Notes: In World War 2, the British Army used two main types of tanks – Cruiser Tanks, designed to fight other tanks, and Infantry Tanks, designed for fire support for the Infantry and as scout tanks. British experience in North Africa revealed that their Cruiser Tank designs were no match for German tanks. Better Cruiser Tanks were needed. One of these was the Comet, based on the Cromwell, but heavily modified and upgraded; in addition, the Comet was to partially replace the inadequate Cromwell. As many parts of previous tanks were used as possible, but virtually all previous tank components had to be upgraded or replaced. As a result, the Comet did not see service until after the Normandy landings in September of 1944; major unit issue did not occur until December of 1944. Due to its late arrival, the Comet did not get any major combat action until the Korean War. The Comet remained in British service until 1958, and in South Africa as late as the 1980s; the Finns used them until 1970, and in 2007 they were sold on the museum and collectors’ markets. The Irish bought 8 Comets in 1959, and used them until 1969. Currently, only Myanmar uses the Comet (in a modified form).

The suspension of the Comet was based on the Cromwell, but heavily modified and upgraded to replace a big problem with the Crowell suspension; the Cromwell tended to shed tracks, break torsion bars, and crack roadwheels and drive sprockets. The turret and hull design was again based on the Cromwell (the Cromwell’s low silhouette was one of its few good features), but armor was improved and the turret rotation rate was increased.

The Comet’s configuration was semi-conventional; the commander had a two-part hatch on the left front deck and has an electrically-traversed cupola; there is no loader’s hatch. There is a step in the frontal armor up to the part of the Comet where the turret is mounted; instead of the driver’s hatch being atop the glacis or this step, the driver has a hatch in between the glacis and the step facing to the front and opening to the right. The driver’s hatch is tiny, barely enough to squeeze through, and the driver was more likely to enter through the commander’s hatch in the turret with the rest of the crew. The radio operator had no hatch at all, and entering his position through the driver’s hatch would require him to be a contortionist, so he also entered through the commander’s hatch. The radio operator also manned a 7.92mm Besa machinegun.

The small turret of the Comet meant that the standard 17-pounder (76.2mm) gun could not be used. A more compact version of the 17-pounder was developed; though it was designated a 77mm gun to avoid confusion with the 17-pounder, it too was actually a 76.2mm gun. This reduced-dimension gun used older 76.2mm ammunition loaded to higher pressures, and therefore the Comet’s ammunition was not interchangeable with standard 17-pounder ammunition. The coaxial machinegun was the same as the hull machinegun; the commander did not have a machinegun, but a Bren gun was available for his use, and normally stored within the turret. The turret had electric traverse, and the gun had rudimentary stabilization.

The engine used in the comet Mk 1 Mk 1 was a Rolls-Royce Meteor Gasoline engine developing 570 horsepower. This, combined with the relatively low weight, gave the Comet relatively decent speed and maneuverability.

The Comet’s protection was greatly improved over the Cromwell, with better armor sloping for the turret and glacis and generally improved armor thickness over the front and side arcs. The gun mantlet was cast from a single piece of steel, and the ammunition was kept in armored bins until needed. These bins were in the hull over the tracks and behind the turret. The Comet’s weight was about the same as the Sherman, but the gun was superior in hitting power and armor protection better.

Very few changes were ever made to what was considered a successful design that was about to be replaced by the Centurion anyway. The Mk 1B had re-designed exhaust louvers on the rear deck to allow infantrymen to ride on the rear deck without being choked by the exhaust, and the engine was upgraded to produce 600 horsepower. Ammo storage rearrangement allowed for more rounds to be carried for the main gun.

The Comets sold to Myanmar (then Burma) had its machineguns replaced by M-60E2s; in addition, the commander’s cupola was given a pintle to mount an M-60 machinegun. These Comets are quite old, and none have (in game terms) a wear value of less than 5.

Notes: Until around the Korean War, the British saw tanks have having two separate roles – the Infantry Tank, designed to support infantry attacks and protect the Infantry from enemy armor; and the Cruiser Tank, meant for direct combat against enemy armor and to spearhead attacks. Early in the Korean War, the British Army realized that this approach to tank development had many problems in a modern army; the line between an Infantry Tank and a Cruiser Tank was becoming more and more blurred, The Infantry Tank with its lesser armor and armament was no longer competitive on the battlefield, and the whole approach of two different types of tanks that were more and more often doing the same job was too costly and required a larger supply structure. Therefore, when looking for a replacement for the Centurion and Conqueror tanks, the British decided to produce a so-called Universal Tank, designed for modern warfare. This became the Chieftain series of main battle tanks, and several non-MBT variants were also built.

The First Chieftain

Development of the Chieftain began in 1958. The Chieftain was to be initially armed with the L-7A2 105mm gun, but in view of Soviet tank developments of the period (or at least what NATO thought the Soviet tanks could do), the British decided to arm the Chieftain with the L-11 120mm rifled gun, before construction of prototypes even started. The Chieftain was to be survivable on the nuclear battlefield, so the Chieftain was equipped with radiological shielding and an overpressure system. Speed was a bit better than that of the Centurion, and the main gun could be depressed much further than that of the Chieftain to allow it to take more advantage of defilades and dug-in tank emplacements. The Mk 1 began service in 1965.

The layout of the Chieftain Mk 1 was standard, with a commander’s hatch on the left side of the turret, a loader’s hatch on the right, and the gunner’s position being below and to the right of the commander. The driver is in the front center of the hull; in a novel position for the time, the driver’s seat was reclined to allow the silhouette to be lower and give the driver more comfort. The commander has emergency override controls for the main gun, and nine vision blocks around his cupola providing 360-degree vision. The commander’s cupola also has an L-37A1 7.62mm machinegun (a variant of the L-7A2 machinegun, the British version of the MAG) on a pintle mount. The commander also sighting magnified periscope than can also be used as an emergency gunsight for the main gun.

The 120mm main gun was equipped with a thermal sleeve as well as a fume extractor; the coaxial L-8A1 (a variant of the British version of the FN MAG machinegun) was located to the right. At the time, the Chieftain had the most powerful main gun of any main battle tank in the world; the L-11A2 gun also uses separate rounds and propellant charges in combustible silk bags. The gunner also had an L-21A1 .50-caliber ranging machinegun based on the M-2HB, and with an effective range of 1900 meters.. The telescopic coincidence sight and the electro-hydraulic gun stabilization were tied together with a very primitive form of a ballistic computer that was quite a help to the gunner by automatically moving the gun to general area of the aiming point, from which the gunner could provide fine aiming. Six smoke grenade launchers are on each side of the turret.

The Mk 1 was equipped with a Leyland L60 engine that was a multi-fuel model which had 585 horsepower. The Mk 1s were produced primarily for operational testing, and only about 40 were built. The Mk 1/1 had improvements to the exhaust system as well an indicator to tell the crew that the engine air filter was too dirty; it is identical to the Mk 1 for game purposes. The Mk 1/2 replaced the commander’s cupola with an improved one, used a further-improved exhaust system, six smoke grenade launchers on each side of the turret, and dual headlights on each side with IR as well as white-light lenses. It’s slightly more expensive, but otherwise identical to the Mk 1 for game purposes. The Mk 1/3 was a Mk 1/1 modified to the Mk 5 standard through the "Totem Pole" program; the Mk 1/4 was the Mk 1/2 put through the same upgrades. (Most Mk 1/4s were later converted to AVLBs in 1986.) Both of these are identical to the Mk 5 for game purposes.

Later Chieftain Marks

The Mk 2 was the first model of the Chieftain to actually see series production. The Mk 2 began service in 1967, and featured as a primary upgrade a new version of the Leyland L60 engine developing 650 horsepower, and a Coventry H30 23 horsepower diesel APU. The L60 proved troublesome mechanically and was not what the British Army wanted for the Chieftain, but NATO standards at the time called for a multifuel engine, so the L60 was adopted over the Rolls-Royce diesel engine the Army wanted. On the left side of the turret is a large white light/IR searchlight (1000 meters range in white light mode, 1500 meters in IR mode); the searchlight has an armored housing and a retractable armored cover. (In game terms, the searchlight housing has an AV of 4).

The Centurion Mk 3 had an APU with improved fuel economy, a dry air cleaner for the engine, a new commander’s cupola with a single hatch instead of a dual hatch, and return rollers, axle arms, and track tensioners which were oil-filled for improved lubrication. The engine was modified through the "Totem Pole" program, which gave the engine improved reliability, improved hot-climate performance, a starter that worked better in low temperatures, and improved brakes. (This was the L60A engine.) In addition, the gun barrel was more easily removed for maintenance; ammunition storage was improved to reduce latch breakages, and the track skirts were modified to strengthen the attachments as well as make them easier to raise for suspension maintenance. For game purposes, the Mk 3 is for the most part identical to the Mk 2, except for the weight of the vehicle, the maintenance time, and the APU consuming only 1.8 liters per period instead of 2 liters. The Mk 3/2 is essentially the same vehicle as the Mk 3, but with improved air circulation for the turret.

The Mk 3/3 had several improvements that (in my opinion) should have made it a Mark of its own. The commander finally had emergency override controls for the main gun. More important modifications included a ranging machinegun with extended range (2500 meters), a laser rangefinder, the improvements in turret air circulation, a modified NBC system, and an engine uprated to 720 horsepower and equipped with a low-loss air cleaner. Turret armor was also improved. The Mk 3/3P is identical, but has improved performance in desert environments and was built specifically for Iran.

In 1970, the Israelis were in the market for a new tank, and they heavily considered the Chieftain. Leyland came up with the Mk 4, which had optimizations for desert conditions found in Israel, and the project went as far as a pre-order and the testing of two Mk 4s at the Yuma Proving Ground in Arizona in the US. In the end, however, the Israelis canceled their order.

The Mk 5 was also a major upgrade for the Chieftain, and it is considered the definitive model of the Chieftain. The engine was changed to the L60 Mk 7A, with has a 750 horsepower engine, improved air cleaners, an enhanced starter, battery heaters, and revised engine covers. The transmission was strengthened to alleviate a common maintenance problem with the transmission. The bins for the bagged charges was improved for safety reasons, and ammunition stowage was rearranged to grant a large increase in ammunition and bagged charge supply. The gunner’s and commander’s sighting telescopes were replaced with improved models, and half the ranging machinegun’s ammunition was removed in recognition that the ranging machinegun was rapidly becoming an out-of date device. The main gun received an improved thermal sleeve, and the travel lock was also improved. A device to detect whether other vehicles are scanning the Mk 5 with IR viewers was added. The commander’s machinegun mount was improved to allow it to elevate straight up. The Mk 5 was first delivered to the British Army in 1972, and soon thereafter to Iran as the Mk 5/P.

The Mk 5/L improved the laser rangefinder module; the Mk 5/2 improved maintenance capabilities for the power pack. (This version was also bought by Kuwait as the Mk 5/2K.)

The Mk 5/3 improved the commander’s cupola, and added the IFCS (Improved Fire Control System). The Mk 5/3P was designed for Iran, and was similar to a standard Mk 5/3 except for an increase in fuel capacity to 975 liters, increased mine protection (floor armor is AV7), and an automatic transmission. The Mk 5/4 is a Mk 5/3 with modifications to allow better stowage of APFSDS ammunition and a better sight graticule for the gunner.

The Mk 6 Chieftains were largely Mk 1 and Mk 2 Chieftains that were upgraded to Mk 5 standards. The Mk 7s were Mk 3s upgraded to Mk 5 standard. The Mk 8 upgraded the Mk 3/3 to the Mk 5 standard. The Mk 9 was a modification to all Chieftains that allowed for more APFSDS round storage.

The primary Mk 10 modification was the Stillbrew armor upgrade. This upgrade was done only to a very limited amount of Chieftains, most of which were stationed in Germany with the BAOR. The Stillbrew armor included very examples of what became Chobham armor for the glacis and turret front. The NBC system was also improved. The Stillbrew armor package, more an experiment than anything else, was withdrawn from the British Army after a few years, but not before being upgraded to the Mk 11 specification. The Mk 11 was fitted with the TOGS (Thermal Observation and Gunnery System). The Mk 11 was the final version of the Chieftain for the British Army; replacement by the Challenger 1 began less than 5 years later. The last version of the Chieftain was the Mk 15; this was built for a few months in 1985, specifically for Oman, and was essentially a Mk 11 without the Stillbrew armor package.

But That’s Not All…

In late 1974, Iran ordered 125 slightly modified Chieftains based on the Mk 5, and 1225 based on the Mk 5/3. These were to have been known as the Shir 1 (for those based on the Mk 5) and Shir 2 (if based on the Mk 5/3). These modified versions had a large number of fire control, night vision, and automotive modifications, most notably the replacement of the Chieftain’s engine and transmission based on the then-upcoming tank that would replace the Chieftain in the British Army (which became the Challenger 1). The coup that brought the Ayatollah Khomeini to power ended this program just as the Shir 1 and 2 were about to enter series production; first deliveries were, in fact, to take place just a few months later.

The Jordanians saw their chance. They had been quite interested in these modified Chieftains for some time, and they therefore placed an order with Vickers Defence (the company that was then producing the Shir tanks) for 274 of the Shir 2 versions. They re-christened then the Khalid (not to be confused with the Pakistani Al-Khalid tank).

The Khalid, for the most part, has the hull of a Chieftain Mk 5/3. However, the rear deck is raised quite a bit to accommodate the new engine, and the turret bustle is also modified to clear the raised roofline. (Many tank experts claim that these modifications have created a dangerous shot trap, but as the Khalid has never seen combat, it’s never been proven conclusively.) The new power pack is based on the Perkins Condor 1200-horsepower diesel, along with a change to the Brown Defence TN-37 automatic transmission. The engine was further optimized for Middle Eastern conditions by improving the cooling system with one derived from a system designed for small aircraft. With the exception of the cooling system, the power pack is 80% identical to that of the Challenger 1. The 23-horsepower APU that had been in all Chieftain variants since the Mk 3 was retained. The suspension is a considerably beefed-up version of the standard Chieftain suspension, with roadwheels that have almost twice the travel than those of the Chieftain.

Fire control is provided by a modernized version of the Chieftain’s IFCS, using more compact components. The Khalid likewise has a modernized version of the TOGS upgrade. The commander can access the gunner’s sighting equipment as well as his own and has override controls for the main gun and coaxial machinegun. The external apertures for the night vision and sighting equipment have armored shutters. Main armament is the same as that of the Chieftain, but the commander can aim and fire his L-37A1 from inside the turret when buttoned up. Jordan does not use the Chieftain’s searchlight.

In 1996, Jordan also ordered a number of appliqué armor kits for their Khalids. Budgetary considerations have considerably slowed the up-armoring of the Khalid, but it is believed that all Khalids now sport this armor package.

Twilight 2000 Notes: In the Twilight 2000 timeline, remaining Chieftains that had been mothballed or were serviceable enough to be put back into working condition began to appear in the front lines again in 1997; however, some 50 were retained for defense in England herself. Iran still used a decent number of Chieftains, but most of Iraq’s Chieftains were unserviceable by the time of the Twilight War. Kuwait never had many Chieftains, but they did take part in the war, as did Omani Chieftains. Jordan had largely converted their Chieftains to the Tariq specification by the time of the Twilight War; most Jordanian "Chieftains" in the Twilight War were in fact Khalids.

Notes: This tank, regarded as the best of the M-4 Sherman line, is a British modification of the M-4A4 Sherman. Modifications include a change of turret to accept a 17-pounder (76.2mm) high-velocity gun. A by-product of this modified turret is the increased armor and sloping of the turret. The vehicle is still in service with some Latin American countries, such as Argentina, which still operates a large number of them.

Notes: The story of the Challenger tank actually began in the late 1960s, when the British began design work on what was to be then a heavily-updated Chieftain. This tank was to be equipped with a revolutionary new secret armor, which is now known as Chobham. At first, the British were cooperating on such a tank with the Germans, but that deal fell apart in about 1977, when the British and German engineers’ diverged to the point that they could no longer work together. For a short time, the British even considering buying into the American XM-1 program, replacing certain components such as the engine, transmission, and main gun to British standards. Another idea was an updated Chieftain hull with a casemated main gun. In the late 1970s, the British MoD began Project Definition, which finally resulted in the Challenger 1; this program benefited greatly from the Shir1/Shir 2/Khalid tanks Built from the Iranian and Jordanian governments, (the Challenger 1 is in many ways an updated Shir 2) but resulted in a quantum leap ahead of the Chieftain. First deliveries to the British Army began in 1983.

One of the first things from Project Definition studies was that the AGT-1500 gas turbine used in the M-1 Abrams was too fuel-hungry and that the Chieftain’s L60 Mk7 engine could never be upgraded enough to provide the large increase in power desired. This resulted in a complete change in powerpacks; the engine would be a Rolls-Royce Condor 12V turbocharged multifuel engine developing 1200 horsepower. This was coupled to a Gear Industries TN37 transmission, and the Challenger 1 is also equipped with a Coventry H30 37-horsepower APU. At the rear of the hull, a pair of 300-liter auxiliary fuel drums may be fitted to extend range. These drums may be dropped at any time and carried at the rear slightly below the level of the rear deck; if they catch on fire, the chance of burning fuel pouring into the engine compartment are less than if they were carried "Soviet-style."

The Challenger’s most radical upgrade was, of course, the incorporation of Chobham armor into the glacis and turret front. The turret has a largely conventional layout inside, with the commander to the right side, using a modified version of the Chieftain Mk 5/3’s cupola. This cupola is usually armed with an integral L-37A2 machinegun. The cupola has all-around vision blocks; the front one could be quickly replaced with a day/night image intensification vision block. The commander can also use the image intensification vision block as a gunsight for the main gun or coaxial, and he does have auxiliary controls for them. However, late-production Challenger 1s had a TOGS upgrade for the commander in 1987, giving him a day/night sight incorporating a thermal imager, including an independent thermal sight/day sight for the commander (what in the Abrams is called a CITS). In front of the loader’s hatch is a swiveling periscope with no magnification. The driver is in the center front of the hull, behind the glacis; his hatch is in a shallow cut in the hull, with a hatch that opens slightly up and then pivots to the side. His forward vision block can be replaced with a night periscope.

(It may be just me, but the Challenger 1’s turret looks oddly irregular, as if it were higher on the commander’s side than the loader’s side.)

First-production Challenger 1s were equipped with the L-11A5 120mm rifled gun, as with late marks of the Chieftain, and an L-8A2 coaxial machinegun. On either side of the front of the turret are 5-barreled smoke grenade launchers. The gunner has an improved version of the Chieftain’s IFCS; the main improvement is to accommodate the Challenger 1 turret’s faster rotation rate and faster main gun elevation/depression capability. The ballistic computer also uses a more compact design with a faster processor and more memory than that of the Chieftain, and other components are 100% solid state and EMP-shielded. The laser rangefinder has a far greater range to keep up with improvements in ammunition and allow for possible future gun technology improvements. The laser rangefinder is mounted on the roof instead of the front of the turret to increase the integrity of the turret’s frontal armor. The suspension is a hydrogas system with aluminum-alloy roadwheels and return rollers and steel sprockets and idler wheels.

The CHIP (Challenger Improvement Program), beginning in 1987 with the aforementioned TOGS upgrade, also included the more agile and faster-acting TN54 transmission. The engine received a DASCU (Digital Automotive System Control Unit), which further increased the operation of the engine and driver’s controls, and adds a system called BITE that allows diagnostic computers direct access to the engine transmission during maintenance without having to pull the powerpack. The APU was replaced with a Perkins Type 4108, with the same 37 horsepower capability, but lower fuel consumption. Other improvements, such as a power increase for the engine and a change to the L-30 main gun, were contemplated but not carried out, as the Challenger 2 was to be soon in production. GPS was also incorporated into the Challenger 1; at first this was put only on command tanks, but later equipped all Challenger 1s after Desert Storm.

As a result of experience in Desert Storm, the Challenger 1 was further upgraded in 1991 with lugs for ERA on the glacis and improved ammunition stowage allowing the carriage of more of the long-rod L-26E1 APFSDU ammunition. No further upgrades are contemplated for the British Army, as most Challenger 1s have now been replaced with Challenger 2s.

While the Challenger 1 was and is a damn fine tank, Vickers Defence knew they could still improve on it. The Challenger 2 started out as a private venture for Vickers in 1986, a huge slate of upgrades that could be applied to what was then the Challenger 1. Vickers built eight new turrets and did several automotive updates to the Challenger, and in 1987, a formal demonstration was held in 1987. The eventual result was production beginning in 1993, using the No. 9 prototype as the base, and improvements were made to virtually the entire tank. The Challenger 2 began service in May 1994.

Externally, the Challenger 2 looks almost identical to the Challenger 1, though the turret appears boxier than that of the Challenger 1, a result of armor improvements. Crew positions are the same as those on the Challenger 1, though the turret positions are slightly shifted to accommodate design changes inside the turret. The commander has eight vision blocks for all-around vision when buttoned up, as well as a magnifying day/night periscope. Under each vision block is a red button; when pushed, the cupola and commander’s seat turns so that the vision block is lined up with the periscope. Originally, the Challenger 2 did not have a CITS, but it was quickly added. The loader has the same vision accommodations as those of the Challenger 1, as does the driver, except that the driver can adjust track tension from his position.

The main gun of the Challenger 2 is an L-30 55-caliber 120mm rifled gun; this gun has a number of improvements over the L-11A5, the foremost of which are increased barrel length for increased range and the CHARM ammunition with "stick" instead of bagged charges. The Challenger 2 can also fire the L-11A5’s bagged charges, but this negates some of the improvements in the autoloading system. Unlike most tank main guns, the bore of the L-30 is also chrome-lined to decrease wear. The L-30 can also fire the CHARM 3 APFSDU round, which is a long-rod penetrator. The charges are stowed in armored bins; any explosive-type rounds are stowed beneath the turret floor. The coaxial machinegun is an EX-34 (L-94A1) 7.62mm ChainGun. The commander and loader have externally-mounted L-37A2 machineguns; the commander’s machinegun can be aimed and fired from under armor. On either side of the turret front are five smoke grenade launchers. A smoke screen can also be laid by injecting diesel fuel into the tank’s exhaust. The gunner has a fully-stabilized sighting and vision system on the turret roof, along with a conventional periscope sight and a telescopic sight coaxial to the main gun (normally used for muzzle reference purposes). The Challenger 2 is powered by the same power pack as powers the Challenger 1 with the CHIP.

Vickers Defence has designed room for growth into the Challenger 2, ranging from gun upgrades to specialist command vehicles. Some that have already been trialed or used include the addition of ERA lugs on the glacis, turret front, turret sides, and hull sides, a CITS and a new 3 kW APU. In 2003, BAE Combat Systems began adding the PBISA (Platform Battlefield Information System Application) to the Challenger 2. This system is similar to the FBCB2 system used on the US M-1A2 (the so-called "electric tank" modifications). This includes computers, modems, GPS, land navigation systems, and software to integrate the Challenger 2s into a tight-woven intelligence net and battlefield coordination system. For Operation Telic (the British participation in Iraq) a kit similar to the American TUSK kit for the Abrams was also devised.

The Challenger 2E was originally called the Desert Challenger since it incorporated improvements learned in Desert Storm. The British Army was not interested, so Vickers Defence is selling it on the export market (hence the "E," for export). The Challenger 2E has most of the basic systems of the Challenger 2. The primary change is the use of the German MTU-EuroPowerPack, with a turbocharged diesel engine developing 1500 horsepower, and is smaller and lighter than the powerpack of the Challenger 1 and Challenger 2. This allows more internal stowage, some of which accommodates larger fuel tanks. The suspension is an updated version of the Challenger 2 hydrogas system. The tracks of the Challenger 2, primarily suited to European conditions, are replaced with a set that is more universally usable. The Challenger 2E has a CITS based on the latest French SAGEM MVS-580 IRIS, which also has its own laser rangefinder. The gunner’s sight is similar and is also roof mounted, except that it is not panoramic; both are gyrostabilized. The Challenger 2E is fitted with a BMS (Battle Management System), which uses a version of the M-1A2 Abrams’ FBCB2 software and a British-built GPS system. The L-30A1 120mm main gun is designed with the L-29 APFSDS-T round in mind, but can fire DU rounds as well. The Challenger 2E can ford to a depth of 2 meters using a kit or 1.07 meters without one; if installed, the system merely has to be turned on to allow the deeper fording. Standard commander’s machinegun is the M-2HB, but the Challenger 2E can take a CROWS-type station if desired by the buyer. Air conditioning and heating are included.

The primary change to Omani Challenger 2s are in the powerpack, which allow the engine to maintain full power in temperatures up to 126 degrees Fahrenheit (52 degrees Celsius). This is done with a modified water-cooling and airflow system, and additional dust filtration. The radiators and fans are physically larger, and air enters and exists through louvers on the rear hull deck. (This has a by-product of reducing the Challenger 2s thermal signature. The cupola-mounted commander’s L-37A1 machinegun has been replaced with a pintle-mounted M-2HB. The Omani Challenger 2 also uses US-built communications gear, improved air conditioning, and a GPS system.

Twilight 2000 Notes: Iranian forces loyal to NATO did receive some Challenger 1’s, but only about 30 or so. A few were also supplied to Israel, and some 40 or so were sold to the Chinese. However, the bulk of the Challenger 1’s went to replace Challenger II losses in Europe or to fight insurgents in the British Isles themselves. The Omanis also got their Challenger 2s. The Challenger 2E became standard production for the British Army, but not until 1995, and less than 200 actually made it to the British Army.

Merc 2000 Notes: These tanks became great seller to those who could afford them.

Notes: Originally, the Vickers-Armstrong Tank was to be a light tank based around the same 20-pounder main gun as the Centurion used, but with a maximum weight of only 24 tons. The Vickers-Armstrong tank was therefore to be (at the time of its inception in 1960) a well-armed, but less-expensive alternative to more expensive tanks, yet still equipped with advanced fire control systems and armor protection. The Vickers-Armstrong Tank would be aimed at the export market, and not at the British Army or NATO.

However, tank developments and world interest had overtaken this idea before it could get off the drawing board. The 20-pounder gun was obsolete, having been replaced in the Western world for the most part by the British L-7 series of 105mm rifled guns. This meant that protection requirements had also increased. In the meantime, the role of the light tank had changed; they were replaced by vehicles that were even lighter than the Vickers-Armstrong Tank light and often wheeled vehicles instead of tracked vehicles. The Vickers-Armstrong Tank didn’t have a market, despite its attractive features. The light tank Vickers had envisioned therefore was enlarged, given thicker armor, and a 105mm main gun; it became a medium tank with advanced features, ideal for many 2^nd and 3^rd-World countries. The first customer became India, in 1964; later customers include Kenya, Kuwait, Nigeria, Malaysia, and Tanzania.

The layout of the Vickers Mk 1 is essentially conventional; the commander is on the right side of the turret, the loader on the left, both with hatches. The gunner is in the turret on the right side of the gun. The driver is on the front right of the vehicle. The driver has a spring-loaded hatch that pops up and then swings to the left, with a latch securing it when it is open. He has a single, wide-angle vision block for use when his hatch is closed. The loader also has a single wide-angle vision block, facing front. The commander’s cupola rotates by a hand crank and has six vision blocks for all-around vision. The commander also has binocular periscope for long-range use, and a machinegun on a pintle attached to the cupola.

Armament is a 105mm rifled gun, with a 7.62mm coaxial machinegun and a 7.62mm commander’s machinegun. The Mk 1 is also equipped with an L-21A2 .50 ranging machinegun. Turret control is all-electric with manual backup; stabilization is also electric by the use of reference gyroscopes, and is essentially a more advanced version of the stabilization system of the Chieftain Mk 2; the Vickers Mk 1 became one of the first tanks to be able to fire with acceptable accuracy on the move. The Vickers Mk 1 also has a primitive ballistic computer. Some Indian versions have a white light/IR searchlight to the left of the main gun.

The Mk 1 used a traditional torsion bar suspension, except that the bars were wrapped to reduce wear and tear, with stops in the hull to limit up and down travel of the arms. The first, second, and last set of roadwheels also have separate torsion bars that give the Mk 1 more cross-country mobility, and they have hydraulic dampers. The tracks are of cast manganese steel for lighter weight. The engine is the a version of the same Leyland L60 on early marks of the Chieftain, but it is a diesel model developing 600 horsepower instead of being a multifuel engine. A 37-horsepower APU is also fitted. The Vickers Mk 1 can be fitted with a floatation screen (take 30 minutes to deploy) that allows the Mk 1 to swim.

The original Vickers-Armstrong Tank was to have Vigilant ATGM launching boxes mounted on either side of its turret to increase its firepower. The Vickers Mk 2 resurrected this idea; on either side of the turret, behind the stowage bins, were two launcher boxes for Swingfire ATGMs. This would have (at the time) given the Vickers Mk 2 unprecedented firepower, especially at long ranges. The idea was not taken up by any country, however, and this variant was never built. The launcher boxes are not nearly as well protected as the turret, however; they have an AV of only 4.

The Mk 3 was originally built to the specifications of the Nigerian Army, but was also the version sold to Kuwait, Kenya, and Tanzania. Many features have been redesigned, including a redesigned turret and ammunition stowage scheme to allow more main gun rounds to be carried, a new cast steel nose with increased armor protection, a more powerful engine, and a better ballistic computer and fire control system.

The powerpack has been replaced by a GM 12V-71T 720-horsepower turbocharged diesel along with a TN-12 Mk 5 automatic transmission. If necessary, the automatic transmission has an override to allow for manual operation of the transmission. (A Rolls-Royce 750-horsepower turbocharged engine is offered as an alternative; for game purposes, performance is the same.)

The commander’s cupola still uses a hand crank (electric traverse is offered as an alternative), but he has a new sight that has day and night channels and x10 magnification. He also has emergency override controls for the main gun and coaxial, as well as sights for those weapons. The commander can also access the gunner’s sight. The commander’s machinegun is fixed to the cupola, but can benefit from the commander’s sights, and be aimed and fired from under armor. The gunner’s fire control equipment is greatly improved, including a more compact and powerful ballistic computer, a laser rangefinder, wind and temperature sensors, corrections for barrel droop, and a thermal sleeve for the main gun. On each side of the turret are a cluster of six smoke grenade launchers.

Designed specifically for Malaysia, the Mk 3(M) is an upgrade of the Mk 3 that is essentially a rebuild of the Mk 3. Service with the Malaysian Army began in 1999. The Mk 3(M) retains the basic Mk 3 hull and turret, but the glacis and hull sides are equipped with lugs for ERA. Fire controlled is further improved, as is gun stabilization and the night vision suite, including thermal imaging for the gunner. The commander can access the gunner’s thermal imager, or use his own night vision equipment. The Mk 3(M) includes an air conditioning system, a GPS system, a laser warning system (tells the crew when a laser is targeting their tank), an NBC overpressure system, and smoke grenade clusters on each side of the turret that are increased to eight on each side. Lugs in the front allow for mine flails of a dozer blade to be mounted.

Twilight 2000 Notes: The Vickers Mk 3(M) was never built in the Twilight 2000 timeline). The countries listed above have their Vickers tanks, in addition to Norway, Denmark, Thailand, and the Philippines. Some 40 Mk 3s were also used by Home Defense forces in the British Isles themselves.