Large MachinesMachines

Rotary Snow Plow

A rotary snow plow is a piece of railroad snow fighting 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 precursor to the rotary snowplow was the wedge snowplow.

Rotary Snow PlowThe rotary was invented in Toronto, Canada, by dentist J.W. Elliot in 1869. He never built a working model or prototype, although he wanted to. Orange Jull of Orangeville, Ontario, expanded on Elliot's design, building working models he tested with sand. During the winter of 1883–1884, Jull contracted with the Leslie Brothers of Toronto to build a full-size prototype that proved successful. Jull later sold his design rights to Leslie Brothers, who formed the Rotary Steam Shovel Manufacturing Company in Paterson, New Jersey. Leslie Brothers contracted with Cooke Locomotive & Machine Works in Paterson to do the actual construction.

Another inventor is said to be Col. Lewis P. Campbell. He is listed in US patent 1848554 (filed in 1929).

Early rotaries had steam engines inside their car bodies to power the blades; a few are still in working order, and in particular one on the White Pass & Yukon Route in Alaska performs annual demonstration runs through thick snow for the benefit of photographers and railway enthusiasts.

Rotaries of newer construction are either diesel- or electric-powered. Many steam plows were converted to electricity. Some electric plows can take their power from a locomotive, while others are semi-permanently coupled to power units, generally old locomotives with their traction motors removed; these are colloquially called "snails. More details