The heaviest American tank at the start of the Second World War was the Medium Tank M2. It looked like an anachronism compared to other tanks in the same class, and so it was quickly replaced by the Medium Tank M3. The M3 was also a temporary measure, and even having completed the Medium Tank M4 the American tank designers were not resting on their laurels. Work on the Sherman's successor began as the tank was just being put into production. The Medium Tank T26E1 was meant to replace the Sherman, but after a number of changes in its development cycle it entered production in a completely different weight class.
Origin of species
The concept of a new generation of tanks formed in May of 1942. The basic tank had a 76 mm gun and was lower than the M4, which allowed the designers to add more armour without exceeding the weight of its predecessor. The tank also used an automatic gearbox. The Ordnance Committee gave permission to build two prototypes indexed Medium Tank T20.
The number of experimental tanks multiplied. Since it wasn't clear how well the idea of an automatic gearbox is going to work out, the army decided to play it safe and also build the Medium Tank T22 using components already tried and tested in the Sherman tank as well as the Medium Tank T23 with an electric transmission that showed itself well in the Heavy Tank T1E1. Each tank had three types of armament. The basic tank would get a 76 mm M1 gun, E1 variants were equipped with a 75 mm gun and an autoloader, E2 variants received the 3" M7 gun from the GMC M10. There was also an E3 variant. These tanks had the 76 mm gun but also a torsion bar suspension.
|The Medium Tank T23 surpassed the Sherman in both armament and armour, but the army's appetites had grown beyond what it could offer.
|90 mm M1 AA gun. The Americans wanted a gun with the same ballistics in their tank.
|One of the experimental tanks from the Aberdeen Proving Grounds, August 3rd, 1944.
|The same tank from the rear.
|View from above. The T26E1 was wider than the Sherman, which led to problems.
|Improved ammunition stowage in the T26E1.
|Final ammunition stowage layout. By discarding the wet ammo rack, the tank could carry 12 additional rounds of ammunition.
|The tank could fit on the 25 ton Trestle Bridge, but the bridge would not be able to hold it. Note that the word Medium is crossed out and Heavy is written in.
|A crane to extract the power plant could be attached to the turret.
|Electric transmission on the Heavy Tank T1E1. The transmission had no luck either here or in the T26E1.
- R.P. Hunnicutt. Pershing: A History of the Medium Tank T20 Series — Echo Point Books & Media, 2015
- Archive of the Canadian Military Headquarters, London (1939–1947), RG 24 C 2