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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. In spite of being surpassed by German medium and heavy tanks late in the war, the M4 Sherman proved to be very reliable, 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.〔Zaloga, Stephen J. ''Panther vs Sherman: Battle of the Bulge 1944''. Osprey Publishing, 2008, p. 28.〕 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 1939–42. The M4 went on to be produced in large numbers. It spearheaded many offensives by the Western Allies after 1942. When the M4 tank went into combat in North Africa with the British Army at El Alamein in the autumn of 1942, it increased the advantage of Allied armour over German armor and was superior to the lighter German long-barrel 50 mm-gunned Panzer III and the short-barrel 75 mm-gunned Panzer IV. 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.〔AGF policy statement. Chief of staff AGF. November 1943. MHI〕 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.〔By 1944 a typical U.S. infantry division was attached to an M4 Sherman battalion, a tank destroyer battalion, or both.〕 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.〔"Tank Tactics: From Normandy to Lorraine" by Roman Jarymowycz 〕 A M4A3E8 variant was introduced, with improved suspension and a high-velocity 76 mm gun as used on the tank destroyers. After World War II, the Sherman, often in updated versions, saw combat in many conflicts, including the Korean War, the Arab-Israeli Wars, and the Indo-Pakistani War of 1965.〔Hunnicutt 1978〕 ==U.S. design prototype== 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.〔(【引用サイトリンク】title=Vehicle List and History )〕 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. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「M4 Sherman」の詳細全文を読む スポンサード リンク
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