Soviet Armored Train Design
Here is an armored vehicle that protects itself and the rest of the train cars behind it from attacks. It also turns a train into a mighty gun platform. The designer wanted to mount three 76mm self loading cannons, two 45mm auto loader anti tank guns, two remotely controlled anti aircraft guns, and twelve heavy machine guns. This diesel-powered juggernaut never went from the paper to the tracks. But what they planned was pretty lethal at least in concept. Although I can’t imagine all this armament would have stopped a strafing fighter from the air.
This I found at the Dieselpunk.org, an online punk culture site.