Comparing: T-54 first prototype vs. T26E4 SuperPershing

Developed at Factory No. 183 in 1944. It was based on the T-44, with many components modified to enhance the armor and armament of the new vehicle. According to one source, the first prototype was built at the end of 1944. However, some other sources mention another date—January 1945. The tank underwent trials in March and April 1945, but never entered mass production.

To increase firepower, a new long-barrelled 90-mm gun was mounted on the T26E1 in January 1945. The prototype was designated the T26E4. Development was discontinued in January 1947 due to problems with the gun and the loading mechanism. A total of 25 vehicles had been built by that time, but never entered service.