Rotary Snowplow Train

A rotary snowplow is a piece of railroad snowfighting equipment. It is characterized by the large circular set of blades on its front end that rotate as a unit to cut through the snow on the track ahead of it.
The rotary was invented by Canadian dentist J.W. Elliot in 1869, but a prototype wasn't built until the Leslie Brothers constructed one in 1883.
Wedge snowplows were the traditional automated method of clearing snow from railroad tracks. These pushed snow off the tracks, deflecting it to the side. Deeper drifts, however, cannot be easily cleared by this method; there is simply too much snow to be moved. For this purpose, the rotary snowplow was devised.