- Vehicle armour
:" For body armour see
armour , for armoured forces seearmoured warfare , for other uses seearmour (disambiguation) .Military vehicles are commonly armoured to withstand the impact of
shrapnel ,bullet s,missile s, or shells, protecting the personnel inside from enemy fire. Such vehicles includetank s,aircraft , andships .Civilian vehicles may also be armoured. These vehicles include cars used by
reporters ,official s and others in conflict zones or where violent crime is common, andpresident iallimousine s. Armoured cars are also routinely used by security firms to carry money or valuables to reduce the risk ofhighway robbery or the hijacking of the cargo.Armour may also be used in vehicles from threats other than deliberate attack. Some
spacecraft are equipped with specialised armour to protect them against impacts from tinymeteor s or fragments ofspace junk . Helicopters may carry armour in the form of debris containment walls built into the casing of theirgas turbines to prevent injuries orairframe damage should the compressor/turbine wheel disintegrate. [ [http://www.pinnaclearmor.com/transport-armor/containment-device.php Containment Device | Transport Armor : Pinnacle Armor - Body Armor and Armoring Products ] ]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.Vehicle armour is sometimes improvised in the midst of an armed conflict. In
World War II , U.S. tank crews welded spare strips of tank track to the hulls of their Sherman, Grant, andStuart tank s.Moran, Michael. [http://www.msnbc.msn.com/id/4731185/ "Frantically, the Army tries to armour Humvees: Soft-skinned workhorses turning into death traps,"] "MSNBC", April 15, 2004.] In theVietnam War , U.S. "gun truck s" were armoured with sandbags and locally fabricatedsteel armour plate.Gardiner, Paul S. [http://www.almc.army.mil/alog/issues/JulAug03/gun_trucks.htm "Gun Trucks: Genuine Examples of American Ingenuity,"] "Army Logistician", PB 700-03-4, Vol. 35, No. 4, July-August 2003, Army Combined Arms Support Command, Fort Lee, Virginia. ISSN 0004-2528] More recently, U.S. troops in Iraq armouredHumvee s and various military transport vehicles with scrap materials: this came to be known as "hillbilly" armor or "haji" armor by the Americans.Armoured Fighting Vehicles
The most heavily armoured vehicles today are the
main battle tank s, which are the spearhead of the ground forces, and are designed to withstandanti-tank missiles,kinetic energy penetrator s, NBC threats and in some tanks even steep-trajectory shells. TheIsrael iMerkava tanks were designed in a way that each tank component functions as additional back-up armour to protect the crew. Outer armour is modular and enables quick replacement of damaged armour.Technologies
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 or withdrawal operations.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 impactingperpendicular ly. An angled surface also increases the chance of deflecting a projectile. This can be seen onv-hull designs, which direct the force of anIED orlandmine away from the crew compartment, increasing crewsurvivability . [ [http://www.windsofchange.net/archives/in_praise_of_senator_biden_survivable_rides_for_the_troops-print.php Winds of Change.NET: In Praise of Senator Biden: Survivable Rides for the Troops ] ]"Appliqué armour" screens have sometimes been bolted or welded onto armoured vehicles to increase protection.
Beginning during the Cold War, many AFVs have "
spall liner s" inside of the armour, designed to protect crew and equipment inside from fragmentation (spalling) released from the impact of enemy shells, especiallyhigh explosive squash head warheads. Spall liners are made ofKevlar ,Dyneema or similar materials.Spaced armour
Armour with two or more plates spaced a distance apart, called spaced armour, when sloped reduces the penetrating power of bullets and solid shot as after penetrating each plate they tend to tumble, deflect, deform, or disintegrate, when not sloped reduces the protection offered by the armour, and detonates explosive projectiles before they reach the inner plates. It has been in use since the
First World War , where it was used on theSchneider CA1 and St Chamond tanks. Many early-WWII German tanks had spaced armour in the form of armoured skirts, to make their thinner side armour more effective against anti-tank fire.The principle of spaced armour protects against
high explosive anti-tank (HEAT) projectiles which create afocus ed jet of plasticised metal, very effective at the focus point, but much less so beyond there. Relatively thin armour plates or even metal mesh, much lighter than fully protective armour, can be attached as side skirts or turret skirts on tanks and other armoured vehicles. This light armour detonates the warhead prematurely so that the jet of molten metal is focussed well before the main armour, becoming relatively ineffective. Factory-made and improvised stand-off armour was introduced in the Second World War to defend against the newBazooka ,Panzerfaust , and other HEAT weapons.In response to increasingly effective HEAT warheads, integral spaced armour was reintroduced in the 1960s on the German Leopard 1. There are hollow spaces inside this type of armour, increasing the length of travel from the exterior of the vehicle to the interior for a given weight of armour, to reduce the shaped charge's penetrating power. 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. For example, a given weight of armour can be distributed in 2 layers 15 cm (6 inch) thick instead of a single 30 cm (12 in) layer, giving much better protection against shaped charges.
Today light armoured vehicles mount panels of metal rods, known as
slat armour or cage armour, and some main battle tanks carry rubber skirts to protect their relatively fragile suspension and front belly armour.The
Whipple shield uses the principle of spaced armour to protect spacecraft from the impacts of very fastmicrometeoroid 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.loped 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 enveloping a certain volume with armour; it thus reduces a vehicle's internal volume, removing space that would go unused, thereby minimizing the vehicle's size and thus mass. 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.
Composite Armour
Composite armour is armour consisting of layers of two or more materials with significantly different chemical properties;
steel andceramic s are the most common types of material in composite armour. 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 asChobham armour . Composite armour's effectiveness depends on its composition and may be effective againstkinetic energy penetrator s as well asshaped charge munition s;heavy metals are sometimes included specifically for protection from kinetic energy penetrators.Reactive armour
"Explosive reactive armour", initially developed by German researcher, Manfred Held working in Israel, uses layers of high
explosive sandwiched between steel plates. When a shaped-charge warhead hits, the explosive detonates and pushes the steel plates into the warhead, disrupting the flow of the charge's liquid metal penetrator (usuallycopper at around 500 degrees Celsius; it can be made to flow like water by sufficient pressure). It is less effective against kinetic penetrators. 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.Cage Armor
Cage armor also known as bar armor, slat armor, and standoff armor is a type of armor designed to protect against
anti-tank rocket-propelled grenade (RPG) attacks. It functions by placing a rigid barrier around the vehicle which causes theshaped charge warhead , which uses a shaped explosion rather than kinetic energy, to explode at a relatively safe distance. [http://www.defense-update.com/products/s/slat-stryker.htm Slat Armour for Stryker ] ] It can be defeated bytandem-charge designs such as theRPG-27 andRPG-29 . [ [http://www.defenseindustrydaily.com/baes-lrod-cage-armor-03473 BAE’s LROD Cage Armor ] ]Electrically charged armour
Electrically charged armour is a recent development in the
United Kingdom by theDefence Science and Technology Laboratory . A vehicle is fitted with two thin shells, separated by insulating material. The outer shell holds an enormous electrical 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. Developers of theFuture Rapid Effect System (FRES) series of armoured vehicles are considering this technology.ee also
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Active protection system
*Armoured fighting vehicle
*Non-military armored vehicles
*Armoured forces
*Body armour
*Plastic armour
*Tank classification References
External links
* [http://web.archive.org/web/20040716065726/http://www.armedforces-int.com/article.asp?pubID=15&catID=232&artID=451 Electrically charged armour]
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