The Australian Defence Force will buy hundreds of armoured vehicles over the coming years, under the Land 400 program, but although these vehicles will offer protection from small arms fire what will protect them against other threats, such as rocket-propelled grenades (RPG)?
The asymmetric aspect of modern warfare will most likely require the Land 400 vehicles and protected mobility vehicles, such as Thales’ Bushmaster and (in all likelihood) Hawkei, to operate in an urban environment, where attacks against them can be launched from concealed positions at very short ranges.
Video footage showing Israeli Army armoured personnel carriers successfully defeating incoming RPG rounds in such an environment during the recent incursion into Gaza highlights the need for some form of active protection system, capable of detecting, processing and neutralising incoming rounds in milliseconds and with minimum collateral damage.
Much of the Land 400 focus in the specialist media has been around the vehicles themselves, but some form of hard-kill active protection system will need to be mandated if the vehicles are to go into harm’s way.
What is an Active Protection System? Active Protection Systems destroy or disable an incoming warhead are known as hard-kill active protection systems, and there are several available on the market today.
Essentially the system must first detect a projectile fired towards, and is on a collision course with, the host vehicle. It must process the information, select, and then deploy the countermeasure to prevent the warhead striking the vehicle and hopefully minimising collateral damage to dismounted troops or other assets nearby.
And it must do all this very, very quickly. The blink of an eye for example, takes about one tenth of a second from start to finish, but a projectile fired from a distance of 15 metres from a vehicle will strike home in only half that time.
Of course hard-kill systems aren’t the only form of protection system, there are passive systems such as the application of protective materials, or combinations (compound) of materials or shaping,
There are also reactive forms of protection, such as explosive reactive armour (ERA), non-energetic reactive armour (NERA), non-explosive reactive armour (NxRA), self-limiting explosive reactive armour (SLERA) and electric armour. All of these, by their very nature, allow the projectile to strike the vehicle in the first instance and may not be applicable to the protection of all vehicles, due to weight issues.
Finally there are soft-kill systems, such as electronic countermeasures (ECM) or obscurants to lure the incoming projectile away by interfering with its guidance system. But these are little use against ballistic weapons such as a rocket-propelled grenade.
Concept of operations Until the 1980s, the protection of main battle tanks and infantry fighting vehicles was largely focussed on the two-dimensional frontal scenario, which did not take into account manoeuvring anti-tank guided munitions (ATGM) and there was a trade off between performance and protection. In addition, logistics and support vehicles were largely unprotected.
Since that time however, the traditional forms of warfare have often given way to the so-called ‘asymmetric’ style of engagement, often in urban areas. Threats range from the highly sophisticated and capable ATGMs, which have been widely exported, as well as the RPG, which is prolific throughout the world due to its low cost and simplicity of operation.
These threats, together with the proliferation of the improvised explosive device (IED) as a weapon of choice of insurgent or non-traditional forces, has meant that it is not only main battle tanks and infantry fighting vehicles which require some form of protection.
The threat scenario in modern warfare therefore includes hand-held anti-tank rockets (ATR), ATGMs, chemical energy rounds, kinetic energy rounds and IEDs.
There are numerous hard-kill systems either available or in use today and each one has its own attributes. Some are designed for main battle tanks, others for the full range of vehicles which require protection on the modern battlefield.
The means of defeating an incoming projectile also varies widely, with some systems using blast grenades to detonate the warhead, while others deflect the weapon using a shock wave.
Sensors include phased array and millimetre wave radars, acoustic and electro optical and infra-red detection system.
Each individual system has its own strengths and weaknesses with variation in detection and reaction times, as well as the intercept point (IP) and minimum defeat distance (MMD).
Not surprisingly perhaps, Israel is one of the first countries to use an active protection system under operational conditions and, as earlier noted, has successfully protected its APCs during the recent (and at the time of writing, ongoing) campaign against Hamas in Gaza.
Israeli Army APCs in Gaza are deployed with the Rafael Trophy system and during his presentation to the recent DMO Defence + Industry conference in Adelaide, Israel’s Ambassador to Australia, Shmuel Ben-Shmuel singled it out for praise.
“The system has a multitude of applications and can be used for main battle tanks, APCs and light armoured vehicles,” he said.
“This ‘iron dome for tanks’ alerts personnel to the launch location and deflects all identified threats.”
Ambassador Ben-Shmuel said that in the first week of the campaign alone, at least five successful intercepts were reported in Israeli media and referred to the posting of video footage on social media of an RPG shown to be successfully neutralised.
Active Defence System Dr Herbert Scholles, managing director of ADS GmbH, a German company owned by Rheinmetall, which offers a hardkill system known as Active Defence System (ADS) explained to ADM how the system works.
Dr Scholles explained that the closer the incoming threat is to the target vehicle when it can be effectively neutralised, the less likelihood there is of collateral damage.
The ADS system countermeasure directs the energy of the detonating explosive charge to mechanically destroy the warhead of an incoming ATGM, ATR or RPG, meaning significantly reduced collateral damage compared with a hit on the vehicle.
Reaction times are therefore very quick and Dr Scholles confirmed that the system is capable of identifying ballistic threats fired from an ‘extremely short range’ and works on the principle of multiple, co-ordinated layers of protective measures.
“ADS is the only protection system in the world that can defend against attacks launched in the immediate vicinity of the vehicle,” he said.
“The precise interaction of the system components makes it possible even for projectiles travelling at more than five times the speed of sound to be destroyed in time. Because of its short reaction time, ADS can successfully combat approaching airborne threats from very close ranges of just a few metres.”
The ADS system provides 360-degree protection and Dr Scholles claims it is the only hardkill APS system capable of intercepting threats fired from a distance of less than ten metres.
It uses a system of ‘prewarners’ which continuously monitor the vicinity around the vehicle, sending data to the central processing system for analysis. If the central processing system determines that the threat is valid, it activates an electro-optical sensor to identify the threat, simultaneously calculating the potential impact point on the vehicle. It then selects the appropriate countermeasure and initiates action to kinetically ‘neutralise’ the threat.
“Additionally it is important to highlight the low collateral damage zone close to the vehicle. In comparison with ADS a full detonation of a warhead at the vehicle will create a much larger zone of damage around the vehicle,” Dr Scholles continued.
“On the other hand, launcher-based systems, which intercepts incoming threats at distances up to 20 metre distance from the protected vehicle causes a larger zone of damage.”
There are a range of subsystems for protection of various sized vehicles and installation and integration will therefore add between 70 and 600 kilograms of weight, depending upon the vehicle and the level of protection desired.
ADS CAB is designed to protect 4x4 and smaller support vehicles, mainly against anti-tank rockets (ATR), with the system weighing somewhere between 70 and 250 kg, depending upon the solution specified by the customer.
ADS HAT is designed to offer 360-degree protection for the hull and/or turret of an armoured fighting vehicle and can also be extended to protect the vehicle against ‘top attacks’, or diving ATGMs. As a high-end protection system, ADS HAT weighs anywhere between 300 and 600 kg.
Finally, ADS APP provides an interface with other systems which may be installed in a vehicle, to share such information as the trajectory or direction of the threat. It also permits integration of other countermeasures such as smoke, or can provide information to a remotely operated weapons station.
ADS also has a multi-hit capability where, if one sensor is occupied with defeating the first threat, other sensors continue to monitor around the vehicle.
Dr Scholles said that peak power consumption ranges from 200 watts for the smaller CAB system, to 1000 watts for heavy vehicles, meaning older vehicles can be adapted effectively. The weight and power requirements therefore render it capable of being integrated into almost any class of vehicle within ‘a few hours’, he noted.
“As technically sophisticated as the individual processes are, they are executed at ‘lightning speed’, Dr Scholles concluded.
“From detecting the threat and analysing its trajectory to classifying the projectile and defeating it, the whole process takes only a few thousandths of a second. The blink of an eye lasts about a tenth of a second, that much time can mean the difference between life and death.”
