Note the tracks, they have Winterketten or track extensions on them. Started in 1942 for winter conditions to move easier through the snow mostly found on Pzkpfw 3 and 4 and StugG 3 tanks. Kharkov 1943.
The bell experiment was a Nazi Germany experiment to try to make a anti-gravity propulsion system that could fly at supper high and low speeds. It was supposed to fly for long times. Even before W.W.2. they were working on this technology. This was done in the later years of world war 2. Hitler was the one who made this project. The reason Hitler made this project is because of two popular theories. 1 is that Hitler is very in to the cult witch means he is very religious.