It was to get the tank out of the cellar, so hard that modern tanks were needed. Then there is this:
It seems the tank’s presence wasn’t much of a secret locally. Several German media reports mention that residents had seen the man driving it around town about 30 years ago. “He was chugging around in it during the snow catastrophe in 1978,” Mayor Alexander Orth was quoted as saying. But he later added: “I took this to be the eccentricity of an old man, but it looks like there’s more to it than that.”
He had an anti-aircraft gun stored away too. For the pointer I thank Andrew Farrant.