Der Schienenzeppelin – from the days when keeping behind the yellow line meant something:
Conceived and built in 1930 by the German rail company Deutsche Reichsbahn, the Schienenzeppelin was a design alternative to the streamlined steam locomotives of its day. It was a slick and relatively lightweight at 20 tons, running on but two axles and powered by a 46-liter BMW V-12.
The same engine was later used to power the light bombers of the Luftwaffe. The engine sent 600 horsepower to a massive ash propeller, tilted seven degrees to produce downforce.