Tanks of the interwar period



This article discusses tanks of the interwar period.

World War I established the validity of the tank concept and between the two world wars, many nations needed to have tanks, but only a few had the industrial resources to design and build them. During and after World War I, Britain and France were the intellectual leaders in tank design, with other countries generally following and adopting their designs. This early lead would be gradually lost during the course of the 1930s to the Soviet Union and, to a lesser extent, to Nazi Germany.

General developments
The final tank designs of 1918 showed a number of trends. The US and British produced the Mark VIII tank. The pinnacle of the rhomboid design, the 34 ft, 37-ton, Mark VIII tank was powered by a 300-hp (224 kW) V-12 engine and capable of 7 mph (11 km/h) cross-country. However, the Renault FT set the pattern for almost all tanks that followed it; these tanks generally had lower track profiles, more compact hulls, and mounted their weapons in turrets.

Worldwide, many sizes of tank 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 were. However, the Spanish Civil War showed that tank-versus-tank engagements and tank-versus-towed antitank gun engagements would now be a major consideration in tank design. It became clear that future 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 Britain, military opinion was divided on the future of tank warfare. J.F.C. Fuller was convinced that only the tank had a future on the battlefield. Basil Liddell Hart foresaw a war where all arms, infantry, tanks and artillery, would be mechanised, resembling fleets of 'land ships', and experiments in these fields did take place but were not adopted. Liddell Hart would be proven correct, but it would not be for sixty years that even the wealthiest countries could make his ideas a reality.

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 BT series in turn influenced the British cruiser tank designs such as the A-13 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 WWII, reliable engines and transmissions, as well as high-speed suspension designs were all available. For example, in 1940, two prototype T-34 tanks completed a gruelling two thousand-kilometre test run by members of its design team, from Kharkov to Moscow, Smolensk, Kiev, and back. The USA, with its huge automobile industry, led the world in high-reliability designs by the beginning of WWII.

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 S-35, 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 Great Britain right to the end of WWII. 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.

Great Britain
Following WWI, many experiments involving armoured vehicles were conducted in Britain. Particularly many advances were made in the areas of suspensions, tracks, communications, and the organization of these vehicles on the battlefield.

Britain continued its technical dominance of tank design from 1915 through at least the early 1930s. British designs, particularly those from Vickers-Armstrong, formed the basis for many of the most common tanks of the 1930s and early WWII. For example, 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. Ironically, the six-tonner, which was arguably the most influential design of the late 1920s, was not adopted by the British Army.

Another notable design was the Vickers Medium Mk II, a pivotal design which combined some of the best traits of WWI tanks into a much faster tank. It had a fully rotating turret on top like the FT, but 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 would go on to serve in WWII, though most of the significance of the design lies in the amount of features that were copied (or at least also used) in later tank designs.

The Vickers Carden-Lloyd machine gun carriers influenced the tankette concept through export and similar designs such as the Soviet T-27, Italian CV-33, German Panzer I and other copies.

A perhaps less significant but also notable design was the Vickers A1E1 Independent, which was a large heavy tank that was 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 as well as 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.

An outstanding achievement of the British Army was the creation of 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. The unit was short-lived, however.

Eventually, 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. The Infantry tanks were tasked with the support of dismounted infantry. The maximum speed requirement matched the walking pace of a rifleman, and the armor 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. The light tanks were tasked with reconnaissance and constabulary-type colonial roles, with cheapness the major design factor. The British doctrine led to a neglect of firepower.

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 R 35 was the most common type; small numbers of the futuristic FCM 36 were built. The R 35 was also exported to several eastern European countries, including 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 WWI-vintage Char 2C was ever operational in this class, being the reason why the breakthrough role was delegated to the Chars de Bataille.
 * Cavalry Tanks (Automitrailleuses). These classes focused on speed in addition to the power and protection of other tank designs, and were intended for both anti-tank and anti-personnel work. As by law all tanks (Chars) had to be part of the Infantry, the Cavalry called its tanks Automitrailleuses. These included the Hotchkiss H35.
 * Armoured Combat Tanks (AMCs or Automitrailleuses de Combat), a medium tank that sacrificed some armour for speed, and had similar armament to the infantry tanks (AMC 34, AMC 35, SOMUA S35).
 * Armoured Reconnaissance (AMRs or Automitrailleuses de Reconnaissance), essentially light tanks (AMR 33;AMR 35), but specifically intended for general reconnaissance and maintaining a security screen. Specialised reconnaissance however would be carried out by AMD's or Automitrailleuses de Découverte, typically armoured cars or half-tracks.

The Renault FT 17 had a long life and saw use in WWII and even later in Indochina. It was utilised as far away as in China, during the Chinese Civil wars, and versions of the tank were used both against and by the Japanese during the invasion of China. A large number found their way into both Republican and Nationalist hands during the Spanish Civil War. They were used in the Russian Revolution by both the Bolsheviks and the White Russians, and later by the Finns against the Soviets. France exported the FT 17 right up to World War II. The design was also developed by the Italians as the Fiat 3000 and the USSR as the T-18.

By the mid-1930s the French Army was replacing the aging FT 17 fleet with a mixed force of light tanks both in the Infantry and Cavalry branches, as well as medium and heavy tanks. The Infantry light tanks included the Renault R 35, which followed the FT 17 concept quite closely with its very small size, two-man crew, and short 37 mm gun armament. It was, however, heavily armored. The R 35 was mostly used to equip the independent tank battalions, an armoured reserve allocated at army level and intended to reinforce infantry divisions in breakthrough operations. French infantry divisions normally had no organic tank component. The R 35 was exported to Poland and Romania. The cavalry had the similar Hotchkiss H 35, armed with the same 37 mm, as well as light recon tanks such as the AMR 35.

France also produced what may have been the best tank of the 1930s, the SOMUA S35. This tank equipped the armoured divisions of the Cavalry which had to execute the exploitation phase of a battle and was probably the best combination of armour, firepower and mobility prior to the appearance of the German PzKpfw IV Ausf. F2 and Soviet T-34. The S 35 had a long 47 mm gun that could kill any tank then in service, as well as heavy cast armour and good speed.

The French char de bataille Char B tank was a very formidable tank, with heavy cast and riveted armour, the same long 47 mm gun as in the S 35, and a hull-mounted 75 mm howitzer. All Char Bs were equipped with radio and the tank was nearly invulnerable to most tanks and towed antitank guns. They equipped the armoured divisions of the Infantry, which were specialised breakthrough units.

In general, French tanks of the 1930s were well-armoured, innovative vehicles that owed little to foreign designs. However, the light tanks lacked firepower and almost all French tanks were crippled by their one-man turrets. Even the vaunted Char B had a commander who was tasked with commanding the vehicle, aiming the main gun, and loading the main gun. If he were a platoon leader or company commander, he had the additional tasks of controlling his other units. Such a heavy set of tasks was overwhelming, and greatly reduced the effectiveness of the tanks. The lack of radios with the light tanks was not seen as a major drawback, since French doctrine called for slow-paced, deliberate manoeuvers in close conformance to plans: the "Methodical Battle" concept, adopted because wargaming showed it to be superior. The role of small unit leaders was to execute plans, not to take the initiative in combat. This was nearly the opposite of German doctrine, which stressed initiative and decision-making at low command levels (Auftragstaktik). In 1939 a belated effort was made to improve flexibility and increase the number of radios

Despite the views of Estienne and later Charles de Gaulle, the French general staff failed in defining an effective military doctrine regarding their use, due to the division of labour between infantry and cavalry tanks. In the Battle of France, despite an advantage in number and armour against the Germans, the French tanks were not used to good enough effect. The infantry tanks were only effective in executing the breakthrough phase of a battle; and thus useless as a mobile reserve. Ironically, cooperation with the infantry was poor. The Cavalry units alone were too few in number.

After the Fall of France, work on new designs, such as the Char G1, officially halted, although there was some clandestine designing done. After the liberation of France, the next tank to be introduced would be the ARL 44 heavy tank, which came too late to participate in World War II, but was used post-war for a time.

Soviet Union
The Soviet Union's efforts in tank design and production must be understood in the context of the experience of the Russian Civil War and the growth of Soviet industry. During the civil war, the use of armored trains and artillery trains was common. This tended to lead to a greater interest in tanks and armored cars compared to some western nations. The rapid growth of heavy industry in the USSR under the Five-Year plans made a large tank fleet possible.

Initially, the tanks and armored cars in Soviet hands were a mix of FT-17 imports and a few British tanks left behind in the civil war. The first Soviet tank, the T-18 (sometimes called MS-1) was a fairly close copy of the FT-17, but with improved suspension and a larger turret. Stalin's enthusiasm for industrialisation and mechanisation drove an aggressive military development program, resulting in by far the largest and broadest tank inventory of all nations by the late 1930s.

In 1926, under a secret annex to the Treaty of Rapallo, the Soviet Union and Germany set up a joint tank school at Kazan in the west of the Urals, which was illegal under the Treaty of Versailles. Both countries learned much about tank design and tactics in this co-operative venture. The Germans provided advice on mechanisation of Soviet heavy industry, and helped develop a sense of professionalism in the Red Army. From 1929, an experimental Mechanised Brigade was formed, training and developing combined-arms tactics with foreign tanks, armoured cars, tractors, and lorries.

The Soviets also spent tens of millions of dollars on U.S. equipment and technology to modernise dozens of automotive and tractor factories, which would later produce tanks and armoured vehicles.

Based on a mixed force of foreign tanks and imported prototypes, the Soviets developed an impressive domestic design and production capability. The T-26 light tank was based on the Vickers E (as were many other tanks of the period), chosen after it beat a Soviet FT derivative in trials. The Soviets purchased some U.S. Christie M1930 tank prototypes, from which they developed the BT series of fast tanks. They also developed the heavier multi-turreted T-28 medium tank and the massive T-35, which followed the design premise of the Vickers A1E1 Independent. Of the tanks produced between 1930 and 1940, 97% were either identical copies of foreign designs, or very closely related improvements. Significantly, the major improvement the Soviet designers made to these foreign designs was an increase in firepower. By 1935, the Red Army ". . . possessed more armoured vehicles, and more tank units than the rest of the world combined." (Zaloga 1984, p. 107)

But from 1937 to 1941, the Red Army's officer corps, the armour design bureaux, and leadership of the factories were gutted by Stalin's Great Purge. Approximately 54,000 officers were repressed. Military knowledge completely stagnated and armoured vehicle production dropped drastically (though still remaining the world's largest). Training and readiness dropped to very low levels. This repression continued until the eve of the war.



The participation by Soviet 'volunteer' tank units in the Spanish Civil War was decisive in forming Soviet tank designs for WWII. Soviet tanks dominated their foreign rivals in Spain due to their firepower, but their thin armor, in common with most tanks of the period, made them vulnerable to the new towed antitank guns being supplied to Infantry units. This finding led directly to a new generation of Soviet tanks. By the eve of World War II, the Soviet Union had some of the world's best tanks (including the T-34 and KV-1, which were basically a generation ahead, coming as a shock to the Wehrmacht). However, the poor training and readiness status of most Red Army units led to a catastrophic defeat of the enormous Soviet Mechanised Corps during the opening phases of Operation Barbarossa, Germany's 1941 invasion of the Soviet Union. Despite their generally good equipment, the Red Army's operational capabilities and motorised logistic support were very inferior.

Germany
Germany, constrained by the terms of the Treaty of Versailles, was not allowed to produce tanks of any kind and only a few armoured cars. In 1926 an unofficial program of tank construction was initiated by Von Seeckt, the commander of the Reichswehr. Built by Rheinmetall-Borsig the first grosstraktor ("big tractor") was similar to the existing British Mk II medium tank, 20 tons with a 75 mm gun. This, and other designs, were tested with Soviet co-operation at a tank school in the Russian Urals. In Germany proper dummy tanks were used in training, apparently at the instigation of then-Major Heinz Guderian, a staff tactical instructor. Guderian had read Fuller, Liddell-Hart and other tank warfare theorists and he had the support of his commanders to develop his theories into reality.

In 1931 the German General Staff accepted a plan for two types of tank, a medium tank with a 75 mm gun and a lighter vehicle with a 37 mm gun. While design and then construction work was carried out, the German army used a variety of light tanks based on the British Carden Loyd tankette chassis. The early tanks were code-named Landwirtschaftlicher Schlepper (La S, "agricultural hauler"), a designation that lasted until 1938. The first of these light tanks ran in early 1934. It was a five ton Krupp design which was dubbed the LKA1. The new government approved an initial order for 150 in 1934 as the 1A La S Krupp. Around 1500 of these light tanks were built.

Later German tanks received a new designation, Panzerkampfwagen (PzKpfw or PzKw), which means "Armoured Fighting Vehicle". The first machine to use this was the two-man PzKpfw I Ausf A influenced by the Carden Loyd tankette, and was a 5.4 ton machine with a 3.5 litre 60 hp (45 kW) petrol engine. It had 13 mm of armour and was armed with twin 7.92 mm machine guns. The more common Ausf B was a little larger to accommodate a 100 hp (75 kW) Maybach engine. Both models were sent to the Spanish Civil War for testing, along with other new German weapons. From the experiences in Spain it quickly became clear that the next generation of tanks would need better armour, greater range and much heavier weapons. The PzKpfw II was around 50% heavier than the PzKpfw I. It had a 20 mm Solothurn antitank gun as main armament, as well as improved armour of up to 30 mm. Also sent to Spain from 1937, the PzKpfw II proved more capable against light infantry, but no better when faced with capable anti-tank guns or other tanks. Despite these weaknesses, production continued until 1941. At the outbreak of war, the German Army had 955 PzKpfw IIs and almost 4000 were built in total.

A major boost to German armour came with the annexation of Czechoslovakia in 1938, giving Germany access to the entire Czech arms industry. The Czechs had two light tank designs later used by the Germans, the Škoda LT35 and the Českomoravská Kolben-Daněk (ČKD) TNHP. The Škoda was a 10 ton machine with a 37 mm main gun and excellent cross-country capabilities; the ČKD was 8.5 tons and also fitted with a 37 mm gun—due to extensive tests it was an extremely reliable machine with a top quality chassis. Both were taken into the German panzer forces, as the PzKpfw 35(t) and the PzKpfw 38(t), and further production was ordered. ČKD was renamed Boehmisch-Maehrische Maschinenfabrik AG (BMM) in 1940 and continued production until 1942, providing the Wehrmacht with 1,168 PzKpfw 38(t) tanks. In 1940, Czech tanks made up around a quarter of the entire German panzer force.

While lighter tanks formed almost the entirety of the German forces, heavier tanks were at least at the prototype stage. In 1934, a number of heavy prototypes were constructed, based around either 75 or 105 mm main guns. Designated Neubaufahrzeug (NbFz) and very similar to contemporary Soviet and British designs, six were built by Rheinmetall and Krupp. Although they were mainly useful for propaganda purposes because only a handful of the tanks were made, three were actually used in combat in Norway. The knowledge of the NbFz and the experiences of the lighter tanks in Spain aided in designing the next generation of tanks, the PzKpfw III and PzKpfw IV. The PzIII was the lighter of the two and was intended for use in anti-tank operations, whereas the heavier PzIV was armed with a short-barrel gun and intended for supporting infantry.

The Panzer III's 37 mm gun was considered underpowered, yet it was used in the interests of standardisation with the infantry. Contracts for the Zugkraftwagen were issued late in 1936. Its weight was limited to a maximum of 24 tons, because it was required to be able to cross existing bridges. Development work continued until 1938 when the Ausf D went into limited production. This 19 ton machine was powered by a 12 litre 320 hp (239 kW) engine. It had a top speed of 25 mph (40 km/h) and was fitted with 30 mm armour all round.

By the outbreak of war, around fifty had been completed and some saw service in Poland. Full-scale production did not begin until October 1939 as the Ausf E. Around 350 PzKpfw IIIs in the E variant were ready by the invasion of France.

Japan
Like the US Army, the Imperial Japanese Army (IJA) did not have tanks of its own in World War I, so initially it started out by purchasing foreign tanks for evaluation during World War I, and then began developing its own designs. After the first world war, a few Whippets (perhaps six) were exported to Japan, where they remained in service until around 1930.

In 1925, in addition to tankettes, the Japanese army began to design tanks to satisfy its own requirements. Before that year, as with most nations, all tanks in Japanese service had been of foreign design and/or manufacture. The first tank of Japanese design, the type 87 Chi-I, was produced in 1927 at the Osaka Arsenal. This tank was compared with an English Vickers Mark C; the type 87 was considered too heavy and too slow, and it was decided to create a new design. The Japanese were among the first to use diesel engines in some of their tank designs. They used light tanks and tankettes heavily in Manchuria and China during the 1930s.

The Type 89 Chi-Ro tank was lighter (9.8 tonnes) and shorter than the type 87. It contained increased armour (6 to 17 mm) and an improved water-cooled engine. After success in initial tests, the type 89 became the first mass-produced Japanese tank. The type 89 had a crew of four, and was armed with a 57 mm type 90 gun and two 6.5 mm type 91 machine guns.

In 1935, the Japanese began production of new tankettes and light tanks. The Type 94 tankette weighed 3.4 tonnes and was generally used as either a tractor to tow an ammunition trailer, or as a patrol/reconnaissance tank. With a crew of two men and a single 6.5 mm type 91 machine gun, the type 94 was produced in large numbers and saw widespread service as late as 1945. Over twice as large as the type 94 (7.4 tonnes), the Type 95 Ha-Go light tank had a complement of three crewmen, a 37 mm gun and the same 6.5 mm type 91 machine gun, and most importantly a diesel engine which would later greatly influence future tank designs in the Soviet Army. Over one-thousand vehicles were built by Mitsubishi, and production continued until 1943.

By 1936 the Japanese Army started to look for a replacement for the type 89. The new medium tank, Type 97 Chi-Ha, was introduced in 1937 and remained in production until 1944. The 15.8-ton tank was armed with a low-velocity 57 mm gun and had armour up to 33 mm thick.

The 1930s were the last time that the Japanese military focused on production and design of tanks. After that period, they were largely preoccupied with establishing naval control and their focus was on production of ships and aircraft. Furthermore, with the emphasis on expansion southward into the pacific ocean region, land battles would be largely replaced by naval warfare, and thus, with the exception of small islands, the domain of the Imperial Japanese Navy. With the end of WWII, and the destruction of the Imperial Navy, the focus on tanks returned when the Japanese military prepared for the defense of the mainland.

United States
After World War I, and still using British and French designs, the United States Tank Corps was reduced in size. Renaults and the new Mk VIII "Liberty Tank" were retained: http://www.ftmeade.army.mil/Museum/Exhibit_MarkVIII_Tank.html The Defense Act of 1920 restricted tanks to infantry use only; as a result, the Tank Corps was disbanded, with the remaining tanks distributed among the infantry.

In 1928, at the request of Secretary of War Dwight F. Davis, the Army formed the Experimental Mechanized Brigade. It consisted of a heavy tank battalion, a light tank battalion, a motorised infantry battalion, a motorised artillery battalion, an engineer company, and a signals company. Due to the use of obsolete equipment, the experiment failed, and the force was disbanded after three months.

In 1934–35, at the request of the Cavalry, three prototype tanks, the T2, T2E1, and T2E2 were produced. Under the terms of the Defense Act of 1920, tanks were restricted to infantry units. To get around the Defense Act, these tanks were called "combat cars".The M1 series entered service in 1937. The T2, inspired by the British Vickers 6-Ton, was standardised as the M1 combat car. The T2E1, a single-turret tank armed with three machine guns, was standardised as the M2A1. The T2E2, a two-turret tank with two machine guns, was standardised as the M2A2.

Throughout the interwar period the US produced only a few hundred tanks. From the end of World War I to 1935, only 15 tanks were produced. Most were derivatives or foreign designs or very poor quality private designs. The Christie designs were among the few bright spots, but the US Army acquired only three Christies and did not pursue the idea any further. Budget limitations and the low priority given to the Army meant that there were few resources for building tanks. The US Army instead developed and tested tank components such as suspensions, tracks, and transmissions. This work paid off when production needed to be initiated upon the outbreak of war.

Immediately before and during World War II, U.S tanks and many other Allied tanks were powered by radial aircraft-type engines. However, the massive production of aircraft caused a shortage of these engines. Because of this, many tanks, particularly the Sherman and the Lee, were powered by as many as five different power-plant arrangements. In addition to Wright and Continental radials, they were powered by Ford V8s, GM truck diesels, and the Chrysler A57 multibank (an arrangement of five 6-cylinder automobile engines that ran as a single unit). After the war, diesel truck-type engines replaced the gasoline-burning radials.

Others
Many other nations that desired tanks could not design or build their own. The 1920s and 1930s saw a widespread export business as smaller or less-industrialized nations purchased tanks abroad. Sometimes, the import of foreign tanks led to the birth of a tank industry in the importing nation.

Poland imported the British Vickers Six-Ton tank and began production of improved models. The pinnacle of this improvement program was the 7TP, which featured a diesel engine and 37 mm gun. Poland also produced the TKS series of tankettes, similar in concept to the Vickers-Carden-Lloyd machinegun carriers of Britain and the UE of France. These vehicles had two-man crews, thin armor, and a single ball-mounted light machinegun.

Czechoslovakia produced several light tanks. In general the Czech designs were very reliable mechanically and comparable in combat value to other light tanks. The CKD tankette was armed with two machineguns and was used in combat in WWII on the Eastern Front. The Panzerkampfwagen 35(t) was a light tank with a 37 mm gun and two machineguns. 434 were built before the Czechoslovak army was disbanded; production continued after the German occupation. The tank was taken into German service and used in the Battle of France and on the Eastern Front crewed by German, Slovakian and Romanian units. The more advanced Panzer 38(t) light tank was also used in great numbers by other powers. Almost one-quarter of the tanks used by Germany in Operation Barbarossa were of Czech manufacture. Both of these vehicles were used as substitutes for the Panzer III but were not its equal. The 38(t), in particular, formed the basis for several important self-propelled guns.

Turkey imported Soviet T-26 and a few T-28 tanks but did not begin series production of any tank.

Sweden's Landsverk firm designed several advanced light tanks, including the 20 mm armed L-60, which also had welded construction and some sloped armor. The L-60 was adopted as the Toldi light tank by Hungary. With its 20 mm gun it was roughly comparable to the German Panzer II or Soviet T-60. The L-60 was also the chassis on which the Landsverk L-62 self-propelled 40 mm anti-aircraft gun was built. Although designed as tank destroyer, the vehicle saw service with Hungarian forces on the Eastern Front as a self-propelled anti-aircraft gun under the name Nimrod. Six were used by Finland after 1942.

Hungary produced the Toldi as well as a medium tank, the Turan. The Turan I was based on a prototype of Czech medium tank Škoda T-21 (Š-II-c), had rivetted construction, and a 40 mm gun. The later Turan II had a 75 mm gun. During WWII these tanks were supplemented by several dozen imported German vehicles.

Latvia and Lithuania imported a few light vehicles such as Vickers-Carden-Lloyd tankettes, FT-17s, and Six-Tonners.

Romania imported some R-35 light tanks from France, as well as some Panzer 35(t)s.

Italy imported the French FT-17 and produced a slightly improved clone, the Fiat 3000. A native Italian design was the L6/40, a very small light tank with a 20 mm Breda cannon and rivetted construction. A medium tank, based on the Vickers Six-Tonner, was the M-11-M13 series. This tank had a very good 47 mm gun, but very thin armor. Italy also produced a large number of CV-33 and CV-35 tankettes based on the Vickers-Carden-Lloyd concept.

In Latin America, the first war where the tank was employed was the Chaco War between Bolivia and Paraguay, in which the former used a small number of British-built tanks and tankettes, whereas the latter had no tanks at all.