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Active Protection System (APS) for tanks


asaf

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An active protection system is a system (usually for a military application) designed to prevent line-of-sight guided anti-tank missiles/projectiles from acquiring and/or destroying a target.

Electronic countermeasures that alter the electromagnetic, acoustic or other signature(s) of a target thereby altering the tracking and sensing behavior of an incoming threat (e.g., guided missile) are designated softkillmeasures.

Measures that physically counterattack an incoming threat thereby destroying/altering its payload/warhead in such a way that the intended effect on the target is severely impeded are designated hardkill measures.

Israel Rafael - Trophy APS (combat proven)

The Trophy is a situational awareness and active protection hard kill system that operates in three major stages: Threat detection and threat tracking followed by hard kill countermeasure (Multiple Explosive Formed Penetrators – MEFP) activation and threat neutralization.The neutralization process takes place only if the threat is about to hit the platform.

Trophy-HV
The Trophy was declared operational by the IDF in August 2009 and is currently in full production. Merkava 4 tanks integrated with Trophy active protection systems are presently being deployed in combat areas along Israel's borders.

Exceptional Capabilities
·360 Degree protection, while permitting sectors of the vehicle-mounted system to be rendered inactive when necessary for the protection of troops on the ground
·360 Degree situational awareness by detecting all incoming threats and identifying their launch position
·Extremely high elevation protection
·Neutralizes threats fired from very short range
·Neutralizes simultaneous threats arriving from one or more directions
·Minimum collateral damage
·Suitable for multiple platforms
·High kill probability while static or on the move
·Reduces platform weight
The Trophy system is adaptable to any combat platform.Once a platform is chosen, a short trade study is completed to work out any integration issues that may arise.Numerous elements are taken into consideration for each vehicle variant or type. For vehicles with relatively basic or light armor, e.g. the Stryker, the Trophy provides full protection against all types of RPG (as well as other threats) due to the fact that the Trophy destroys these types of threats without detonation.
Currently, the full Trophy HV system weighs 800 kg. Since space and weight will continue to be major issues on combat platforms, not only for current forces, but also for new vehicle programs, i.e. FCS / FRES, great efforts to miniaturize the electronics of the Trophy have been made.The result is additional systems for lighter vehicles:

Trophy-MV
The Trophy-MV offers the same hard kill capabilities as the Trophy-HV andincludes built-in soft kill capabilities as well. The Trophy-MV (previously Trophy II) is at TRL 7 and the first prototype is currently undergoing enhanced field testing.
Trophy-MV a 450kg APS, for light- and medium-weight (10-30 ton) vehicles

Trophy-LV
This active protection hard kill system for light armored vehicles utilizes the same superior operating principles as the Trophy-HV and Trophy-MV at a fraction of the weight. Trophy-LV’s high kill probability against advanced threats, including the most sophisticated shoulder-launched AT rocket propelled grenades, makes it a significant force-multiplier at shorter ranges on the modern battlefield.
The Trophy-LV’s dimensions are specially designed for easy integration and installation onto smaller platforms without impairing system performance. This ensures 360 protection including the vehicle’s windows and doors with minimal risk of collateral damage. The Trophy-LV is an all-round efficient, affordable, and cost-effective solution that is currently undergoing field testing in a variety of operational scenarios.

Operational Concept

1.Radar identifies and tracks incoming threat/s and delivers the exact threat launching point to a battle management system or weapon station.
2.The computer identifies the threat, determines whether it will hit the vehicle, and if so:
3.A ballistic cover opens.
4.A countermeasure head slews to the proper location.
5.The computer continues to track, acquire, and plot the best intercept solution.
6.The countermeasure is launched and neutralizes the threat.
The Trophy systems have a very high kill probability and testing has shown them to be successful against all known CE threats (RPG, ATGM, tank-fired CE, etc.) The systems’ average collateral damage is estimated at a <1% chance of a dismounted soldier being injured by Trophy or an incoming threat.

In response to concerns that the RPG-30 had fallen into the hands of Hezbollah fighters, Israel Defense reported that the Rafael weapons development authority developed a defense system called the "Trench Coat" that can counteract the RPG-30, by utilizing a 360-degree radar to detect all threats and, in the case of one, launch 17 projectiles, one of which should strike the incoming missile.

Israel IMI - Iron Fist APS

IRON FIST provides a combined Soft-and Hard-Kill Active protection System, adaptable to various platforms from light vehicles to heavy AFVs.

IRON FIST employs a sophisticated, multi-sensor early warning system, utilizing both infrared and radar sensors, providing the crew with enhanced situational awareness and early warning from potential threats. Upon a threat warning, the modular system employs the multi-layered defenses, comprising electro-optical jammers, Instantaneous smoke screens and, if necessary, an interceptor-based hard kill Active Protection System (APS). The IRON FISTeffectively protects against the full spectrum of Anti-Tank (AT) threats including AT Rockets fired at short range, in open area or urban environment, AT Guided Missiles, High Explosive AT and Kinetic Energy rounds.

The IRON FIST is currently in advanced development at IMI. The company has installed the system for demonstrations in light and heavy armored vehicles, where IRON FIST capability demonstrators underwent full end-to-end interception tests, against all threat types, operating on the move and in urban scenarios. In these installations, IRON FIST proved highly effective, with its wide angle protection, minimal weight penalty and modest integration requirements.

IRON FIST APS was selected by the Israel Defense Forces (IDF) as the Active Protection System designed to protect the Namer heavy infantry fighting vehicle.

Russia Kolomna - Arena APS

The Arena (Russian: Арена) is an active protection system (APS) developed at Russia's Kolomna-based Engineering Design Bureau for the purpose of protecting armoured fighting vehicles from destruction by light anti-tank weapons, anti-tank guided missiles (ATGM), and missiles with top attack warheads. It uses a Doppler radar to detect incoming warheads. Upon detection, a defensive rocket is fired that detonates near the inbound threat, destroying it before it hits the vehicle.

Arena is the successor to Drozd, a Soviet active protection system from the late 1970s, which was installed on several T-55s during the Soviet war in Afghanistan. The system improved the vehicle's survivability rate, increasing it by up to 80%. Drozd was followed by Shtora in the late 1980s, which used an electro-magnetic jammer to confuse inbound enemy anti-tank missiles and rockets. In late 1994 the Russian Army deployed a large number of armoured fighting vehicles to Chechnya, where they were ambushed and suffered heavy casualties. The effectiveness of Chechen rocket-propelled grenades against Russian combat vehicles prompted the Kolomenskoye machine-building design bureau to devise the Arena active protection system in the early and mid-1990s. An export variant, Arena-E, was also developed. The system has been tested on the T-80UM-1, demonstrated at Omsk in 1997, and was considered for use on the South Korean K2 Black Panther main battle tank.

The Arena system was primarily designed to defeat threats such as the rocket propelled grenade and the anti-tank missile, including newer anti-tank missiles with longer ranges. The active protection system can protect against missiles fired from both infantry carried rocket launchers and from helicopters, which attack the vehicle directly or by overflying it. Modern rocket propelled grenades can penetrate almost 1 metre (39 in) of steel armour, posing a serious threat to tanks operating in environments of asymmetric warfare. Therefore, increased tank protection requires either an increase in armour thickness and weight, or alternatively the use of an active protection system, like Arena.

US Raytheon - Quick Kill

Raytheon's Quick Kill™ Active Protection System (APS) can intercept and shoot down an extended set number threats, including rocket-propelled grenades and anti-tank missiles with surgical accuracy with minimum potential for collateral damage. Quick Kill can provide protection from these threats in many different mission applications, such as combat vehicles, ships or fixed sites.

Raytheon's approach to this technological breakthrough is equivalent to firing a weapon around a corner and hitting another weapon, while both speed through the air at hundreds of meters per second - literally in the blink of an eye. Raytheon was the first company to develop and then prove this concept of engagement by successfully intercepting an RPG at close range.

The Quick Kill system consists of a multi-mission, fire-control radar that detects and tracks incoming threats, combined with hard-kill countermeasures that serve as a hit avoidance system, enabling multi-tracking and simultaneous multi-engagement of enemy fire for vehicle and squad protection.

Raytheon's APS is based on the same radar technology deployed to perform sense and warn operations at active Forward Operating Bases and has been extremely successful in providing timely warning against rocket and mortar attacks.

the system's vertical launch countermeasure is unique in its ability to engage threats fired from any angle or elevation, providing all weather, full 360 degree hemispherical vehicle and crew protection with each countermeasure.

Quick Kill is a mature and highly advanced system that provides force protection capability that is essential to the future survivability of combat vehicles.

US Artis - Iron Curtain

Iron Curtain is an active protection system (APS) designed by Artis, an American technology development and manufacturing firm headquartered in Herndon, Virginia. The system is designed to protect military vehicles and other assets by intercepting threats such as rocket-propelled grenades and rendering them inert. It has been included as part of the joint services' MRAP program as well as the Army's Ground Combat Vehicle program.

Iron Curtain uses two independent sensors, radar and optical, high-speed computing, and tightly controlled counter-munitions to minimize the false alarm rate and increase accuracy. The system, which began in 2005 as a DARPA program, is able to defeat threats even if fired from an extremely close range.

Germany Rheinmetall - AMAP-ADS APS

The ADS-Active Defence-System belongs to a new generation of standoff active protection technologies. It is one of the world's most advanced and effective systems for protecting military vehicles of practically every weight class from operational threats, especially light antitank weapons, guided missiles and certain improvised explosive devices (IEDs). The ADS system is based on the hard-kill principle, in which incoming projectiles are detected and instantly destroyed by directed energy immediately before reaching their target. It is the only high-performance close-in defence system which minimizes collateral damage in the vicinity of the vehicle.

Turkish Aselan - Akkor APS

The Akkor APS includes a centralised control unit and internal display, with the soft-kill system including laser-warning receivers and smoke dispensers; the hard-kill system includes four radar units for 360° coverage and two twin-cell trainable launchers armed with two hard-kill unguided 'smart' munitions.

Serial production of the Akkor system is envisaged to begin in 2017 so that the system will be available for Turkey's first batch of 250 Altay MBTs. The company says it has been funding the development of Akkor since 2008 and has been conducting field tests of the radar, central computer systems, and the hard-kill munitions since 2010.

Based on cross-sections of the Akkor 'smart' munitions seen at IDEF, Akkor's kill-mechanism seems to rely on a high-explosive concussive blast effect to defeat incoming threats. The 'smart' element comes from the detonation method, which has variously been reported as being proximity-based or down to an intelligent fuze programmed prior to launch by the Akkor control system.

Ukraine Microtek - Zaslon APS

The Zaslon active protection suite was developed by Ukrainmash, a Ukrainian AFV modernization firm that specializes in developing add-on armor, active protection systems and upgrade kits for T-72, T-55 and BMP armored vehicles.

The Zaslon system consists of a radar based detection module, a guidance module and a customer specified number of static counter-measures modules. Each counter-measure module packs two explosive charges, which are ejected toward the target before detonating and forming a dense fragmentation ring that destroys incoming projectiles on impact. Modules can point forward, sideways or vertically, to protect from top attacks. The system’s response time is 0.1 seconds.

A typical installation protects 150 – 180 degrees, and is capable of defeating incoming projectiles at speeds between 70 and 1,200 m/sec. It can be used to protect fixed sites or armored vehicles. Depending on the protection level required, the system adds from 50 to 130 kg. per module.

Swedish Aerospace - Leds 150

The system is able to counter most known threats against armoured vehicles with soft and hard kill methods.

LEDS-150 consists of laser warning sensors, an ADC-150 Active Defence Controller, a number of MCTS Munition Confirmation and Tracking Sensors, and High Speed Directed Launchers, HSDL, which allows the combination of soft- and hard-kill countermeasure deployment capability to the platform, optional displays, and interconnecting harnesses.

This system uses the Denel Dynamics Mongoose-1 missile to destroy the incoming threat in 5 to 15 meters distance from the protected vehicle.LEDS-150 covers all 360 degrees azimuth; its elevation coverage is from -15 to +65 degrees.

France Thales - Shark APS 

Shark is a ground-breaking solution for vehicle protection, using a revolutionary optopyrotechnic system. It has been awarded by the Prix Chanson this year.

The Prix Chanson, named after Engineer General Paul Chanson, who created it, is awarded each year by the French defence procurement agency in recognition of an outstanding contribution to progress in the field of land armaments. This year, Thales subsidiary TDA and the Institut Saint Louis have been selected for their work in the field of optopyrotechnic initiation and its application in countermeasures for the active protection of armored vehicles and their occupants. This innovation has been brought to a successful conclusion, with the concrete application SHARK.

This ground-breaking technology actually utilizes several optopyrotechnic detonators with laser ignition. The SHARK active protection system is designed to protect armored fighting vehicles from shaped charge (Rocket Propelled Grenade and anti-tank missiles) and IED (Improvised Explosive Device) while degrading the potential threat of KE threats. The system provides full 360 degrees hemispherical coverage, with distributed, overlapping sensor-countermeasures modules located all around the vehicle. Each module covers a specific sector, detecting any threat fired toward the vehicle and engaging it by blast effect at close-in range, specifically designed to comply with operational restrictions of specific environments.

S.Korea - Kaps APS

The Korean Active Protection System (KAPS) is an indigenously developed hard-kill active protection system designed to protect the K2 from anti-tank threats. It uses a three-dimensional detection and tracking radar and a thermal imager to detect incoming threats. Warheads can be detected out to 150 meters from the tank, and a defensive rocket is fired to destroy them at 10 - 15 meters away. The KAPS can neutralize rocket-propelled grenades and anti-tank guided missiles. The system may be installed on other platforms in the future like warships, helicopters, and buildings. Unit price per system is ₩670 million ($600,000)
 

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One thing I do not understand about APS is why it took so long for passive jammers like shtora and sarab to see widespread use.  They're very simple; essentially very bright, pulsing lightbulbs tuned to the correct frequency.  After the massive Israeli tank losses to ATGMs in 1973, it should have been obvious that something needed to be done to address the vulnerability of tanks to missiles.  The response ended up being Blazer ERA, which took something like seven years to develop.  And it's not like other Western countries had massive programs in parallel, the US even ended up buying Israeli Blazer kits for USMC M60s!

 

What I'm saying is that prior to the adoption of the Leopard 2, all Western tanks would have died like mayflies in an actual war with the USSR, that this was glaringly obvious, and that Western tank developers seemed strangely reticent to do anything about this.

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1 hour ago, Collimatrix said:

One thing I do not understand about APS is why it took so long for passive jammers like shtora and sarab to see widespread use.  They're very simple; essentially very bright, pulsing lightbulbs tuned to the correct frequency.  After the massive Israeli tank losses to ATGMs in 1973, it should have been obvious that something needed to be done to address the vulnerability of tanks to missiles.  The response ended up being Blazer ERA, which took something like seven years to develop.  And it's not like other Western countries had massive programs in parallel, the US even ended up buying Israeli Blazer kits for USMC M60s!

 

What I'm saying is that prior to the adoption of the Leopard 2, all Western tanks would have died like mayflies in an actual war with the USSR, that this was glaringly obvious, and that Western tank developers seemed strangely reticent to do anything about this.

Ahhh yes. The famous European "We don't face this kind of threat yet" approach - when you are only prompted to act when the body bags start running out.

It's a good thing though that 80% of NATO is the US of A.

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On 11.8.2017 at 11:08 AM, Collimatrix said:

One thing I do not understand about APS is why it took so long for passive jammers like shtora and sarab to see widespread use.  They're very simple; essentially very bright, pulsing lightbulbs tuned to the correct frequency.  After the massive Israeli tank losses to ATGMs in 1973, it should have been obvious that something needed to be done to address the vulnerability of tanks to missiles.  The response ended up being Blazer ERA, which took something like seven years to develop.  And it's not like other Western countries had massive programs in parallel, the US even ended up buying Israeli Blazer kits for USMC M60s!

 

What I'm saying is that prior to the adoption of the Leopard 2, all Western tanks would have died like mayflies in an actual war with the USSR, that this was glaringly obvious, and that Western tank developers seemed strangely reticent to do anything about this.

 

I think there are multiple factors that need to be considered. Shtora and Sarab are effective nowadays, but only against older missile types. Why are these systems effective? Because there was enough time to analyze the existing missile systems, that was quite hard back in the Cold War. The Soviets with Shtora faced a much greater amount of competition, still the system appeared rather late (~1985) and failed to intercept the TOW and MILAN missiles during the Greek tests. So it seems rather questionable, that a 1970s tank (a tank "prior to the adoption of the Leopard 2") could make good use of a Shtora/Sarab system.

 

One thing to consider: The majority of opposing ATGMs in the 1970s and even in the 1980s still were MCLOS missile systems, at least for the Warsaw Pact countries. The Soviet Army could afford all the new and fancy stuff, the other countries in the Warsaw Pact not so much. For example East-Germany received the Fagot ATGM in 1975, the Konkurs and Metis were delivered in 1983 and 1984, while the gun-launched Bastion ATGM was adopted in 1988 and the Shturm missile was adopted in 1989. Even then the Malyutka remained the most numerous missile, though apparently a number of them were upgraded to SACLOS systems. The SPG-9 and RPG-7 were considered to be the main tank killers though.

The Soviet Union adopted Shtora, because they faced a very different opposition. West-Germany alone had something in the area of 3,000-4,000 SACLOS launchers (316 Jaguar 1, 165 Jaguar 2, 170 Wiesel with TOW, ~2,100 Marder with Milan, several hundred Fuchs and Wolf with Milan, 212 PAH-1 helicopters, + several infantry systems).

 

I can understand that it's a bit sad that most modern vehicles don't have an APS, but even the Soviets had a reluctance when it came to adopting APS. No system is perfect, so when you don't have to invest lots of money into a system of potentially limited value, then you won't do it. Even before the Israelis used Blazer for the first time, there was an ERA package being tested on the Leopard 1, which provided protection against 105 mm APFSDS ammo. Just think about that, an armor that could have a Kontakt-5-like impact on tank and gun development a decade earlier!

 

I think it comes down to NATO not having access to enough data on Soviet tanks and missiles. The existence of the T-64 was pretty much unknown during the 1970s, while info on the T-72 was extremely scarce... I have an old edition of Jane's, where the author assumed that the T-64 and T-72 were both the same tank (blaming different reporting names from UK and US for the two designations) and were fitted with either a 115 mm or 122 mm rifled gun, while not a single word about composite armor is mentioned...

NATO believed that ATGMs could deal with all Soviet tanks and that the larger number and higher sophistication of NATO ATGM systems would mean that Soviet tanks were even less likely to survive.

 

When it became clear that the Soviets had composite armor and had developed more modern missile systems, the NATO tanks all were upgraded. The US Army's M60 was meant to receive ERA, but after the M1 Abrams became widespread, it was considered cheaper to not buy it. The ERA package adopted on the M60A1 of the USMC (originally designed for the US Army) is btw. not Blazer, but made in France (it's called something like "ACA" or" AAC"). The AMX-30 received a version of the same ERA system to protect against ATGMs. The Leopard 1 was meant to receive composite armor, but that was canceled after the Soviet Union was gone.

 

31g.jpg

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"Benefits of APS yet to be fully realised".

What is this bullshitry? APS has been demonstrated in combat to a great potential and its benefits are very well realized by those who don't deliberately insist on living in the 80's.  Oh wait there was already an APS back then. 

It's not so much about benefits not being realized as much as it is the fault of poor procurement procedures across most of the western hemisphere.

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1 hour ago, SH_MM said:

Interessting that they still work on anti-KE performance, given that the ADS managed to defeat certain types of (simulated) APFSDS during tests already in 2007 according to German and Swedish sources.

Interesting, but not surprising. RAFAEL has worked on, and even successfully tested, a modified version of Trophy to defeat KE over a decade ago, but much like the ADS it is still developmental.

 

I'm guessing that despite the technological feasibility, which was proven, the reason for not having this capability is it not being demanded. But then, the company representative says this is a highly demanded capability. So this is the confusing part.

 

The IDF has only recently raised this demand for the Barak program (Merkava 4 upgrade), after opting for an anti-CE solution for a long time, and the US Army also opted not to test any anti-KE capable APS despite 2 available factors:

1)Iron Fist was offered in its full sized version, not only the IF-LC. Or at the very least, was well known to the program management.

2)RAFAEL has been in the process of refitting Iron Fist launchers to the Trophy system since at least 2014, so the effort should be available to the US, and most of the components should be non-developmental and with high TRL.

 

Where is this demand they're talking about?

First let's see a demand for any APS at all.

 

Bonus: I was not aware the German Army had the ADS for the Boxer in mind.

But that's the wrong approach. APS should go to frontline units first - Puma and Leopard. Want to protect expeditionary forces? First give them an IFV Boxer, then talk about beefing up its protection. 

Israel did the mistake of not arming its Namers soon enough. I hate to see others repeat our mistakes.

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On 19.9.2017 at 1:20 PM, Mighty_Zuk said:

But that's the wrong approach. APS should go to frontline units first - Puma and Leopard. Want to protect expeditionary forces? First give them an IFV Boxer, then talk about beefing up its protection. 

Israel did the mistake of not arming its Namers soon enough. I hate to see others repeat our mistakes.

 

I disagree. The Boxer is the vehicle with the biggest need for an APS. It carries the biggest amount of soldier, has the thinnest armor of the previously mentioned vehicles and no other APS. The Puma has thicker armor, ERA and AMAP-SC NERA against RPGs and the MUSS softkill APS against ATGMs. Depending on how effective MUSS is - but I don't think there is any public source on this matter - there is no need for a hardkill APS. The Leopard 2 on the other hand has interfaces to mount thick anti-shaped charge armor on the sides, while the front should be immune to all existing ATGMs. The Turkish losses showed that armor alone is not enough, but when a tank crew doesn't react to the two tanks on the left and right side being blown up by ATGMs, then the issues probably won't be solved with sticking an APS onto it.

 

bw-tracked-leopard2a7+u-004.jpg

 

As the probability of a war in Europe is close to zero, the Boxer is the most likely to see combat. It is the lightest of the three vehicles both in terms of weight (meaning it will be airlifted into operation theaters earlier) and political baggage (the bigger the gun of the vehicle, the more thoughts do politicians spend on "Will we remind someone of the Nazis, when we send over this vehicle?"). The Boxer is a front-line vehicle - that of the motorized/light infantry (Jäger), while the Puma is operated by the mechanized infantry (Panzergrenadiere).

 

That doesn't mean I that I'd be against adopting additional active protection systems or further passive armor on the vehicles. Personally I'd stick three different types of APS on the AFVs to maximize protection. But when there is a limit to budget, time and electrical power on some existing vehicles, I'd start to add an APS to the vehicle with the biggest need. If there weren't any limitations, I'd put a combination of MUSS and a grenade-based system (AVePS, Iron Fist, LEDS-150) ontop of the turret, while the sides would be fitted with the ADS hardkill system.

 

 

 

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Paul J. Hazell's Armor  states that the most important factor for anti-APFSDS APS is to hit the penetrator when it is quite far away from the vehicle.  It takes a significant amount of time (and thus distance) for the rod to yaw enough to reduce its penetration.  Also, yawing (or even fracturing) the incoming long rod doesn't get rid of the KE of the threat, or even substantially change its vector, it just makes it penetrate less efficiently.  As an example, an APS which could hit a long rod with 20:1 L/D ratio hard enough and far out enough to induce a 20 degree yaw (apparently even this amount of yaw is technically challenging) would reduce the penetration of the long rod by 60%.  40% of the penetration of a modern APFSDS round is still quite a bit of penetration, so any vehicle with anti-APFSDS APS is still going to need a substantial amount of passive armor to absorb the intercepted threats.

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On 19.09.2017 at 11:51 AM, SH_MM said:

Interessting that they still work on anti-KE performance, given that the ADS managed to defeat certain types of (simulated) APFSDS during tests already in 2007 according to German and Swedish sources.

 

Germans few yers ago had shown poles (and not only) abilities AMAP-ADS to stop DM63 from <200m distance.

The target was empty Leopard-2A4 hull and turret (only whit armour + ADS). There was sevral shoots from 120mm DM-63.

No perforation, the deepest mark from rebound long-rod have circa 50-80mm deep (mesured by hand for one polish officer there so inacurrate).

Anyway - ADS is able to stop long-rod even whit Vmuzzel = 1700m/s

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On 20.9.2017 at 6:25 PM, Collimatrix said:

Paul J. Hazell's Armor  states that the most important factor for anti-APFSDS APS is to hit the penetrator when it is quite far away from the vehicle.  It takes a significant amount of time (and thus distance) for the rod to yaw enough to reduce its penetration.  Also, yawing (or even fracturing) the incoming long rod doesn't get rid of the KE of the threat, or even substantially change its vector, it just makes it penetrate less efficiently.  As an example, an APS which could hit a long rod with 20:1 L/D ratio hard enough and far out enough to induce a 20 degree yaw (apparently even this amount of yaw is technically challenging) would reduce the penetration of the long rod by 60%.  40% of the penetration of a modern APFSDS round is still quite a bit of penetration, so any vehicle with anti-APFSDS APS is still going to need a substantial amount of passive armor to absorb the intercepted threats.

 

That is true for APS using HE-blast grenades who work by tilting the projectile in flight. There are different ways to defeat long-rod penetrators, some of which don't require much space. Dr. Manfred Held designed an APS that essentially launched heavy ERA tiles against the incoming projectile, which worked extremely well against APFSDS ammunition (reduction to less than 10% penetration power).

image010.jpg

 

However the weight efficiency is strongly decreased by such a system.

 

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On 9/23/2017 at 9:12 AM, SH_MM said:

 

That is true for APS using HE-blast grenades who work by tilting the projectile in flight. There are different ways to defeat long-rod penetrators, some of which don't require much space. Dr. Manfred Held designed an APS that essentially launched heavy ERA tiles against the incoming projectile, which worked extremely well against APFSDS ammunition (reduction to less than 10% penetration power).

image010.jpg

 

However the weight efficiency is strongly decreased by such a system.

 

 

 

These are interesting pictures.  High-speed x-ray I'm guessing?

What I don't understand is how launching ERA tiles into an incoming APFSDS works better than having the APFSDS trigger the ERA itself.  Having ERA that is triggered by a radar detector has been around conceptually for decades, and the idea would have some advantages against HEAT warheads.  However, that is because the jet of a HEAT warhead does not move at uniform velocity.  The tip of the jet (or "precursor" in some articles) is moving a lot faster, and has typically already penetrated the ERA cassette by the time the explosive in the ERA cassette detonates.  Thus, the ERA cannot feed additional material into it.

 

But for a heavy ERA system intended to also work against APFSDS by breaking up the penetrator, what is the advantage of hitting it earlier?

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On 24.9.2017 at 7:07 PM, Collimatrix said:

What I don't understand is how launching ERA tiles into an incoming APFSDS works better than having the APFSDS trigger the ERA itself.  Having ERA that is triggered by a radar detector has been around conceptually for decades, and the idea would have some advantages against HEAT warheads.  However, that is because the jet of a HEAT warhead does not move at uniform velocity.  The tip of the jet (or "precursor" in some articles) is moving a lot faster, and has typically already penetrated the ERA cassette by the time the explosive in the ERA cassette detonates.  Thus, the ERA cannot feed additional material into it.

 

But for a heavy ERA system intended to also work against APFSDS by breaking up the penetrator, what is the advantage of hitting it earlier?

 

Unfortunately the whole situation regarding this APS is a bit confusing. There in only one single paragraph of the document from where the photo is taken, which describes a hypothetical new APS. Now my understanding is that not a single prototype of this APS was built - or at least not at the time of writing the description of this APS - so all images (besides some of the drawings) in the article are showing other types of APS with similar/the same mechanism to illustrate how the new APS would work. Essentially Dr. Manfred Held theorized a type of APS with the aim to provide 1.5 times the space efficiency and 2 to 4 times the weight efficiency (vs KE and HEAT respectively) in relation to the Leopard 2A5's frontal turret armor.

 

The photo from earlier shows an APFSDS rod hit by three "impactors" without any further statement on how these impactors will look like. These could be metal plates/bars, composite plates or ERA tiles as mentioned in an older document from Manfred Held, where he provided a drawing with ERA/NERA plates.

 

9nIBJcV.jpg

 

 

The APS theorized by Dr. Held combines multiple different approaches and systems. The outermost "layer" is formed by shaped charge countermeasures linked to a high-precision sensor units to defeat RPGs and ATGMs - such an APS was designed by Dr. Held and tested in Germany during the late-1960s already. If this system fails, the pre-cursor warhead (in case it's a tandem warhead) will be stopped by a relatively thick steel plate (which can be reinforced by a layer of ERA or other reactive armor), then the other APS might start to work. The second shaped charge warhead will be defeated by a layer of heavy integral ERA, which has a thick enough cover plate to stop any sort of remaining jet fragments of the first/pre-cursor warhead.

Behind the front of the armor plate, there are trigger mechanisms (either a electric cicuit that will be shortened by the APFSDS or an explosive charge that will be detonated), which then sets of an explosive charge to launch the anti-KE impactors. These impactors consists of metal bars, but in one of the drawing they are located in the center of an ERA tile, thus implying that the whole ERA tile with  the bar was fired. However the text mentions that there remains back-up heavy ERA in case the APS fails to defeat the APFSDS (and to counter more advanced APFSDS with telescopic rods or greater L/D ratio), which is a bit in conflict with the drawing. In the end there the drawing could represent another APS type/variant; there is no complete overview showcasing the whole system.

 

The concept of throwing ERA (or NERA) into the path of a penetrator is made for enhancing the effects. The penetrator will have more time to tilt and its fragments will have more time to spread along a larger surface, significantly reducing the penetration. Throwing steel plates into the path of a penetrator at a larger stand-off distance already provides better efficiency than ERA, so using NERA/ERA or composite armor panels instead is supposed to be even more effective.

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On 20.9.2017 at 7:25 PM, Collimatrix said:

Paul J. Hazell's Armor  states that the most important factor for anti-APFSDS APS is to hit the penetrator when it is quite far away from the vehicle.  It takes a significant amount of time (and thus distance) for the rod to yaw enough to reduce its penetration.  Also, yawing (or even fracturing) the incoming long rod doesn't get rid of the KE of the threat, or even substantially change its vector, it just makes it penetrate less efficiently.  As an example, an APS which could hit a long rod with 20:1 L/D ratio hard enough and far out enough to induce a 20 degree yaw (apparently even this amount of yaw is technically challenging) would reduce the penetration of the long rod by 60%.  40% of the penetration of a modern APFSDS round is still quite a bit of penetration, so any vehicle with anti-APFSDS APS is still going to need a substantial amount of passive armor to absorb the intercepted threats.

Where did you get those numbers? 

So far the figures I've heard, from IMI, were 90% penetration reduction from a mere 7° yaw. At such angle, what you're getting is mostly a teething effect.

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