-date=2012-01-29 |url-status=dead |archive-url=https://web.archive.org/web/20180401081931/http://defense-update.com/features/du-1-04/passive-armor.htm |archive-date=2018-04-01 }}</ref> A vehicle is fitted with two thin shells, separated by insulating material. The outer shell holds an enormous [[electric charge]], while the inner shell is at ground. If an incoming HEAT jet penetrates the outer shell and forms a bridge between the shells, the electrical energy discharges through the jet, disrupting it. Trials have so far been extremely promising, and it is hoped that improved systems could protect against KE penetrators. The developers of the [[Future Rapid Effect System]] (FRES) series of armoured vehicles are considering this technology.{{Citation needed|date=February 2009}}

==See also== * [[Active protection system]] * [[Armoured fighting vehicle]] * [[Armoured forces]] * [[Main battle tank]] * [[Non-military armored vehicles|Non-military armoured vehicles]] * [[Personal armor|Personal armour]] * [[Plastic armour]]

== References == {{Reflist|30em}}

==External links== {{Commons category|Armoured vehicles}} * [https://web.archive.org/web/20040716065726/http://www.armedforces-int.com/article.asp?pubID=15&catID=232&artID=451 Electrically charged armour] * [http://armour.ws Modern armoured vehicles] {{Webarchive|url=https://web.archive.org/web/20110817032206/http://armour.ws/ |date=2011-08-17 }}

{{Types of armour}}

{{DEFAULTSORT:Vehicle armour}} [[Category:Vehicle armour| ]] [[Category:Armoured warfare]] [[Category:History of the tank]] [[Category:Armoured fighting vehicle equipment]]