A tank is an armored fighting vehicle used as the main weapon in ground battles. Tanks are designed to balance strong weapons, thick armor, and the ability to move across rough terrain using tracks and a powerful engine. Most tanks have a large gun mounted in a rotating turret. They are an important part of modern military forces and play a key role in combined arms combat, where different types of military units work together.

Modern tanks are mobile weapons that carry a large-caliber gun in a rotating turret. They also have smaller weapons like machine guns or missiles. Heavy armor protects the crew, fuel, and important systems inside the tank. Tanks use tracks instead of wheels, which helps them move over rough ground, mud, and snow better than vehicles with wheels. This allows tanks to reach better positions on the battlefield. Tanks can attack directly with their powerful guns or defend by providing cover and protection for friendly troops. Even though newer anti-tank weapons can sometimes destroy older tanks with one shot, tanks remain flexible and can move quickly to respond to changing battle situations. The use of tanks in modern armies created a new type of warfare called armored warfare.

Before the invention of the main battle tank, tanks were grouped based on weight (like ultralight, light, medium, heavy, or super-heavy) or their purpose (such as breaking through enemy lines, scouting, or fighting infantry). Some tanks are large, heavily armored, and have big guns, while others are smaller, lighter, and faster. Smaller tanks can move quickly and are used for scouting or attacking enemies. They usually avoid fighting larger, heavier tanks unless they catch them by surprise during a side attack.

Etymology

In 1915, the word "tank" was first used in the military to describe British "landships" to keep their secret before they were used in battle.

On December 24, 1915, a meeting occurred at the Inter-Departmental Conference. Representatives from groups such as the Director of Naval Construction's Committee, the Admiralty, the Ministry of Munitions, and the War Office attended. They discussed plans for machines called "Caterpillar Machine Gun Destroyers or Land Cruisers." Albert Gerald Stern, who later became head of the Mechanical Warfare Supply Department, said in his autobiography that at the meeting, he mistakenly added that the name "tank" had been adopted by all countries in the world.

Lieutenant-Colonel Ernest Swinton, who was the meeting's secretary, was told to use a word that did not reveal the true meaning in his report. That evening, he talked with another officer, Lt-Col Walter Dally Jones, and they chose the word "tank." The next night, the word "tank" first appeared in the meeting's report. Swinton's book about using tanks, which used the word "tank" throughout, was published in January 1916.

In July 1918, Popular Science Monthly reported: (F.J. Gardiner, F.R.Hist.S.)

D'Eyncourt's account differs from Swinton's and Tritton's. This appears to be an imperfect memory. He said the name problem arose "when we shipped the first two vehicles to France the following year" (August 1916), but by then the name "tank" had been used for eight months. The tanks were labeled "With Care to Petrograd," but people believed they were a type of snowplough.

The term "tank" is used in English-speaking countries, but other countries use different names. In France, the second country to use tanks in battle, the word "tank" or "tanque" was first used, but later changed to "char d'assaut" ("assault vehicle") or simply "char" ("vehicle") due to Colonel J.B.E. Estienne's influence. During World War I, German sources referred to British tanks as "tanks" and their own as "Kampfwagen." Later, tanks were called "Panzer," short for "Panzerkampfwagen," meaning "armoured fighting vehicle." In Arabic, tanks are called "Dabbāba." The same word is used in Turoyo (a western dialect of Aramaic), but Swadaya (an eastern dialect) uses "rashupta." In Italian, a tank is a "carro armato" ("armed wagon"). Norway uses "stridsvogn," Sweden uses "stridsvagn" ("battle wagon"), and Denmark uses "kampvogn" ("fight wagon"). Finland uses "panssarivaunu" ("armoured wagon"), though "tankki" is also used. Poland uses "czołg," derived from the verb "czołgać się" ("to crawl"), describing the vehicle's movement. In Hungary, tanks are called "harckocsi" ("combat wagon"), though "tank" is also common. In Japan, the term "sensha" (戦車, "battle vehicle") is used, borrowed from Chinese. This term is also used in Korean as "jeoncha" (전차 / 戰車). Modern Chinese literature uses the English-derived term "tǎnkè" (坦克, "tank") instead of "zhànchē" (戰車, "battle vehicle") used earlier.

Development overview

The modern tank was developed over 100 years from the first simple armored vehicles, thanks to technological improvements like the gasoline engine, which made it possible for heavy armored vehicles to move quickly. These advances greatly changed the abilities of tanks since their first use. In World War I, tanks were created at the same time by Great Britain and France to help end the long, slow battles in trenches on the Western Front. The first British tank prototype, called Little Willie, was built by William Foster & Co. in Lincoln, England, in 1915. Major Walter Gordon Wilson designed the gears and body, and William Tritton of William Foster & Co. designed the tracks. This design later became the British Army's Mark I tank, which was first used in battle in September 1916 during the Battle of the Somme. The word "tank" was used by the British early on to hide the true purpose of these vehicles (see etymology). While Britain and France built thousands of tanks in World War I, Germany did not believe in their usefulness and had few resources, so it built only twenty.

During the time between World War I and World War II, tanks grew larger and more powerful. New ideas about armored warfare were developed. The Soviet Union used tanks and planes together for the first time in a large attack in August 1939 at Khalkhin Gol (Nomonhan) against Japan. Later, they created the T-34, which became an important early version of the main battle tank. A few weeks later, Germany began using large groups of tanks in fast attacks called blitzkrieg ("lightning war"), which combined tanks with fast-moving soldiers, guns, and planes to break enemy lines and destroy resistance.

In the second half of World War II, weapons like high-explosive anti-tank warheads became common, leading to lightweight weapons that soldiers could carry, such as the Panzerfaust, which could destroy some tanks. Tanks in the Cold War were designed to handle these weapons, and better armor, especially armor made from different materials, was developed in the 1960s. Improved engines, gears, and suspension systems allowed tanks to become larger. Gun technology also changed, with better shells and aiming systems.

During the Cold War, the idea of the main battle tank became important in modern armies. In the 21st century, as wars became more focused on uneven fighting and the Cold War ended, the use of cost-effective anti-tank weapons like rocket-propelled grenades (RPGs) increased worldwide. This made it harder for tanks to operate alone, so modern tanks are now often grouped into teams that include infantry in armored vehicles and supported by planes for scouting or attacking.

History

The tank is a modern version of an old idea: giving soldiers moving protection and powerful weapons. Key inventions, like the internal combustion engine, armor, and continuous tracks, made the modern tank possible.

In 119 BC, during the Battle of Mobei in the Han–Xiongnu War, the Han general Wei Qing led his army across the Gobi Desert. He found the Xiongnu leader Yizhixie’s main force waiting to surround them. The Han used armored wagons called "Wu Gang Wagon" in circle formations. These protected Chinese soldiers from Xiongnu cavalry attacks and let them use their ranged weapons effectively. This created a stalemate, giving Han troops time to rest. Later, they used a sandstorm to launch a surprise attack and defeated the Xiongnu.

Some sources suggest that Leonardo da Vinci and H. G. Wells may have imagined or "invented" the tank. Leonardo’s 15th-century drawings show a wheeled, man-powered vehicle with cannons. However, such a heavy vehicle would be hard to move over long distances, and animals could not fit inside. In the 15th century, Jan Žižka built armored wagons called "Wagenburg" with cannons, which were used successfully in battles during the Hussite Wars. The idea of the "caterpillar track" came from trying to improve vehicle mobility by spreading weight, reducing ground pressure, and increasing traction. Experiments with this idea began in the 17th century and became practical by the late 19th century.

It is often said that Richard Lovell Edgeworth created the caterpillar track. In 1770, he patented a "machine that should carry and lay down its own road." However, his own description of the invention was a horse-drawn wooden carriage with eight retractable legs that could climb over walls. This was not similar to a caterpillar track. Armored trains appeared in the mid-19th century, and other armored vehicles powered by steam or petrol were also proposed.

In H. G. Wells’s 1903 story The Land Ironclads, he described armored vehicles with internal power plants that could cross trenches. Some parts of the story match later tanks, but Wells’s vehicles used outdated steam technology and pedrail wheels. After seeing British tanks in 1916, Wells said he was not their inventor, but he had shared an idea. It is possible that Ernest Swinton, a British tank pioneer, was influenced by Wells’s story.

The first combination of a tank’s three main parts—armor, power, and tracks—appeared before World War I. In 1903, a French officer proposed placing a field gun in an armored box on tracks. A British officer suggested adding a gun and shield to a tracked vehicle. The first armored car was built in Austria in 1904, but these vehicles could only move on rails or smooth ground. Practical caterpillar tracks were needed for tanks to move across all types of terrain.

In 1908, Antarctic explorer Robert Falcon Scott argued that motor traction was needed for travel to the South Pole. His engineer, Reginald Skelton, designed caterpillar tracks for snow. These tracked vehicles were built by the Wolseley Tool and Motor Car Company and tested in Europe. Scott’s expedition member Apsley Cherry-Garrard later said Scott’s "motors" inspired British tanks.

In 1911, an Austrian officer, Günther Burstyn, proposed a small, three-person tank with a rotating gun turret. Around the same time, an Australian engineer named Lancelot de Mole submitted a tracked armored vehicle design to the British War Office. In Russia, Vasiliy Mendeleev designed a tracked vehicle with a large naval gun. These ideas were rejected and forgotten by 1914, even though de Mole’s design was later recognized as equal to early British tanks.

From late 1914, a few British Army officers tried to convince the government to build armored vehicles. Although they suggested using caterpillar tractors, the Army did not believe these could be adapted for war. Because of this, early tank development in Britain was handled by the Royal Navy.

In 1915, Royal Naval Air Service officers who had used armored cars on the Western Front persuaded Winston Churchill, the First Lord of the Admiralty, to form the Landship Committee. Eustace Tennyson d’Eyncourt, an experienced naval engineer, led the committee. Industrialists and naval officers worked together on the project. Many people contributed to the tank’s development, so no one person can be called the sole inventor.

Lt. Walter Gordon Wilson R.N. designed the tank’s gearbox and developed practical tracks. William Tritton, whose company built agricultural machinery, helped create the first tank prototypes. In 1915, a commission was given to build a machine that could cross a 4-foot-wide trench. The project was kept secret, and the first design, called "Little Willie," was tested in September 1915. A better design, nicknamed "Mother," was later chosen as the model for future tanks. The first tank order was placed in February 1916, and a second in April. Fosters built 37 tanks, and the Metropolitan Railway Carriage and Wagon Company built 113. These tanks, called "Male" and "Female" based on their weapons, later fought in the first tank battle in history.

Design

The three main factors that determine a tank's ability to perform well are firepower, protection, and mobility. Firepower refers to the tank's ability to find, attack, and destroy enemy tanks and other targets using a large-caliber cannon. Protection means how well the tank's armor, shape, and camouflage help the crew avoid being seen, stay safe from enemy attacks, and keep the tank working during and after a battle. Mobility includes how well the tank can be moved by train, ship, or plane to a battlefield, how it can travel by road or over rough ground toward the enemy, and how it can move across the battlefield during combat, even over obstacles or rough terrain. Different tank designs have changed over time based on how these three features are balanced. For example, in 1937, French tanks focused more on firepower and protection than mobility because they worked closely with infantry. Another example is the development of heavy cruiser tanks, which had strong armor and firepower to challenge German tanks like the Tiger and Panther.

Tanks have been grouped based on weight, role, or other factors, and these groupings have changed over time and in different countries. How tanks are classified depends on the ideas about armored warfare that were popular at the time, which have changed as technology improved. No single classification system works for all times or all countries. For example, weight-based classifications differ between countries and eras.

In World War I, the first tanks were designed to cross wide trenches, so they were large and long, like the British Mark I, and were called heavy tanks. Smaller tanks, like the French Renault FT, were used for other combat roles and were called light tanks or tankettes. Later tanks during and after the war had different designs based on new ideas about how tanks should be used. Classifications varied by country, with names like "cavalry tanks," "fast tanks," and "breakthrough tanks" used in different places.

During World War II, many early tank designs were found to be ineffective and were replaced, leaving mostly tanks that could do many different tasks. These tanks were easier to classify based on weight, which led to new definitions for heavy, light, and medium tanks. The British used cruiser tanks, which were fast, and infantry tanks, which had more armor but were slower. Tank destroyers are vehicles designed to fight enemy tanks. Assault guns can act like both infantry tanks and tank destroyers. Some tanks were modified to carry flamethrowers for attacking enemy strongholds up close. As the war continued, tanks became larger and more powerful, leading to the creation of super-heavy tanks.

During the Cold War, experience and technology helped clarify tank roles. With the widespread use of modern main battle tanks, which are designed to be versatile and adaptable, most other classifications were no longer used. Main battle tanks usually have a good balance of speed, armor, and firepower, even as technology improves these features. Because they are large, main battle tanks can work with lighter vehicles like light tanks, armored personnel carriers, and infantry fighting vehicles for tasks such as reconnaissance, amphibious assaults, or fighting enemies without main battle tanks.

The main weapon in modern tanks is a large-caliber cannon mounted in a rotating turret. Modern tank guns are smoothbore and can fire many types of ammunition, including armor-piercing rounds like KEPS, APDS, or APFSDS, and high-explosive shells like HEAT, HESH, or ATGMs to destroy enemy tanks. They can also fire HE shells to attack unarmored vehicles or troops and fortifications. In close combat, canister shot may be used to avoid harming friendly forces with shrapnel.

A gyroscope helps keep the main gun steady, allowing it to be aimed and fired while moving or stopping quickly. Modern tanks also have thermal sleeves to prevent the gun barrel from warping due to heat, bore evacuators to reduce smoke and fumes in the crew compartment, and muzzle brakes to improve accuracy and firing speed.

Traditionally, tanks relied on visual identification using telescopic periscopes inside the tank. Sometimes, tank commanders opened hatches to see outside, which improved awareness but made them vulnerable to snipers. These methods are still used today, but newer electronic systems have been developed. In the 2010s, laser rangefinders and other electronic tools became more common for detecting targets.

In some cases, spotting rifles were used to check the path and distance to a target. These rifles were attached to the main gun and fired tracer rounds that matched the gun's trajectory. The gunner would watch the tracer's flight and fire the main gun when the tracer hit a hard surface. This method was replaced by laser rangefinders.

Modern tanks use advanced night vision and thermal imaging to see in the dark, during bad weather, or in smoke. Computerized fire-control systems help aim the gun with high accuracy. These systems use laser rangefinders to measure distance, thermocouples, anemometers, and wind vanes to adjust for weather effects, and muzzle referencing systems to correct for barrel temperature and wear. Two measurements of a target's movement help calculate its path, which is combined with the tank's movement and ballistics to determine the best aim point.

Tanks often carry smaller weapons for short-range defense, such as when fighting infantry or light vehicles. A typical setup includes a general-purpose machine gun mounted next to the main gun and a heavier anti-aircraft machine gun on the turret. Some tanks also have a machine gun on the hull. These weapons are similar to those used by infantry.

A tank's protection depends on its ability to avoid being seen (through low profile and camouflage), avoid being hit, resist damage from enemy fire, and keep working even if damaged. This is achieved with armor, reactive defenses, and other measures like armor plating.

Command, control, and communications

Controlling and organizing tanks in battle has always been difficult, especially because of communication problems. However, modern armies have improved this by using connected systems that help with communication and increase awareness of the battlefield.

Tank armor, loud engines, rough terrain, dust, smoke, and the need to keep hatches closed make it hard for tank crews to communicate. This can make small groups of tanks or individual vehicles feel isolated. In the past, radios were not strong enough to be used inside tanks, but some tanks during the Battle of Cambrai had Morse code transmitters. Field telephones were not commonly used on tanks. During World War I, when radios failed, some crews sent messages by releasing carrier pigeons through openings in the tank. Communication between vehicles was sometimes done using hand signals or flags, a method used by the Red Army and Soviet Army during the Second and Cold Wars. Messengers on foot or horseback were also used.

The German military focused on wireless communication early on, giving their tanks radios and training units to use them properly. This helped them react quickly to changes during battles, giving them an advantage over Allied forces, which initially had better weapons but lacked radios. By mid-war, Western Allied tanks began using radios, while Russian tanks used them less often.

Today, tanks use microphones in crew helmets for internal communication and to connect to radio networks. Some tanks have external microphones on the back to talk with nearby soldiers. Radio networks use clear rules to avoid confusion. A recent improvement is combining information from the tank’s fire control system, laser rangefinder, GPS, and terrain maps using strong electronic systems. This information is shown on a screen in the tank, helping the commander see enemy and friendly units. Sensors on nearby tanks, planes, drones, or soldiers can share data. This improves the commander’s ability to understand the battlefield and choose targets. Orders are sent through the network with text and images, reducing the need for manual reporting. This system is called Network-centric warfare in the U.S., Network Enabled Capability in the U.K., or Digital Army Battle Management System in Israel. Advanced tanks like the K-2 Black Panther now use fully integrated radar systems for fire control, allowing them to spot and identify enemy tanks from farther away and improve accuracy.

Understanding the battlefield and communicating are two of the four main tasks of modern main battle tanks. To help crews understand their surroundings, tanks use a system that combines augmented reality and artificial intelligence.

Improvements in tank defense have led to active protection systems, which include two types:

• Soft-kill systems use radar to detect incoming missiles or projectiles. When detected, smoke screens or smoke grenades are released to confuse the missile, making it miss the tank.
• Hard-kill systems destroy incoming missiles or projectiles by launching anti-missile weapons. This method is more reliable.

Both types of protection are used on tanks like the K2 Black Panther, Merkava, and Leopard 2A7.