The Sherman Tank
As the United States prepared for war, the U.S. Army Ground Forces kept its tank park to a minimum number. One universal medium tank would supply vehicles for both armored divisions with their deep penetration mission and independent tank battalions with their task of infantry support.
When German panzer divisions overran France in the late spring of 1940, the United States owned 18 medium tanks, all of them nearly-useless M2 models. The Army requested a brand-new tank design, one with sufficient armor to defeat the anti-tank guns of the day and those projected for the near future, and a 75mm gun mounted in a rotating turret.
That would provide a tank superior to anything the French or Germans fielded in 1940, with a comfortable edge over any developments expected in the near future. Design work began immediately, and soon ran into difficulties: no American foundry could cast a turret large enough to house a 75mm gun.
The M3 medium tank.
As a stopgap, a tank with a hull-mounted 75mm gun and a small turret bearing a high-velocity 37mm gun would be designed while work continued on the new turret. The M3 medium tank carried the M2 75mm gun, a weapon derived from the T6 experimental anti-aircraft gun, itself a modified version of the French-designed M1897 75mm Soixante-Quinze. The weapon gave good performance firing high-explosive rounds, to be expected given its heritage, and had an anti-tank round that was considered adequate at the time.
The M2 cannon gave way to the longer-barreled M3 during the production run of the M3 medium tank, which improved performance. Built to artillery specifications, the M2/M3 also had a very long barrel life, a fairly useless feature in a tank (which would not be expected to survive in combat long enough for barrel wear to become an issue).
The M3 prototype completed in March 1941 and the first production model rolled off the line at Detroit Arsenal Tank Plant in June, before the factory had even finished construction. All 6,258 tanks built came from the big Detroit plant, where production ended in December 1942. A little under half were shipped to Britain, and a little under a quarter of the total to the Soviet Union.
The Army’s Ordnance Committee had ordered design work on the M3’s replacement even as the M3 entered production, but even though the new tank’s characteristics had been decided in August 1940, actual design did not commence until February 1941.
This new M4 tank, initially called the T6, kept much of the lower structure of the M3: its lower chassis, drive train, engine and suspension. The small turret with its 37mm gun went away to be replaced by a larger turret with the M3 75mm cannon. The reduction of cannon from two to one also allowed a drop in crew to five men (from six or seven; early M3 models had a separate radio operator while later versions gave that task to the driver).
The T6 prototype was completed in September 1941, and following testing production began in February 1942. Ten American plants, most of them in the industrial Mid-West, eventually produced the new tank, along with one (Montreal Locomotive Works) in Canada. Hundreds of sub-contracted factories scattered across the country produced components.
The very first M4 went to the U.S. Army for testing, but the remainder of the first batch went to Britain. The British, confused by the identical American M-numbers given to seemingly every piece of equipment, christened the new tank the “Sherman.” The name slowly came into informal use among the Americans, creeping into official documents but not into widespread use until after the war.
The new tanks first saw action at El Alamein in October 1942, where they gave the British a significant edge over German and Italian tanks and gave the U.S. Army Ground Forces command an exaggerated idea of their tank’s capabilities. The Sherman could rightly claim to be the most advanced tank in the world at the time of its introduction, outside the Soviet Union at least, but new Soviet and German models were already in production that would rip away that designation.
The tank had adequate armor to repel Axis 50mm and smaller anti-tank rounds; the long-barreled 75mm gun of late-model PzKpfw IV medium tanks could penetrate the Sherman, and the 88mm anti-aircraft guns pressed into a ground role could easily shred it, but they did the same to every other Allied tank as well. The M3 75mm cannon, in turn, could deal with the armor of Axis tanks found in the desert theater and also provide excellent performance against soft targets.
Most importantly, the new tank proved extremely reliable. The worst mechanical problems had been worked out with the preceding M3 medium tank, and the Sherman underwent steady improvements throughout its production run, receiving steadily better engines and suspensions.
Almost all of those changes involved the engine; Sherman tanks retained a great deal of interchangeability of parts even between different models. Many surviving Shermans are not of a single identifiable model thanks to many parts and even complete turrets intended for one model having been used to repair a tank of another. This effect is probably more common among surviving tanks, as many of these came from tanks abandoned on firing ranges or training grounds that required extensive rebuilding before they could be made presentable as museum pieces or monuments. Even so, the U.S. Army and Marines were almost constantly on the offensive during the war and so could recover their own knocked-out tanks. Those too far gone for repair would be cannibalized for parts.
Nineteen versions of the M4 Sherman were produced during World War II. All but one had gasoline engines; the diesel-powered M4A2 went chiefly to the Soviet Union with some going to Britain (where they were passed on to Polish exile units) and the U.S. Marines. Somewhere between 45,000 and 50,000 Sherman tanks were produced – sources differ on this number and even within the same source, the allocation numbers often to not add up. It appears that 19,200 went to the U.S. Army and 1,100 to the U.S. Marines. Britain received 17,100 (passing some on to the Canadians, Indians, New Zealanders and Polish exiles) while 4,100 went to the Soviet Union, 800 to China, 650 to the Free French and 50 to Brazil.
One important upgrade to the Sherman came in the summer of 1944, when M4 tanks with the high-velocity 76mm M1 cannon began to appear in Europe. The M1 gun had begun development in August 1942, as the 3-inch anti-tank gun used in the M10 tank destroyer was considered too heavy for use in a tank.
The new weapon passed its tests well, but proved difficult to fit into the Sherman without a counterweight that made the turret too cramped. The designers solved the problem by discarding the standard Sherman turret and replacing it with that prepared for the T23 medium tank, the designated successor (as the M27) to the Sherman.
The M1 76mm gun had a much less effective high-explosive round (0.9 pounds of explosive compared to 1.5 pounds in the M3 75mm gun’s shell). It was much more accurate, and provided considerably better armor penetration. On the other hand, it did not have a very good smoke round and did not have a white phosphorous round at all – supposedly a “marker round” for artillery, it proved a deadly chemical weapon against both enemy infantry and tanks (the powerful fans of a Tiger tank would suck the white phosphorous into the vehicle’s fighting compartment, forcing the crew to abandon their tank or die of horrific chemical burns).
Throughout the war, American units fielded a mix of Sherman tanks armed with 75mm and 76mm guns. While the new gun had much better performance against enemy armor, statistics shows that 70 percent of all rounds fired by tanks were high-explosive and only 20 percent armor-piercing (the remainder were smoke).
Slightly more than 1,600 Shermans were armed with the M4 105mm howitzer, a vehicle-mounted version of the standard M2 howitzer that equipped American and Allied artillery batteries. The howitzer provided much greater firepower against soft targets (4.8 pounds of high explosive, TNT or amatol, compared to 1.5 pounds for the 75mm M1) but much less capability against armored targets even with the M67 high explosive anti-tank round.
Fisher Tank Arsenal produced just over 250 of the M4A3E2 “Jumbo,” a Sherman with an extra inch of armor and correspondingly lower speed. It proved very popular with its crews; all Jumbos began with a 75mm gun but some acquired a 76mm main armament during repairs. The U.S. Army kept all of these for itself, except for one Jumbo given to the Free French.
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Mike Bennighof is president of Avalanche Press and holds a doctorate in history from Emory University. A Fulbright Scholar and award-winning journalist, he has published over 100 books, games and articles on historical subjects.
He lives in Birmingham, Alabama with his wife, three children and his dog, Leopold.