Challenger II

1The FV4034 Challenger II is a British main battle tank (MBT) in service with the armies of the United Kingdom and Oman. It was designed and built by the British company Vickers Defence Systems (now known as BAE Systems Land & Armaments). The UK placed orders for 127 Challenger I tanks and remaining Chieftains in 1991 in an effort to phase out the now aging Chieftain variants. An additional 259 in 1994 and In 1993 Oman ordered 18 Challenger 2 tanks and an order for a further 20 tanks was placed in November 1997 that were delivered ahead of schedule in spring of 1998.



The Challenger 2 is the third vehicle of this name, the first being the A30 Challenger, a World War II design using the Cromwell tank chassis with a 17-pounder gun. The second was the Persian Gulf War era Challenger 1, which was the British army’s main battle tank (MBT) from the early 1980s to the mid-1990s. The Challenger 2 successfully completed its Reliability Growth Trial in 1994. Three vehicles were tested for 285 simulated battlefield days, due to the rapid advancements in military battle plans over the last century. Military vehicles need to able to cross fast amounts of terrain – of all types- as a result of less static warfare being conducted. Each day of testing consisted:2

  • 27 km (17 mi) of on-road travel.
  • 33 km (21 mi) of off-road travel.
  • 34 main armament rounds fired.
  • 1,000 7.62 MG rounds fired.
  • 16 hours weapon system operation.
  • 10 hours main engine idling.
  • 3.5 hours main engine running.

The British Army maintained its requirement for a four-man crew (including a loader) after risk analysis of the incorporation of an automatic loader suggested that auto-loaders reduced battlefield survivability. Mechanical failure and the time required for repair were prime concerns. Similar to every British tank since the Centurion, and most other British AFVs, Challenger 2 contains a boiling vessel (BV) for water, which can be used to brew tea, produce other hot beverages and heat boil-in-the-bag meals contained in field ration packs. This BV requirement is general for armoured vehicles of the British Armed Forces, and is unique to the armed forces of the UK and India.

The Challenger II possesses a Perkins 26.6 litre CV12 diesel engine capable of delivering 1,200 HP (890 kW), used in conjunction with a David Brown TN54 epicyclical transmission with 6 forward gears and 2 reverse gears. The Challengers suspension uses a rather unique system involving the displacement of second-generation hydrogas. This, plus the specially designed William Cook Defence hydraulically adjustable double-pin track system allows the Challenger II to put accurate fire down range whilst moving at full land speed, which for the record is 37 mph (60 km/h) on road); 25 mph (40 km/h). With a maximum cross country Range of 280 mi or 450 km on road); 156 mi (250 km) cross country, on internal fuel.



The Challenger 2 is equipped with a 120-millimetre (4.7 in) 55-calibre long L30A1 tank gun, the successor to the L11 gun used on Chieftain and Challenger 1. The gun is made from high strength Electro Slag Remelting (ESR) steel with a chromium alloy lining and, like earlier British 120 mm guns, it is insulated by a thermal sleeve to enable faster cooling for the barrel after firing in an effort to remain hidden from enemy thermal imaging that may be canvasing the area. It is fitted with a muzzle reference system and fume extractor, and is controlled by an all-electric control and stabilisation system with the turret has a rotation time of 9 seconds through 360 degrees.

4Uniquely among NATO main battle tank armament, the L30A1 is rifled and along with its predecessor, Royal Ordnance L11A5, the only Third Generation Main Battle Tank Guns to use a rifled barrel. This is because the British Army continues to place a premium on the use of high explosive squash head (HESH) rounds in addition to Armour-piercing fin-stabilized. It should also be noted that as other nations often do not out such a high price on the use of HESH ammunition, they often opt for smoothbore guns because of the bonuses that they possess, this does however mean that they cannot use HESH ammunition to any extent what so ever. The Challenger II can hold a maximum of 49 rounds of ammunition (of varied types) for its L115A5 120mm in the Turret, generally around the gun for ease of access as well as in the turret basket.

As with earlier versions of the 120 mm gun, the propellant charges are loaded separately from the shell or KE projectile. A combustible rigid charge is used for the APFSDS rounds, and a combustible hemispherical bag charge for the HESH and Smoke rounds. An electrically fired vent tube is used to initiate firing of the main armament rounds. (The main armament ammunition is thus described to be “three part ammunition”, consisting of the projectile, charge and vent tube.) The separation of ammunition pieces also aids in ensuring lower chances of ammo detonation upon receiving an enemy projectile.

The barrel is 55 calibres long (L55) and is made of electro-slag refined (ESR) steel. The bore and chamber are electro-plated with chromium to give a barrel life of 1500 effective full charges. The breech mechanism is a split sliding-block breech. One vertically sliding block holds the abjuration ring (which is necessary because the propellant charges are combustible cases or bags) and is locked for firing by a second block. When the second block falls, the first is released to open the breech.

The 120mm L115A5 rifled gun used a rather diverse amount of ammunition types as the British MOD foresaw many different situation that would require a different type of ordinance. As a result of this, the following test is all of the different types of ammunition that could be loaded into the L115A5, Weather or not such ammunition is still in use is unfortunately not disclosed.

  • APFSDS L23. This has a monobloc tungsten nickel copper long rod penetrator, and used the L8 combustible case charge, although it can use a modified L14 charge. The muzzle velocity is 1,534 metres per second (5,030 Ft. /s). It was used in the Gulf War, but is now probably withdrawn.
  • APFSDS L26 (alias CHARM 1). This has a depleted uranium (DU) long rod penetrator and uses the L14A1 or L14A2 combustible case charges.
  • APFSDS L27A1 (alias CHARM 3). This also has a DU projectile, but with a greater length-to-diameter ratio and is thus “significantly more effective”. The round uses the L16A1 combustible case charge.
  • CHARM 3 training round (C3TR). Because DU rounds are normally fired in wartime only, a tungsten-based projectile is used for training purposes. Opposition to the use of depleted uranium even in wartime has led to the further development of the training round as the L28 round.
  • DS/T Prac L20A1 This is a relatively low-cost training projectile with the sub projectile penetrator made from steel with a light alloy nose. It is lighter, but matches the L23 trajectory to 2,000 metres (6,600 Ft.). Its use also extends barrel life.5
  • HESH L31 This is employed as a general purpose high explosive round, though it also has a good anti-armour performance, and is effective against fortifications and structures. The HESH L31 is fired using the L3 bag charge. Muzzle velocity is 670 metres per second (2,200 Ft. /s).
  • SH/Prac L32A6 A training projectile, which matches the trajectory of the HESH L31. It is available as a completely inert form, or can be filled with an inert HE substitute (a composition of calcium sulphate and castor oil) or an inert HE substitute plus a live fuse and a flash pellet for spotting purposes.
  • WP Smoke L34 Matches the HESH L31 in ballistic performance. It is the same shape, though is supplied in a different colour to prevent confusion


This is an example of the L94A1 chain gun mounted on a FV512 Infantry support vehicle.

The Challenger 2 is also armed with a L94A1 chain gun EX-34 7.62 mm chain gun coaxially to the left of the main gun, and a 7.62 mm L37A2 (GPMG) machine gun mounted on a pintle on the loader’s hatch ring. 4,200 rounds of 7.62 mm ammunition are carried. The Challenger can also mount a remote weapons system bearing a 7.62 mm L37A2 (GPMG) machine gun, a 12.7mm heavy machine gun or a 40mm automatic grenade launcher, though the use of 40mm grenade launchers on such a vehicle is generally not a common sight as Challenger II crews are instructed to extend the distance of combat as much as possible and play to the strengths of the vehicle, therefore using such a weapon with a limited range would generally be detrimental to this.



The Challenger 2 is one of the most heavily armoured and best protected tanks in the world. The turret and hull were originally protected by specially designed composite armour codenamed “Chobum”, which incidentally is the same composite armour that can be found on both the Abrams and Leopard tanks. It should also be known that this has since been upgraded to a second generation of “Chobum” armour that is now referred to as “Dorchester”), the details of which are classified but which is said to be more than twice as strong as steel. Crew safety was paramount in the design, using a solid state electric drive for its turret and gun movement, thus removing the traditional risk of hydraulic rupture into the crew compartment. Explosive reactive armour kits are also fitted as necessary along with additional bar armour.7 The nuclear, biological and chemical (NBC) protection system is located in the turret bustle. The tank’s shape is also designed with stealth technology to reduce radar signature. On each side of the turret are five L8 smoke grenade dischargers. The Challenger 2 can also create smoke by injecting diesel fuel into the exhaust manifolds.

Like all modern day militaries, there are always looking to improve the effectiveness of most if not all aspects of their military, both administrative and physical elements such as their armoured forces. Because of this, The Challenger II’s armour was upgraded on the sides of the turret, skirts, bar armour added to the rear. Smoke grenade launchers visible on turret front. Counter-IED ECM antennas are on the platform on the turret, and additional ECM equipment overhangs the left and right front fenders. In addition to this, a nuclear, biological and chemical (NBC) protection system is located in the turret bustle. On each side of the turret are five L8 smoke grenade dischargers, from Thales AFV Systems Ltd (formerly Helio Mirror Company). Finally, Challenger 2’s can also set a smoke screen via a sudden injection of diesel fuel into the engine exhausts.



The digital fire control computer is produced by Computing Devices Company (now General Dynamics – Canada). General Dynamics UK is supplying the platform battlefield information system application (PBISA) for the British Army Challenger 2 tanks. PBISA integrates the commander’s display, inertial navigation system, digitisation processing computer and driver’s display panel. Land Systems is responsible for system integration and some of the software. PBISA entered service in December 2005.8

British Army Challenger 2 tanks are being fitted with the Bowman tactical, digital communications system. Prime contractor for Bowman is General Dynamics UK. Bowman provides secure voice and data communications and automatic location of units. Challenger tanks fitted with the system were deployed to Iraq in early 2006.

The commander has a panoramic VS 580-10 gyro stabilised sight from SAGEM (formerly SFIM Industries). A laser rangefinder is incorporated into an intermediate assembly. Elevation range is +35° to -35°. The commander’s station is equipped with eight periscopes which provide 360° vision. The thermal observation and gunnery sight II (TOGS II), from Thales (formerly Pilkington) Optronics, provides night vision. The sensor is based on UK TICM 2 common modules. The thermal image, with magnification ×4 and ×11.5 is displayed in the gunners and commander’s sights and monitors. The gunner has a Thales Optronics stabilised Gunner’s Primary Sight, consisting of visual channel, 4Hz laser rangefinder and display. The laser rangefinder has a range of 200m to 10km. The driver is also equipped with an image-intensifying passive driving periscope (PDP) from Thales Optronics, for night driving

Combat History


The Challenger 2 had been used in peacekeeping missions and exercises before, but its first combat use came in March 2003 during the invasion of Iraq. 7th Armoured Brigade, part of 1st Armoured Division, was in action with 120 Challenger 2s around Basra. The type saw extensive use during the siege of Basra, providing fire support to the British forces and knocking out multiple enemy tanks, mainly T-54/55s.

10On the 25th of March 2003, A friendly fire (“blue-on-blue”) incident that occurred in the city of Basra, involving a one Challenger 2 of the Black Watch Battle group (2nd Royal Tank Regiment) mistakenly engaged another Challenger 2 of the Queen’s Royal Lancers after detecting what was believed to be an enemy flanking manoeuvre on thermal equipment. The attacking tank’s second HESH round hit the open commander’s hatch lid of the QRL tank sending hot fragments into the turret, killing two crew members. The strike caused a fire that eventually led to an explosion of the stowed ammunition, destroying the tank. It remains the only Challenger 2 to be destroyed on operations.

Another example of the Challenger II’s battle record would be the events of April 6th, 2007 in Basra, Iraq where a shaped charge from an IED penetrated the underside of a tank resulting in the driver losing three of his toes and causing minor injuries to another soldier.

Variants of the Challenger II


Challenger 2E has a new integrated weapon control and battlefield management system, which includes a gyro stabilised panoramic SAGEM MVS 580 day / thermal sight for the commander and SAGEM SAVAN 15 gyro stabilised day / thermal sight for the gunner, both with eye safe laser rangefinder. This allows hunter / killer operations with a common engagement sequence. An optional servo-controlled overhead weapons platform can be slaved to the commander’s sight to allow operation independent from the turret. The power pack has been replaced with a new 1,500hp Euro pack with transversely mounted MTU 883 diesel engine coupled to Renk HSWL 295TM automatic transmission. The smaller but more powerful engine allows more space for fuel storage, increasing the vehicle’s range to 550km.

Challenger II Trojan

The Challenger Armoured Repair and Recovery Vehicle (CRARRV) is an armoured recovery vehicle based on the Challenger 1 hull and designed to repair and recover damaged tanks on the battlefield. It has five seats but usually carries a crew of three soldiers from the Royal Electrical and Mechanical Engineers (REME), of the recovery mechanic and vehicle mechanic/technician trades. There is room in the cabin for two further passengers (e.g. crew members of the casualty vehicle) on a temporary basis.

The Trojan Armoured Vehicle Royal Engineers is a combat engineering vehicle designed as a replacement for the Chieftain AVRE (ChAVRE). It uses the Challenger 2 chassis, and carries an articulated excavator arm, a dozer blade, and attachment rails for fascines. Entering service in 2007, 33 were produced.

Challenger II Titan

The Titan armoured bridge layer is based on aspects of the Challenger 2 running gear and will replace the Chieftain Armoured Vehicle Launched Bridge (ChAVLB). The Titan came into service in 2006 with the Royal Engineers, with 33 in service. Titan can carry a single 26-metre long bridge or two 12-metre long bridges. It can also be fitted with a bulldozer blade.

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