T20 Medium Tank T20 Medium Tank The Medium Tank T20 was part of a series of medium tanks designed by the United States during the Second World War, to be the successor to the Medium Tank M4 "Sherman", and culminated in the M26 Pershing. Almost immediately after the M4 Sherman was standardized, the US Ordnance Department started work on a successor. The Ordnance Department had already been working on heavily armored infantry tank design for the British, using M4 parts. The new project was started on the 25 May 1942, it was originally designated M4X. Starting with the T20, the Ordnance Department initially
Tanks in the Cold War at long range. The World War II concept of heavy tanks, armed with the most powerful guns and heaviest armour, became obsolete since they were just as vulnerable as other vehicles to the new medium tanks. Likewise, World War II had shown that lightly armed, lightly armoured tanks were of little value in most roles. Even reconnaissance vehicles shown a trend towards heavier weight and greater firepower during World War II; speed was not a substitute for armor and firepower. An increasing variety of anti-tank weapons and the perceived threat of a nuclear war prioritized the need for additional armor.