Asymmetrical warfare--armour: due to the operations in the Balkans, Afghanistan and Iraq new requirements in armoured protection for fighting vehicles have emerged. While laboratories and research facilities were focusing on protection systems developments against smart weapons, most of the casualties were made by so-called dumb threats.

With the realisation that two thirds of the American soldiers killed in Iraq actually fell victim to improvised explosive devices, mines and RPG7 hand-held weapons, ballistic armour protection is back in force in all inventories. For all the dreamers who assumed that a combination of smart stealth technologies and electronic protection would have solved the problem of survivability on the battlefield, it is now time to wake up.

However, the lesson learned by western armies is an old story for the Israeli Army. Years of struggle against Hesbollah militias and Palestinians fighting organisations in south Lebanon and occupied territories have taught the Israeli forces a few lessons about the devastating effects of creatively applied rudimentary weapons.

Improvised Explosive Devices

Merkavas and others Israeli heavy armoured vehicles remained undefeated until the Palestinians heard about armoured vehicles being destroyed in the Balkans and Sri Lanka by heavy buried explosive charges. The time had come to try this approach themselves. A buried charge generally consists of 50 to 150 kg of explosive or many piled mines or even 152 or 155 mm shells.

In order to destroy the targeted tank, tactics and techniques must be combined. The role of the tactics is to draw the tank into a mousetrap. In the Gaza strip the favoured trick is to lay a phoney ambush against an Israeli convoy or patrol, whereupon the tanks summoned to the rescue are drawn into a chase with the Palestinians fighters running through the narrow streets of the city to lead the tanks over the spot where the charge is buried. The Israeli Army has lost at least three Merkavas and two M60 Magash 7s in such actions. The myth of Israel's main battle tank invulnerability was torn to pieces.

In December 2003 a US Army M1A1 tank was destroyed in the same manner near Baghdad. The blast was so powerful that the turret was thrown twenty meters away from the chassis (see title picture), which clearly shows the limits of armouring and perhaps the need to develop new tactics in which routine should play no part. More recently, in May 2004, two heavy Israeli armoured personnel carriers were destroyed within two days time in the Gaza strip.

The triggering mechanism of such charges consists of a simple electric wire or a mobile telephone signal. There is no armour technology able to protect a main battle tank floor against such heavy charges. The only countermeasures are tactics: intelligence, reconnaissance and surveillance of roads and routes. Nevertheless, the Israelis often use electronic jammers to preventively trigger Hesbollah remote-controlled bombs laid along the Lebanese border.

The Mine Threat

The German BWB (Bundesamt fur Wehrtechnik und Beschaffung or the Federal Office for Defense Technology and Procurement), has contracted Krauss-Maffei Wegmann to supply 15 mine protection kits for the Leopard 2. Thus equipped, the tanks are known as Leopard 2A6Ms. The kit has been defined by a Leopard 2 working group consisting of German, Dutch, Norwegian, Swedish and Swiss members. Ten Swedish STRV122 vehicles will receive the kit.

The protection suite is designed to cope with the most often encountered mines in the Balkans and especially explosively forged penetrators. However this underbelly installation is not sufficient to protect crew and vehicle because of the secondary effects of a mine blast. Additional follow-on measures include a new escape hatch, a modified driver seat and a new receptacle for the turret slip ring, as well as leaving the bottom row of the hull's 120 mm ammunition stowage area empty.

At the Eurosatory exhibition in June 2004, Giat presented its latest developments in mine protection technologies. The French company is now promoting an add-on armour kit able to defeat the famous TMRP-6 that combines blast and explosively forged penetrators. The technology has drawn the interest of the French army for both the Leclerc and the engineers' vehicle. Giat is also active in protection against regular blast mines, having developed applique solutions for wheeled vehicles such as the VAB, the VBCI and certain lorries.

The mine protection is now a mandatory requirement for all armoured fighting vehicles. The latest request for info issued by Belgium and Denmark for armoured reconnaissance vehicles includes protection against six to eight kg blast mines under the belly--a very high design constraint to say the least.

South African engineers, who have garnered huge experience in mine protection, have drawn a very empirical rule related to mine and vehicle protection: in order to prevent a vehicle from overturning its weight in tonnes must be equal to the mine weight in kilos; in other words, should an eight-kilo mine explode under the vehicle, the vehicle must weigh at least eight tons not to turtle over.

Weight is a key factor against a blast mine and mine protection requirements are thus not easy to meet in the case of light to medium vehicles. During an armoured fighting vehicle symposium in Schrivenham, Plasan Sasa from Israel showed a short video clip of tests involving an M113. A simple eight-kilo mine explosion under the last wheel projected the vehicle in the air in such a way that the vehicle toppled on its side. In fact the blast effect generated a pry-off force sufficient to move the vehicle in this manner. That proves that the South-African rule is really empirical since an M113 weighs more than eleven tonnes.

This is why the new trend in mine-resistant light vehicle design is the 'citadel' concept. This idea relies on a central, highly resistant structure--where the crew is seated. The automotive components are attached to the structure by means of fusible mechanical links, which pose little resistance to the blast; thus only low forces are transmitted to the citadel, which remains intact and does not cartwheel over. This concept is applied to the new Iveco-Alvis Vickers LMV and to the Mowag Eagle 4 based on the Duro chassis.

Ubiquitous RPG7

RPG7s can be easily picked up from street stalls for as little as a couple of hundred dollars in most 'grey zones' and other troublesome spots around the world. The weapon's proliferation makes it the single most serious ground-launched threat to today's armoured fighting vehicles.

RPG is a generic term to define a complete family of hand held anti-tank rocket propelled grenades of Russian origin, but now manufactured in a number of countries (there are Chinese, Bulgarian and former Yugoslavian versions, to name but a few). Depending on manufacturing process, quality standards and technologies used, RHA penetration is between 250 mm and 450 mm. The latest versions feature a tandem warhead to defeat add-on explosive reactive armour protection. The standard operating scenario is the following: a highly motivated individual waits patiently on the roof of a village house and eventually pulls the trigger to cause major damage to passing armoured vehicles.

Today's protection techniques mainly rely on ballistic armour, both passive and reactive, but a new solution has emerged and is known as the 'grill' system. It now equips the US Army Stryker amongst others. There is no point in dwelling on ERA and passive technologies since these subjects have been detailed in recent issues of Armada International, but new products are coming on the market and are worthy of a few lines.

Israel Military Industries has revealed its new L-Vas--Light Vehicle Armour System. The system is based on add-on modules that can be tailored to any vehicle shape. For obvious marketing issues, the L-Vas is generally promoted on an M113. The L-Vas is claimed to provide RPG7 protection and stop 14.5 API bullets fired from a 300-metre range.

The multiple-impact absorption capability of the L-Vas is more than three shots per square metre. It is said to combine low sensitivity explosive sandwich and Nera technology.

In Germany the future Puma will be protected against RPGs in its heaviest version (42 tonnes) by an armour kit. Many companies are bidding for its development. To this end Verseidag, Dynamit Nobel and the IABG institute are working on a new explosively reactive armour concept called Ultrax. This is presented as a fragment-free explosive armour since it features no metallic parts. Indeed one of the main drawbacks of classic metallic explosive reactive armour is that the shrapnel and flying plates they generate constitute a lethal threat to the dismounted infantry, who are sometimes but a few metres away. The German team experimented with a new sandwich in which glass fibre panels replace the steel plates. After detonation the new explosive module only generates disorganised glass fibres and non-lethal debris. The surface weight is only 170 kilos per square metre. A sloped steel plate that is located behind the ERA block provides the ballistic protection against kinetic energy projectiles.

In France Giat is working under a DGA contract on the development of an add-on kit for the future 8 X 8 VBCI that will feature the same performance--as will, by the way, the US Army's solution for its new Stryker vehicle.

However, as an interim solution the US Army has developed a new slat armour kit for its Stryker in Iraq. The system triggers projectiles in a stand-off fashion without their reaching the vehicle hull. The distance between the vehicle and the grill is around 1.5 foot (460 mm). The weight is 5200 pounds (2400 kg) and it is claimed to be 3000 pounds lighter than classic add-on anti-RPG reactive armour.

The main drawbacks of the system are its bulky shape and only an estimated 50 per cent efficiency against PG7/7M RPG models (these statistics emanate directly from front-line Stryker experience).

The slat concept is also used to protect the exhaust grill of the M1 Abrams.

The grill technology is not very new. It has been used many times is the past by the Russian army on their BTR60/70, the Israeli Merkava in the form of chains or by the WW2 German tank crews.

Electric Armour

The British Ministry of Defence has tasked the Defence Science and Technology Laboratory (Dstl) with a mission to seek ways of reducing the weight of armoured vehicles by 50 per cent over the coming two decades. Assessing that a continuous improvement of classical concepts (explosive and passive) would not drive to the expected goal, Dstl scientists quickly concluded that they had to find a new approach.

A shaped charge-generated jet is nothing more than a length of copper wire. If a current of more than twelve amps is sufficient to blow and disintegrate the fuse of a household electrical appliance, why shouldn't a high temperature and a powerful electrical field disperse a high-speed copper jet? It does. In a demonstration to high-level British Army and Ministry of Defence customers and invited American experts in spring 2002, a target vehicle (an old FV 432) was submitted to repeated attacks. Post-shot examinations showed that the vehicle had sustained no internal damage whatsoever.

The system consists of bulletproof metal plating, insulation, power distribution lines and storage capacitors. The operating principle is the following: the electric energy is used to load two metallic plates separated by an insulator with a different polarity; upon hitting the outer plate, the RPG, or any equivalent warhead, is normally set off, the copper jet is formed, runs through the insulator and reaches the inner plate where it establishes an electric connection that properly fuses and vaporises it.

The system weighs around two tonnes whereas the 350 mm thick rolled homogeneous armour offering a similar protection to an FV432 would tip the scales at 32 tonnes, considering that the total surface to be protected hovers around twelve square metres. This simple calculation shows that the electrical armour has an amazing mass efficiency factor of 16.

Electric armour is presently at the technology demonstrator stage, but is seriously being considered in America for the Future Combat System. It would not be the first time that armour technology crosses the Atlantic, in the 1970s the Chobham/Burlington composite layered armour went the same way.

The French-German Institut Saint-Louis is said to work on the same concept and it is reported that some French companies like TDA are following the experimental studies of the laboratory in order to further exploit the basic research and development outcome. The sceptical argue that the concept is plagued with huge safety issues regarding high current management to protect the crew, and possible electromagnetic incompatibility with other vehicle subsystems. However, sharp memories will recall that the same sort reluctance was expressed against combustible cartridges some years ago. It boils down to applying proper user rules. After all, the use of ETC or Rail Gun technologies will pose the same problems in the future, but here again, once the problem is properly defined so will be the solutions.

The New Ballistic Star

The above research work does not preclude experimentation on new ballistic materials. In the past five years impressive research activity has been deployed around a very promising metal: titanium. Until the 1990s titanium was almost exclusively used in the aerospace industry with a notable exception in Soviet Union-era Russia where Alpha submarine hulls and large helicopter rotor hubs were manufactured with this expensive metal. Having made the necessary changes, in October 2003 the International Titanium Association meeting in the United States resulted in a number of companies loudly promoting that "low cost titanium" was obtainable through Electron Beam Single Melt processing. The raw material is nothing more than recycled aerospace industry titanium scrap. Timet, one of the largest titanium suppliers, has designated this new alloy EBSM-ARW, in which ARW stands for ARmor-Weldable.

In 2001 the US Army started a programme with a view to replacing the M1's depleted uranium mesh armour with titanium alloy. General Dynamics Land Systems, the Armor Research Laboratory, Tacom and British laboratories were involved in the programme. However, the French were the first to disclose information on the nature of the ballistic protection used on the VBCI and the latest version of the Leclerc tank by revealing that titanium (most probably TA6V alloy) was used in the armour blocks of both vehicles (interestingly, TA6V is used in such extreme activities as space and odontology). It is now strongly believed that an intensive use of titanium is made by the Germans, British and Israelis in their latest versions of Leopard 2, Challenger 2 and Merkava 4.

From a pure ballistic point of view two identical thicknesses of titanium and RHA boast almost similar properties. With a very favourable density of 4.5, TA6V offers a theoretical mass efficiency of 1.7. However this factor must be tweaked depending on the specific ballistic behaviour of titanium against shaped charges, long rod projectiles and armour-piercing bullets. One could even--and correctly--argue that this value is rather poor against shaped charges. In fact, the titanium is most efficient in countering kinetic energy rounds.

Apart from its remarkable ballistic property, titanium is also weldable, which makes it most promising for the design and manufacture of structures. Some companies are already working on complete titanium vehicle hulls. A French project was presented in 2003 in view of the EBRC programme for the future family of medium fighting vehicles.

In Germany titanium is candidate to the crew survivability cocoon design of future combat vehicles. United Defense, for its part, has built the front part of the Wheeled Future Combat System demonstrator chassis in titanium. The vehicle was exhibited many times in 2002 and 2003.

Proliferation of Add-ons

The broadening market of ballistic protection is now being fed by a continuously growing number of specialised companies. Peacekeeping operations have shown that armour protection is required everywhere and no longer the privilege of combat vehicles. Jeep-types, lorries and other logistics carriers need protection as well. Ceramics, high hardness steel, aluminium alloys, Aramid fibres are combined to present ready-to-use, add-on solutions.

Armour Systems International's Aztic 100 is a good example. It is a peel-and-stick module capable of withstanding multiple hits from 7.62 or 12.7 machineguns. HP White Laboratories in America has already certified the Aztic 100 to level 3 (7.62 Nato) National Institute of Justice protection. The semi-flexible panels can be bonded to almost any surface including metal, plastic, glass fibre and concrete. They feature a multi-resistance capacity against salt water, ultraviolet rays, acids and toxic agents. With minimal training, combat and maintenance personnel can quickly and easily apply the armour in the field by peeling the panel's release liner and pressing it firmly to the surface. This simple action provides ballistic protection to soft-skinned vehicles, Hummers and lorries.

Permali Gloucester supported British Army operations in Iraq by responding to an urgent requirement to enhance the armour protection of CVR(T) reconnaissance vehicles.

Design, prototyping, testing and manufacture were completed in four months with the support of Alvis Vickers and Dstl. The kits, shipped to Iraq and installed on the spot, are said to provide protection against armour-piercing bullets and splinters. Permali Gloucester is teamed with Plasan Sasa in Israel.

In France Giat and Ares Protection have pooled their expertise to promote common applique solutions for light/medium vehicles. The systems draw on the huge technical investments made by the DGA and the French Army in favour of the VBCI, the Leclerc S3 as well as the EBG, AMX10P and AMX10RC upgrade programmes. This represents a new strategic orientation for Giat, as indeed, although the company has more than forty decades of armour technology behind its belt, strangely enough only the French armoured fighting vehicles have had the privilege of using its expertise and competencies in this field. Giat's catalogue now includes a comprehensive range of technologies (titanium alloys, high hardness steels, ceramics, ERA, Nera and Aramid fibres) that covers almost all protection levels listed under Stanag 4589.

An M113 was exhibited at Eurosatory in June 2004 fitted with various samples of armour solutions able to withstand armour-piercing projectiles up to 35 mm, RPG7, artillery 20 FSR blast mines, bomblets and EFP mines. Spall liners are also available for the vehicle.

Ares Protection recently won the Italian competition for the up-armouring of 82 M113s. The French company will supply add-on composite panels made of small alumina cylinders fixed on an Aramid back-plate and embedded in a sort of plastic foam. This technology, called Liba (for Lightweight Ballistic Armour), is said to protect the vehicle against medium-calibre armour-piercing rounds.

Aluminium Add-on

Aluminium alloys are appreciated as excellent structure materials. The M113, the Warrior, AMX10P/RC, Stormer, Bradley, the BMP3 and the new VBCI all benefit from the combined resistance, light weight and high ballistic oppositional properties of 5083 and 7020 light alloys. Those vehicles can be easily uparmoured. A 30 to 40 millimetre-thick aluminium plate can withstand the blast/shock effect of explosively reactive add-on modules. Interestingly though, it was recently revealed that aluminium alloys themselves could be used as add-on armour. The Italian Centauro was exhibited at Eurosatory with 70 mm thick aluminium plates bolted onto the chassis and turret. Those plates boast Stanag protection level 4.

France's Auverland decided to use external aluminium plates backed with a highly hardened steel structure to give the new PVP (Petit Vehicule Protege) Stanag protection level 2. This fully metallic solution was selected due to its low cost compared to more sophisticated ceramics/Aramid fibres panel solutions, although the latter could be used to reach Stanag levels 3 to 4.

Armoured Hummer

Every day destroyed Humvees (or Hummers) make the headlines of newspapers and television news reports. As mentioned at the beginning of this article, most of the casualties suffered by US forces in Iraq are due to improvised explosives devices, AK47 lead ambushes and mines. This high level of losses has driven the US Army to acquire more than 14,000 ballistic kits to up-armour its Humvees.

The Anniston, Red River and Latterkenny depots and the Rock Island arsenal are manufacturing 500 kits a week for the American forces deployed in Iraq. The kits are based on metallic solutions developed by the Army Research Laboratory.

O'Gara-Hess & Eisenhardt, an Armor Holding company, has developed metal solutions which include high-hardness steel, roll-bonded dual hardness steel and titanium, seamlessly welded and over-lapped to eliminate potential gaps. The company uses also resin impregnated Aramids, such as Kevlar, as well as a non-ferrous composite, custom moulded to fit a vehicle's inner skin to create a perimeter shell of protection.

In Israel, Plasan Sasa is marketing a composite solution based on ceramic and Aramid fibres. In fact, the company has recently received a contract worth over $100 million via Armour Holdings to mount its APK kit on no less than 920 Oshkosh Medium Tactical Vehicle replacements for the US Navy.