Survivability: in a built-up area, the simplest rocket-launched grenade can suddenly turn itself into an effective top-attack weapon if fired from the roof or the terrace of a building. With the generalisation of conflicts in built-up areas, even the most modern tank has to be adapted the new 'laws' imposed by this environment.

In Britain it has been realised that the Challenger 2 loader's gun had become the vehicle's most used weapon, this because it of its higher flexibility, speed of operation and capability to fire at high elevation angles, which the tank's machine gun, being slaved to the turret, cannot match. However, in the current configuration of the Challenger, the loader is badly exposed to enemy fire. The British Army, through the Urgent Operational Requirement process, is currently studying ways of improving the protection of the loader by fitting a remote control weapon station to allow him to fire a 7.62-mm machine gun from under armour.

Other main battle tank improvement programmes are more ambitious as evidenced by the American Tusk and Busk, the Israeli Merkava kits, the German PSO and the French Azur.

Tusk and Busk

The US Army has begun fitting the Tank Urban Survival Kit (Tusk) on its General Dynamics M1A1/M1A2 tanks to reduce their vulnerability in urban environments in Iraq. <<The tank was not designed to do what it's doing now in Iraq,>> said Captain David Centeno, assistant product manager of the Tusk project, at the 2007 Armor Warfighting Conference at Fort Knox, Kentucky in early May. <<You take this massive tank and put it in the middle of a city, now you have to design something to enable it to survive and still do its mission in a city.>> The Tusk was developed by General Dynamics at the request of the US Army's M1 tank project manager and is based on extensive feedback from M1 crews that have served in Iraq.

The service's goal is to ship 565 kits to Iraq so that all tanks will be fitted with the Tusk by the third quarter of 2008. GDLS received a $ 45 million contract in August 2006 to produce 505 Tusk sets with Arat production funded in a separate $ 59 million contract. In December 2006 GDLS received an $ eleven million contract modification, to a contract potentially worth up to $ 60 million, to produce 250 mine floors. The army's fielding plan will remove tanks from operation for as little time as possible; units will be able to install the complete Tusk in the field in about twelve hours and the following day will be trained on the new equipment. A Tusk II enhancement, which will include a rear-view camera for the driver, is expected to be fielded in mid-2008. Under Tusk III the army is seeking to introduce a remotely operated weapons station armed with a 12.7-mm machine gun and is now evaluating which system is most suitable for the M1.

The US Marine Corps intends to fit elements of the Tusk to its M1 fleet. The Australian Army acquired 59 ex-US Army M1A1 AIM tanks under project Land 907 to replace its fleet of Leopard 1 tanks. In the second phase of the project the service tentatively plans to spend between AS 150 million and A$ 200 million to upgrade the M1 to a standard similar to Tusk.

The US army has also begun fielding the Bradley Urban operations and Survivability Kit (Busk) designed to improve the effectiveness of the M2/M3 Bradley fighting vehicle in urban operations. The Product Manager Bradley/M113 and other army officials visited ten battalions in 2004 to discuss the Bradley's performance in Operation Iraqi Freedom. The primary components of the Busk are given in a box on the page following, but also under consideration is mounting a slat armour to protect the rear ramp, although this may not be the final solution.

Merkava

Not surprisingly, Israel is also fielding low-intensity conflict/urban operations upgrade kits on its Merkava Mk 3 and Mk 4 tanks. The kit for the Mk 3 includes a heavier bottom plate better able to withstand the blast of large IEDs. The 12.7-mm machine gun mounted on top of the tank's 120-mm main gun is linked to the fire control system so that the gunner can fire it under armour protection. The commander's cupola has been redesigned to improve visibility. Marking poles are mounted on the extremities of the tank so that it is easier for the commander and driver to manoeuvre in confined spaces. Steel mesh is fitted to protect optics, intakes and exhausts. An observation window and firing hatch are mounted in the rear door so a sniper can ride in the rear compartment to provide close protection. The kit for the Mk 4 includes more advanced elements.

Azur

In March 2006 the French Army Technical Service (Service Technique de l'Armee de Terre) awarded contracts to the manufactures of the Nexter Leclerc tank, the Renault 6 x 6 VAB armoured personnel carrier and the Panhard 4 x 4 VBL scout vehicle to develop Action en Zone URbaine (Azur) modification kits for these vehicles. The prototypes were unveiled at Eurosatory in Paris, June 2006.

On the Leclerc Azur the original side skirts have been replaced by new passive armour skirts and bar armour has been fitted around the rear of the hull. Additional armour has been fitted to the turret roof and protection against petrol bombs has been installed over the rear engine decks. To provide close protection a remote control weapon station fitted with a machine gun is mounted. The VBL Azur demonstrator incorporates a 360[degrees] surveillance device, a non-lethal grenade launcher, smoke dischargers on the front and back of the vehicle, wire cutters, a strengthened front bumper with extra storage capacity, covered engine air intakes and a manually operated searchlight. The army conducted an initial evaluation of the Azur demonstrators in November and December 2006 at its new Centre d'entrainement en zone urbaine (urban training centre) at Sissonne in various operational scenarios and is now considering the results.

PSO

Germany's Krauss-Maffei Wegmann unveiled the company-funded prototype of its Leopard 2A6 tank optimised for operations in an urban environment at Eurosatory 2006 under the designation Leopard 2 Peace Support Operations (PSO). Advanced passive armour side skirts have been mounted along the sides of the hull along with the addition of armour to the sides and roof of the tank's turret. To minimise the exposure of the crew the machine gun on the commander's cupola has been replaced by a remote controlled weapon station behind the loader's hatch. This can be armed with a 7.62-mm or 12.7-mm machine gun or a 40-mm automatic grenade launcher. The tank's optics are better protected against damage from falling debris and thrown stones. A hydraulically operated dozer blade, operated by the driver, is fitted to the front of the hull enabling the tank to clear barricades and rubble. KMW has developed a mine protection kit for German and Swedish Leopard 2s deployed on international operations and this can be fitted to the PSO variant for additional protection.

Tank Munitions 

Several countries are developing multipurpose 120-mm tank rounds better suited for the contemporary operational environment. The French Army has placed an initial order for 1000 rounds of the new Nexter High Explosive-Tracer Mk II rounds which can be used against buildings and bunkers as well as light and medium armoured vehicles. Nexter is considering the use of a time fuze to enable the round to be detonated above dug-in targets.

Nexter is also developing the Polynege top-attack projectile, which is intended to defeat targets such as main battle tanks, light armoured vehicles, dismounted troops, and infrastructures beyond the line of sight out to eight km. Under DGA contracts Nexter will conduct a demonstration flight in 2007 and will later demonstrate the terminal-attack stage of the system. At time of writing, Nexter announced that it was about to disclose more information on the subject, so watch for your next issue of Armada International.

To succeed its DM 12 A2 Germany's Rheinmetall Waffe Munition is producing a new HE round designed to enable successful engagement of soft and semi-hard targets. The warhead contains steel and heavy metal design fragments and is equipped with a time fuse featuring a percussion function that can be set with or without delay. The tank's fire control system sets the time delay of the fuze.

Israeli Merkava tanks carry the 120-mm Anti-Personnel/Anti-Materiel (Apam) round, recently developed by Israel Military Industries. According to IMI, <<[the primary threat] that the Apam deals with is anti-tank squads equipped with extremely lethal AT weapons. These squads, spread out massively in the modern battlefield, on the ground, in vehicles, in buildings and bunkers, have become a major threat to today's MBTs.>> The Apam, is designed to defeat five target types:

* dismounted infantry

* light armoured vehicles

* 50.8 cm of double-reinforced concrete

* bunkers of sand and timber construction

* hovering helicopters.

The Apam flies on an overhead attack trajectory to dispense six submunitions which shower lethal fragments over a zone 50 metres long and 20 metres wide. To attack bunkers the Apam is fired as a unitary round.

The M1040 round fired by the Stryker MGS leverages the work done by Ardec and General Dynamics Ordnance and Tactical Systems in developing the M1028 120-mm canister round for use by US Army and US Marine Corps M1A1/ M1A2 Abrams tanks. The project followed a request from US Forces in Korea in 1999 for a round that could be used against dismounted anti-armour missile teams. The programme documents stated: <<The range requirements for the canister cartridge are 200 to 500 meters (threshold) and 100 to 700 meters (objective). The requirement is to defeat equal to or greater than 50% of a ten-man squad with one shot, and equal to or greater than 50% of a 30-man platoon with two shots.>> The round dispenses approximately 1100 tungsten balls as soon as it clears the muzzle and is also effective against normal block walls, concertina wire and cars. The round was chosen as one of the army's top ten inventions in 2004 and was fielded in Iraq the following year.

Ardec is developing the 120-mm XM1069 Line-of-sight Multipurpose (Los-MP) munition to defeat 'hardened targets and enemy personnel through the employment of a multi-mode programmable base detonating fuze and blast fragmenting target penetrating warhead'. The Los-MP round is intended to replace the M830 Heat, the M830A1 High Explosive Anti-Tank-Multi Purpose--Tracer, the M908 High Explosive-Obstacle Reduction-Tracer and the M1028 rounds, thus offering significant tactical and logistical advantages and hopefully lowering acquisition costs. Developmental rounds have been tested against double-reinforced concrete walls, earth and timber bunkers, anti-personnel targets and a T55 tank. The round is being developed as part of the Future Combat System programme for use by the Mounted Combat System, which is planned to enter service in 2015. The army has expedited development to meet current operational needs and if the funding request in the fiscal year 2008 budget is approved the Los-MP could be fielded as soon as 2010.

Systems in Tusk

* the stabilised Counter-Sniper/Anti-Materiel Mount (CSAMM), which enables an M2 12.7-mm heavy machine gun to be mounted above the M1's 120-mm main armament. The M2 slews with the tank's main gun and gives the crew a weapon to accurately engage targets without using the main armament or exposing themselves. More than 130 CSAMMs have already been installed in Iraq

* Abrams Reactive Armor Tiles (Arat) fitted to the sides of the hull to provide enhance protection against Heat warheads fired from hand-held weapons such as RPGs

* shaped belly armour to divert the blast of an IED and a new driver's seat which provides better protection. This aluminium armour, which weighs about 1360 kg, can be fitted in two hours

* a tank infantry phone mounted at the rear of the chassis to enable infantrymen to talk directly to the tank crew and assist in directing fire

* a thermal weapon sight for the loader's machine gun

* a transparent armoured gun shield for the loader's machine gun

* a thermal Driver's Vision Enhancer to improve the driver's vision at night and in poor visibility conditions

* a remote thermal sight for the commander of the M1A1 enabling him to fire his M2 12.7-mm heavy machine gun when closed down

* a power distribution box with circuit protection to support the various Tusk elements.

Merkava Mk 4 Kit

* an overhead weapon station that will be operated by the loader: designs from Rafael, IMI and Elbit are being evaluated

* the Vectrop Tank Sight System which mounts four protected cameras in blind spots around the tank to provide the driver with rear and side views

* a hunter-killer sight developed by ODF Optronics is mounted on a mast on the turret roof to improve the commander's situational awareness

* a front-mounted ram to enable the Merkava to clear barricades and other obstacles

* an active protection system will also be fitted. This could be either the Rafael Trophy or the IMI Iron Fist.

Busk Main Components

* a high-powered, hand-held battle command spotlight which provides three million candlepower using 24-volt vehicle power and an existing connector. This can be used to search for IEDs placed along roads at night and to identify vehicles at a standoff distance before they approached traffic control points

* a lightweight, non-conductive 'dome tent' structure to protect the turret and crew from low-hanging electrical power lines at speeds up to 50 km/h

* external optical components, such as the Commander's Independent Viewer (CIV) on the A3 model, are protected by a mesh encased in a steel frame which does not affect normal sighting functions

* a Commander's Light Automatic Weapon (Claw) mounted on the CIV and integrated with the A3 Fire Control System so that it can be fired under armour with existing fire control components. The Claw can be either the 5.56-mm M249 Squad Automatic Weapon or the 5.56mm M231 Firing Port Weapon 

* enhanced protection against mine and IED explosions.