29.12.12

Cold War - Soviet Union's Foreign Policy under Khrushchev




Almost immediately after Stalin died, the collective leadership began altering the conduct of Soviet foreign policy to permit better relations with the West and new approaches to the nonaligned countries. Malenkov introduced a change in tone by speaking out against nuclear war as a threat to civilization. Khrushchev initially contradicted this position, saying capitalism alone would be destroyed in a nuclear war, but he adopted Malenkov's view after securing his preeminent position. In 1955, to ease tensions between East and West, Khrushchev recognized permanent neutrality for Austria. Meeting President Dwight D. Eisenhower in Geneva, Switzerland, later that year, Khrushchev confirmed Soviet commitment to "peaceful coexistence" with capitalism. Regarding the developing nations, Khrushchev tried to win the goodwill of their national leaders, instead of following the established Soviet policy of shunning the governments while supporting local communist parties. Soviet influence in the international alignments of India and Egypt, as well as of other Third World countries, began in the middle of the 1950s. Cuba's entry into the socialist camp in 1961 was a coup for the Soviet Union.

Soviet tanks in Budapest in 1956
With the gains of the new diplomacy came reversals as well. By conceding the independence of Yugoslavia in 1955 as well as by his de-Stalinization campaign, Khrushchev provoked unrest in Eastern Europe, where the policies of the Stalin era weighed heavily. In Poland, riots brought about a change in communist party leadership, which the Soviet Union reluctantly recognized in October 1956. A popular uprising against Soviet control then broke out in Hungary, where the local communist leaders, headed by Imre Nagy, called for a multiparty political system and withdrawal from the Warsaw Pact, the defensive alliance founded by the Soviet Union and its East European satellites in 1955. The Soviet army crushed the revolt early in November 1956, causing numerous casualities. Although the Hungarian Revolution hurt Soviet standing in world opinion, it demonstrated that the Soviet Union would use force if necessary to maintain control over its satellite states in Eastern Europe.

Mao and Khrushchev in 1958
Outside the Soviet sphere of control, China grew increasingly restive under Chinese Communist Party chairman Mao Zedong. Chinese discontent with the new Soviet leadership stemmed from low levels of Soviet aid, feeble Soviet support for China in its disputes with Taiwan and India, and the new Soviet doctrine of peaceful coexistence with the West (which Mao viewed as a betrayal of Marxism-Leninism). Against Khrushchev's wishes, China embarked on a nuclear arms program, declaring in 1960 that nuclear war could defeat imperialism. The dispute between militant China and the more moderate Soviet Union escalated into a schism in the world communist movement after 1960. Albania left the Soviet camp and became an ally of China, Romania distanced itself from the Soviet Union in international affairs, and communist parties around the world split over orientation to Moscow or Beijing. The monolithic bloc of world communism had shattered.

Khrushchev and Kennedy meet at Geneva in June 1961
Soviet relations with the West, especially the United States, seesawed between moments of relative relaxation and periods of tension and crisis. For his part, Khrushchev wanted peaceful coexistence with the West, not only to avoid nuclear war but also to permit the Soviet Union to develop its economy. Khrushchev's meetings with President Eisenhower in 1955 and President John F. Kennedy in 1961 and his tour of the United States in 1959 demonstrated the Soviet leader's desire for fundamentally smooth relations between the West and the Soviet Union and its allies. Yet Khrushchev also needed to demonstrate to Soviet conservatives and militant Chinese that the Soviet Union was a firm defender of the socialist camp. Thus in 1958 Khrushchev challenged the status of Berlin; when the West would not yield to his demands that the western sectors be incorporated into East Germany, he approved the erection of the Berlin Wall around those sectors in 1961. To maintain national prestige, Khrushchev canceled a summit meeting with Eisenhower in 1960 after Soviet air defense troops shot down a United States U-2 reconnaissance aircraft over Soviet territory. Finally, mistrust over military intentions hobbled East-West relations during this time. The West feared the Soviet lead in space technology and saw in the buildup of the Soviet military an emerging "missile gap" in the Soviet Union's favor. By contrast, the Soviet Union felt threatened by a rearmed Federal Republic of Germany (West Germany), by the United States alliance system encircling the Soviet Union, and by the West's superior strategic and economic strength. To offset the United States military advantage and thereby improve the Soviet negotiating position, Khrushchev in 1962 tried to install nuclear missiles in Cuba, but he agreed to withdraw them after Kennedy ordered a blockade around the island nation. After coming close to war in the Cuban missile crisis, the Soviet Union and the United States took steps to reduce the nuclear threat. In 1963 the two countries established the "hot line" between Washington and Moscow to reduce the likelihood of accidental nuclear war. In the same year, the United States, Britain, and the Soviet Union signed the Limited Test Ban Treaty, which forbade testing nuclear weapons in the atmosphere.
_________________________________________________________________________________

Nikita Sergeyevich Khrushchev (April 15 [O.S. April 3] 1894 – September 11, 1971) led the Soviet Union during part of the Cold War. He served as First Secretary of the Communist Party of the Soviet Union from 1953 to 1964, and as Chairman of the Council of Ministers, or Premier, from 1958 to 1964. Khrushchev was responsible for the partial de-Stalinization of the Soviet Union, for backing the progress of the early Soviet space program, and for several relatively liberal reforms in areas of domestic policy. Khrushchev's party colleagues removed him from power in 1964, replacing him with Leonid Brezhnev as First Secretary and Alexei Kosygin as Premier.
Khrushchev was born in the Russian village of Kalinovka in 1894, close to the present-day border between Russia and Ukraine. He was employed as a metalworker in his youth, and during the Russian Civil War was a political commissar. With the help of Lazar Kaganovich, he worked his way up the Soviet hierarchy. He supported Joseph Stalin's purges, and approved thousands of arrests. In 1939, Stalin sent him to govern Ukraine, and he continued the purges there. During what was known in the Soviet Union as the Great Patriotic War (Eastern Front of World War II), Khrushchev was again a commissar, serving as an intermediary between Stalin and his generals. Khrushchev was present at the bloody defense of Stalingrad, a fact he took great pride in throughout his life. After the war, he returned to Ukraine before being recalled to Moscow as one of Stalin's close advisers.
In the power struggle triggered by Stalin's death in 1953, Khrushchev, after several years, emerged victorious. On February 25, 1956, at the 20th Party Congress, he delivered the "Secret Speech," denouncing Stalin's purges and ushering in a less repressive era in the Soviet Union. His domestic policies, aimed at bettering the lives of ordinary citizens, were often ineffective, especially in the area of agriculture. Hoping eventually to rely on missiles for national defense, Khrushchev ordered major cuts in conventional forces. Despite the cuts, Khrushchev's rule saw the tensest years of the Cold War, culminating in the Cuban Missile Crisis.
Some of Khrushchev's policies were seen as erratic, particularly by his emerging rivals, who quietly rose in strength and deposed him in October 1964. He did not suffer the deadly fate of some previous losers of Soviet power struggles, but was pensioned off with an apartment in Moscow and a dacha in the countryside. His lengthy memoirs were smuggled to the West and published in part in 1970. Khrushchev died in 1971 of heart disease.

Sources:

http://www.mongabay.com/history/soviet_union/soviet_union-foreign_policy_under_khrushchev.html

http://en.wikipedia.org/wiki/Nikita_Khrushchev


23.12.12

Aircrafts - F-86 Sabre vs MiG-15 (with video)









Which was the better fighter, the Sabre or the MiG? As in most questions of this type, the answer is--it depends!
Throughout the Korean war, American intelligence on the capabilities of the MiG-15 was limited largely to Sabre pilots' fleeting impressions of the Russian-built aircraft when they encountered it in combat. These impressions were reinforced by a description of a MiG-15 flown to Denmark in March of 1953 by a Polish defector, and also by the examination of a wrecked MiG salvaged from 17 feet of water off the North Korean coast in July of 1951.
On September 21, 1953, Lt. No Kum-Suk of the Korean People's Armed Forces Air Corps defected to the South along with his MiG-15bis. This presented the USAF with its first flyable example of its MiG-15 opponent, and gave US intelligence the first chance to compare its initial impressions with actual flight test data. The MiG was dismantled and flown to Okinawa aboard a C-124 Globemaster. There, it was reassembled and flown by a crew of experienced test pilots including Maj. Gen. Albert B. Boyd, Major Charles E. "Chuck" Yeager, and Capt H. E. Collins. The MiG was painted with USAF markings, and was assigned the fictitious serial number "616", because Capt. Collins had used this same number on a plane he had once flown. The actual MiG serial number was 2015357. This aircraft was later flown to Wright Patterson Air Force Base in Ohio. Lt. No's MiG-15bis is currently on display at the Wright Patterson Air Force Base Museum, painted in its original North Korean markings.
The test flights confirmed the initial impressions of combat pilots in Korea. The MiG-15 was faster than the F-86A and F-86E at altitudes above 30,000 feet, but slower at lower altitudes. Early F-86Fs were superior in speed to the MiG only up to 35,000 feet, whereas the "6-3" F-86Fs were faster than their MiG opponents all the way up to the Sabre's service ceiling.
One of the primary advantages of the MiG over the Sabre was its 4000-foot advantage in service ceiling. It would often happen that F-86s would enter MiG Alley at 40,000 feet, only to find MiGs circling 10,000 feet above them. There was nothing that the Sabre pilots could do unless the MiGs decided to come down and do battle. The high-flying MiGs could pick the time and place of battle, and their higher speed at high altitudes enabled them to break off combat at will when things got too tight. Many a MiG escaped destruction by being able to flee across the Yalu where the Sabres were forbidden to pursue.

The Sabre was much heavier than the MiG and had a superior diving speed. Both the MiG and the F-86 could go supersonic in a dive, but the Sabre was much more stable than the MiG in the transonic speed regime. One way for a Sabre to shake a MiG sitting on its tail was for the F-86 pilot to open his throttle all the way up and go over into a dive, pulling its pursuer down to lower altitudes where the F-86 had a performance advantage. Above Mach 0.86, the MiG-15 suffered from severe directional snaking, which made the aircraft a poor gun platform at these high speeds. Buffeting in the MiG began at Mach 0.91, and a nose-up tendency initiated at Mach 0.93. The high-speed stability problems of the MiG-15 were so severe that it was not all that uncommon for a MiG to go into the transonic regime during an air battle, only to lose its entire vertical tail assembly during violent combat maneuvering. The rate of roll of the MiG was too slow, and lateral-directional stability was poor at high altitudes and speeds.
One of the most serious weaknesses of the MiG-15 was its tendency to go into uncontrollable spins, especially in the hands of inexperienced pilots. Many Sabre victories in Korea were scored without the F-86 pilots ever having to fire their guns--they merely forced their MiG opponents into spins from which their pilots could not recover. An experienced MiG pilot could get himself out of a spin, but the aircraft was somewhat unstable and lacked good stall warning properties.
The turning radius of the MiG was good, somewhat better than that of the F-86A, E and early F. However, this advantage was largely eliminated by the advent of the "6-3" wing of the later F-86F. The good turning radius of the MiG was compromised by poor stalling characteristics. These bad stalling characteristics could get a green MiG pilot into serious trouble during the stress of a dogfight, causing his fighter to suddenly stall, go into an uncontrollable spin, and fall out of the sky.
In contrast, the spinning characteristics of the Sabre were excellent, and gave most pilots no trouble at all. If the F-86 was forced into a spin, recovery was usually effected by simply neutralizing the controls.

The MiG-15 armament of one 37-mm N-37 cannon and two 23-mm NR-23 guns was designed for attacking bombers, and was not really intended for use against fighters. Forty rounds of 37-mm ammunition and 160 rounds of 23-mm ammunition were carried, a rather low ammunition capacity. The 37-mm gun fired at a rate of 450 rpm, whereas the 23-mm guns each fired at a rate of 650 rpm. The MiG's armament had a good punch, but the rate of fire was too slow to make it effective against nimble, rapidly-maneuvering fighters. In contrast, the F-86's armament of six 0.50-in machine guns had a rapid firing rate and the aircraft carried an ample supply of ammunition. However, the machine guns of the Sabre lacked the stopping power of the MiG's cannon. It was not uncommon for a Sabre pilot to empty all 1600 rounds of his ammunition at a MiG, only to see it escape unscathed.
The gunsight of the MiG-15 was of the simple gyro type, similar to that of the early F-86A. It lacked any radar ranging capability. The radar ranging gunsight of the later Sabres made the F-86 a much more accurate gun platform than the MiG, but this accuracy was sometimes wasted because of the low weight of fire from the machine guns.
The MiG was much lighter than the Sabre, weighing only 11,070 pounds loaded. The take off run to clear a 50-foot obstacle was only 2500 feet, as compared with 3660 feet for the F-86A.
Internal fuel capacity of the MiG was 372 US gallons, compared with 435 gallons for the Sabre. This gave the MiG a range of 480 miles, which could be increased to 675 miles with drop tanks.
During the Korean War, 792 MiG-15s were destroyed by F-86 pilots, with 118 probables being claimed. 78 Sabres were definitely lost in air-to-air combat against the MiGs, with a further 13 Sabres being listed as missing in action. This is about a ten-to-one superiority. From this result, one might naturally conclude that the F-86 was the superior fighter. However, a factor which must also be considered is the relative level of experience and competence of the opposing pilots. The US Sabre pilots were all highly trained and competent airmen, many of whom had extensive World War 2 combat experience. With the exception of some Russian World War 2 veterans who flew MiG fighters in Korea, the MiG pilots were often sent into combat with only minimal flying experience. MiG pilots often exercised poor combat discipline. During the course of battle, MiG pilots would often break off into confusion and panic, firing wildly, and leaving their wingmen unprotected. Often, a MiG pilot in trouble would eject from his plane before anyone actually shot at him. Many MiG pilots were so inexperienced that in the heat of battle they would end up getting themselves into uncontrollable spins and crashing. At times, MiG pilots would fire their cannon in an attempt to lighten their loads, without really aiming at anything. Most of the MiG pilots were extremely wary of combat, and usually did not attempt to fight unless they saw an advantage opening up. In contrast, the Sabre pilots were aggressive and eager for combat, and wanted nothing more than for the MiGs to come over the Yalu so that they could add to their scores.





So, which plane would you rather be sitting in, the MiG-15 or the F-86? Perhaps Chuck Yeager said it best--"It isn't the plane that is important in combat, it's the man sitting in it."











Sources: 


  1. F-86 Sabre in Action, Larry Davis, Squadron/Signal Publications, 1992. 
  2. The North American Sabre, Ray Wagner, MacDonald, 1963. 
  3. The American Fighter, Enzo Angelucci and Peter Bowers, Orion, 1987. 
  4. Flash of the Sabre, Jack Dean, Wings Vol 22, No 5, 1992. 
  5. MiG--A History of the Design Bureau and its Aircraft, Piotr Butowski and Jay Miller, Aerofax, 1991.

19.12.12

18.12.12

Tanks - T55




Remembering The T-55 Tank
by Frank Chadwick


Tom Clancy once described the T-55 as “the last good tank the Soviets made.” There is something to that. I think the phrase “revolutionized warfare” is grossly overused, but the Soviet T-55 certainly represented a turning point in tank design.
The model for tank design, and tactics, which matured during World War II, called for three classes of tanks, based on armament and protection: light, medium, and heavy.

Light tanks initially were used for most of the traditional cavalry roles, but by the end of the war had been relegated to reconnaissance. That was a job better handled by dedicated reconnaissance vehicles, and so the light tank, as a class of combat vehicles, faded away.
Medium tanks were the workhorse vehicles of armored formations. Designed to be easy to mass-produce, medium tanks were reasonably well-armed and protected, but their protection definitely took a back seat to mobility and reliability, while their armament was emphatically a dual-purpose gun with as much attention paid to fighting infantry as enemy armor.
Heavy tanks occupied the high end of the tank park – heavily armed and armored (as their name suggests), they were able to engage and destroy any vehicle they would encounter, including enemy heavy tanks, while their armor rendered them relatively safe from anything but the largest enemy anti-tank weapons. They also placed a heavy burden on maintenance, logistics, and infrastructure resources of the forward troop commands, and were difficult to build and expensive, which generally limited the number actually deployed.
The post-war generation of tanks followed this trend, at least at first, although the categories experienced some fairly rapid weight-creep.
The U.S. developed its World War II-era heavy tank, the M26 Pershing, into a family of post-war medium tanks (not surprising, considering the Pershing weighed about the same as the German Panther), armed with a 90mm gun. The Pershing itself spawned the M46 (a 1948 version which was only a slight improvement over the original), the M47 (entering service in 1952), and the M48 Patton (1953). The heavy end of the equation was filled by the M-103, a 65-ton mother of a tank, mounting a 120mm gun (requiring two loaders instead of one), which was reasonably-well protected but slow and with an overloaded (and hence temperamental) drive train. It entered service in 1957.

The British post-war medium was the Centurion, another development of a tank fielded in the closing days of World War II and equipped with an 83.4mm (20-pounder) gun. The heavy counterpart was the 120mm-armed Conqueror, which tipped the scales at 66 metric tons. The British built about 180 Conquerors between 1955 and 1959, but they suffered from the same problems as the U.S.M103: poor reliability, poor mobility, and a big logistical footprint.
The Soviets started out with the same conceptual mix, using the wartime T-34/85 as their medium tank and the IS (Iosef Stalin)-3 as their heavy, replaced by the slightly improved IS-10 in1952 (and almost immediately renamed T-10 upon the death of Stalin).
The Soviet IS-series heavies mounted a 122mm gun and weighed in at about 46 metric tons, so were quite a bit lighter than the western heavy tanks. That is significant, because it indicated where the Soviets went next with their tank design thinking.
The World War II-era German Panzer V Panther had good protection, mobility, and firepower. It virtually formed a class all its own — not quite up to facing the heavy tanks, but outclassing every other “medium” tank on the battlefield. Of course, it was a medium in name only. At 44.8 metric tons, it was virtually the same weight as the Soviet IS-2 and heavier than the U.S. Pershing (which came in at a bit under 42 metric tons). But it was designed to be mass-produced, and became the largest-production German tank of the war.
The western allies essentially followed the German lead, fielding a mass-produced medium tanks in the 40-45 ton range and a high-end heavy tank ten to twenty tons heavier – the force structure equivalent of the German Panther and the German Tiger. The Soviets took a different path.
In 1953 the Soviets began fielding the first mass-produced version of the T-54, which was soon replaced on the assembly lines by the T-55. The design merged the T-34 and IS design streams into a single all-purpose modern battle tank. It weighed 40 metric tons, had between 100 and 200mm of armor in front, and mounted a high velocity 100mm gun (which had slightly better armor-piercing performance than the IS-series’ 122mm gun). In other words it was the same weight or lighter than the Western medium tanks (42 metric tons for the Pershing and 52 for the Centurion), had as good or better frontal armor, and a better gun. It wasn’t going to set any world land speed records, but it was much more reliable than contemporary heavy tanks,  had the logistical and infrastructure footprint of a medium tank, and was designed to be mass produced.
In a stroke, T-55 rendered most of NATO’s tank park conceptually obsolete and changed the dynamics of tank production industrial strategy. Instead of a high-low mix of mediums and heavies, the future battlefield would be dominated by a single all-purpose vehicle, the Main Battle Tank.
Britain and the United States both responded by declaring the cumbersome heavy tanks obsolete and scrambling to up-gun their medium tanks to MBT status. The weapon of choice was the British-designed L-7 105mm gun, maybe the best all-around tank gun ever fielded. The British mounted it directly on the Centurion while the US re-designed the turret of the M48 to accept the new gun and dubbed the resulting vehicle the M60. (Later we would manage to fit the 105 in the M48 turret, and the M48A5 version is virtually identical in performance to the M60.)
As good a tank as the M60 was, and it was a fine all-around combat vehicle, it was always an expedient. Later the British would field the Chieftain, we the M1 Abrams, the Germans the Leopard, and the French the AMX-30. But all of these tanks are inspired by, or reactions to, that first glimpse of the T-54/55.
It is easy to forget today the sensation that T-55 caused at the time. Eventually we would find out that the 100mm gun had accuracy problems, the loader station was very awkward and slowed the rate of fire, the suspension tended to shed tracks unless the driver knew what he was doing (and a lot of T-55 drivers didn’t), but all of that came later. For a while, the Soviets had the best all-around combat tank in the world. By comparison, all the Soviet tank designs which followed were junk.

source: http://greathistory.com/remembering-the-t-55-tank.htm


17.12.12

BattleGroup Modern Rules - Campaign 2013


BATTLE GROUP MODERN RULES


THE CAMPAIGN

contact details:  fasoulasj@yahoo.gr & vmiliarakis@yahoo.com


16.12.12

Tanks - Centurion


CENTURION MBT



Development

In 1943, the Department of Tank Design was asked to start design work on a new heavy cruiser tank under the designation A41. This tank was required to have good armour protection, be armed with a 17-pounder gun and have a good cross-country performance: a high road speed was not considered essential at that time. The first mock-up of the A41 was completed in 1944 and six prototype tanks were completed in early 1945. These were sent to Germany but arrived too late to see any combat. The A41 later became known as the Centurion Mk 1 and the up-armoured A41A became the Centurion Mk 2, both armed with the 17-pounder gun. Throughout its life the Centurion has proved capable of being up-armoured and up-gunned. It was originally armed with the 17-pounder which was replaced first by the 20-pounder and finally by the 105 mm L7 series rifled gun which was subsequently adopted by many other countries. Other improvements carried out during its life included increased fuel capacity, contrarotating commander's cupola and improved stowage. All British models of the tank used the same basic Meteor petrol engine and transmission.
Production of the Centurion was undertaken by the Royal Ordnance Factories at Leeds and Woolwich, Vickers at Elswick and Leyland Motors at Leyland. Most were built at Leeds and Elswick. Production of the Centurion was finally completed in 1962, by which time 4,423 tanks had been built, of which at least 2,500 were exported.
In the British Army the Centurion was replaced from the late 1960s by the Chieftain MBT. By 1999, Sweden remained the only user of the Centurion MBT in Europe.


Description (Mk 13}

The all-welded steel hull of the Centurion is divided into three compartments: driving at the front, fighting in the centre, and engine and transmission at the rear.
The driver sits at the front of the hull on the right side and has two hatch covers that open either side of his position, each with a periscope. To the left of the driver a quantity of ammunition is carried.
The turret in the centre of the hull is of cast construction with the roof welded into position. There is an ammunition resupply hatch mounted externally in the left side of the turret and stowage boxes on either side of the turret. Most vehicles have a wire stowage rack at the rear of the turret. The loader is seated on the left of the turret, the commander on the right, and the gunner in front of and below the commander.
The commander's cupola can be manually traversed through 360° by hand and is provided with split hatches, a periscopic sight with a ballistic pattern and seven periscopes for all-round observation. A searchlight mounted at the commander's station can be fitted with an infra-red filter. The gunner has a periscopic sight with ballistic pattern graticule, linked to a range drum for targets between 3,000 and 8,000 m. The commander's and gunner's sights are linked by a heat-compensated bar.
The loader is provided with twin hatch covers that open front and rear and a single observation periscope.
The engine compartment at the rear is separated from the fighting compartment by a fireproof bulkhead. Air is drawn in through the engine deck louvres by two fans. Power is transmitted from the engine through the clutch to the transversely mounted Merritt-Brown Z51R transmission. This is a combined change-speed and steering mechanism and incorporates a differential. Drive from the output epicyclic gears at each end of the gearbox is transmitted through an internally toothed coupling ring and an externally toothed driving shaft to the final drive.
The Horstmann suspension consists of three units on each side, each carrying two pairs of roadwheels sprung by one set of concentric springs. The first and last roadwheel units are fitted with shock-absorbers. The drive sprocket is at the rear, idler at the front and there are six track-return rollers, the four dual roller centre ones and the single front and rear ones which support the inside of the track only. The tops of the cast manganese steel tracks are covered by removable armour skirts which provide protection against HEAT projectiles.
As originally built the Centurion was not fitted with any infra-red night vision equipment, but in the 1960s many British Army Centurions were fitted with infra-red driving lights, an infra-red searchlight to the left of the main armament and infra-red sights for both the commander and gunner. The tank has no NBC system or amphibious capability although a deep fording kit was developed. A dozer blade can be mounted at the front of the hull for clearing obstacles and preparing fire positions. One of the shortcomings of the Centurion was its short operational range, although later production tanks had increased fuel capacity and the Mk 5 could tow a monowheel trailer full of fuel to increase its operational range.
Main armament of the Centurion Mk 13 is the Royal Ordnance 105 mm L7A2 rifled tank gun which is provided with a fume extractor, and many countries have fitted a thermal sleeve. It has an effective range of 1,800 m with APDS-T rounds or between 3,000 and 4,000 m using HESH. A well-trained crew can fire 8 rds/ min.
The weapon is normally aimed using a 12.7 mm (0.50) ranging machine gun mounted coaxially with the main armament which has a maximum range of 1,800 m and fires in three-round bursts using tracer ammunition. The gun is fully stabilised and the gunner can select any one of the following modes of operation: manual elevation and traverse, non-stabilised power traverse, stabilised powered elevation and traverse or emergency, single-speed power traverse.
The 105 mm gun fires the following types of ammunition, all of which are of the fixed type with the projectile securely attached to a brass cartridge case which contains the propellant and initiated by an electric primer: APDS-T (L28A1), APDS-T (L52A1), APFSDS-T (L64 and later developments), DS/T (L45A1), HESH (L37) and Smoke (L39), all manufactured by Royal Ordnance. It will also fire ammunition manufactured by many other countries such as Austria, Canada, France, Germany, Israel and the USA.
Mounted coaxially to the left of the main armament is a 7.62 mm (0.30) machine gun and there is a similar weapon on the commander's cupola for anti-aircraft use. Six electrically operated smoke grenade dischargers are mounted either side of the turret.
There have probably been more variants of the Centurion than any other post-Second World War vehicle in the MBT class. A full list of the gun tank models and variants of the vehicle still in service follows; experimental vehicles have been excluded.




Centurion Gun Tank Models

Centurion Mk 1 armed with 17-pounder (76.2 mm) gun;
none remains in service.
Centurion Mk 2 armed with 17-pounder gun; none
remains in service.
Centurion Mk 3 armed with 20-pounder(83.8 mm) gun;
none remains in service, most brought up to Mk 5
standard.
Centurion Mk 4 was to have been a close support
model armed with 95 mm howitzer but was not placed
in production.
Centurion Mk 5 was designed by Vickers at Elswick and
armed with a 20-pounder gun.
Centurion Mk 5/1 is Mk 5 up-armoured.
Centurion Mk 5/2 is Mk 5 with a 105 mm gun.
Centurion Mk 6 is a Mk 5 up-armoured, with additional
fuel capacity at rear of hull and 105 mm gun.
Centurion Mk 6/1 is a Mk 6 with infra-red night vision equipment and stowage basket at rear of turret. Centurion Mk 6/2 is Mk 6 with 12.7 mm ranging machine gun for 105 mm gun.
Centurion Mk 7 was designed by Leyland and is designated the FV4007. Armed with a 20-pounder gun with fume extractor and carries 61 rounds of 20-pounder ammunition.
Centurion Mk 7/1 is a Mk 7 up-armoured and designated FV4012.
Centurion Mk 7/2 is a Mk 7 with a 105 mm gun. Centurion Mk 8 was developed from the Mk 7 and has a resiliently mounted gun mantlet with no canvas cover and the commander's cupola is contrarotating. The commander can also raise his twin hatch covers in an umbrella fashion for improved visibility without revealing his position. Centurion Mk 8/1 is Mk 8 up-armoured. Centurion Mk 8/2 is Mk 8 with 105 mm gun. Centurion Mk 9 is Mk 7 up-armoured and up-gunned with 105 mm gun, designated the FV4015. Centurion Mk 9/1 is Mk 9 with infra-red night vision equipment and stowage basket on rear of turret. Centurion Mk 9/2 is Mk 9 with 12.7 mm ranging machine gun.
Centurion Mk 10 is Mk 8 up-armoured, up-gunned with 105 mm gun and with an ammunition capacity of 70 rounds, designated the FV4017. Centurion Mk 10/1 is Mk 10 with infra-red night vision equipment and stowage basket on rear of turret. Centurion Mk 10/2 is Mk 10 with 12.7 mm ranging machine gun.
Centurion Mk 11 is Mk 6 with ranging machine gun, infra-red night vision equipment and stowage basket on turret rear.
Centurion Mk 12 is Mk 9 with infra-red night vision equipment, 12.7 mm ranging machine gun and stowage basket on turret rear.
Centurion Mk 13 is Mk 10 with 12.7 mm ranging machine gun and infra-red night vision equipment.

Variants
  • Centurion (Mk 2) ARV (FV4006)
The Mk 2 was preceded by the Mk 1 ARV but none remains in service. The ARV Mk 2 is essentially a Centurion MBT with its turret removed and replaced by an all-welded superstructure behind the driver's position. The commander's cupola can be traversed through 360° and is fitted with a 7.62 mm (0.30) machine gun. Mounted at the rear of the hull are spades which are used to stabilise the vehicle when the winch is being used. The winch's 31,000 kg capacity can be increased with the aid of snatch blocks to a maximum of 90,000 kg. The vehicle has a loaded weight of 50,295 kg and a crew of four. Full details of the Centurion ARV Mk 2 were given in Jane's Military Vehicles and Logistics 1995-96, page 49. All Centurion Mk 2 ARVs were built by Vickers Defence Systems at Newcastle-upon-Tyne, with 345 being built between 1954 and 1959.
  • Centurion BARV (FV4018)
This is used only by the British Army and only 12 were built for use by amphibious forces. It is basically a Centurion tank with its turret replaced by a superstructure enabling it to operate in water up to 2.895 m deep. It has a crew of four, one of whom is a trained diver. Loaded weight is 40,643 kg. Full details of the Centurion BARV were given in Jane's Military Vehicles and Ground Support Equipment 1987, page 48. There are a total of five BARVs still operational, three at the Amphibious Trials and Training Unit, Royal Marines, one on board HMS Fearless or HMS Intrepid and one in reserve at Ashchurch. There is a requirement for a new BARV.
  • Austrian Centurions
For some years Austria has been using Centurion 105 mm, M47 and Charioteer turrets in the static defence role, and purchased 120 Centurions from the Netherlands at £3,800 each for static defence use. A photograph of the Austrian static Centurion 105 mm turret appears in the Coastal artillery guns and missiles (including fixed fortification weapons) section later in this book.

  • Israeli Centurions
Details of Israeli Centurion MBTs are given in this section under Israel. Details of their armoured personnel carrier versions are given in the Armoured personnel carriers (tracked) section under Israel.
  • Jordanian Centurions
Centurions of the Jordanian Army have been refitted with the American General Dynamics Land Systems, Muskegon Operations AVDS-1970 series diesel engine in place of the original Meteor petrol engine. These upgraded vehicles are called the Tariq. They have also been fitted with a Belgian SABCA fire-control system which incorporates a laser range-finder manufactured under licence from the Hughes company of the USA. This system is similar to the SABCA fire-control system installed in the Leopard 1 MBTs used by Australia, Belgium and Canada. They have also been fitted with a US HR Textron turret drive and stabilisation system and hydropneumatic suspension. The last of 293 conversions to the Tariq standard was completed in 1985.
In early 1986, Kidde-Graviner of the UK was awarded a contract by Jordan to supply its Crew Bay fire and explosion suppression system for installation in all Jordanian Army Khalid, Tariq and M60A1/M60A3 MBTs plus the ENGESA EE-11 Urutu (6x6) APCs which were delivered in 1987.
These will be replaced in the nearfuture by ex-British Army Challenger 1 MBTs under a deal signed early in 1999.
  • Singaporean Centurions
It is believed that Singapore has a minimum of 12 Centurions, six of which are based in Brunei and six in Taiwan. All of these have 105 mm guns and new diesel engines. Some reports indicate that Singapore may have as many as 63 Centurion MBTs.
  • South African Centurions
Details of the extensive improvements carried out by South Africa to its Centurion MBTs, now called the Olifant.
  • Swedish Centurions
Late in 1981, the Swedish FMV awarded a contract worth some SKr150 million to Bofors for the upgrading of the Swedish Centurion Strv 101 and 102 MBTs.
The programme was carried out in two stages covering firepower and mobility. The first retrofitted vehicle was delivered to the Swedish Army early in 1983. This contract covered the following:
(1) A new fire-control system from Bofors Aerotronics based on its export version computer. New gun-control equipment, including solid-state amplifiers, a gyro unit and new gunner's and commander's control handle.
(2) A new gunner's day sight incorporating a laser range-finder and spot injection unit was provided by Ericsson.
(3) A modified cupola retaining the existing commander's sight but including an armoured hood to provide protection when observing head-out.
Bofors provided the Lyran twin launcher for the 71 mm illuminating system with a range of 1,300 m.
Late in 1982, the Swedish Army placed an order worth some SKM80 million with Allison (CD-850-6A automatic transmission) and General Dynamics Land Systems (previously Teledyne Continental) AVDS-1790-2DC diesel engine for subsystems to be used in the Strv 101 and Strv 102 Centurion MBTs. Chassis conversion work was carried out by Hag'glunds Vehicle. Integration of the chassis and turret took place at a Swedish government arsenal in southern Sweden. It is believed that about 80 of the Swedish Army's Centurion MBTs were fitted with a new diesel power pack.
Early in 1989, the Swedish Army took delivery of its first Swedish-made mineclearing roller systems which can be fitted to both the Centurion and S-tanks. This is called the Mine Roller I with the Coupling 1 linking the system to the Centurion and Coupling 2 linking the system to the Strv 103B/C or S-tanks. The overall weight of the mineclearing roller is 6,000 kg while the coupling weighs 1,000 kg. The system can be fixed to the vehicle in 30 to 40 minutes and it is usually used at a speed of 8 to 15 km/h. Full details of this are given in Jane's Military Vehicles and Logistics 1999-2000, page 264.
Early in 1985, the Swedish armed forces successfully completed trials of a Centurion MBT with the British Hydrostrut suspension system which has been developed jointly by Air-Log and the now Vickers Defence Systems Leeds and has also been tested on a British Army Chieftain MBT. The Hydrostrut suspension system can be retrofitted to any existing Centurion in one day and no modification to the hull is necessary.
With the introduction of the Leopard 2 and the later Leopard 2A5 MBTs all of the S-tanks and most of the Centurion tanks will be phased out of service with the Swedish Army. It is expected that a number of the Centurion tanks will be deployed on Gotland island in the Baltic Sea.
  • Canadian Centurions
Canada bought enough Centurions to fill 3 regiments in Canada and one in Germany they were used till the mid 70's when they were replaced by the Leopard C1 MBT. That converts to about 60 tanks per regiment plus spares.
Many of the tanks were sold to Israel which converted them to diesel.


Centurion Quantities:
Austria 120, Israel 1000, Jordan 293, Singapore 12, South Africa 224. Sweden 554. 
Total: 2203

source:http://www.army-guide.com/eng/product903.html