A tank is an armoured fighting vehicle designed for front-line combat. Tanks have heavy firepower, strong armour, and good battlefield manoeuvrability provided by tracks and a powerful engine; usually their main armament is mounted in a turret.
It is frequently claimed that Richard Lovell Edgeworth created a caterpillar track. It is true that in 1770 he patented a "machine, that should carry and lay down its own road", but this was Edgeworth's choice of words. His own account in his autobiography is of a horse-drawn wooden carriage on eight retractable legs, capable of lifting itself over high walls. The description bears no similarity to a caterpillar track. Armoured trains appeared in the mid-19th century, and various armoured steam and petrol-engined vehicles were also proposed.
The first combinations of the three principal components of the tank appeared in the decade before World War One. In 1903, Captain Léon René Levavasseur of the French Artillery proposed mounting a field gun in an armoured box on tracks. Major William E. Donohue, of the British Army's Mechanical Transport Committee, suggested fixing a gun and armoured shield on a British type of track-driven vehicle. The first armoured car was produced in Austria in 1904. However, all were restricted to rails or reasonably passable terrain. It was the development of a practical caterpillar track that provided the necessary independent, all-terrain mobility.
In 1911, a Lieutenant Engineer in the Austrian Army, Günther Burstyn, presented to the Austrian and Prussian War Ministries plans for a light, three-man tank with a gun in a revolving turret, the so-called Burstyn-Motorgeschütz. In the same year an Australian civil engineer named Lancelot de Mole submitted a basic design for a tracked, armoured vehicle to the British War Office. In Russia, Vasiliy Mendeleev designed a tracked vehicle containing a large naval gun. All of these ideas were rejected and, by 1914, forgotten (although it was officially acknowledged after the war that de Mole's design was at least the equal to the initial British tanks). Various individuals continued to contemplate the use of tracked vehicles for military applications, but by the outbreak of the War no one in a position of responsibility in any army gave much thought to tanks.
In a memorandum of 1908, Antarctic explorer Robert Falcon Scott presented his view that man-hauling to the South Pole was impossible and that motor traction was needed. Snow vehicles did not yet exist however, and so his engineer Reginald Skelton developed the idea of a caterpillar track for snow surfaces. These tracked motors were built by the Wolseley Tool and Motor Car Company in Birmingham, tested in Switzerland and Norway, and can be seen in action in Herbert Ponting's 1911 documentary film of Scott's Antarctic Terra Nova Expedition (at minute 50, here ). Scott died during the expedition in 1912, but expedition member and biographer Apsley Cherry-Garrard credited Scott's "motors" with the inspiration for the British World War I tanks, writing: "Scott never knew their true possibilities; for they were the direct ancestors of the 'tanks' in France".
The modern tank is the result of a century of development from the first primitive armoured vehicles, due to improvements in technology such as the internal combustion engine, which allowed the rapid movement of heavy armoured vehicles. As a result of these advances, tanks underwent tremendous shifts in capability in the years since their first appearance. Tanks in World War I were developed separately and simultaneously by Great Britain and France as a means to break the deadlock of trench warfare on the Western Front. The first British prototype, nicknamed Little Willie, was constructed at William Foster & Co. in Lincoln, England in 1915, with leading roles played by Major Walter Gordon Wilson who designed the gearbox and hull, and by William Tritton of William Foster and Co., who designed the track plates. This was a prototype of a new design that would become the British Army's Mark I tank, the first tank used in combat in September 1916 during the Battle of the Somme. The name "tank" was adopted by the British during the early stages of their development, as a security measure to conceal their purpose (see etymology). While the British and French built thousands of tanks in World War I, Germany was unconvinced of the tank's potential, and built only twenty.
The word tank was first applied to the British "landships" in 1915, before they entered service, to keep their nature secret.
As the result of an approach by Royal Naval Air Service officers who had been operating armoured cars on the Western Front, the First Lord of the Admiralty, Winston Churchill formed the Landship Committee, on 20 February 1915. The Director of Naval Construction for the Royal Navy, Eustace Tennyson d'Eyncourt, was appointed to head the Committee in view of his experience with the engineering methods it was felt might be required; the two other members were naval officers, and a number of industrialists were engaged as consultants. So many played a part in its long and complicated development that it is not possible to name any individual as the sole inventor of the tank.
However leading roles were played by Lt Walter Gordon Wilson R.N. who designed the gearbox and developed practical tracks and by William Tritton whose agricultural machinery company, William Foster & Co. in Lincoln, Lincolnshire, England built the prototypes. On 22 July 1915, a commission was placed to design a machine that could cross a trench 4 ft wide. Secrecy surrounded the project with the designers locking themselves in a room at the White Hart Hotel in Lincoln. The committee's first design, Little Willie, ran for the first time in September 1915 and served to develop the form of the track but an improved design, better able to cross trenches, swiftly followed and in January 1916 the prototype, nicknamed "Mother", was adopted as the design for future tanks. The first order for tanks was placed on 12 February 1916, and a second on 21 April. Fosters built 37 (all "male"), and Metropolitan Carriage, Wagon, and Finance Company, of Birmingham, 113 (38 "male" and 75 "female"), a total of 150. Production models of "Male" tanks (armed with naval cannon and machine guns) and "Females" (carrying only machine-guns) would go on to fight in history's first tank action at the Somme in September 1916. Great Britain produced about 2,600 tanks of various types during the war. The first tank to engage in battle was designated D1, a British Mark I Male, during the Battle of Flers-Courcelette (part of the wider Somme offensive) on 15 September 1916. Bert Chaney, a nineteen-year-old signaller with the 7th London Territorial Battalion, reported that "three huge mechanical monsters such as [he] had never seen before" rumbled their way onto the battlefield, "frightening the Jerries out of their wits and making them scuttle like frightened rabbits." When the news of the first use of the tanks emerged, Prime Minister David Lloyd George commented,
On 24 December 1915, a meeting took place of the Inter-Departmental Conference (including representatives of the Director of Naval Construction's Committee, the Admiralty, the Ministry of Munitions, and the War Office). Its purpose was to discuss the progress of the plans for what were described as "Caterpillar Machine Gun Destroyers or Land Cruisers." In his autobiography, Albert Gerald Stern (Secretary to the Landships Committee, later head of the Mechanical Warfare Supply Department) says that at that meeting "Mr. (Thomas J.) Macnamara (M.P., and Parliamentary and Financial Secretary to the Admiralty) then suggested, for secrecy's sake, to change the title of the Landships Committee. Mr. d'Eyncourt agreed that it was very desirable to retain secrecy by all means, and proposed to refer to the vessel as a "Water Carrier". In Government offices, committees and departments are always known by their initials. For this reason I, as Secretary, considered the proposed title totally unsuitable. In our search for a synonymous term, we changed the word "Water Carrier" to "Tank," and became the "Tank Supply" or "T.S." Committee. That is how these weapons came to be called Tanks," and incorrectly added, "and the name has now been adopted by all countries in the world."
The machines described in Wells' 1903 short story The Land Ironclads are a step closer, insofar as they are armour-plated, have an internal power plant, and are able to cross trenches. Some aspects of the story foresee the tactical use and impact of the tanks that later came into being. However, Wells' vehicles were driven by steam and moved on pedrail wheel, technologies that were already outdated at the time of writing. After seeing British tanks in 1916, Wells denied having "invented" them, writing, "Yet let me state at once that I was not their prime originator. I took up an idea, manipulated it slightly, and handed it on." It is, though, possible that one of the British tank pioneers, Ernest Swinton, was subconsciously or otherwise influenced by Wells' tale.
Colonel Ernest Swinton, who was secretary to the meeting, says that he was instructed to find a non-committal word when writing his report of the proceedings. In the evening he discussed it with a fellow officer, Lt-Col Walter Dally Jones, and they chose the word "tank". "That night, in the draft report of the conference, the word 'tank' was employed in its new sense for the first time." Swinton's Notes on the Employment of Tanks, in which he uses the word throughout, was published in January 1916.
Germany fielded very few tanks during World War I, and started development only after encountering British tanks on the Somme. The A7V, the only type made, was introduced in March 1918. with just 20 being produced during the war. The first tank versus tank action took place on 24 April 1918 at the Second Battle of Villers-Bretonneux, France, when three British Mark IVs met three German A7Vs. Captured British Mk IVs formed the bulk of Germany's tank forces during World War I; about 35 were in service at any one time. Plans to expand the tank programme were under way when the War ended.
In July 1918, Popular Science Monthly reported:
Germany, Italy and the Soviet Union all experimented heavily with tank warfare during their clandestine and “volunteer” involvement in the Spanish Civil War, which saw some of the earliest examples of successful mechanised combined arms —such as when Republican troops, equipped with Soviet-supplied tanks and supported by aircraft, eventually routed Italian troops fighting for the Nationalists in the seven-day Battle of Guadalajara in 1937. However, of the nearly 700 tanks deployed during this conflict, only about 64 tanks representing the Franco faction and 331 from the Republican side were equipped with cannon, and of those 64 nearly all were World War I vintage Renault FT tanks, while the 331 Soviet supplied machines had 45mm main guns and were of 1930s manufacture. The balance of Nationalist tanks were machine gun armed. The primary lesson learned from this war was that machine gun armed tanks had to be equipped with cannon, with the associated armour inherent to modern tanks.
The three traditional factors determining a tank's capability effectiveness are its firepower, protection, and mobility. Firepower is the ability of a tank's crew to identify, engage, and destroy enemy tanks and other targets using its large-calibre cannon. Protection is the degree to which the tank's armour, profile and camouflage enables the tank crew to evade detection, protect themselves from enemy fire, and retain vehicle functionality during and after combat. Mobility includes how well the tank can be transported by rail, sea, or air to the operational staging area; from the staging area by road or over terrain towards the enemy; and tactical movement by the tank over the battlefield during combat, including traversing of obstacles and rough terrain. The variations of tank designs have been determined by the way these three fundamental features are blended. For instance, in 1937, the French doctrine focused on firepower and protection more than mobility because tanks worked in intimate liaison with the infantry. There was also the case of the development of a heavy cruiser tank, which focused on armour and firepower to challenge Germany's Tiger and Panther tanks.
The five-month-long war between the Soviet Union and the Japanese 6th Army at Khalkhin Gol (Nomonhan) in 1939 brought home some lessons . In this conflict, the Soviets fielded over two thousand tanks, to the around 73 cannon armed tanks deployed by the Japanese, the major difference being that Japanese armour were equipped with diesel engines as opposed to the Russian tanks equipped with petrol engines. After General Georgy Zhukov inflicted a defeat on the Japanese 6th Army with his massed combined tank and air attack, the Soviets learned a lesson on the use of gasoline engines, and quickly incorporated those newly found experiences into their new T-34 medium tank during World War II.
Prior to World War II, the tactics and strategy of deploying tank forces underwent a revolution. In August 1939, Soviet General Georgy Zhukov used the combined force of tanks and airpower at Nomonhan against the Japanese 6th Army; Heinz Guderian, a tactical theoretician who was heavily involved in the formation of the first independent German tank force, said "Where tanks are, the front is", and this concept became a reality in World War II. Guderian's armoured warfare ideas, combined with Germany's existing doctrines of Bewegungskrieg ("maneuver warfare") and infiltration tactics from World War I, became the basis of blitzkrieg in the opening stages of World War II.
Tanks of the interwar period evolved into the much larger and more powerful designs of World War II. Important new concepts of armoured warfare were developed; the Soviet Union launched the first mass tank/air attack at Khalkhin Gol (Nomonhan) in August 1939, and later developed the T-34, one of the predecessors of the main battle tank. Less than two weeks later, Germany began their large-scale armoured campaigns that would become known as blitzkrieg ("lightning war") – massed concentrations of tanks combined with motorised and mechanised infantry, artillery and air power designed to break through the enemy front and collapse enemy resistance.
In the Second World War only Germany would initially put the theory into practice on a large scale, and it was their superior tactics and French blunders, not superior weapons, that made the "blitzkrieg" so successful in May 1940. For information regarding tank development in this period, see tank development between the wars.
Much like the Soviets, when entering World War II six months later (December 1941), the United States' mass production capacity enabled it to rapidly construct thousands of relatively cheap M4 Sherman medium tanks. A compromise all round, the Sherman was reliable and formed a large part of the Anglo-American ground forces, but in a tank-versus-tank battle was no match for the Panther or Tiger. Numerical and logistical superiority and the successful use of combined arms allowed the Allies to overrun the German forces during the Battle of Normandy. Upgunned versions with the 76 mm gun M1 and the 17-pounder were introduced to improve the M4's firepower, but concerns about protection remained—despite the apparent armour deficiencies, a total of some 42,000 Shermans were built and delivered to the Allied nations using it during the war years, a total second only to the T-34.
When Germany launched its invasion of the Soviet Union, Operation Barbarossa, the Soviets had a superior tank design, the T-34. A lack of preparations for the Axis surprise attack, mechanical problems, poor training of the crews and incompetent leadership caused the Soviet machines to be surrounded and destroyed in large numbers. However, interference from Adolf Hitler, the geographic scale of the conflict, the dogged resistance of the Soviet combat troops, and the Soviets' massive advantages in manpower and production capability prevented a repeat of the Blitzkrieg of 1940. Despite early successes against the Soviets, the Germans were forced to up-gun their Panzer IVs, and to design and build both the larger and more expensive Tiger heavy tank in 1942, and the Panther medium tank the following year. In doing so, the Wehrmacht denied the infantry and other support arms the production priorities that they needed to remain equal partners with the increasingly sophisticated tanks, in turn violating the principle of combined arms they had pioneered. Soviet developments following the invasion included upgunning the T-34, development of self-propelled anti-tank guns such as the SU-152, and deployment of the IS-2 in the closing stages of the war, with the T-34 being the most produced tank of World War II, totalling up to some 65,000 examples by May 1945.
Tanks were used to spearhead the initial US invasion of Iraq in 2003. As of 2005, there were 1,100 M1 Abrams used by the United States Army in the course of the Iraq War, and they have proven to have an unexpectedly high level of vulnerability to roadside bombs. A relatively new type of remotely detonated mine, the explosively formed penetrator has been used with some success against American armoured vehicles (particularly the Bradley fighting vehicle). However, with upgrades to their armour in the rear, M1s have proven invaluable in fighting insurgents in urban combat, particularly at the Battle of Fallujah, where the US Marines brought in two extra brigades. Britain deployed its Challenger 2 tanks to support its operations in southern Iraq.
Whilst several experimental machines were investigated in France, it was a colonel of artillery, J.B.E. Estienne, who directly approached the Commander-in-Chief with detailed plans for a tank on caterpillar tracks, in late 1915. The result was two largely unsatisfactory types of tank, 400 each of the Schneider and Saint-Chamond, both based on the Holt Tractor.