Tanks were initially deployed in World War I, engineered to overcome the deadlock of trench warfare. Between the two world wars, tanks were further developed. Although they had demonstrated their battlefield effectiveness, only a few nations had the industrial resources to design and build them. During and after World War I, Britain and France pioneered tank technology, with their models generally serving as a blueprint for other countries. However, this initial advantage would slowly diminish during the 1930s, shifting in favor of the Soviet Union and, to a lesser degree, Nazi Germany.
General developments
The final tank designs of 1918 were influenced by a number of developments and demonstrated several trends in tank design. One such example was the joint US and British Mark VIII tank, which was envisioned as a heavy tank design that could be utilized by both nations as well as the French. The purpose of this tank was to address the limitations of earlier British heavy tanks.
The Mark VIII measured 34 feet (10 meters) in length and weighed 37 tons. It was powered by a 300-horsepower (224-kilowatt) V-12 engine and could reach a top speed of 7 miles per hour (11 kilometers per hour) across difficult terrain. Only 100 of these tanks were built. It was the lighter Renault FT that would set the standard for nearly all tanks that followed it. This tank featured a lower track profile and a more compact hull, as well as a turret-mounted weapon system.
Worldwide, several types of tanks were considered, and much of the development effort went into light tanks that were useful primarily against infantry or for colonial police-type work. The worldwide economic difficulties of the 1920s and 1930s led to an increased emphasis on light tanks as they were much cheaper to produce than medium or heavy tanks. However, the Spanish Civil War showed that tank-versus-tank engagements and tank-versus-towed anti-tank gun engagements would now be a major consideration for the future of tank warfare. It became clear that tanks would need to be heavily armoured and carry larger guns. Tank shape, previously guided purely by considerations of obstacle clearance, now became a trade-off between a low profile, desirable for stealth, and weight savings.
In the UK, a great deal of study on the future of tank warfare was carried out, and there were some differences. Whilst both J.F.C. Fuller and Basil Liddell Hart foresaw a war where all arms, infantry, tanks, and artillery, would be mechanised, Fuller's theories looked at all-arms formations with artillery, infantry, and military engineers mounted on similar vehicles to keep pace with the tanks. He foresaw armies using heavy all-arms formations to break through opponents defences, allowing lighter, faster units to make rapid advances, thereby not allowing the enemy to re-establish any defences.
Liddell Hart considered that armoured vehicles would carry their own supporting infantry, in much the same way as modern warships carry their own marine detachments; he also proposed using indirect attack, effectively going around any defences. During the late 1920s the British Army established the Experimental Mechanized Force, to test these theories and look at the basic problems of managing, controlling and commanding all arms formations, including the use of aircraft.
Many of the units involved in this force were posted to North Africa, where their experience played a major part in the British success in the East African Campaign and General Wavell's initial successes in the Western Desert campaign. The British used three classes of tank: the 'Infantry tank', for supporting the infantry; the 'Cruiser tank', for fast moving encounter battles and reconnaissance; and the 'light tank', for reconnaissance, escort and internal security.
In the U.S., J. Walter Christie developed a series of fast tanks, based on his revolutionary Christie suspension system. This was combined with very high power-to-weight ratios achieved by fitting large aircraft engines in his tanks. Although his prototypes were capable of very high speeds, and in some cases designed to be air transportable, disputes with the United States Army Ordnance Corps and a high price (compared with what the US military was willing to pay) meant they were never produced in the USA.
Christie's prototypes were however purchased by the Soviet Union, and were to be developed into the BT tanks and eventually, on the eve of World War II, the famous T-34. The success of the BT series, when observed by Fuller at Russian Army maneuvers influenced the British to buy a Christie M1931 tank, imported as a "Tractor", which led to Christie's suspension incorporated into British cruiser tank designs such as the A13 Cruiser Mk IV, Crusader, and others.
Today it may be difficult to understand why the tank idea found such resistance from the leadership of several armies. Part of the explanation is that the entire automotive industry was in its infancy. Tanks were rightly considered unreliable, troublesome equipment as late as the early 1930s. Weak engines, poor transmissions, and fragile, short-life tracks contributed to this reputation.
The otherwise-incomprehensible resistance to tanks from 'traditional' military leadership can be partly understood in this light; a tank battalion that loses most of its vehicles due to mechanical failure on a 50-mile movement is not a reliable asset in combat. The international success of the Vickers Six-Ton tank is due more to its high reliability than any brilliance in the design. However, as the decade passed, engines, transmissions and tracks all improved. By the beginning of World War II, reliable engines and transmissions, as well as high-speed suspension designs were all available.
A final trend in the between-the-wars period was changes in manufacturing methods. France pioneered the use of very large castings to form gun mantlets, turrets and eventually, with the SOMUA S35, entire tank hulls. The widespread use of casting was copied by the US and USSR, and to a lesser extent in the UK. Casting enables the fast manufacture of ballistically well-shaped components. Germany never made much use of large cast components, limiting casting to smaller items such as mantlets.
Welding gradually replaced riveting and bolting as a means of fastening rolled armor plate together. Rivets can shear off when struck by enemy fire, resulting in additional crew casualties. Germany and the USSR led the way with welding, although the US followed closely. Riveting and bolting remained in use in some countries such as Hungary, Japan, and Italy, and to a lesser extent, in the United Kingdom right to the end of World War II.
Finally, the US and USSR led the way in rationalizing designs for fast production, eliminating unnecessary components or manufacturing steps that added little value. In contrast, French and German pre-war (and even wartime) tanks often incorporated features that added cost or manufacturing complexity out of proportion to their combat value.
United Kingdom
Following World War I, many experiments involving armoured vehicles were conducted in Britain. The most significant advances were made in the areas of suspensions, tracks, communications, and the organization of these vehicles on the battlefield. British designs, particularly those from Vickers-Armstrong, formed the basis for many of the most common tanks of the 1930s and early World War II. The Vickers Six Ton Tank was the basis for the Polish 7TP, the Soviet T-26, and was a major influence on the Italian M-11 and M-13 series and the Czech LT-35. The six-ton Vickers tank was not adopted by the British Army.
The Vickers Medium Mk II, which combined some of the best traits of World War I tanks into a much faster tank, had a fully rotating turret on top like the FT, and mounted a dual-use 3-pounder gun (that could fire both high-explosive and anti-tank shells) with a coaxial machine gun. It also had a radio, a machine-gunner position in the front of the hull, and some limited use of sloped armour. Some of these tanks served in World War II, though it was more significant for features that were utilized in later tank designs.
The Vickers Carden-Loyd machine gun carriers influenced the tankette concept through export which led to similar designs such as the Soviet T-27, Italian CV-33, German Panzer I and other copies.
The Vickers A1E1 'Independent', was a large heavy tank built in 1925. It had a large main turret and four smaller turrets. This design concept was later used by the Soviet T-28 and T-35 tanks and the German Neubaufahrzeug.
Exponents of the replacement of the cavalry function by armoured vehicles were Liddell Hart and Fuller. Their opponents misinterpreted (either mistakenly or deliberately) them as proponents of an all-tank fighting force, though their views did specify that artillery and infantry should be mechanised to make them as fast and manoeuvrable as the tanks they advocated, and experiments were curtailed.
The British Army created the Experimental Mechanised Force in the late 1920s. This was a small Brigade-sized unit developed to field-test the use of tanks and other vehicles. The unit pioneered the extensive use of radio to control widely separated small units but was relatively short-lived.
By the 1930s, British experiments, and their strategic situation, led to a tank development programme with three main types of tank: light, cruiser, and infantry. Infantry tanks were tasked with the support of dismounted infantry. The maximum speed requirement matched the walking pace of a rifleman, and the armour on these tanks was expected to be heavy enough to provide immunity to towed anti-tank guns. Armament had to be sufficient to suppress or destroy enemy machine gun positions and bunkers. Cruiser tanks were tasked with the traditional cavalry roles of pursuit and exploitation, working relatively independently of the infantry. This led to cruiser tank designs having great speed. To achieve this they were lightly armoured and tended to carry anti-tank armament. Light tanks were tasked with reconnaissance and constabulary-type colonial roles, with cheapness the major design factor. Vickers-Armstrong built a series of light tanks, to be sold either to the British Army, who wanted to keep costs down, or to foreign militaries.
France The French used a very wide range of tanks, including many unique types. France was the second largest tank producer in the world, behind the Soviet Union (see French armoured fighting vehicle production during World War II). Their cavalry tank class filled the role of what are now called MBTs. They also fielded a heavy tank design, and several lighter types for scouting and infantry support. In addition to these types, they were also working on super-heavy breakthrough tanks (FCM F1). The French didn't have an independent Tank Corps. All tanks belonged to either the Infantry or the Cavalry.
Infantry Tanks (Chars) Light Tanks (Chars Légers), generally similar to other nations' light tanks, though they were intended to be used more for infantry support rather than scouting, and as such were better armoured but slower than many other light tanks. The Renault R35 was the most common type; small numbers of the futuristic FCM 36 were built. The R35 was also exported to several eastern European countries, including Romania and Poland. Medium Tanks (Chars de Bataille), these were in fact meant to be specialised breakthrough tanks (Char D1, Char D2, Char B1). Heavy Tanks (Chars Lourds); only the World War I-vintage Char 2C was ever operational in this class, being the reason why the breakthrough role was delegated to the Chars de Bataille.