Tanks in World War II
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This article deals with the history of the tank in World War II.
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[edit] Overview
During World War II, the tank reached new heights of capability and sophistication. The early tanks of Nazi Germany were technologically inferior to many of their opponents' tanks in the areas of armour and firepower. It was in their tactical employment that German tanks dominated all rivals early in the war. German doctrine stressed the use of combined-arms involving mobilee infantry and air support, and, after its surprising success during the execution of Fall Gelb, the tactic of the Blitzkrieg (lightning warfare). This doctrine required the Germans to equip their tanks with radios, which provided unmatched command and control. In contrast, almost all light French tanks lacked radios, essentially because their battle doctrine was based on a more slow-paced, deliberate conformance to planned movements. This required fewer radios at all levels. French tanks generally outclassed German tanks in firepower and armor in the 1940 campaign, but their poor command and control doctrine made these advantages irrelevant to the final outcome.
Just as in WWI, there was experimentation with effective tank sizes. On the heavy side, the United States experimented with the T-28 at 95 tons and Nazi Germany developed the 188-metric ton Panzer VIII Maus, though neither entered service. The trend towards heavier tanks was unmistakable as the war proceeded. In 1939, most tanks had maximum armor of 30 mm or less, with guns no heavier than 37-47 mm. Medium tanks of 1939 weighed around 20 tons. By 1945, typical medium tanks had maximum armor over 100 mm thick, with guns in the 75-85 mm range and weights of 30 to 45 tons. Light tanks, which dominated most Armies early in the war, gradually faded out and were used only in very limited roles.
Turrets, which had always been considered, but were not previously a universal feature on tanks, were recognised as essential. It was appreciated that if the tank's gun was to be used to engage armoured targets, then it needed to be as large and powerful as possible, making one large gun with an all-round field of fire vital. Also, mounting the gun in a turret ensured that the tank could fire from behind some cover. Hull-mounted guns required that most of the vehicle be exposed to enemy fire. Multiple-turreted or multi-gun designs such as the Soviet T-35, US Medium Tank M3, French Char B or British A9 Cruiser Mk I slowly became less common during World War II. It was recognized that a tank crew could not effectively control the fire of several weapons; also, newer dual-purpose guns eliminated the need for multiple weapons. Most tanks still retained a hull machine gun, and usually one or more machineguns in the turret, to protect them from infantry.
It was during this war that tanks began to be normally equipped with radios, vastly improving their command and control. By 1943, two-way radio was nearly universal. Tanks were adapted to a wide range of military jobs, including mine clearance and engineering tasks. Specialized models, such as flame-thrower tanks, recovery tanks for towing disabled tanks, and command tanks with extra radios and dummy turrets were also used. Some of these tank variants live on as other classes of armoured fighting vehicle, no longer called "tankies". All major combatant powers also developed tank destroyers and assault guns - armoured vehicles carrying large calibre guns, but often no turrets. Turreted vehicles are expensive to manufacture compared to nonturreted vehicles. One trend seen in WWII was the usage of older, lighter tank chassis to mount larger weapons in fixed casemates as tank destroyers or assault guns. For example, the Soviet T-34 could mount an 85 mm gun in the turret, but the same chassis could carry the much more effective 100 mm gun in a fixed casemate as the SU-100. Likewise, the obsolete German Panzer II light tank was modified to take a powerful 75 mm PAK-40 gun in an open-topped, fixed casement as the Marder II.
[edit] Nazi Germany
The Third Reich's Panzer force was not especially impressive at the start of the war. Plans called for two main tanks: the Panzer III medium tank and the Panzer IV infantry tank. However, by the beginning of the invasion of Poland, only a few vehicles were available. As a result, the invasions of Poland and France were carried out primarily with the inferior Panzer I and Panzer II light tanks, with some cannon-armed light tanks from Czechoslovakia. As the war proceeded, production of the heavier tanks ramped up.
During the Operation Barbarossa, the German invasion of the USSR in 1941, it was discovered that the Soviet T-34 tank outclassed the Panzer III and IV. Its sloped armour could defeat most German weapons, and its 76.2 mm gun could penetrate the armour of all German tanks. The Panzer III, which was intended to be the main medium tank, was upgraded to a longer, higher-velocity 50 mm gun. Even this was only marginally effective. Thus the Panzer IV, originally intended to be a support tank, became the de facto main medium tank re-armed with a long-barrelled, high velocity 75 mm gun. A new tank, the Panzer V Panther, was developed, incorporating lessons learned from the T-34. The Nazis' traumatic experiences against the Soviet heavy tanks, with cases of single KV tanks holding up entire German tank units, spurred them to develop even heavier designs including the Tiger and Tiger II Königstiger ("King Tiger").
[edit] United Kingdom
Britain had been the worldwide trend-setter in tank development from 1915, but lost its leadership position as the war approached. The British Army entered the war with an array of poor designs and hobbled by poor doctrine. British tank use focused on Cavalry-type missions and Infantry support, without the focus on combined-arms tactics that saturated German and Soviet thinking. The result was a series of under-armed, mechanically unreliable designs such as the A9, A10 and Crusader (A15) cruiser tanks, the Matilda (A11) and Matilda II (A12) infantry tanks, and a series of deathtrap light tanks suitable for reconnaissance work only. The few bright spots of British tank design included the Valentine, Churchill (A22), Cromwell (A27M), and Comet I (A34). The Valentine was a reliable, heavily-armored Infantry-support tank used successfully in the desert and by the Red Army as a light tank. The Churchill had heavy armor and good off-road capability. The Cromwell was in most respects the equal of the early model US Sherman or German Pzkw-IV, but was fielded only in small numbers beginning in 1944. The Comet I was an excellent design fielded in the final months of the war.
Beginning about mid-1942, most British tank units were equipped with US-supplied vehicles such as the Stuart light tank, the Lee (or the Grant variant thereof) and the Lee's/Grant's replacement the Sherman.
Immediately before and during the war, the British produced an enormous array of prototype tanks and modified tanks for a variety of specialist tasks (see Hobart's Funnies). For example, the Churchill AVRE mounted a 290 mm (11.4") direct-fire mortar which was used for destroying buildings and clearing obstacles.
[edit] Soviet Union
The Soviet Union began and ended the war with more tanks than the rest of the world combined. A common misconception has it that most of these tanks were obsolete. In fact the most common tank in Soviet service in 1941 was the T-26. Most T-26s were armed with a 45 mm gun capable of penetrating most German tanks at normal combat ranges; many had radios, and the design was mechanically sound although incapable of further development. The BT tank series, based on the Christie suspension system, were usually armed with the same 45 mm gun and were the most mobile tanks in the world. Close-support versions of both tanks existed, armed with 76.2 mm howitzers. However, the BT was at the end of its design life. The Red Army also fielded thousands of light recon tanks such as the amphibious T-37 and T-38, based on the French AMR design. These had limited combat value; although highly mobile, they were armed only with 7.62 mm machineguns and had paper-thin armor. The Red Army also had about 400 T-28 medium tanks, which were in most respects equal to the German Pzkw-IV. Again, though, this design dated from 1931 and was at retirement age. The USSR ended the 1930s with a fleet of tanks almost completely derived from foreign designs, but would later field some of the most important trend-setting tanks of the war. The problem the Soviet tank force faced in 1941 was not primarily the technical quality of its vehicles, but the very poor state of maintenance, the appalling lack of readiness, and the poor command situation brought on by the purges[citation needed]. The Red Army had in 1940 adopted an advanced doctrine that it was simply incapable of executing.
On the eve of war, the Red Army had embarked on two closely-related projects to reorganize its mechanized forces and re-equip them with modern designs incorporating the lessons of the Spanish Civil War and the Winter War. Some of these designs would leapfrog past the rest of the world.
Several excellent designs were just entering production in 1940-41. The most significant would be the T-34. This was originally designed as the successor to the BT series, but with its heavy armor and heavy dual-purpose gun, it became the best medium tank of the first half of WWII. The T-34 eventually replaced almost all other Soviet tanks. The basic design was good enough that it remained battleworthy right up to 1945, upgraded along the way with heavier guns, new turrets, and other modifications. The other significant design was the KV series tanks. These were armed with the same excellent 76.2 mm gun as the T-34, and had the same V-2 diesel engine. However, the KV had torsion bar suspension and much heavier armor than the T-34. The KV was slow, intended as a breakthrough tank. The KV-2 close-support version was armed with a 152 mm howitzer. The KV series was the main Soviet heavy tank until 1943, when production ended and most had been expended. Early in 1944, the KV's successor was the IS-2, armed with a 122 mm gun and with heavier armor and better mobility. The new Infantry-support tank of 1941 was the T-50, armed with a 45 mm gun but with torsion-bar suspension and excellent armor. Production problems with its new engine led to the tank being cancelled after less than 70 were made; however, it was intended to be the replacement for the T-26. Finally, the light reconnaissance role was to be filled by the amphibious T-40 and the cheaper, non-amphibious T-60.
At the beginning of Operation Barbarossa most of the Soviet Union's tank forces were composed of the T-26 tank series and BT. A few T-40s had appeared, along with about 900 unreliable early T-34 tanks, and perhaps 500 KV-1 and KV-2s. Many early T-34s were easily captured or destroyed. Much of this early failure was due to lack of coordination, ill-supplied and ill-trained tank crews, and the lack of readiness of the Red Army in general. Another difficulty for the T-34 was that it had only a four man crew, meaning that the tank commander had to double as the gunner. Although spared from loading duties, as French tank commanders had been, it still crippled the tank commander's ability to maintain awareness of the battle field while firing the tanks main gun, giving a tactical advantage to German armor.
In 1941, great numbers of T-60s appeared, supplemented in 1942 with the similar T-70. Both light tanks had torsion-bar suspension, light armor, and small truck engines. Their simple construction kept them in production even though their combat value was limited. The T-60 had only a 20 mm gun while the T-70 had a 45 mm. However, both had one-man turrets, making them difficult to crew effectively. The T-70 formed the basis for the much more important SU-76 later in the war.
The T-34, however, effectively made all German tanks produced to that date obsolete. In fact, at its height the T-34 was deemed so successful, and so capable in every role, that production of all other tanks was stopped (with the exception of the IS-2) to allow for all available resources to be used exclusively for this tank. The T-34 forced the Germans to adopt new, heavier designs such as the Panther and Tiger, which in turn forced upgrades to the Soviet, US, and British tank fleets. Perhaps more significantly to the ultimate course of the war, the move to more complex and expensive German tank designs overwhelmed the already critically strained German tank-production capability, reducing the numbers of tanks available to German forces and thus helping to force Germany to surrender the initiative in the war to the Allies.
Mid-war, the KV series began to show its flaws. Better German antitank guns made it vulnerable, and its slow speed and lack of mechanical reliability were great handicaps. In view of the fact that it carried the same gun as the T-34 in a slower, much more expensive chassis, production was curtailed and nearly stopped in 1943.
Later in the war, the light tank role was increasingly filled by Lend-Lease supplies of US M-3 light tanks and British and Canadian Valentine tanks. Ironically the T-34 was as fast or faster than many of the light tanks that were supposed to scout for it, further encouraging reductions in Russian light tank production.
In response to better German tanks, the Soviets began to produce the T-34-85 in the winter of 1943-44, which had an 85-mm gun, while retaining superiority in speed and mobility over the German tanks—an advantage it enjoyed until the very end of the war. This model was also significant in that it had a much larger turret with a 3 man crew, finally allowing the tank commander to concentrate fully on maintaining a tactical awareness of the battlefield. The Soviets also responded with the 122 mm-armed IS-2 heavy tank. The IS-2 managed to carry heavier armour than the KV but with no weight increase in comparison to the KV-1. This was done by thinning the rear armor and moving most of the armour to the front of the tank, where it was expected to take most of its hits. Heavy tank IS-2 with its powerful gun, sloped thick armor was arguably the most powerful tank of the war.
The IS-3 variant, produced in mid-1945 had a much more streamlined look to it, and a larger, bowl-shaped tapered turret. Remarkably, the IS-3 had thicker armour but actually weighed slightly less than the IS-2, remaining under 50 tons (as compared to the Tiger II's 68). The armor design of the IS-3 was an enormous influence on postwar tank design, as seen in the Soviet T-55 and T-62 series, the US M48, and the West German Leopard.
Soviet tank production outstripped all other nations with the exception of the United States. They accomplished this through a ruthless standardization on a few designs, generally forgoing minor qualitative improvements and changing designs only when upgrades would result in a major improvement.
[edit] United States
US production equipped not only the US forces but the forces of France (after 1942), Britain, and other Allied nations. Similarly to the USSR, the US selected a few good basic designs and standardized on those models. Given the lack of US tank design and production experience, it is remarkable that the US designs were as good as they were.
Prior to US entry in the war, the US Army had only a few tanks. The Light Tank M2 series was the most important. These light tanks were mechanically very reliable, with good mobility. However, they had a high silhouette due to the use of radial aircraft engines. Only a few saw combat on Guadalcanal. The Light Tank M3 series of 1941 was an improvement of the M2, with more armor and a 37 mm gun. The new medium tank just entering production in 1940 was the M2A1. This was a hopelessly poor design. It had thin armor, a high silhouette, a 37 mm main gun and seven machineguns.
Beginning in 1940, new US tank designs were prepared. The Battle of France had shown the importance of medium tanks, and the US Army had a requirement for a medium tank with a 75 mm gun. Eventually this would become the famous Medium Tank M4, the most important tank of the war for the Western allies.
The first U.S. tanks to fight in the war were the Light Tank M3 and Medium Tank M3 (the "Grant" version had a British-designed turret and a six-man crew; the "Lee" version retained the original turret and seven-man crew). They were deeply flawed in many ways, yet were the best tanks available to the western Allies, and were superior to most of their German counterparts in armor protection and firepower at the time. The Light Tank M3 was about as well-armed as the British cruiser tanks in the desert, yet was much more reliable mechanically. Its 37 mm main gun was more powerful than the main guns carried by German recon tanks. The official name given to the Light Tank M3 was 'Stuart' a nickname also used was 'Honey' for this vehicle. The M3 and its improved derivative, the Light Tank M5 series, remained in service throughout the war. By 1943 its 37 mm gun made it a very dangerous tank to serve in, but no better replacement was available. The Light Tank T7 design was proposed as a successor in 1943, armed with a 57 mm gun and with better armor. However, the design was never standardized for production.
The appearance of the US Medium Tank M3 in the summer of 1942 finally gave the British a gun capable of dealing with German tanks and towed anti-tank guns better than their 2-pounders and 6-pounders. Although the British 6-pounder (57 mm) gun had better armor penetration than the M-3's 75 mm, it fired a much smaller high-explosive warhead. The Medium Tank M3 could successfully attack German antitank guns that had previously taken a heavy toll of British tanks, and was reasonably effective against German tanks of the day.
When first fielded the Medium Tank M3 was a match for German medium tanks, but it had the significant disadvantage of its 75 mm main armament being mounted in the hull. It had a fully traversable turret with a 37 mm cannon as well, but the turret combined with a hull gun gave it a very tall profile. The US 1st Armored Division also employed the Medium Tank M3 in Africa. It was stopgap solution, never intended to be a design of major importance. In US and British service, the Medium Tank M3 was phased out at the end of the North African campaign. Nevertheless it continued in service in the Red Army for some time, where its crews named it the ‘grave for seven brothers’.
The most important US design of the war was clearly the Medium Tank M4. The Medium Tank M4 became the most-produced tank of the Second World War, and has the honour of being the only tank to be used by virtually all Allied forces (thanks to the American lend-lease program). M4's formed the main tank of US, British, Canadian, French, Polish, and Chinese units. The M4 was the equal of the German medium tanks, the PzKpfw III and PzKpfw-IV at the time it first saw service in 1942. Over 4,000 Shermans were supplied to the USSR beginning in mid-1943. The M4 remained a match for its most common opponents (the Pzkw-IV and various German self-propelled guns) throughout the war, but by late 1943 the German Panther and Tiger I were grave threats to the Sherman Tank.
Flawed US armor doctrine played a major role in keeping the M4 undergunned in 1944-1945. US doctrine emphasized that tanks were to be used primarily for infantry support and exploitation. However, the role of fighting tanks was intended to be carried by the tank destroyer branch, armed with both towed and self-propelled guns such as the 3 inch Gun Motor Carriage M10. The 3" GMC M10 was thinly armored, with an open-topped turret mounting a 3-inch gun that was very powerful by mid-war standards.
Technically, the M4's design was capable of handling larger guns than the 75 mm and 76 mm guns with which they left the factory. The M36 Jackson with the powerful 90 mm gun also entered service in the spring of 1944 and could destroy the front glacias of a Panther at 600 meters and was one of the best guns in the allied inventory. Retrofit kits with the 90 mm gun were also mated to the M4 Jumbo giving the Americans one of the best Allied tanks overall, with frontal armor superior to the Tiger and the one of the most powerful allied guns. Postwar, the Israeli Army would mount a 105 mm Anti-tank gun on the M4.
By the time of the Normandy Campaign, the M4 had become the everyman tank of the Allied forces. Some Shermans were equipped with the Duplex Drive system (Sherman DD), which allowed it to swim using a collapsible screen and inflated rubber tubes. Along with this were the M1 Dozer Blade (a Sherman with a bulldozer blade), the Sherman beach armored recovery vehicle (BARV), the Sherman T34 (which had a multiple rocket launcher installed above the turret), the POA-CWS-H5 (a Sherman with a flame-thrower), the Sherman Twaby Ark (which allowed the Sherman to act as a temporary bridge), and the Sherman Crab Mark I (a Sherman with a mine flail), as well as many other variants.
The US also produced what is arguably the best light tank of WWII, the Light Tank M24, to fill the role of infantry support tank. The M24 had torsion-bar suspension, high mobility, and a compact 75 mm gun. Ergonomically the tank was quite good also. However, the M24 did not appear in combat until December 1944 and equipped only a few US units by the end of the war. Also near the end of the war the Heavy Tank M26 Pershing finally made it into operational deployment. The Heavy Tank M26 Pershing was a very modern design with torsion-bar suspension, heavy armor, and an excellent 90 mm gun. However, it was somewhat underpowered, having the same Ford GAA engine as the M4A3. The M26 basic design was good enough to form the basis for all postwar US tanks through the end of the M60 series.
The superiority of German second-generation tanks was not met until the end of the war, but the Germans had already lost the initiative by 1943. The sheer power of US production, superior US combined-arms tactics, and German errors on all levels meant that US forces generally prevailed. Interestingly, this was the same pattern that was seen at the beginning of the war when weakly armored and undergunned German panzers crushed their much more powerful French, British, and Russian opponents in the early blitzkriegs.
Compare the US 90 mm to the British 17 pounder
90mm: Shell wt = 10.94 kg, mv = 808 m/s; KE = 3.57 mega-joules (.77 kg TNT)
17pdr (76.2mm): Shell wt = 7.71 kg, mv = 884 m/s; KE = 3.01 mega-joules (.65 kg TNT)
http://web.archive.org/web/20010710230433/www.wargamer.org/GvA/weapons/usa_guns7.html
http://web.archive.org/web/20010420095140/www.wargamer.org/GvA/weapons/british_guns5.html
US Army tests Normandy 1944
