A rotary snowplow is a piece of railroad snow removal equipment with a large circular set of blades on its front end that rotate to cut through the snow on the track ahead of it. The precursor to the rotary snowplow was the wedge snowplow. The wedge plow or Bucker plow was first developed by railroad companies to clear snow in the American West. The wedge plow forces snow to the sides of the tracks and therefore requires a large amount of force due to the compression of snow.

The wedge plow is still in use today in combination with the high-maintenance rotary snowplow. The plow has a smooth surface so snow will slide over the plow face rather than accumulating to be pushed along as an increasing mass. Wooden plows were carefully constructed of individually fitted boards and painted frequently to maintain a smooth surface. Steel plows can be sprayed with water in sub-freezing temperatures to form a smooth layer of ice on the plow surface. 2nd: The plow has a horizontal wedge to lift snow above the level of snow accumulation beside the track.

A cutting edge low above the rails usually employed a cast iron or steel leading edge for durability against ice and for weight to discourage the tendency of the wedge to climb over hard-packed snow causing derailment by lifting the wheels off the rails. Under most conditions, the tendency to climb was reduced by weight of snow on the upper side of the wedge, and by downward reaction force accompanying upward acceleration of lifted snow.However, this downward snow loading may be absent when a plow first strikes a snow drift or packed snow face where the plow train has previously stalled. Before making a running start against such conditions, prudent crews would dig into the lower edge of the drift or snow face creating a notch to receive and guide the leading edge of the horizontal wedge.