Introduction to Tank
Tank, an armored motor vehicle designed to fight while it is moving. It differs from other armored vehicles—such as self-propelled guns and personnel carriers—in that its primary mission is to attack, rather than to defend, transport, or scout. The branch of the U.S. Army concerned with tank warfare is called Armor. The tank is the principal weapon of armored divisions and an important supporting weapon of infantry divisions. In the U.S. Army, an armored division has about 300 tanks, and an infantry division about 50.
Tanks move on crawler, or Caterpillar-type, tracks, permitting them to travel cross country. The engine—a gasoline or diesel internal-combustion engine or a turbine engine—is mounted in the rear and transmits power to the tracks by geared wheels. Other wheels, variously called bogies, idlers, or road wheels, support the tank on its tracks but do not transmit power. Most present-day tanks have maximum speeds of 30 to 45 mph (48 to 72 km/h) and can travel 130 to about 300 miles (210 to 480 km) without refueling.
The main gun of a modern tank ranges in size (bore diameter) from 75 to 125 mm and is usually mounted in a turret that can be turned in a full circle. The effective range of the gun varies with the type of ammunition and the target. A high-velocity 105-mm gun can be effective against a tank up to 3,500 yards (3,200 m) away and against troops at a distance of about 8,000 yards (7,300 m). A gyroscopic stabilizing device steadies the gun to keep it on target when the tank is moving over rough ground. Tanks also carry machine guns.
The typical tank has a crew of four—a commander (usually a sergeant or lieutenant), a driver, a gunner, and a loader. The driver looks through a periscope and steers the tank with controls that vary the speed of the tracks. (In a right turn, for example, the left track moves faster than the right track.) A two-way radio links each tank with other members of its unit.
There are two basic kinds of tanks, the main battle tank (MBT) and the light tank. The MBT is heavily armored and weighs from 32 to 45 metric tons. The caliber of its main gun ranges from 105 to 125 mm. The MBT is primarily an offensive weapon, designed to break through enemy defenses for such purposes as opening the way for infantry, cutting the enemy's supply lines, or dashing ahead to capture strategic points. Even in a defensive situation, the MBT, where possible, is employed offensively, meeting enemy tanks with attacks of its own.
The light tank is less heavily armored and usually less well-armed, carrying a 75-mm or 90-mm gun. It is designed for reconnaissance, but sometimes is outfitted with a 105-mm gun to perform as a low-cost substitute for the MBT. Because of its relatively light weight, about 14 metric tons, the light tank can be easily transported in airplanes for use by airborne assault forces. Light tanks are also used in counterinsurgency warfare and in quelling civil disturbances.
All tanks have certain limitations. They are handicapped in mountainous or swampy regions. Increases in armor protection and in weight of armament cut down speed and cruising range. Maintenance of the complicated machinery is a constant problem, as is supply, especially of fuel and ammunition.
Antitank Weapons
The most versatile antitank weapon is probably the tank itself, which can maneuver into the best possible position for attack and can fire quickly and accurately.
Long-range artillery can be highly effective and has the advantage of being safe from the attacking tanks' guns. Unless the enemy attack is from an expected direction, however, much valuable time is lost in bringing the guns into position. Aerial attack—with bombs, light cannon, and air-to-ground missiles—can be deadly, but accurate aim is difficult.
For medium and close ranges, the surface-to-surface guided missile is the principal weapon for destroying tanks. One kind of missile is wire-guided—it reels out thin wires through which electric signals are sent to adjust the aim. Another kind is automatically guided by infrared devices and computers that make adjustments during flight. Bazookas (rocket launchers) and grenades can be used to disable a tank by damaging its tracks but are rarely able to destroy one.
Passive defensive measures include the use of land mines, ditches, and obstacles (such as concrete obstructions). These devices can stop individual tanks but can rarely do more than slow down a major tank attack.
History
World War IIn the early weeks of World War I the firepower of machine guns and artillery made above-ground operations so costly that trench warfare soon developed. Many ideas were tried in an effort to break the resulting stalemate. Lieutenant Colonel Ernest D. Swinton of the British army watched a Caterpillar tractor travel through mud and broken ground behind the lines and saw it as the basis for an armored vehicle. He took his idea to the Committee of Imperial Defence, but only Winston Churchill, then first lord of the admiralty, saw its possibilities.
Churchill put a Royal Navy group to work developing a “landship. (Because of this naval origin tanks retain such nautical terms as hatch, ports, hull, deck, bow, and superstructure.) As experiments continued in secrecy, parts made in different factories were labeled as parts for “tanks—presumably water tanks to be used in Russia or Mesopotamia.
Tanks were used in combat for the first time during the Battle of the Somme, September 15, 1916, but the surprise effect was wasted by employing only 49 vehicles in scattered groups. At Cambrai, November 29, 1917, the British used 378 tanks backed by six infantry divisions and penetrated six miles (10 km) into the German defenses. The U.S. Tank Corps, using French tanks, was first in action at St. Mihiel, on September 12, 1918.
The first British tanks were 34 feet (10 m) long, each with a crew of 11 manning two 6-pounder guns (cannon) and five machine guns. Top speed was 6 mph (10 km/h). The French developed the Renault light tank with a crew of two. Tanks were used as moving forts to protect infantry following close behind.
After the war B. H. Liddell Hart and J. F. C. Fuller in Great Britain, Heinz Guderian in Germany, Charles de Gaulle in France, and Adna R. Chaffee in the United States advocated use of tanks in masses for shock effect and to avoid the costly stalemate of trench warfare by restoring mobility to land forces. Conservative military men were slow to accept this concept. They considered the tank an auxillary weapon to be used in support of infantry.
In Germany, however, the theories of Liddell Hart and the other early tank planners were put into practice under Adolf Hitler, and there was created a powerful armored force capable of decisive action.
World War IIBy World War II, armies had developed three principal kinds of tanks—heavy (27 to 41 metric tons), medium (14 to 27 metric tons), and light (6 to 14 metric tons). Heavy and medium tanks were designed for battle, while light tanks were designed for reconnaissance as a mechanized equivalent of cavalry. The heavy tank was the most heavily armored and least vulnerable, but because of its slowness and lack of maneuverability, it had to be supported by lighter and faster medium tanks. In World War II, the bulk of the tank forces was composed of medium tanks.
The theories of the tank strategists proved their worth in 1939 when Germany defeated Poland in.36 days using panzer (armored) divisions as spearheads to exploit every breakthrough. This use of armor, combined with air power and rapidly moving infantry, was called blitzkrieg (lightning war).
In the same manner Germany defeated France in a matter of weeks in 1940. A rapid thrust across France by German panzer forces, spearheaded by a tank corps led by General Guderian, was the decisive factor.
The first great battles in which both sides used tanks as their primary weapons took place in the deserts of North Africa. The German commander in North Africa, General Erwin Rommel, proved to be World War II's greatest tactician in armored warfare as he repeatedly defeated far larger and stronger forces sent against him.
The largest tank battle of the war, involving some 6,000 tanks, was the Battle of Kursk, which was fought on the Russian front in July, 1943. The battle, in which both sides suffered heavy losses, brought to an end Germany's last major offensive against the Russians.
One of the most spectacular uses of tanks in World War II was by General George S. Patton's Third Army following its breakthrough at St. L, France, on July 14, 1944. Patton's armored divisions led an advance of 400 miles (640 km), reaching the German border on September 12, but a lack of supplies forced a halt.
The U.S. Army had 16 armored divisions in World War II. Other armored units were mechanized cavalry groups and separate tank battalions. Antitank weapons developed during the war included the tank destroyer, bazooka, and recoilless rifle. (The tank destroyer, an armored vehicle carrying a heavy gun, was the forerunner of self-propelled artillery.)
After World War IITanks played an important role in the early stages of the Korean War, but when the war became stalemated in mountainous terrain tanks were used mainly as fixed artillery. In the guerrilla fighting in Vietnam in the 1960's there was little opportunity for employment of armor in mass formations.
The first large use of tanks after the Korean War occurred during the Arab-Israeli wars of 1967 and 1973, when both sides committed hundreds of tanks to battle. In the 1973 conflict surface-to-surface antitank missiles carried by infantrymen destroyed large numbers of tanks, and some military experts declared that the tank was obsolete. Both the Arabs and the Israelis, however, continued to place value on the use of tanks and in the years after the war steadily increased their armored forces.
The principal development in the building of tanks during the 1960's and 1970's was the creation of the main battle tank (MBT), which was designed to replace both the medium tank and the heavy tank. It combines the speed of a medium tank with the armor and firepower of a heavy tank. MBT's include the Abrams (United States), AMX (France), Chieftain (Great Britain), Leopard (Germany), Morkava (Israel), and T-72 and T-80 (Russia).
During the 1980's, munition designers increased the penetrating power of antitank weapons, and tank designers responded by developing new forms of armor. The United States developed an extra-strength armor cast in flat slabs and, later, an armor made of a highly dense composite of steel and uranium. Israel and Russia both employed “reactive armor, basically a covering of explosives over the tank's armor plate; the explosives detonate when struck by a shell or missile, preventing it from penetrating.
In the Persian Gulf War (1991), the 100-hour land offensive that ended the war involved thousands of tanks, the largest number in a single operation since the Battle of Kursk in World War II.