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Chieftain Main Battle Tank (UK)In 1956, Leyland Motors (who had been the lead designer for the Centurion Mk. 7) built three prototypes, designated the FV4202. It was similar to the Centurion but had only five roadwheels, a new turret that lacked a mantlet and the driver sat in a reclined position to reduce the height of the hull. The last two details were adopted for the new Chieftain main battle tank (FV4201) whose overall specification was issued in 1958. The first mock-up was built in 1959 and the first prototype later the same year.A further six prototypes had been built by April 1962 and during that year crews from the 1st and 5th Royal Tank Regiments came from Germany to help test the new vehicle. Two prototypes of the new Chieftain went over to Germany in December 1962 to commence trials there. The Chieftain was accepted for service in 1963 and entered service in 1967 with the 11th Hussars and 17/21 Lancers. Two production lines for the Chieftain were set up, the first at the Royal Ordnance factory in Leeds (bought by Vickers in 1986), and the second, at the Vickers' plant at Elswick. Around 900 Chieftains were built for the British Army with production being completed in the early 1970s. Iran ordered 707 Chieftains in 1971 (Mk. 3/3(P) and Mk. 5/3(P)) with a number of armoured recovery vehicles and bridgelayers. Iran also took delivery of some 187 improved Chieftains, designated the FV4030/1 which carried more fuel, had improved mine protection and additional shock absorbers as well as electronic control of the David Brown Defence Equipment TN12 transmission. Subsequent to this, in 1974 Iran ordered 1,225 Shir 2s, but as an interim measure ordered 125 Shir 1s but the order was cancelled in 1979 after the Islamic Revolution.
Jordan however, ordered the Shir 1 under the name Khalid, which had a number of modifications including a new Perkins Engines Company Condor V-12 1200 diesel (1,200hp), a David Brown Defence Equipment TN37 transmission and a Howden Aircontrol cooling system. The British Army eventually accepted the Shir 2 for service as the Challenger. Oman also bought a number of Chieftain Mk. 15s (named Qayd Al Ardh) in the mid-1980s. The hull of the Chieftain is made of cast and rolled steel sections welded together. The driver sits at the front of the hull, with the loader on the left and commander and gunner on the right of the turret. The Chieftain mounts a Royal Ordnance 120mm L11A5 rifled gun fitted with a Pilkington Optronics laser rangefinder. In the 1970s, British Army Chieftains were fitted with the Thermal Observation and Gunnery Sight (TOGS - which was also fitted to the Challenger), GEC-Marconi fully integrated Improved Fire Control System, Stillbrew armour and the No. 11 NBC system. A 7.62mm L8A1 machine gun is mounted coaxially with the main gun and a 7.62mm L37A1 machine gun is mounted on the commander cupola. The engine is a Leyland L60 No. 4 Mk. 8A diesel, which generates 750hp and is coupled to a TN12 transmission. There are a number of specialised variants of the Chieftain which are still in service with the British Army. These include the Armoured Vehicle Royal Engineer (AVRE designated the FV4203), Armoured Repair and Recovery Vehicle (ARRV) and Armoured Recovery Vehicle (ARV designated FV4204) and Armoured Vehicle-Launched Bridge (AVLB designated FV4205) which carries the No. 8 or No. 9 Tank Bridge.
(Mk. 5) Hull length: 7.52m. Hull width: 3.5m (with skirts). Height: 2.9m. Crew: 4. Ground Clearance: 0.51m. Weight: 55,000kg (combat). Ground pressure: 0.9kg/sq.cm. Max speed: 48km/h. Max range (internal fuel): up to 500km on road. Armament: 120mm rifled main gun, 1 x 7.62mm MG coaxial, 1 x 7.62mm MG on commander's cupola.
Work on a successor to the Centurion began in 1951 under the development name Medium Gun Tank No. 2 . After the turbulent developments of World War II, developers were given a free hand to research and test new technologies. Above all, the British Rhine Army in northern Germany was immediately confronted with numerous medium battle tanks of the Soviet Army : the T-34 and T-54 , which were supported by heavy tanks such as the IS-3 . That is why NATO pursued a “quality over quantity” strategy. The tank should have superior armament and strong armor the mobility should at least correspond to that of the Centurion, with the emphasis on good mobility in the battlefield and not on a high maximum speed. The British General Staff also demanded a maximum weight of 45 tons. All these requirements could not be implemented with the available technology at this point in time, so that the so-called Concept Study Program was initiated, which was to develop the necessary techniques in a broad research process. The United States and Britain worked closely together on the development of the new tank, as at that time they were the only NATO members to develop new tanks and manufacture them in significant numbers.
As armament, the US 105-mm cannon T-104 was first considered, which was to be installed in a tower with a diameter of 2.54 m. However, since the space for this cannon was insufficient because of its size and the use of conventional cartridge ammunition and the turret could not be enlarged further because of the weight restriction, serious problems arose when handling the ammunition. An automatic loading machine was proposed as a solution to the complicated handling of the cartridges, but this was rejected because of its high complexity. In addition, only 40 cartridges could have been carried in the loading machine, which was not considered sufficient. In 1953, at a conference between weapons engineers and tank engineers, the possibility of installing a cannon with a liquid propellant charge was even considered. The liquid propellant charge would have offered some advantages, since the loader only had to load the projectile, not the propellant charge a significant increase in muzzle velocity would also have been possible. However, due to insufficient financial resources and the fact that the depot for the liquid propellant charge would have taken up too much space, this idea was dropped. Instead, the developers considered combustible bag propellants, which have long been used on ships but never in a main battle tank. The bag propellants also offered some advantages over conventional ammunition: the weight of the metal cases was saved, the development of smoke from empty cases was prevented, and due to their small size, it was easier to accommodate them in the fighting compartment. The T-104 was ultimately not installed in the vehicle, but the concept of split ammunition was retained. The requirement of the military for a penetration capacity of 120 mm armor steel with 60 ° inclination at a distance of about 1800 m required the development of a new 120 mm cannon.
After Leyland Motors had been selected as the contract partner to manufacture the vehicles, the name was changed to FV4201. In order to stay within the weight limits and at the same time ensure sufficient ground clearance, the tub of the vehicle had to be designed very flat so that the driver had to sit in a lying position. The suspension also had to be adjusted as a conventional suspension with torsion bars could not be built into the shallow tub. The first three prototypes were produced in 1956 to test the feasibility of the driver's lying position. These first prototypes were essentially based on components from the Centurion. After the successful completion of these tests, development stalled for a short time as Great Britain and the USA tried to standardize as many parts of their respective tanks as possible and thus make them interchangeable. Both parties could not agree on a common concept for the weapon system. The British insisted on a 120mm drawbar cannon, while the Americans insisted on a 90mm or 105mm smoothbore cannon. Ultimately, no agreement was reached, so that both countries continued to pursue their own concepts.
In November 1957 there was a further delay in the project when the elevation range of the primary weapon was to be increased from previously −7.5 ° to + 15 ° to −10 ° to + 20 °. This required an increase in the size of the tower, which resulted in an increase in weight. At the same time, the army demanded that the armor protection on the turret and hull front should be improved, as experience from the Korean War had shown that splinters from artillery shells could not penetrate the armor, but partially tear open the welds.
At the end of 1957, the NATO standardization committee decided that all combat vehicles should be equipped with multi-fuel engines. This set the project back again as a new engine had to be found that could run on different fuels. The choice fell on an opposed piston engine from Junkers Jumo , which had been used in aircraft during World War II. In order to be able to use the engine designated as L60, however, the engine room had to be enlarged. At the same time, the total weight of the vehicle increased by a further ton and approached the 50-ton mark.
In August 1958, the first production orders were placed with various companies to produce the first complete prototypes. Leyland Motors made the hulls and drives, Vickers- Armstrong was responsible for making the turrets and installing the weapons systems, and Self-Changing Gears Limited made the semi-automatic gearbox and gear block. A total of 14 prototypes with the designations P1 to P6 and W1 to W6 were produced. Two nameless specimens were given to the newly founded Bundeswehr for test purposes, and the British Army received two prototypes of the Leopard 1 at the same time .
The first driving tests of the prototypes P1 and P2 began in the first quarter of 1960. This revealed serious problems with the engine and transmission. Converting the engine to a different type of fuel took too long, the crankshafts wore out too quickly, and the gearbox tended to overheat. Some of these problems could be resolved by throttling the engine and other measures, but the total weight increased to 50 tons. The suspension, which was designed for only 45 tons, then also had to be overhauled. Overall, the tests were very slow because of these problems.
The tests with the weapon system, which was designated as L11, began with the prototype W3 in April 1961. Despite some defects in the weapon system, the tests were very successful. After the night vision equipment had also been successfully tested on the prototypes P3 and P4, two vehicles were sent to Germany for troop trials. These showed some weaknesses of the tank - the off-road mobility was only very unsatisfactory because of the low ground clearance. Therefore, the rollers were replaced and changes were made to the suspension so that the ground clearance could be increased by 12.7 cm. In addition, the engine and transmission have been further revised to improve mobility and reliability. The Chieftain was accepted for series production on May 1, 1963, which began shortly thereafter.
After the introduction of the Chieftain Mark 5, older models were brought up to the technical standard of the Mark 5 using the so-called Totem Pole Conversion Program . The program was divided into three areas: Area X mainly concerned the fire control system, while Areas Y and Z concerned mobility aspects.
The Chieftain was selected to meet the requirement for the Universal Commonwealth Heavy Battle Tank proposal which would see the Commonwealth standardize the Commonwealth armies on a single heavy tank design. This would ease integration of the various armed forces on joint operations. However several countries began tailoring their tanks to their own needs and soon this advantage was lost.
295 Chieftains were never acquired by the Australian Army in 1971 to replace the Centurions then in service. The Leopard 1 tank was selected. They were
A heavily camo'd Australian Chieftain MBT
initially the standard production model but were soon upgraded to carry SS.11 missiles on rails positioned on either side of the main gun in the same fashion as the French with their AMX-13 tank. This necessitated an additional sight on the turret for targetting the missiles.
23 Chieftains served in Chile against Argentinean forces between 1982 and 1983. 3 of these were damaged beyond repair by mortars and artillery. They never encountered Argentine armour.
In 1986 the Australians began a comprehensive upgarde package which included Explosive Reactive Armour (ERA) which greatly improved surviviability and new targetting systems. The SS.11s were deleted in this upgrade because of the growing fear that if they were hit by enemy fire they could explode and destroy the tank.
Australian Chieftains fought alongside the newly introduced Challenger MBTs against Indonesian and Chinese armoured vehicles in the western pacific region. Their large size made their use on some of the islands difficult but in places such as Timor they peformed well easily outclassing their opponents who primarily used Soviet and Chinese tanks. They remained in service throughout the 1990s in case of the resumption of hostilities but by 1999 the Australian government felt it was time to let them go.
Britain [ edit | edit source ]
The British Army was the largest user of the Chieftain acquiring 823 examples. An early upgrade saw the addition
Wreck of a Chieftain in Canada after the '91 War
of a single launcher on top of the turret for a Swingfire anti-tank missile. Later versions could also carry Blowpipe surface to air missiles for defence against helicopters but neither of these arrangements proved ideal and useage was limited.
146 British Chieftains fought in the Falklands and Chile against Argentina between 1982-3. They proved far superior to anything Argentina could muster against them including recently delivered American M60A Patton tanks. By the '91 Disaster the Chieftain had largely been displaced by the Challenger but was still a major component of the land fighting during and after the war particularly on the plains of Germany and in the Middle East fighting alongside Israeli forces. The heavy armour and firepower of the Chieftain was a distinct advantage in these theaters. Against the US forces in Canada the Chieftain performed well but was more evenly matched against US tanks than when fighting Soviet tanks.
Hong Kong [ edit | edit source ]
24 basic model Chieftains were acquired by the Hong Kong Defence Forces . Training of crews was conducted in Australia. The 24 examples never left Hong Kong during their entire lives although for additional training purposes Hong Kong crews deployed as far afield as Europe and South Africa using other Commonwealth nations' equipment. None of the 24 vehicles survived the '91 Disaster.
South Africa [ edit | edit source ]
South Africa only operated a handful of Chieftains. South African army leaders felt that upgraded Centurion MBTs
South African Chieftain in Namibia
were more suited to their needs. 45 examples were delivered in 1968 before production was halted. The South Africans used their Chieftains in a breakthrough role similiar to the Conquorer.
The South Africans used their Chieftains in the fighting in Namibia and Angola during the 1980s. They proved formidable being more than a match for Communist tank forces. During one notable incident during a skirmish near the village of Tsumeb three Chieftains engaged and destroyed nine Cuban Type 59, three Type 63 and several soft vehicles before retreating. Despite this success their use was largely limited however the type taking second place to the Centurions..
Chieftain MBT Mk 2/3 FV4201
Chieftain MBT (Main Battle Tank) MK 2/3 FV 4201 02 EB 05 was originally built by Vickers Armstrong, at their Elswick works in Newcastle as a FV4201 Chieftain MBT (Main Battle Tank) Mk2. It would be rebuilt into Mk2XY, Mk 6 and Mk 9 standard during its service life. We know it went on to become an SP (Special Projects vehicle) for RARDE where she was used as a test bed for research into stealth technology and other projects we are not privileged to know about.
The Chieftain Main Battle Tank Mk 2 is fitted with Ordnance 120mm L11 gun firing HE (high explosive) and APDS (Armour Piercing Discarding Sabot). On the exterior of the commanders cupola is a 7.62mm General Purpose Machine Gun (GPMG) for use by the commander for defence against ground troops and low flying aircraft. The gunner has control of a second 7.62mm GPMG mounted alongside the main gun. As originally made 02 EB 05 would have been fitted with a 0.5 in Browning MG adapted for ranging purposes alongside the main armament, this would later be removed following the fitment of a Tank Laser Sight (TLS) to the gunners station. You will also notice smoke dischargers on both sides of the turret, which would provide a readily available smoke screen to allow the vehicle to manoeuvre under its cover.
The Chieftain Main Battle Tank Mk 2 is fitted with the Leyland L60 MK4A, 19 litre, 6 cylinder 12 piston, vertically opposed, water cooled, 2 stroke diesel engine, producing 650bhp at 2100rpm giving the vehicle a top speed of 25.3mph, an electrical generator rated at 28.5 v 150 amp was fitted along with hydraulic and electrical starter motors. This engine was subject to numerous modifications throughout its life to improve power output and enhance reliability
The vehicle is also fitted with an H30 No.4 Mk7A 3 cylinder, 6 piston vertically opposed, 2 stroke Diesel engine, producing 27bhp and used to drive a 28.5v 350 amp generator for charging the batteries and powering the turret electrical systems. This auxiliary engine also drove a hydraulic pump to power the Main Engine Hydraulic starter. Some examples were also fitted with small alternator, in line with the main generator to provide a small ac current to trickle heat the vehicle batteries during cold conditions.
David Brown TN12 Merrit-Wilson type gearbox, semi automatic electrical selection, giving 6 forward speeds, and 2 reverse speeds with a mechanically selected back up of one forward and one reverse gear.
Horstmann Suspension Unit
The suspension is of the Hortmann type, a system that uses Coil Springs and has the advantage of a relatively long travel. Housed within a self-contained Bogie which is bolted to the outside of the hull it causes little or no encroachment on internal hull space, consequently, the entire suspension unit may be relatively easily removed and replaced if damaged, e.g., by Mine. There are six pairs of road wheels on each side with the drive sprocket at the rear and idler at the front, three track return rollers are fitted.
- Weight 53.5 tons
- Width 11ft 2in.
- Height 9ft 5in.
- Length 24ft 8in.(Hull)
- 35Ft 5in (gun forward)
- 32ft 3in (gun in crutch)
Crew of four Driver, Gunner, Commander and Radio Operator / Loader
Service History of 02 EB 05 Chieftain Mk 2
22.01.1967 Date into service
April 1970 Delivered via Antwerp as Mk2 to 2RTR (2 nd Royal Tank Regiment), Caen Barracks, Hohne.
July 1970 Queen´s Own Hussars, Caen Barracks, Hohne.
1973/4 Probable Base Overhaul to Mk2XY standard, 23 Base Wksp REME, Wetter.
April 1974 The Royal Hussars (Prince of Wales Own), Athlone Barracks, Sennelager.
1978 -1982 Royal Scots Dragoon Guards, Athlone Barracks, Sennelager.
1982/3 Probable Base Overhaul to IFCS (Mk9) standard, 23 Base Workshop, Wetter.
1983-1984 5th Royal Inniskilling Dragoon Guards, Imphal Barracks, Osnabrück.
1984-1987 4RTR (4th Royal Tank Regiment), Imphal Barracks, Osnabrück.
1987 – 2000 FVRDE Chertsey (fighting vehicle research and development establishment)
Chieftain Mk 1 40 training vehicles for 1965–1966. Issued to 1 RTR and 5 RTR for troop trials.
Chieftain Mk 2 First service model with 650 hp engine
Chieftain Mk 3 Extra equipment fitted giving rise to several sub-marks. New cupola.
Chieftain Mk.5 Final production variant, with upgrades to the engine and NBC protection system.
Chieftain Mk.6 is essentially the Mk.2 Chieftain upgraded as a part of the “Totem Pole” program (or “Exercise Totem Pole”) to more or less Mk.5 standard. The entire program is rather convoluted and was actually split into three parts: X, Y and Z. Part X dealt with the new improved sighting system, part Y dealt with some improved automotive characteristics and commander’s control system (the commander was now able to fire the main gun for example) and part Z included improvements to the engine and gearbox.
The Mk.6 was the Mk.2 with X, Y and Z improvements built in (whereas only partially improved versions would be called Mk.2 (X) or Mk.2 (Y)). To make matters more complicated, there were actually several Mk.6 variants:
- 6/L included the “L” kit for the Tank Laser Sight (TLS) Mk.1 No.1
- 6/1 included the TLS No.1 Mk.2 or TLS No.3 Mk.1 and the Muzzle Reference System (MRS)
- 6/2 was essentially Mk.6/1 with the ranging machinegun removed (please note that some sources claim the ranging MG was merely modified, not removed)
- 6/3 was like the Mk.6/2 but featured a new and improved fire control system among other things, such as commander’s sights
- 6/4 was like the Mk.6/3, but with ammunition stowage modified for the needs of the L23 APFSDS round and with further modifications made to the sights
There are even more similar subtleties. The Mk.6/4 variant for example was split into the Mk.6/4 with sight modifications and the Mk.6/4/1 with ammo rack modifications. Another example would be the Clansman radio set that added the “C” suffix to the tank designation. There are many more details like this, but their full extent is unfortunately beyond the scope of this article.
Chieftain Mk.10 Mark 9 upgrade, addition of Stillbrew Crew Protection Package to the turret front and turret ring.
Chieftain Mk.11 Mark 10 upgrade, searchlight replaced with the Thermal Observation and Gunnery System (TOGS), manufactured by Barr and Stroud.
Chieftain Mk.12/13 Proposed further upgrades, cancelled when the Challenger 1 was introduced.
Chieftain ARV – Armoured Recovery Vehicle
Chieftain AVLB – Armoured Bridge-layer
Chieftain AVRE – Armoured Vehicle Royal Engineer
Chieftain ARRV – Armoured Recovery and Repair Vehicle.
By 1989 development of the Chieftain’s replacement was in full swing with nine prototypes built by VDS, with full production starting in 1993, which slowly entered service of May 1994 and was called the Challenger 2 Main Battle Tank. Both tanks only share 5% of common parts and are not the same tank, nor an upgrade.
The original idea by the Ministry Of Defence, was for a mixture of Challenger 1’s and 2’s within the British Army, but this was dropped, additional numbers of the Challenger 2 were ordered and the Challenger 1 was phased out of the British Army by 2000. Some are in British museum collections, gate guards on UK bases and 1 is confirmed in a private owners British collection.
The British Challenger 2 Tank Firepower
The CR2 Main Armament is the L30, which is manufactured by BAE Systems Land Systems (formerly RO Defence). The L30 is rifled, giving the CR2 greater accuracy, as the rifling imparts a spin to the fired round which stabilizes it and prevents it from tumbling, as well as giving the CR2 the ability to fire heavier rounds. The 120mm L30 cannon is made from Electro Slag Re-melting steel (ESR) to lengthen the cannons life and increase its accuracy.
To quote one British CR2 crewman ” Thanks to the quality of the L30, the old issue of wearing down of the rifling through repeated firing is almost non-existent. On average we fire 450+ rounds a year on active vehicles during training exercises and we averaged 200 during Operation Telic 1. In all my years of service, I’ve never known an L30 to be replaced due to wearing of the rifling “.
He went on to say ” The L30’s rifled barrel is more than capable of firing and withstanding the ammunition required during a normal conventional operations training year and has done since 1998. When the recommended rates of fire are adhered to and the correct maintenance and service of the weapon system is carried out, the barrel has no disadvantage over that of a smoothbore “.
Private Tank Car Crush Driving Experience Day UK
The Private Tank Car Crush Driving Experience totals three activities, which include driving and a car crush on the morning or afternoon of your choice.
Driving a British Army FV432 Armoured Personnel Carrier
Driving the Big Russian v8 turbo powered Russian 2S1 Grozdilza
Tour of the Armoury and take some “Charlie’s Angels” pictures posing with the machine Guns
Then the best bit, blast over a clean complete family Saloon in 56 tons of Chieftain Main Battle Tank!
To initiate the firing sequence in the L30 CHARM3 120mm gun all 3 parts of ammunition must be in place, firstly the Projectile is loaded, followed by a bag charge of tightly wrapped cordite strips.
Then the breach is closed and a Vent Tube is automatically loaded inside a special chamber within the breach blocks. When the firing switch is pressed a small electrical charge is sent to the back of the vent tube and it is fired.
The Vent tube blasts a jet of fire through a special guide in the breach blocks and into the chamber via a small hole. this is then channelled into the back of the Bag charge which has a small built in bag of fine powder in its base.
Upon firing and recoil the empty Vent tube is ejected out the back of the breach and is caught by a cloth shield. Another Vent tube is then automatically loaded. and the loading sequence can begin once more.
Thou some may class the vehicle as using a three part ammo, the Vent Tubes are loaded into the breach in a magazine, so are not manually loaded with the projectile and charge by the operator during each loading sequence, therefore we still refer to the Challenger 2 as using 2 part ammo.
The Challenger 2 is capable of firing several types of ammunition:
1. Armour Piercing Fin-Stabilised Discarding Sabot (APFSDS for short) is the L27 CHARM3 and has a DU tip to avoid “mushrooming” on contact with the enemy armour. Tankies call this round “FIN”. The L14 propellant system is based on a rigid Combustible Case Charges (CCC for short) and loaded after the FIN.
2. High Explosive Squash Head (HESH for short) is a multi-functional round. When it impacts on a wall/armour, the explosive spreads on to the outer surface, known as a “pat” and then is detonated, which sends a shockwave through the armour blowing off an inner section known as a “Spalding”, which is the size of a plate and fly’s around the turret cooking off the ammo, cutting hydraulics and carving the crew up. The blast can also damage the sights, sensors, tracks and main gun inflicting either a firepower kill or mobility kill. Its extremely effective as a demolition round and anti-personnel. Its armed by the rifling of the L30 and requires a low m/v to form the pat, so is fired at a high trajectory to gain range using the L3A3 cordite stick charge.
3. White Phosphorous is used for Covering Withdrawals, Covering enemy positions and used as a Marker for Target/obstacle recognition. The L34 is the same size and weight as a HESH round and three are carried on a typical bomb load unless a specific reason is pre defined.
1. DS/T (Discarding Sabot Training) DST to the crew. It is made of Tungsten and cheaper than the L27 CHARM3.
2. The HESH Training Round is Called SH/P “shuss Pee” to its crews, made from Portland Concrete and totally Inert, its size and weight is that same of what a HESH round is, 17.5kg
3. There is no White Phosphorous training round.
A bomb load is made up of 33 FIN, 3 Smoke and 13 HESH. In a Sabre Troop the Troop leader can redistribute the HESH or Smoke about his 3 Tank Callsigns. Or choose to carry more HESH on his Tank (The Centre Callsign) This is called being “HESH Heavy” giving the Troop Corporal on his left and Troop Sergeant on his right more KE rounds ,as they are more likely to engage enemy tanks first.
For close encounters, the Challenger 2 is equipped with a co-axial Boeing 7.62mm chain gun, which is located to the left of the main gun. The loader has a 7.62mm GPMG L37A2 anti-air machine gun, mounted on the cupola.
Upgrading to the German L55 smoothbore
The British Challenger 2 Tank with L55 smoothbore
There are two types of main guns used on tanks, rifled and smoothbore. Both have advantages and disadvantages. Rifling imparts a spin to the fired round which stabilizes its flight and prevents it from tumbling. This increases its range and accuracy compared to a smoothbore, which automatically starts to tumble as its left the muzzle.
The energy released from the combustion of the rounds charge builds up behind the round as it travels down the main gun. Some of the energy escapes through the grooving of the rifling. Energy doesn’t escape with a smoothbore, which requires a higher level of muzzle velocity to stop the round from tumbling. A number of tanks using shorter smoothbores are swapping to cal Length 55 main guns to increase muzzle velocity, AKA the L55. The increased length means that the round has further to travel down the barrel, which means the energy from the charge has longer to build up, pushing the round hard out of the muzzle, increasing its velocity. This then means the round takes longer to tumble and increases the range and accuracy as well as the punch to get through the enemies armour.
It was for this reason that a lot of people have mistakenly believed that the CR2 was swapping over to a L55 smoothbore. This is incorrect. The British do not name their main guns after their cal Length like the Germans, so people are unaware that the CR2 L30 main gun is a cal Length 55 and therefore already has a high muzzle velocity. The reason the British Army field tested the German L55 smoothbore was for a cost cutting exercise to purchase cheaper rounds.
It was found with previous generation rifled main guns, that as the round makes its way down the barrel it starts to wear down the rifling, shortening the main guns life, where as this wouldn’t happen on smoothbores, therefore it was found to be more cost effective to use smoothbores when operating large tank fleets, like the USA’s Abram and Germany’s Leopard 2, which totalled ten thousand plus during the Cold War and why both vehicles were equipped with smoothbores. This means there are more smoothbores and as such, a higher demand for the number of smoothbore rounds, which in turn drives down their production costs and makes them cheaper to purchase.
The Challenger 2 will not be fitted with the German L55 smoothbore Main Gun!!
Smoothbores use one part rounds and store these in one large box in the rear of the turret. Rifled uses 2 part. This means the non explosive part is kept in the turret and the explosive charge (2nd part) is kept separately in the hull. The field tests showed that the one part rounds did not fit in the existing storage set up and to fit a normal compliment of 1 part rounds would require a new turret, of which the cost would be higher than any savings made buying cheaper rounds, especially considering at the time some turrets were only four years old!
BAE did conduct some research in trying to move storage in the turret around, but only a maximum of six 1 part rounds could be stored. It’s for these reasons that the British Army are no longer pursuing the adoption of a smoothbore main gun.
Future supply chain of new ammunition
However TankNutDave has learnt that during 2009, a new HESH round manufactured in Belgium has been trialled. This means that the Challenger 2 now has available a new Tungsten FIN and HESH rounds, if and when required, which secures a line of ammunition for its calibre Length 55 rifled main gun, the L30 when required in the future.
However it also incorporated a lot of revolutionary design features, some of which did not work as well as expected. For example, in order to reduce height the driver lies in a reclining position and changes gear with his foot. The gun uses a self-combusting, bagged charge in place of a brass cartridge case and the tank is powered by a multi-fuel engine.
The engine was a Leyland design, developed from a pre-war German diesel aircraft engine. It has six vertical cylinders containing twelve opposed pistons, working on the two-stroke principle. Although essentially a diesel it was capable of running on a variety of fuels. The TN12 gearbox, offering six forward speeds and two reverse, includes a triple-differential steering system.
The Tank Museum’s Chieftain Mk11C
Late production Chieftains were continually upgraded. This Mark 11 would have been built as a Mark 5, with an uprated engine, which was subsequently fitted with Improved Fire Control System (IFCS), Thermal Observation and Gunnery System (TOGS) and the additional Stillbrew armour on the turret front and around the driver’s hatch. Chieftain served with the British Army into the early nineties and enjoyed modest success on the export market in the Middle East.
Chieftain MK 5
The Chieftain was one of the most advanced tanks at the time of it's introduction in 1966. It served as the main battle tank for the UK during the 60's, 70's, and 80's till it was replaced by the Challenger. It was a combination of the Centurion's mobility and the Conqueror's heavy 120mm gun (The definition of the main battle tank which combined the medium and heavy tank into one platform). It also was the first tank to place the driver in a reclined position which allowed the front hull to be steeply angled. Early models had a weaker engine that lead to lower top speeds but by the MK5 in the 70's it had a much more powerful 850 hp engine and better mobility. It was designed with a lot of input from Isreal though it was decided at the end not to let Israel produce the tank and instead they tested a few examples and created the Merkava. This tank was exported to several middile eastern countries where it saw most of its combat use but it wasn't exported to any other Nato countries.
Usage in battles
Follow the team's push and take some nice fortified position with sight on the capture point, destroying any scout vehicles that attempt to get close while looking for planes. Conducting both actions at once is crucial to not only deny the enemy a recon point but also for self-preservation to keep the Marksman protected. Fighting at a distance will be best to minimize convergence distance to avoid wasting ammunition on the lead. Vertical traverse of cannons is almost instant, so that should not be a concern when shifting from ground to air target. As the main belt's ammo runs out, move closer to the capture point to rearm. With this tactic, use the secondary belt only for self-defence on the capture point, or if it's really necessary for a teammate's survival.
Alternatively, you could go straight for capture point defence and unload secondary belts onto every passing plane, light tank, SPAA and poorly armoured MBT, then immediately rearm. Since your guns convergence is 1-2km depending on upgrades, there is little chance that any vehicle which is travelling in a straight line can dodge your double cannon lead. However, don't expect to successfully push away medium tanks, if your belt isn't APDS, and it's very likely that the enemy's return fire will heavily damage or hull break you, as capture points rarely provide any cover, so move out and use your main belt, when forced to.
Using radar-assisted aim is advised since it's more accurate and can lead to hits at over 3km range. To conserve ammo, however, do not just blindly follow it, especially in arcade, as arcade mode aircraft tend to dodge direct shots - do some short bursts around it. If you are standing on a frontline, remember that Marksman is very tall and it is not rare for some tankers to get annoyed by your presence and try to shoot the radar off the turret, even if the turret itself is almost entirely behind cover and attack achieves nothing else, so try to move somewhere remotely safe if you are expecting an air raid.
In arcade mode your combat ability is severely limited, due to many maps being 2 x 2 km wide at best, so on such maps you could try to train your crew with very high "keen vision", then try to camp enemy base entrances across the map, using the fact that your shells have little penetration falloff over distance and slight armour angling. This would require great map knowledge, though. As soon as enemy planes or attack helicopters appear, destroy them.
On big maps in arcade mode, keep in mind, that every sniper tank on enemy team might try to shoot in your direction, as soon as they are done destroying medium tanks, or if hostile light tank "scout" you. It is very hard to snipe planes from spawn on such maps, so try to secure some "trench line" in form of a hill, which you can use to follow your team even under sniper fire. Snipe lightly armoured tanks back, if they expose themselves. Having high "keen vision" greatly helps at this as well.
Some enemies to be concerned about:
- Soviet tanks: Avoid them as much as possible. With the gun convergence and reduced movement speed, it will not be easy to defeat them in a duel, as their frontal armour is almost always impenetrable, even for APDS belt. Detrack them and communicate with teammates to finish them off. Sometimes their medium tank drivers are very arrogant and underestimate Marksman, due to how rarely it is spaded and do not immediately turn their frontal armour towards it, thinking that you cannot destroy them anyway - punish them by shredding their tank with APDS belt, or by firing AP belt into generally weak side-bottom part of their tank.
- Maus: It's invulnerable. Best not to show up in parts of that map it controls.
- Centauro: This is the epitome of all tanks Marksman wants to shoot at - it is mobile, can reach and flank your position in a minute and has scouting as well. Fortunately, it also has the armour of a light tank, so if you see it out of cover, drop your lock on and fire at it, before it hides away.
- Helicopters: While helicopters are slow and may look like an easy target, they can change direction of flight and throw off radar aim or try to drop altitude, avoiding shots from over two kilometres away, so keep checking where it is trying to turn or roll, instead of just firing at the radar aiming reticle. Also, due to Marksman cannon convergence, try to keep them away from you or spread shots horizontally, as it is not rare to only cut off weapon pylons off attack helicopter, but fail to actually disable its gunner/co-pilot, so if after critical hit on a helicopter or setting it on fire ATGM still flies directly at your SPAA, it is better to hide behind something. Rocket carpet bombing is also dangerous for Marksman due to turret being very big, so try to move out of the way of the main volley, if only a bit - a close miss of weak rockets should fail to penetrate chieftain hull. The radar will keep your aim true, so don't worry about accuracy during movement too much. After a certain point, helicopters acquire 8 km range ATGMs and outclass you entirely, which is when you have to swap to the next generation SPAA, especially in RB.
Pros and cons
- Guns produce a great effect upon shell contact on target, requiring only one or two hits to down a plane
- Can fire effectively at longer ranges than Falcon and has radar guidance on top of that
- Compared to Gepard and Type 87 has relatively easy time shooting down planes even without use of a sniper scope
- Secondary belts allow for safer rearms compared to Falcon and Vulcan
- Has a stable radar system with full 360° target tracking - it rarely ever needs to be manually locked on
- Low mobility - it can't outrun most of its opponents and moving around the map at it's rank can be a challenge in itself
- LFP is a weak spot even for some light tanks, turret is lightly armoured and is a big target for rockets and other explosives - keeping 1.3 km distance is crucial when fighting light tanks and other SPAA
- Due to very tall profile it is an easy target, when compared to other SPAA of the rank. it is hard to never show it to medium tanks or SPG in order to avoid being hull broken
- The cannon's convergence makes the Marksman weaker in close combat, as it can only hit targets with one gun at short range
- Ammunition count is low, firing in 20-30 shot bursts is almost a must
- APDS ammo is now put into a separate belt, which may be inconvenient to use with a low ammunition capacity
- Slower rate of fire than other SPAA
- Radar system lacks track while scan and has relatively poor range
- Still does not have gunner night vision, although radar mostly compensates for that (can cause problems at pitch black maps of 9.0+)
Cold War Edit
Medium tanks were the earliest MBTs. MBTs started replacing medium tanks when guns on medium tanks became powerful enough to win against heavy tanks.  Heavy tanks could not carry armor strong enough to win against medium tanks.
The nuclear weapon threat and other anti-tank weapons in the Cold War made countries add more protection to survive in all types of combat. Weapon designers made powerful cannons to defeat the armor. 
The British Centurion is generally considered to have been the world’s first main battle tank, although the term was not popularised until long after it entered service. The British followed this up with the Chieftain main battle tank, which entered service in 1966. The first Soviet main battle tank was the T-64  and the first American MBT was the M60 Patton.  By the late 1970s, MBT's were manufactured by France, West Germany, Britain, India, Japan, the USSR, Sweden, Switzerland, and the United States. 
The Soviet Union made MBTs very quickly because it needed them for their type of war.  The Soviet Union improved the cannon by replacing the loader crewman with an automatic autoloader. This made the turret smaller which also makes the tank harder to see or hit  The Soviet Union made missiles that could be shot much farther than other ammunition. 
Gulf War Edit
After the Cold War, American tanks quickly defeated Iraqi tanks in the Gulf War. The American MBTs were still not as good as attack helicopters at destroying Iraqi tanks.  Some said that the MBTs could not stop an enemy force from attacking.