M4 Sherman

The M4 Sherman, officially Medium Tank, M4, was the most numerous battle tank used by the United States and some other Western Allies in World War II. It proved to be reliable and mobile. In spite of being outclassed by German medium and heavy tanks late in the war, the M4 Sherman was cheaper to produce and available in greater numbers. Thousands were distributed through the Lend-Lease program to the British Commonwealth and Soviet Union. The tank was named after the American Civil War General William Tecumseh Sherman by the British.

The M4 Sherman evolved from the interim M3 Medium Tank, which had its main armament in a side sponson mount. The M4 retained much of the previous mechanical design but put the main 75 mm gun in a fully traversing turret. One controversial feature, a one-axis gyrostabilizer was not precise enough to allow firing when moving but did help keep the reticle on-target, so that when the tank did stop to fire, the gun would be aimed in roughly the right direction. The designers stressed mechanical reliability, ease of production and maintenance, durability, standardization of parts and ammunition in a limited number of variants, and moderate size and weight. These factors combined with M4 Sherman's then-superior armor and armament outclassed German light and medium tanks of 1939–41. The M4 went on to be produced in large numbers. It spearheaded many offensives by the Western Allies after 1942. A similar vehicle was developed at the same time in Canada, the Ram tank, however greater Sherman production and availability meant that the Ram was never used in action as a tank (many were converted to self-propelled guns and 'Kangaroo' armoured personnel carriers).

When the M4 tank arrived in North Africa in 1942, it was superior to the lighter German long-barrel 50 mm-gunned Panzer III and short-barrel 75 mm-gunned Panzer IV.[citation needed] For this reason, the US Army believed the M4 would be adequate to win the war, and no pressure was exerted 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 American army. Even by 1944, most M4 Shermans kept their dual purpose 75 mm M3. By 1944 and 1945, the M4 was inferior to German heavy tanks but was able to fight on with support from growing numbers of fighter-bombers and artillery pieces.

The relative ease of production allowed huge numbers of the M4 to be manufactured, and significant investment in tank recovery and repair units allowed disabled vehicles being repaired and returned to service. These factors combined to give the Americans numerical superiority in most battles, and many infantry divisions were provided with M4s and tank destroyers. During the Normandy campaign, German panzer divisions were rarely at full strength, and some U.S. infantry divisions had more fully tracked armored fighting vehicles than the depleted German panzer divisions. A M4A3E8 variant was introduced, with improved suspension and a high-velocity 76 mm gun as used on the tank destroyers.

Post World War II the Sherman, often in updated versions, saw combat in many conflicts, including the Korean War, Arab-Israeli Wars, and the Indo-Pakistani War of 1965.

M4 Sherman
Class Vehicle
Type Armoured Fighting Vehicle
Manufacturer Pressed Steel Car Company
Production Period 1942 - 1944
Origin United States of America
Country Name Origin Year
United States of America 1942
Country Name Operational Year Retirement Year
United States of America 1942 1955 View
ManufacturerName Production From Production To Quantity
Baldwin Locomotive Works View
American Locomotive Company View
Pullman Company View
Detroit Tank Arsenal (Chrysler) View
Pressed Steel Car Company 1942 1944 6748 View

The U.S. Army Ordnance Department designed the Medium Tank M4 as a replacement for the Medium Tank M3. 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 tried by the British in Africa against early German tanks, 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.

Detailed design characteristics for the M4 were submitted by the Ordnance Department on 31 August 1940, but development of a prototype was delayed while the final 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 became the Sherman.

The Sherman's reliability resulted from many 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 tank then in use by the Axis nations, though it would later fall short against the much heavier tanks developed by Germany.

The T6 prototype was completed 2 September 1941. Unlike later M4s, the hull was cast and had a side hatch, which was eliminated from production models. The T6 was standardized as the M4 and production began in October.

The first production began with the Lima Locomotive Works on the assembly line set for tanks for British use. The first production Sherman was given over to the US Army for evaluation and it was the second tank of the British order that went to London. Named Michael probably after Michael Dewar, head of the British tank mission in the U.S., it was displayed in London and is now an exhibit at Bovington Tank Museum.

In World War II, the U.S. Army ultimately fielded 16 armored divisions, along with 70 independent tank battalions, while the U.S. Marine Corps fielded six independent Sherman tank battalions. A third of all Army tank battalions, and all six Marine tank battalions, were deployed to the Pacific Theater of Operations (PTO). Prior to September 1942, President Franklin D. Roosevelt had announced a production program calling for 120,000 tanks for the Allied war effort, which would have created 61 armored divisions. Although the American industrial complex was not affected by enemy aerial bombing nor submarine warfare as was Japan, Germany and, to a lesser degree, Great Britain, an enormous amount of steel for tank production had been diverted to the construction of warships and other naval vessels. Steel used in naval construction amounted to the equivalent of approximately 67,000 tanks; and consequently only about 53,500 tanks were produced during 1942 and 1943.

The Army had seven main sub-designations for M4 variants during production: M4, M4A1, M4A2, M4A3, M4A4, M4A5, and M4A6. These designations did not necessarily indicate linear improvement. For example, A4 did not indicate it was better than an A3. These sub-types indicated standardized production variations, which were in fact often manufactured concurrently at different locations. The sub-types differed mainly in engines, although the M4A1 differed from the other variants by its fully cast upper hull, with a distinctive rounded appearance. The M4A4 had a longer engine system that required a longer hull, a longer suspension system, and more track blocks, and thus the most distinguishing feature of the A4 was the wider spacing between the bogies. M4A5 was an administrative placeholder designation for Canadian production. The M4A6 had an elongated chassis and additional armor, but fewer than 100 of these were ever produced.

While most Shermans ran on gasoline, the M4A2 and M4A6 had diesel engines. The M4A2 with a pair of GMC 6–71 straight six engines, the M4A6 a Caterpillar RD1820 radial. These, plus the M4A4, which used the Chrysler A57 multibank engine, were mostly supplied to other Allied countries under Lend-Lease. "M4" can refer specifically to the initial sub-type with its Continental radial engine (R-975), or generically, to the entire family of seven Sherman sub-types, depending on context. Many details of production, shape, strength and performance improved while in production, without a change to the tank's basic model number. These included more durable suspension units, safer "wet" (W) ammunition stowage, and stronger armor arrangements, such as the M4 Composite, which had a cast front hull section mated to a welded rear hull. British nomenclature differed from that employed by the U.S.

Other Designation(s)M4 (Sherman I) [mid production]
Manufacturer(s)Pressed Steel Car Co., Baldwin Locomotive Works, American Locomotive Co., Pullman Standard Car Co., Detroit Tank Arsenal
Production Quantity6748Production PeriodJuly 1942-Jan. 1944
TypeMedium TankCrew5
Length /hull (m)5.89Barrel Overhang (m)0
Width (m)2.62Height (m)2.74
Combat Weight (kg)30300Radio EquipmentSCR508/528/538
Primary Armament75mm Gun M3Ammunition Carried97
Traverse (degrees)360°Elevation (degrees)-10° to +25°
Traverse speed (360°)15 sec.SightM55, M38
Secondary Armament2 x .30 caliber MG M1919A4 (coaxial, bow)Ammunition Carried4750
1 x .50 caliber MG HB M2 (AA)300

Engine Make & ModelContinental R975 C1Track Links79/track
Type & DisplacementR9, 15.9 litersTrack Width42.1 cm
Horsepower (max.)400hp@2400rpmTrack Ground Contact373.4 cm
Power/Weight Ratio13.2 hp/tonneGround Pressure13.7 psi
Gearbox5 forward, 1 reverseGround Clearance (m)0.43
FuelGasoline (Petrol)Turning Radius (m)18.9
Range on/off road (km)193Gradient (degrees)31°
Mileage (liters/100km)412 on roadVertical Obstacle (m)0.61
Fuel Capacity (liters)796Fording (m)1.0
Speed on/off road34 km/hTrench Crossing (m)2.3
Armor DetailFrontSideRearTop/Bottom
Hull51mm@34-90°38mm@90°38mm@80°-90°25mm@0°(front) 13mm@0°(rear)

End notes