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Reactive armour

Reactive armour is a type of vehicle armour used in protecting vehicles, especially modern tanks, against shaped charges and hardened kinetic energy penetrators. The most common type is explosive reactive armour (ERA), but variants include self-limiting explosive reactive armour (SLERA), non-energetic reactive armour (NERA), non-explosive reactive armour (NxRA), and electric armour. NERA and NxRA modules can withstand multiple hits, unlike ERA and SLERA.

M60A1 Patton tank with Israeli Blazer ERA
A T-72 tank layered with reactive armour bricks

When a shaped charge strikes the upper plate of the armour, it detonates the inner explosive, releasing blunt damage that the tank can absorb.

Reactive armour is intended to counteract anti-tank munitions that work by piercing the armour and then either killing the crew inside, disabling vital mechanical systems, or creating spalling that disables the crew — or all three.

Reactive armour can be defeated with multiple hits in the same place, as by tandem-charge weapons, which fire two or more shaped charges in rapid succession. Without tandem charges, hitting precisely the same spot twice is much more difficult.

History edit

 
Reactive armour "DYNA" for T-72 MBT

The idea of counterexplosion (kontrvzryv in Russian) in armour was first proposed by the Scientific Research Institute of Steel (NII Stali) in 1949 in the USSR by academician Bogdan Vjacheslavovich Voitsekhovsky (1922–1999).[citation needed] The first pre-production models were produced during the 1960s. However, insufficient theoretical analysis during one of the tests resulted in all of the prototype elements being detonated.[citation needed] For a number of reasons, including the aforementioned accident and a belief that Soviet tanks had sufficient armour, the research was ended. No more research was conducted until 1974, when the Ministry of the Defensive Industry announced a contest to find the best tank protection[citation needed].

Picatinny Arsenal[who?] experimented with testing linear cutting charges against anti-tank ammunition in the 1950s, and concluded that they may be effective with an adequate sensing and triggering mechanism, but noted "tactical limitations"; the report was declassified in 1980.[1]

A West German researcher, Manfred Held, carried out similar work with the IDF in 1967–1969.[2] Reactive armour created on the basis of the joint research was first installed on Israeli tanks during the 1982 Lebanon war and was judged very effective.[by whom?]

Explosive reactive armour edit

 
The advanced Kontakt-5 explosive reactive armour on this T-90S is arranged in pairs of plates, giving the turret its prominent triangular profile.

An element of explosive reactive armour (ERA) is either made out of a sheet or slab of high explosive sandwiched between two metal plates, or multiple "banana shaped" rods filled with high explosive which are referred to as shaped charges. On attack by a penetrating weapon, the explosive detonates, forcibly driving the metal plates apart to damage the penetrator. The shaped charges on the other hand, each detonate individually, launching one spike-shaped plate each, meant to deflect, detonate or cut the incoming projectile.

The disruption is attributed to two mechanisms. First, the moving plates change the effective velocity and angle of impact of the shaped charge jet, reducing the angle of incidence and increasing the effective jet velocity versus the plate element. Second, since the plates are angled compared to the usual impact direction of shaped charge warheads, as the plates move outwards the impact point on the plate moves over time, requiring the jet to cut through fresh plates of material. This second effect significantly increases the effective plate thickness during the impact.

 
Reactive armour detail

To be effective against kinetic energy projectiles, ERA must use much thicker and heavier plates and a correspondingly thicker explosive layer. Such heavy ERA, such as the Soviet-developed Kontakt-5, can break apart a penetrating rod that is longer than the ERA is deep, again significantly reducing penetration capability. Modern APFSDS however, can not be broken apart by ERA, as it usually has a strong, depleted uranium core.

An important aspect of ERA is the brisance, or detonation speed of its explosive element. A more brisant explosive and greater plate velocity will result in more plate material being fed into the path of the oncoming jet, greatly increasing the plate's effective thickness. This effect is especially pronounced in the rear plate receding away from the jet, which triples in effective thickness with double the velocity.[3]

 
How ERA works

ERA also counters explosively forged projectiles, as produced by a shaped charge. The counter-explosion must disrupt the incoming projectile so that its momentum is distributed in all directions rather than toward the target, greatly reducing its effectiveness.

Explosive reactive armour has been valued by the Soviet Union and its now-independent component states since the 1980s, and almost every tank in the eastern-European military inventory today has either been manufactured to use ERA or had ERA tiles added to it, including even the T-55 and T-62 tanks built forty to fifty years ago, but still used today by reserve units. The U.S. Army uses reactive armour on its Abrams tanks as part of the TUSK (Tank Urban Survivability Kit) package and on Bradley vehicles and the Israelis use it frequently on their American built M60 tanks.

ERA tiles are used as add-on (or appliqué) armour to the portions of an armoured fighting vehicle that are most likely to be hit, typically the front (glacis) of the hull and the front and sides of the turret. Their use requires that a vehicle be fairly heavily armoured to protect itself and its crew from the exploding ERA.

A further complication to the use of ERA is the inherent danger to anyone near the tank when a plate detonates, though a high-explosive anti-tank (HEAT) warhead explosion would already cause great danger to anyone near the tank. Although ERA plates are intended only to bulge following detonation, the combined energy of the ERA explosive, coupled with the kinetic or explosive energy of the projectile, will frequently cause explosive fragmentation of the plate. The explosion of an ERA plate creates a significant amount of shrapnel, and bystanders are in grave danger of fatal injury. Thus, infantry must operate some distance from vehicles protected by ERA in combined arms operations.

Sensitivity edit

ERA is insensitive to impact by kinetic projectiles up to 30 mm in caliber. A 20 mm APIT autocannon round penetrates a Serbian ERA sample but fails to detonate it. However, computer simulations indicate that a small caliber (30 mm) HEAT projectile will detonate an ERA, as would larger shape charges and APDSFS penetrators.[4]

Non-explosive and non-energetic reactive armour edit

NERA and NxRA operate similarly to explosive reactive armour, but without the explosive liner. Two metal plates sandwich an inert liner, such as rubber.[5] When struck by a shaped charge's metal jet, some of the impact energy is dissipated into the inert liner layer, and the resulting high pressure causes a localized bending or bulging of the plates in the area of the impact. As the plates bulge, the point of jet impact shifts with the plate bulging, increasing the effective thickness of the armour. This is almost the same as the second mechanism that explosive reactive armour uses, but it uses energy from the shaped charge jet rather than from explosives.[6]

Since the inner liner is non-explosive, the bulging is less energetic than on explosive reactive armour, and thus offers less protection than a similarly-sized ERA. However, NERA and NxRA are lighter, safe to handle, safer for nearby infantry, can theoretically be placed on any part of the vehicle, and can be packaged in multiple spaced layers if needed. A key advantage of this kind of armour is that it cannot be defeated via tandem warhead shaped charges, which employ a small forward warhead to detonate ERA before the main warhead fires.

Electric armour edit

Electric armour or electromagnetic armour is a proposed reactive armour technology. It is made up of two or more conductive plates separated by an air gap or by an insulating material, creating a high-power capacitor.[7][8][9][10][11] In operation, a high-voltage power source charges the armour. When an incoming body penetrates the plates, it closes the circuit to discharge the capacitor, dumping a great deal of energy into the penetrator, which may vaporize it or even turn it into a plasma, significantly diffusing the attack. It is not public knowledge whether this is supposed to function against both kinetic energy penetrators and shaped charge jets, or only the latter. As of 2005, this technology had not yet been introduced on any known operational platform.

Another electromagnetic alternative to ERA uses layers of plates of electromagnetic metal with silicone spacers on alternate sides. The damage to the exterior of the armour passes electricity into the plates, causing them to magnetically move together. As the process is completed at the speed of electricity the plates are moving when struck by the projectile, causing the projectile energy to be deflected whilst the energy is also dissipated in parting the magnetically attracted plates.[citation needed]

See also edit

References edit

  1. ^ https://apps.dtic.mil/sti/tr/pdf/AD0105141.pdf[bare URL PDF]
  2. ^ Jones, Clive; Petersen, Tore T. (1 November 2013). Israel's Clandestine Diplomacies. Oxford University Press. ISBN 9780199365449. from the original on 18 February 2023. Retrieved 28 October 2020 – via Google Books.
  3. ^ Held, Manfred (20 August 2004). "Dynamic Plate Thickness of ERA Sandwiches against Shaped Charge Jets". Propellants, Explosives, Pyrotechnics. 29 (4): 245–246. doi:10.1002/prep.200400051.
  4. ^ Ugrčić, Marinko (2004). "Criteria and evaluation of ballistic sensitivity of explosive reactive armor". Scientific-Technical Review (Serbia). 54 (1). Retrieved 16 May 2023.
  5. ^ . Archived from the original on 2008-08-30. Retrieved 2008-08-10.
  6. ^ Non-explosive energetic material and a reactive armour element using same 2017-07-12 at the Wayback Machine, US Patent Application 20060011057, accessed August 29, 2007.
  7. ^ U.S. Military Uses the Force 2013-04-09 at the Wayback Machine (Wired News).
  8. ^ 'Star Trek' shields to protect supertanks 2008-01-04 at the Wayback Machine (The Guardian).
  9. ^ "'Electric armour' vaporises anti-tank grenades and shells - Telegraph". 19 August 2002. from the original on 2017-03-21. Retrieved 2018-04-02.
  10. ^ . Archived from the original on 2011-09-27. Retrieved 2011-04-28.
  11. ^ . Archived from the original on 2007-10-15. Retrieved 2007-10-17.

General references edit

  • Manfred Held: "Brassey's Essential Guide to Explosive Reactive Armour and Shaped Charges", Brassey 1999, ISBN 1-85753-225-2
  • Graswald, Markus; Gutser, Raphael; Breiner, Jakob; Grabner, Florian; Lehmann, Timo; Oelerich, Andrea (2019-04-14). "Defeating Modern Armor and Protection Systems". 2019 15th Hypervelocity Impact Symposium. American Society of Mechanical Engineers. doi:10.1115/HVIS2019-050. ISBN 978-0-7918-8355-6. S2CID 240881543.

External links edit

  • Defence Science and Technology Laboratory: Electric Armour - The threat of RPGs[permanent dead link]

reactive, armour, type, vehicle, armour, used, protecting, vehicles, especially, modern, tanks, against, shaped, charges, hardened, kinetic, energy, penetrators, most, common, type, explosive, reactive, armour, variants, include, self, limiting, explosive, rea. Reactive armour is a type of vehicle armour used in protecting vehicles especially modern tanks against shaped charges and hardened kinetic energy penetrators The most common type is explosive reactive armour ERA but variants include self limiting explosive reactive armour SLERA non energetic reactive armour NERA non explosive reactive armour NxRA and electric armour NERA and NxRA modules can withstand multiple hits unlike ERA and SLERA M60A1 Patton tank with Israeli Blazer ERAA T 72 tank layered with reactive armour bricksWhen a shaped charge strikes the upper plate of the armour it detonates the inner explosive releasing blunt damage that the tank can absorb Reactive armour is intended to counteract anti tank munitions that work by piercing the armour and then either killing the crew inside disabling vital mechanical systems or creating spalling that disables the crew or all three Reactive armour can be defeated with multiple hits in the same place as by tandem charge weapons which fire two or more shaped charges in rapid succession Without tandem charges hitting precisely the same spot twice is much more difficult Contents 1 History 2 Explosive reactive armour 2 1 Sensitivity 3 Non explosive and non energetic reactive armour 4 Electric armour 5 See also 6 References 7 General references 8 External linksHistory edit nbsp Reactive armour DYNA for T 72 MBTThe idea of counterexplosion kontrvzryv in Russian in armour was first proposed by the Scientific Research Institute of Steel NII Stali in 1949 in the USSR by academician Bogdan Vjacheslavovich Voitsekhovsky 1922 1999 citation needed The first pre production models were produced during the 1960s However insufficient theoretical analysis during one of the tests resulted in all of the prototype elements being detonated citation needed For a number of reasons including the aforementioned accident and a belief that Soviet tanks had sufficient armour the research was ended No more research was conducted until 1974 when the Ministry of the Defensive Industry announced a contest to find the best tank protection citation needed Picatinny Arsenal who experimented with testing linear cutting charges against anti tank ammunition in the 1950s and concluded that they may be effective with an adequate sensing and triggering mechanism but noted tactical limitations the report was declassified in 1980 1 A West German researcher Manfred Held carried out similar work with the IDF in 1967 1969 2 Reactive armour created on the basis of the joint research was first installed on Israeli tanks during the 1982 Lebanon war and was judged very effective by whom Explosive reactive armour edit nbsp The advanced Kontakt 5 explosive reactive armour on this T 90S is arranged in pairs of plates giving the turret its prominent triangular profile An element of explosive reactive armour ERA is either made out of a sheet or slab of high explosive sandwiched between two metal plates or multiple banana shaped rods filled with high explosive which are referred to as shaped charges On attack by a penetrating weapon the explosive detonates forcibly driving the metal plates apart to damage the penetrator The shaped charges on the other hand each detonate individually launching one spike shaped plate each meant to deflect detonate or cut the incoming projectile The disruption is attributed to two mechanisms First the moving plates change the effective velocity and angle of impact of the shaped charge jet reducing the angle of incidence and increasing the effective jet velocity versus the plate element Second since the plates are angled compared to the usual impact direction of shaped charge warheads as the plates move outwards the impact point on the plate moves over time requiring the jet to cut through fresh plates of material This second effect significantly increases the effective plate thickness during the impact nbsp Reactive armour detailTo be effective against kinetic energy projectiles ERA must use much thicker and heavier plates and a correspondingly thicker explosive layer Such heavy ERA such as the Soviet developed Kontakt 5 can break apart a penetrating rod that is longer than the ERA is deep again significantly reducing penetration capability Modern APFSDS however can not be broken apart by ERA as it usually has a strong depleted uranium core An important aspect of ERA is the brisance or detonation speed of its explosive element A more brisant explosive and greater plate velocity will result in more plate material being fed into the path of the oncoming jet greatly increasing the plate s effective thickness This effect is especially pronounced in the rear plate receding away from the jet which triples in effective thickness with double the velocity 3 nbsp How ERA worksERA also counters explosively forged projectiles as produced by a shaped charge The counter explosion must disrupt the incoming projectile so that its momentum is distributed in all directions rather than toward the target greatly reducing its effectiveness Explosive reactive armour has been valued by the Soviet Union and its now independent component states since the 1980s and almost every tank in the eastern European military inventory today has either been manufactured to use ERA or had ERA tiles added to it including even the T 55 and T 62 tanks built forty to fifty years ago but still used today by reserve units The U S Army uses reactive armour on its Abrams tanks as part of the TUSK Tank Urban Survivability Kit package and on Bradley vehicles and the Israelis use it frequently on their American built M60 tanks ERA tiles are used as add on or applique armour to the portions of an armoured fighting vehicle that are most likely to be hit typically the front glacis of the hull and the front and sides of the turret Their use requires that a vehicle be fairly heavily armoured to protect itself and its crew from the exploding ERA A further complication to the use of ERA is the inherent danger to anyone near the tank when a plate detonates though a high explosive anti tank HEAT warhead explosion would already cause great danger to anyone near the tank Although ERA plates are intended only to bulge following detonation the combined energy of the ERA explosive coupled with the kinetic or explosive energy of the projectile will frequently cause explosive fragmentation of the plate The explosion of an ERA plate creates a significant amount of shrapnel and bystanders are in grave danger of fatal injury Thus infantry must operate some distance from vehicles protected by ERA in combined arms operations Sensitivity edit ERA is insensitive to impact by kinetic projectiles up to 30 mm in caliber A 20 mm APIT autocannon round penetrates a Serbian ERA sample but fails to detonate it However computer simulations indicate that a small caliber 30 mm HEAT projectile will detonate an ERA as would larger shape charges and APDSFS penetrators 4 Non explosive and non energetic reactive armour editMain article Non explosive reactive armor NERA and NxRA operate similarly to explosive reactive armour but without the explosive liner Two metal plates sandwich an inert liner such as rubber 5 When struck by a shaped charge s metal jet some of the impact energy is dissipated into the inert liner layer and the resulting high pressure causes a localized bending or bulging of the plates in the area of the impact As the plates bulge the point of jet impact shifts with the plate bulging increasing the effective thickness of the armour This is almost the same as the second mechanism that explosive reactive armour uses but it uses energy from the shaped charge jet rather than from explosives 6 Since the inner liner is non explosive the bulging is less energetic than on explosive reactive armour and thus offers less protection than a similarly sized ERA However NERA and NxRA are lighter safe to handle safer for nearby infantry can theoretically be placed on any part of the vehicle and can be packaged in multiple spaced layers if needed A key advantage of this kind of armour is that it cannot be defeated via tandem warhead shaped charges which employ a small forward warhead to detonate ERA before the main warhead fires Electric armour editThis section needs expansion You can help by adding to it March 2008 Main article Electric armour Electric armour or electromagnetic armour is a proposed reactive armour technology It is made up of two or more conductive plates separated by an air gap or by an insulating material creating a high power capacitor 7 8 9 10 11 In operation a high voltage power source charges the armour When an incoming body penetrates the plates it closes the circuit to discharge the capacitor dumping a great deal of energy into the penetrator which may vaporize it or even turn it into a plasma significantly diffusing the attack It is not public knowledge whether this is supposed to function against both kinetic energy penetrators and shaped charge jets or only the latter As of 2005 this technology had not yet been introduced on any known operational platform Another electromagnetic alternative to ERA uses layers of plates of electromagnetic metal with silicone spacers on alternate sides The damage to the exterior of the armour passes electricity into the plates causing them to magnetically move together As the process is completed at the speed of electricity the plates are moving when struck by the projectile causing the projectile energy to be deflected whilst the energy is also dissipated in parting the magnetically attracted plates citation needed See also editComposite armour Gurney equationsReferences edit https apps dtic mil sti tr pdf AD0105141 pdf bare URL PDF Jones Clive Petersen Tore T 1 November 2013 Israel s Clandestine Diplomacies Oxford University Press ISBN 9780199365449 Archived from the original on 18 February 2023 Retrieved 28 October 2020 via Google Books Held Manfred 20 August 2004 Dynamic Plate Thickness of ERA Sandwiches against Shaped Charge Jets Propellants Explosives Pyrotechnics 29 4 245 246 doi 10 1002 prep 200400051 Ugrcic Marinko 2004 Criteria and evaluation of ballistic sensitivity of explosive reactive armor Scientific Technical Review Serbia 54 1 Retrieved 16 May 2023 Protection Systems For Future Armored Vehicles Archived from the original on 2008 08 30 Retrieved 2008 08 10 Non explosive energetic material and a reactive armour element using same Archived 2017 07 12 at the Wayback Machine US Patent Application 20060011057 accessed August 29 2007 U S Military Uses the Force Archived 2013 04 09 at the Wayback Machine Wired News Star Trek shields to protect supertanks Archived 2008 01 04 at the Wayback Machine The Guardian Electric armour vaporises anti tank grenades and shells Telegraph 19 August 2002 Archived from the original on 2017 03 21 Retrieved 2018 04 02 Electrified Vehicle Armour Could Deflect Weapons Archived from the original on 2011 09 27 Retrieved 2011 04 28 Advanced Add on Armor for Light Vehicles Archived from the original on 2007 10 15 Retrieved 2007 10 17 General references editManfred Held Brassey s Essential Guide to Explosive Reactive Armour and Shaped Charges Brassey 1999 ISBN 1 85753 225 2 Graswald Markus Gutser Raphael Breiner Jakob Grabner Florian Lehmann Timo Oelerich Andrea 2019 04 14 Defeating Modern Armor and Protection Systems 2019 15th Hypervelocity Impact Symposium American Society of Mechanical Engineers doi 10 1115 HVIS2019 050 ISBN 978 0 7918 8355 6 S2CID 240881543 External links edit nbsp Wikimedia Commons has media related to Reactive armour Defense Update Reactive Armour Suits Defense Update Advanced Protection for Modern Armoured Vehicles Defence Science and Technology Laboratory Electric Armour The threat of RPGs permanent dead link Retrieved from https en wikipedia org w index php title Reactive armour amp oldid 1188053778, wikipedia, wiki, book, books, library,

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