Thinking outside the box is where inventions come from. That and the need to get things done simpler and easier. In the 1920’s Armstead created a screw-propelled vehicle by combining a Fordson tractor and helical pontoons. They also fitted the pontoons on a Chevrolet car. Turning these vehicles was much like steering a skid-loader or Caterpillar dozer is today; by slowing one side and speeding up the other. As a utility snow machine, it seemed to work well.
Of course, this concept gave way to a more conventional tracked vehicle, no doubt inspiring the inventors of today’s snowmobiles. Still, this video made my morning. Since the snow is lacking in several parts of what was last year a tremendous snowmobiling winter, take 10 minutes and enjoy this video (and the vintage music).
More about it can be found here: http://en.wikipedia.org/wiki/Screw-propelled_vehicle#Armstead_Snow_Motor