This screw-propelled vehicle was designed to cope with difficult snow and ice terrain. Instead of tracks, the vehicle is moved by the rotation of two horisontal cylinders fitted with a helical flange that engages with the snow surface.
The Armstead Snow Motor was developed in the early 1920's. Leading Detroit automobile makers had organized a company entitled "Snow Motors Inc" to put out a machine that would negotiate the deepest snowdrifts at six to eight miles an hour. The vehicle consisted of a tractor power-plant mounted on two revolving cylinders instead of wheels.