M4 Sherman
The M4 Sherman, officially Medium Tank, M4, was the medium tank most widely used by the United States and Western Allies in World War II. The M4 Sherman proved to be reliable, relatively cheap to produce, and available in great numbers. It was also the basis of several other armored fighting vehicles including self-propelled artillery, tank destroyers, and armored recovery vehicles. Tens of thousands were distributed through the Lend-Lease program to the British Commonwealth, Soviet Union, and other Allied Nations. The tank was named by the British after the American Civil War General William Tecumseh Sherman.
The M4 Sherman tank evolved from the M3 Lee, a medium tank developed by the United States during the early years of World War II. Despite the M3's effectiveness, the tank's unconventional layout and the limitations of its hull-mounted gun prompted the need for a more efficient and versatile design, leading to the development of the M4 Sherman.
Development
The M4 Sherman retained much of the mechanical design of the M3, but it addressed several shortcomings and incorporated improvements in mobility, firepower, and ergonomics. One of the most significant changes was the relocation of the main armament—initially a 75 mm gun—into a fully traversing turret located at the center of the vehicle. This design allowed for more flexible and accurate fire control, enabling the crew to engage targets with greater precision than was possible on the M3.The development of the M4 Sherman emphasized key factors such as reliability, ease of production, and standardization. The U.S. Army and the designers prioritized durability and maintenance ease, which ensured the tank could be quickly repaired in the field. A critical aspect of the design process was the standardization of parts, allowing for streamlined production and the efficient supply of replacement components. Additionally, the tank's size and weight were kept within moderate limits, which facilitated easier shipping and compatibility with existing logistical and engineering equipment, including bridges and transport vehicles. These design principles were essential for meeting the demands of mass production and quick deployment.
The M4 Sherman was designed to be more versatile and easier to produce than previous models, which proved vital as the United States entered World War II. It became the most-produced American tank of the conflict, with a total of 49,324 units built, including various specialized variants. Its production volume surpassed that of any other American tank, and it played a pivotal role in the success of the Allied forces. In terms of tank production, the only World War II-era tank to exceed the M4's production numbers was the Soviet T-34, with approximately 84,070 units built.
On the battlefield, the Sherman was particularly effective against German light and medium tanks during the early stages of its deployment in 1942. Its 75 mm gun and relatively superior armor provided an edge over the tanks fielded by Nazi Germany during this period. The M4 Sherman saw widespread use across various theaters of combat, including North Africa, Italy, and Western Europe. It was instrumental in the success of several Allied offensives, particularly after 1942, when the Allies began to gain momentum following the Allied landings in North Africa and the subsequent campaigns in Italy and France. The ability to produce the Sherman in large numbers, combined with its operational flexibility and effectiveness, made it a key component of the Allied war effort.
The Sherman's role as the backbone of U.S. armored forces in World War II cemented its legacy as one of the most influential tank designs of the 20th century. Despite its limitations—such as relatively thin armor compared to German heavy and medium tanks like the Tiger and Panther—the M4 was designed to be both affordable and adaptable. Its widespread deployment, durability, and ease of maintenance ensured it remained in service throughout the war, and it continued to see action even in the years following World War II in various conflicts and regions. The M4 Sherman remains one of the most iconic tanks in military history, symbolizing the industrial might and innovation of the United States during the war.
When the M4 tank went into combat in North Africa with the British Army at the Second Battle of El Alamein in late 1942, it increased the advantage of Allied armor over Axis armor and was superior to the lighter German and Italian tank designs. For this reason, the US Army believed that the M4 would be adequate to win the war, and relatively little pressure was initially applied for further tank development. Logistical and transport restrictions, such as limitations imposed by roads, ports, and bridges, also complicated the introduction of a more capable but heavier tank. Tank destroyer battalions using vehicles built on the M4 hull and chassis, but with open-topped turrets and more potent high-velocity guns, also entered widespread use in the Allied armies. Even by 1944, most M4 Shermans kept their dual-purpose 75 mm gun. By then, the M4 was inferior in firepower and armor to increasing numbers of German upgraded medium tanks and heavy tanks but was able to fight on with the help of considerable numerical superiority, greater mechanical reliability, better logistical support, and support from growing numbers of fighter-bombers and artillery pieces. Later in the war, a more effective armor-piercing gun, the 76 mm gun M1, was incorporated into production vehicles. To increase the effectiveness of the Sherman against enemy tanks, the British refitted some Shermans with a 76.2 mm Ordnance QF 17-pounder gun.
The relative ease of production allowed large numbers of the M4 to be manufactured, and significant investment in tank recovery and repair units allowed disabled vehicles to be repaired and returned to service quickly. These factors combined to give the Allies numerical superiority in most battles, and many infantry divisions were provided with M4s and tank destroyers. By 1944, a typical U.S. infantry division had attached for armor support an M4 Sherman battalion, a tank destroyer battalion, or both.
After World War II, the Sherman, particularly the many improved and upgraded versions, continued to see combat service in many conflicts around the world, including the UN Command forces in the Korean War, with Israel in the Arab–Israeli wars, briefly with South Vietnam in the Vietnam War, and on both sides of the Indo-Pakistani War of 1965.
U.S. prototype
The United States Army Ordnance Department designed the M4 medium tank to replace the M3 medium tank. The M3 was an up-gunned development of the M2 medium tank of 1939, in turn, derived from the M2 light tank of 1935. The M3 was developed as a stopgap measure until a new turret mounting a 75 mm gun could be devised. While it was a big improvement when used by the British in Africa against German forces, the placement of a 37 mm gun turret on top gave it a very high profile, and the unusual side-sponson mounted main gun, with limited traverse, could not be aimed across the other side of the tank. Though reluctant to adopt British weapons into their arsenal, the American designers were ready to accept proven British ideas. These ideas, as embodied in a tank designed by the Canadian General Staff, also influenced the development of the American Sherman tank. Before long American military agencies and designers had accumulated sufficient experience to forge ahead on several points. In the field of tank armament, the American 75 mm and 76 mm dual-purpose tank guns won the acknowledgment of British tank experts. Detailed design characteristics for the M4 was submitted by the Ordnance Department on 31 August 1940, but the development of a prototype was delayed while the production designs of the M3 were finished and the M3 entered full-scale production. On 18 April 1941, the U.S. Armored Force Board chose the simplest of five designs. Known as the T6, the design was a modified M3 hull and chassis, carrying a newly designed turret mounting the M3's 75 mm gun. This would later become the Sherman.The Sherman's reliability resulted from features developed for U.S. light tanks during the 1930s, including vertical volute spring suspension, rubber-bushed tracks, and a rear-mounted radial engine with drive sprockets in front. The goals were to produce a fast, dependable medium tank able to support infantry, provide breakthrough striking capacity, and defeat any existing Axis nations tank.
The T6 prototype was completed on 2 September 1941. The upper hull of the T6 was a single large casting. It featured a single overhead hatch for the driver and a hatch in the side of the hull. In the later M4A1 production model, this large casting was maintained, although the side hatch was eliminated, and a second overhead hatch was added for the assistant driver. The modified T6 was standardized as the M4, and first production completed in February 1942. The cast-hull models would later be re-standardized as M4A1, with the first welded-hull models receiving the designation M4. In August 1942, a variant of the M4 was put forth by the Detroit Arsenal to have angled, rather than rounded hull and turret armor. The changes were intended to improve the tank's protection without increasing weight or degrading other technical characteristics.
Doctrine
As the United States approached entry into World War II, armor usage was governed by Field Manual 100–5, Operations. That manual stated:The M4 was, therefore, not intended primarily for infantry support. It placed tanks in the "striking echelon" of the armored division and placed the infantry in the "support echelon", without directing that tanks should only seek to attack other tanks, thus leaving target selection up to the field commander based on what types of targets were available. A field manual covering the use of the Sherman described fighting enemy tanks, when necessary, as one of the many roles of the Sherman, but devoted only one page of text and four diagrams to tank-versus-tank action out of 142 pages. This early armored doctrine was heavily influenced by the sweeping early successes of German blitzkrieg tactics. By the time M4s reached combat in significant numbers, battlefield demands for infantry support and tank-versus-tank action far outnumbered the occasional opportunities of rear-echelon attack.
United States doctrine held that the most critical anti-tank work stopping massed enemy tank attacks was primarily to be done by towed and self-propelled anti-tank guns, operated by "Tank Destroyer" battalions, with friendly tanks being used in support if possible. Speed was essential to bring the tank destroyers from the rear to destroy incoming tanks. This doctrine was rarely followed in combat, as it was found to be impractical. Commanders were reluctant to leave tank destroyers in reserve; if they were, it was also easier for an opposing armored force to achieve a breakthrough against an American tank battalion, which would not have all of its anti-tank weapons at the front during the beginning of any attack.