Challenger 2 tank

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FV 4034 Challenger 2
Challenger 2 Tank
Type	Main battle tank
Place of origin	United Kingdom
Production history
Manufacturer	Alvis Vickers
Specifications
Weight	62.5 tonnes
Length	8.3 m (11.50 m with gun forward)
Width	3.5 m (4.2 m with appliqué armour)
Height	2.5 m
Crew	4 (commander, gunner, loader/operator, driver)
Armour	Chobham/Dorchester Level 2 (classified)
Primary armament	L30A1 120 mm rifled with 52 rounds
Secondary armament	coaxial 7.62 mm L94A1 EX-34 (chain gun), 7.62 mm L37A2 Commander's cupola machine gun
Engine	Perkins CV-12 Diesel 1,200 hp (895 kW)
Power/weight	19.2 hp/tonne
Suspension	hydropneumatic
Operational range	450 km (279 miles)
Speed	59 km/h (37 mph)

The FV4034 Challenger 2 is the main battle tank (MBT) currently in service with the armies of the United Kingdom and Oman. Built by the British company Vickers Defence Systems (now part of BAE Systems Land and Armaments). The manufacturer advertises it as the world's most reliable main battle tank^[1] although military operations in desert conditions have exposed significant problems which had to be addressed.^[2] As of January 2008, two Challenger 2s have been damaged and one destroyed (by a friendly fire engagement by another Challenger II) in combat.

Challenger 2 is an extensive redesign from Challenger 1, the MBT from which it was developed. It uses the basic hull and automotive parts of its predecessor but all else is new. Fewer than 5% of components are interchangeable.

Challenger 2 has now replaced Challenger 1 in service with the British Army and is also used by the Royal Army of Oman. The UK placed orders for 127 Challenger 2 tanks in 1991 and an additional 259 in 1994. Oman ordered 18 of the tanks in 1993 and a further 20 in November 1997. Challenger 2 entered service with the British Army in 1998, with the last delivered in 2002. It is expected to remain in service until 2035. Deliveries for Oman were completed in 2001. Challenger 2 has seen operational service in Bosnia, Kosovo-Serbia and Iraq (2003–present).

History

Challenger 2 is the third vehicle of this name, the first being the A30 Challenger, a Second World War design using the Cromwell tank chassis with a 17 pdr gun. The second was the Persian Gulf War era Challenger 1, which was the British army's MBT from the early 1980s to the mid-1990s.

Vickers Defence Systems (later Alvis Vickers, now BAE Systems Land Systems) began to develop a successor to Challenger 1 as a private venture in 1986. Following the issue of a staff requirement for a next-generation tank, Vickers formally submitted its plans for Challenger 2 to the Ministry of Defence (MOD). They were awarded a £90 million contract for a demonstrator vehicle in December 1988. In June 1991, after competition from other tank manufacturers designs (including the M1A2 Abrams, the Leopard 2 (Improved) and the Leclerc), the MOD placed a £520 million order for 127 MBTs and 13 driver training vehicles. This was augmented in 1994 with an order for a further 259 tanks and 9 driver trainers (worth £800 million). Oman ordered 18 Challenger 2s in 1993 and a further 20 tanks November 1997.

Production began in 1993 at two primary sites: Elswick, Newcastle upon Tyne and Barnbow, Leeds, although over 250 subcontractors were involved. The first tanks were delivered in July 1994.

Challenger 2 successfully completed its Reliability Growth Trial in 1994; Three vehicles were tested for 285 simulated battlefield days. Each day is known to have consisted of:

• 27 km of On-road Travel
• 33 km of Off-road Travel
• 34 Main Armament Rounds fired
• 1,000 7.62 MG rounds fired
• 16 h Weapon System Operation
• 10 h Main Engine Idling
• 3.5 h Main Engine Running

An equally important milestone was the In-Service Reliability Demonstration (ISRD) in 1999. 12 fully crewed tanks were tested at the Bovington test tracks and at Lulworth Bindon ranges. The tank exceeded all staff requirements.

The tank went into service with the British Army in June 1998 with the Royal Scots Dragoon Guards in Germany and the last vehicles were delivered in 2002. Oman received its last tanks in 2001. It is expected to remain in service until around 2035.

The Trojan minefield breaching vehicle and the Titan bridge-laying vehicle based on aspects of the Challenger 2 were shown in November 2006; 66 are to be supplied by BAE Systems to the Royal Engineers, at a cost of £250M.^[3]

Design

Armament

Challenger 2 is equipped with an 120 mm/ 55 (in barrel length) calibre/4.724" , L30A1 tank gun ^[4], the successor to the gun used on Chieftain and Challenger 1. The gun is made from high strength electro-slag refining (ESR) steel with a chromium alloy lining and, like earlier British 120 mm guns, is insulated by a thermal sleeve. It is fitted with a muzzle reference system, fume extraction and is gyro-stabilised. The turret has a rotation time of 9 seconds through 360 degrees. Because the British Army continues to place a premium on the use of high explosive squash head (HESH) rounds in addition to saboted rounds, Challenger 2's cannon is rifled, making it unique among the NATO MBTs. HESH rounds continue to be used by the British for three reasons; they have a longer range than saboted penetrator rounds, they are more effective against buildings and thin-skinned vehicles, and are also cheaper than the CHARM 3.

Forty-nine rounds can be carried from a selection of APFSDS, HESH or smoke. A depleted uranium APFSDS round known as CHARM 1 (Challenger Armament) was produced, later replaced by the improved CHARM 3. As with earlier versions of the 120 mm gun, the rounds are in two parts, a charge and a warhead. Contrary to speculation, this does not reduce the rate of fire of Challenger 2; in fact, a loader can often sustain a higher rate of fire than auto-loaders with single-piece ammunition. Further, separate charge sticks reduce the likelihood of enemy fire igniting the ammunition.

The gun is controlled by raftan all-electric control and stabilisation system. An L94A1 EX-34 7.62 mm chain gun is fitted to the left of the main gun. A 7.62 mm L37A2 machine gun for anti-air defence is mounted in front of the loader's hatch. 4,200 rounds of 7.62mm ammunition are carried.

The digital fire control computer from Computing Devices Co of Canada contains two 32-bit processors with a MIL STD1553B databus, and has capacity for additional systems; for example a Battlefield Information Control System.

The commander has a panoramic SAGEM VS 580-10 gyrostabilised sight with laser rangefinder. Elevation range is +35° to -35°. The commander's station is equipped with eight periscopes for 360° vision, and it takes only twelve seconds (+/- 2 seconds) for the turret to make a full rotation

The Thermal Observation and Gunnery Sight II (TOGS II), from Thales, provides night vision. The thermal image is displayed on both the gunner's and commander's sights and monitors. The gunner has a stabilised primary sight using a laser rangefinder with a range of 200 m to 10 km. The driver is equipped with a Thales Optronics image-intensifying Passive Driving Periscope (PDP) for night driving.

Defence

Challenger 2 is one of the most heavily armoured and best protected tanks in the world.^[5] The turret and hull are protected with second generation Chobham armour (also known as Dorchester) the details of which are still classified. Explosive Reactive Armour (ERA) kits are also fitted as necessary. The 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. Challenger 2 can also create smoke by injecting diesel fuel into the exhaust manifolds.

Drive System

• Engine: Perkins CV12 diesel engine delivering 1,200 hp (895 kW).
• Gearbox: David Brown TN54 epicyclical transmission (6 fwd, 2 rev).
• Suspension: Second-generation Hydrogas.
• Track: William Cook Defence Hydraulically Adjustable double-pin.
• Maximum speed: 45 mph, 75 km/h (road) 25 mph, 40 km/h (cross country)
• Range: 280 miles, 450 km (road) 156 miles, 250 km (cross country).

Crew and accommodation

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 are prime concerns. A human loader is able to maintain a higher rate of fire than is possible with current auto-loaders, and can assist with maintenance of the vehicle.

Like every British tank since the Centurion, 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 ration packs. Most other British AFVs also have BVs.^[6]

Operational usage

Challenger 2 had already been used in peacekeeping missions and exercises before but its first combat use came in March 2003 during the invasion of Iraq. 7 Armoured Brigade, part of 1st Armoured Division, was in action with 120 Challenger 2s. The tanks saw extensive use during the siege of Basra, providing fire support to the British forces. The tank's availability was excellent and the problems that were identified during the large Saif Sareea II exercise of eighteen months earlier were solved by the issuing of Urgent Operational Requirements for equipment such as sand filters.

In one encounter within the urban area a Challenger 2 came under attack from irregular forces with machine guns and rocket propelled grenades. The drivers sight was damaged and while attempting to back away under the commander's directions, the other sights were damaged and the tank threw its tracks entering a ditch. It was hit directly by eight rocket propelled grenades from close range and a MILAN anti-tank missile, and was under heavy small arms fire for hours. The crew survived remaining safe within the tank until the tank was recovered for repairs, the worst damage being to the sighting system. It was back in operation six hours later after the repairs. One Challenger 2 operating near Basra survived being hit by 70 RPGs in another incident.^[7]

There have been only two Challenger 2s damaged in combat and one destroyed:

• A friendly fire ("blue-on-blue") incident on 25 March 2003 in Basra in which one Challenger 2 of the Black Watch Battlegroup (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 round entered the open commander's hatch of the QRL Tank and detonated internally, destroying the tank and killing two crew members. It remains the only Challenger 2 to be completely destroyed on operations.^[8]
• August 2006 - the driver of a Challenger 2, Trooper Sean Chance, lost three of his toes when an RPG-29 penetrated the lower frontal hull armour (which is significantly weaker than that of the turret) during an engagement in al-Amarah, Iraq.^[9]
• April 6, 2007 - in Basra, Iraq, an IED shaped charge penetrated the underside of the tank, resulting in the driver losing a leg and causing minor injuries to another soldier^[10].

The BBC quotes a British MoD spokesman as saying Challenger 2 was:

Well armoured but in an operational theatre it's not the case that you can have absolute protection. This was not in any way new technology - the device involved was the same type of shaped charge that we have seen used very regularly. No-one has ever said Challenger tanks are impenetrable. We have always said that a big enough bomb will defeat any armour and any vehicle.

—http://news.bbc.co.uk/1/hi/world/middle_east/6583607.stm