Sherman, T-34 and Cromwell: These Three Allied Tanks Won World War II
Allied tanks were engineered for mass production and to handle routine battlefield tasks well, rather than being over-engineered to survive the heaviest guns or penetrate the thickest armor.
The Allied victory over Nazi Germany was won on the back of well over tens of thousands of medium tanks churned out by Allied factories over the course of the war. These war-winning weapons stemmed Nazi attacks from the gates of Moscow to Tunisia and the Battle of the Bulge, and swarmed in their thousands to surround and eliminate the Wehrmacht’s ground forces in campaign such Stalingrad, Operation Cobra and the Bagration offensive.
These victories were won despite the well-known fact that by 1943 the Allied tanks were outclassed by heavier German Panther and Tiger tanks that at times dealt them lopsided losses.
The Allied medium tanks, in fact, shared very similar armaments, degrees of armor protection and mobility. Their key trait was that they boasted just enough firepower and armor to get the jobs done, and could be mass produced to an unprecedented scale. This allowed the United States and Soviet Union to fully leverage their larger industrial base to overwhelm the Third Reich’s creaky industrial base, which relied on over-engineered designs built by slave-labor.
This article will compare the relative strengths and weaknesses of the legendary Sherman and T-34—as well as the British Cromwell, a similar-performing medium tank introduced in 1944.
The Cromwell and Sherman both had five-man crews: a tank commander, a gunner, a driver, a loader and a radio operator. Furthermore, each tank was equipped with its own radio receiver, allowing tank units to split apart to perform individual maneuvers and separate missions.
Early-war T-34s, by contrast, had a crew of four: a tank commander who doubled as a loader, a gunner, a driver and a machine-gunner/radio operator. This meant the tank commander had to do double-duty—or triple duty if he was also a unit commander.
Moreover, often only officer’s tanks were equipped with radios earlier in the war, which meant instructions had to be passed on orally or by signal flags from platoon commanders to their subordinates.
As a result, Soviet tank platoons typically maneuvered closely together, and could not react to changing orders as quickly. The T-34 also had notoriously uncomfortable ergonomics and a cramped turret.
The Sherman and Cromwell tanks were protected by up to three inches of armor, with lower degrees of protection on the sides and rear. The lighter 1941-model T-34 had only 45 to 60 millimeters of armor, but this was heavily sloped up to 60 degrees, resulting in comparable effectiveness.
This degree of protection largely protected the vehicles from frontal hits by early-war German 37-millimeter and 50-millimeter guns, and low-velocity 75-millimeter howitzers. The T-34 particularly made a big splash when it began seeing action in 1941, posing significant problems to the otherwise devastating initial German assault on the Soviet Union.
However, starting in 1942, the T-34 and Sherman could be reliably penetrated by long-barreled 75-millimeter guns entering German service. Ironically, the even heavier guns used by the Tiger and Panther tanks were tremendous overkill against the Allied medium tank’s armor.
A well-designed tank can sometimes survive penetrating hits. The Sherman, however, developed a reputation for having its ammunition “brew up” in flames after impact. This led to later “W” or “Wet-Storage” models of the Sherman which stored ammunition in water-insulated compartments, significantly reducing the frequency of combustion.
The T-34 crews had a different problem: the tank’s heat-treated steel was prone to spalling into deadly fragments from non-penetrating hits.
Armament and Upgrades
The Sherman, T-34 and Cromwell all employed remarkably similar medium-caliber guns. The Sherman, and most models of the Cromwell, used a 38-caliber 75-millimeter gun, while starting in 1941, the T-34 used a 41-caliber 76-millimeter gun. These were effective even against entrenched infantry and even could shoot shotgun-like cannister anti-personnel rounds.
The guns’ armor-piercing rounds could reliably penetrate German Panzer III and IV medium tanks and their turretless assault gun derivatives, but were infamously ineffective against the thick frontal armor of the Tiger and Panther. In one engagement, three Tigers rolled head-long through a battalion of Cromwells, destroying two-dozen before they were knocked out.
Early-model Cromwell I tanks had used high-velocity 57-millimeter 6-pounder guns with superior armor-penetration. However, these lacked effective anti-personnel munitions, so the 75-millimeter gun models were adopted instead. The Soviets also experimentally deployed several hundred T-34 “tank hunters” with 57-millimeter weapons.
In 1944, up-gunned variants of the Sherman and T-34 were introduced to deal with the Tiger and Panther problem. The T-34/85 boasted a heavier 85-millimeter gun which also had a deadlier anti-personnel blast effect. This was combined with a fifth crew member and a more heavily armored turret.
The M4A3E8 “Easy 8” Sherman mounted a 76-millimeter gun with modestly improved penetration using regular armor-piercing shells and had very high penetration using a limited supply of tungsten high-velocity shells. However, the 76-millimeter gun had significantly weaker anti-personnel effects.
Arguably the best up-gunned World War II Sherman was the British Sherman Firefly, which carried a powerful 3-inch 17-pounder gun. However, the British attempt to upgrade the Cromwell with a 17-pounder resulted in the poorly armored and ill-balanced Challenger tank. After serving in the Battle of Normandy, the Challenger was hastily withdrawn from service.
All three tanks mounted additional machine guns in the hull and turret for anti-personnel use and ranging against armored targets. The Sherman alone additionally mounted a heavy .50-caliber machine gun on the turret for air defense.
Mobility and Reliability
The Sherman and T-34 could attain 28 and 32 miles per hour respectively, a very decent pace for tanks of the era. The Cromwell’s most distinguishing quality was its higher speed of 40 miles per hour, which allowed it even to “leap” over significant gaps.
The T-34’s Christie suspension was particularly noted for its ability to traverse heavy snow and mud, common impediments on the Eastern Front. However, the Sherman’s relatively narrow-set tracks sometimes struggled to negotiate rough terrain compared to the wider-set tracks of the T-34, Cromwell and German tanks.
On the other hand, the Sherman developed a reputation for excellent reliability, while the sometimes crudely-manufactured T-34 could experience frequent breakdowns.
Russia produced a staggering 84,000 T-34 tanks during World War II. Such was the pace of production, that tanks in Stalingrad were even rolled directly off the factory line straight into battle. The city of Chelyabinsk was dubbed “Tankograd” due to the over 60,000 workers gathered to assemble tanks there. Massive economies of scale caused the production price to fall from 269,000 rubles to just 135,000, and man-hours to descend from 9,000 hours to eventually just 3,200 hours per tank.
The United States’ mighty industrial machine built up 49,000 M4 tanks and shipped most of these 33 to 40-ton tanks across the Atlantic and Pacific Oceans, with thousands entering British, French, Chinese and Soviet service. The Shermans were built comparatively expensively at around 48,000 man-hours and $55,000 each—or $800,000 in contemporary dollars.
The United Kingdom with its much more limited resources built only 6,000 Cromwells, which served primarily in armored reconnaissance regiments and the famous 7th Armored Division.
Meanwhile, the scary German Tigers required 300,000 man-hours—and for every Tiger that rampaged amongst the Allied medium tanks, many more were lost due to fuel shortages and mechanical breakdowns. The arguably better Panther still clocked in at 55,000 hours.
The key conclusion is that the Allied tanks were engineered for mass production and to handle routine battlefield tasks well, rather than being over-engineered to survive the heaviest guns or penetrate the thickest armor. Upgrades introduced in 1944 gradually helped address undeniable shortcomings in armor penetration when facing the smaller force of German heavy tanks.
Sure, the Sherman or T-34 weren’t favored to win in a head-on one-on-one confrontation versus heavier Nazi foes. But the countries building them planned their military-industrial base to win the war.
Sébastien Roblin holds a master’s degree in conflict resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing, and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.