The first rotary snowplow was designed, but never built, by J.W. Elliot, a dentist in 1869. It took a trio of Canadian entrepreneurs to produce the first working Rotary Snowplow. The designer, Orange Jull, and the builders, Edward and John Leslie, constructed a prototype of their unstoppable invention in Orangeville, Ontario in the 1880s
It was turned down by investors until a new design was proposed by 1883-84, when the Leslie Brothers of Orangeville manufactured it and had it tested by the Canadian Pacific Railway. The Leslies soon purchased the manufacturing rights to the plow and went into business building ‘Leslie’ type rotaries.
The basis of the Rotary Snowplow is a sloped steel casing that scooped snow from the tracks into a revolving fan inside a wheel. The wheel is driven by a rotary engine on a shaft. Blades on the rim of the wheel catch the snow and it is propelled through an opening at the top of the wheel.
Older snowplows had an air communication line that was hooked to the engine. The modern snowplows have an electrical box that is placed in the engine and is attached to the plow by an electrical cord. By 1910 the Pere Marquette had 16 snowplows and purchased its last snowplow, the SP-22 in 1944. The snowplow allowed for the cleaning of the tracks during winter in an efficient way, thus enabling trains to run under harsher conditions.