The Rotary Snowplow Southern Pacific MW No. 205 A Fearsome Frigid Fighter

Major snowstorms in the Sierra Nevada Mountain range can jeopardize California's connection to the rest of the country. Railroads use all available means to clear the route. When these fail, they call upon the snowplow to battle the forces of nature.

The rotary design used today was developed in the 1880s. This particular model, MW205, was built in 1920 by the American Locomotive Company (ALCO). Southern Pacific Railroad received the snowplow in January 1921. From 1921 to 1967, the snowplow was assigned service in Sparks, Nevada. After service in Truckee, California in 1999, the Union Pacific Railroad donated MW205 to the Museum in 2008.

The Union Pacific Railroad had several rotary snowplows in its arsenal of snow-fighting equipment. MW205 was one of the rotaries involved in the rescue of the City of San Francisco luxury passenger train that was trapped by blizzard conditions in 1952.

Snow shovels and the rotary snowplow come to the rescue of the City of San Francisco passenger train in 1952.

MW205 Stats:

  • Built: ALCo, Paterson, NJ. November 1920
  • Placed in service: January 1921
  • Numbering History: SPMW #715 (1921)
  • #706 (March 1931) #7205 (October 1931) #205 (1962)
  • Engine: 567B diesel
  • Cylinders: 16
  • Horsepower: 1 ,500 at 80 rpm
  • Weight, loaded: 251,000 lbs. (11,3852 kg)

In service, two rotary engines are often placed back to back to one another in case of an avalanche, so they can return back to their station. To fully power a rotary snowplow, it is hooked up to a B unit behind it which provides the electricity it needs to run. Then, pushing both from the behind is a steam engine.

A diagram of how Rotary Snowplows are powered
A view of the inside of the Rotary Snowplow
A diagram of the internal workings of the Rotary Snowplow

Today, rotary snowplows are used only in extreme snowfall conditions. Machines like Jordan Spreaders and bulldozers keep up with regular Sierra snowfall. Jordan Spreaders push the snow out of the way instead of chopping it up. But every now and then, the winter storms are so fierce, the Rotary Snowplow is called to battle with the elements.

A gallery of photos of the Rotary Snowplow

Check out this view to see what the rotary snowplow looks like in action!