A rotary snowplow (

American English American English, sometimes called United States English or U.S. English, is the set of variety (linguistics), varieties of the English language native to the United States. English is the Languages of the United States, most widely spoken lang ...

) or rotary snowplough is a piece of

railroad Rail transport (also known as train transport) is a means of transport using wheeled vehicles running in railway track, tracks, which usually consist of two parallel steel railway track, rails. Rail transport is one of the two primary means of ...

snow removal Snow removal or snow clearing is the job of removing snow after a snowfall to make travel easier and safer. This is done both by individual households and by governments institutions, and commercial businesses. De-icing and anti-icing De-icin ...

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. It was developed in the late 19th century for use when snow is too deep to be removed by a wedge snowplow.

History

Rotary snow plow train and unknown persons - DPLA - 7a393f3e045fad3629d6aaad268b3121

The rotary was invented in

Toronto Toronto ( , locally pronounced or ) is the List of the largest municipalities in Canada by population, most populous city in Canada. It is the capital city of the Provinces and territories of Canada, Canadian province of Ontario. With a p ...

, Canada, by dentist J.W. Elliot in 1869. He never built a working model or prototype. Orange Jull of Orangeville, Ontario, expanded on Elliot's design, building working models he tested with sand. During the winter of 1883–84, 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 Paterson ( ) is the largest City (New Jersey), city in and the county seat of Passaic County, New Jersey, Passaic County, in the U.S. state of New Jersey.railroad tracks. These pushed snow off the tracks, deflecting it to the side. Deeper drifts cannot easily be cleared by this method; there is simply too much snow to be moved. For this purpose, the rotary snowplow was devised. Rotary steam shovel at work

Rotary plows are often deployed when snow is too deep or hard-packed for traditional plows. The ability to operate slowly, as there is no requirement for train momentum to break up the snow, is often an advantage in mountainous regions, where a high speed derailment could be disastrous. Many rotary plows are not self-propelled, so one or more

locomotive A locomotive is a rail transport, rail vehicle that provides the motive power for a train. Traditionally, locomotives pulled trains from the front. However, Push–pull train, push–pull operation has become common, and in the pursuit for ...

s are coupled behind it to push the plow along the line. An engine within the plow's carbody rotates the large circular assembly at the front of the plow. The blades on this wheel cut through the snow and force it through a channel just behind the disk to an output chute above the blade assembly. The chute can be adjusted to throw the snow to either the left or the right side of the tracks. An operator sits in a cab above and behind the blade assembly to control the speed of the blades and the direction of output from the chute. With the increasing prevalence of

diesel locomotives A diesel locomotive is a type of railway locomotive in which the prime mover (locomotive), power source is a diesel engine. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is con ...

, multiple-unit train controls have been added to the cabs, so that the pushing locomotives can be controlled from the plow. In areas of particularly deep snowfall, such as California's Donner Pass, railroads sometimes created a train consisting of a rotary snowplow at each end, with the blade ends pointing away from each other, and two or three locomotives coupled between them. With a plow on each end, the train was able to return to its starting location even if the snow covered the tracks it had just passed over. Such a train would also be able to clear multiple track mainlines efficiently as it could make a pass in one direction on one track, then reverse direction and clear the next track. This practice became standard for the

Southern Pacific Railroad The Southern Pacific (or Espee from the railroad initials) was an American Railroad classes#Class I, Class I Rail transport, railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was oper ...

on Donner Pass following the January 1952 stranding of the '' City of San Francisco'' train; during attempts to clear the

avalanche An avalanche is a rapid flow of snow down a Grade (slope), slope, such as a hill or mountain. Avalanches can be triggered spontaneously, by factors such as increased precipitation or snowpack weakening, or by external means such as humans, othe ...

s that had trapped the train, two rotary plows were trapped by subsequent avalanches, and the crew of a third was killed when their plow was hit by an avalanche. Rotary snowplows are expensive because of their high maintenance costs, which the railroad incurs regardless of whether they are needed in a given year. As a result, most railroads have eliminated their rotaries, preferring to use a variety of types of fixed-blade plows that have significantly lower maintenance costs, in conjunction with

bulldozers A bulldozer or dozer (also called a crawler) is a large tractor equipped with a metal blade at the front for pushing material (soil, sand, snow, rubble, or rock) during construction work. It travels most commonly on continuous tracks, though s ...

, which can be used year-round on maintenance-of-way projects. In addition, because rotaries leave an

open-cut In civil engineering, a cut or cutting is where soil or rock from a relative rise is removed. Cuts are typically used in road, rail, and canal construction to reduce a route's length and grade. Cut and fill construction uses the spoils from cu ...

in the snowbank that fixed-blade plows cannot push snow past, once rotaries have been used, they must be used for all further significant snowfalls until the

snowpack Snowpack is an accumulation of snow that compresses with time and melts seasonally, often at high elevation or high latitude. Snowpacks are an important water resource that feed streams and rivers as they melt, sometimes leading to flooding. Snow ...

has melted. Since rotaries, which need energy to power the blades, also cost more to operate than fixed-blade plows, they are now generally considered to be a tool of last resort for the railroads that own them. The few remaining rotary plows in North America are either owned by museum railroads or are kept in reserve for areas with poor road access and routine severe snowfall conditions. The largest remaining fleet of rotaries consists of

Union Pacific Railroad The Union Pacific Railroad is a Railroad classes, Class I freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Pacific is the second largest railroad in the United Stat ...

's six plows reserved for Donner Pass. Japan sees widespread use of rotary snowplows in its many mountain passes.

Power

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 and 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 motor A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric vehicle, electric or hydrogen vehicles, or electric multiple unit trains. Traction (engineering), Traction motors are used in electrically powe ...

s removed; these are colloquially called ''snails''. (This is derived from the fact that engineless but motored units that take their power from another locomotive are ''

slugs Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a sma ...

''; thus the opposite, with engine but no motors, is a ''snail''.)

Hall of Fame induction

In 2001, the rotary snowplow was inducted into the North America Railway Hall of Fame. The hall of fame recognizes and establishes an enduring tribute to the people and things that have made significant contribution relating to the railway industry in North America. The rotary snowplow was inducted in the "Technical Innovations" category with "National" significance.

Preservation

Alaska Railroad The Alaska Railroad is a Class II railroad that operates freight and passenger trains in the state of Alaska. The railroad's mainline runs between Seward, Alaska, Seward on the southern coast and Fairbanks, Alaska, Fairbanks, near the center of ...

#4 is on display at the Potter Section House State Historic Site south of

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. * Colorado & Southern No. 99201 is on display at the

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Golden, Colorado Golden is a home rule city that is the county seat of Jefferson County, Colorado, United States. The city population was 20,399 at the 2020 United States census. Golden lies along Clear Creek at the base of the Front Range of the Rocky Moun ...

. * Denver & Rio Grande Western 3' narrow-gauge rotary snowplows OM and OY are owned by the Cumbres & Toltec Scenic Railroad in Chama, New Mexico. OM was built in 1880 and converted to narrow gauge in 1907, it last ran in 1976 and has been on display since. OY was built in the 1920s and last ran in 1997 where it was then put on display until recently when it was restored in preparation for a February 2020 photography special celebrating the C&TS' 50th anniversary, and is currently in operational condition. *

Long Island Railroad The Long Island Rail Road , or LIRR, is a railroad in the southeastern part of the U.S. state of New York, stretching from Manhattan to the eastern tip of Suffolk County on Long Island. The railroad currently operates a public commuter rail ...

#193 is on display at the

Steamtown National Historic Site Steamtown National Historic Site (NHS) is a List of railway museums, railroad museum and Heritage railway, heritage railroad located on in downtown Scranton, Pennsylvania, at the site of the former Scranton yards of the Delaware, Lackawanna and ...

Scranton, Pennsylvania Scranton is a city in and the county seat of Lackawanna County, Pennsylvania, United States. With a population of 76,328 as of the 2020 United States census, 2020 census, Scranton is the most populous city in Northeastern Pennsylvania and the ...

. *

Northern Pacific Northern Pacific may refer to: * Northern Pacific Airways, an upcoming airline * Northern Pacific Field Hockey Conference, an NCAA Division I conference * Northern Pacific Hockey League, an American Tier III junior ice hockey league * Northern Paci ...

#2 is on display at the Lake Superior Railroad Museum in

Duluth, Minnesota Duluth ( ) is a Port, port city in the U.S. state of Minnesota and the county seat of St. Louis County, Minnesota, St. Louis County. Located on Lake Superior in Minnesota's Arrowhead Region, the city is a hub for cargo shipping. The population ...

. * Northern Pacific #10 is on display at the Northwest Railway Museum in

Snoqualmie, Washington Snoqualmie ( ) is a city next to Snoqualmie Falls in King County, Washington, United States. It is east of Seattle. Snoqualmie is home to the Northwest Railway Museum. The population was 14,121 at the 2020 census. Etymology The name "Sno ...

. It was built in November 1907. * Oregon Short Line #762 is on static display at the

Mid-Continent Railway Museum The Mid-Continent Railway Museum is a railway museum, railroad museum in North Freedom, Wisconsin, North Freedom, Wisconsin, United States. The museum consists of static displays as well as a round trip ride aboard preserved railroad cars. Hi ...

in North Freedom, Wisconsin. * Rotary Snowplow "B" is on display at the

Nevada Northern Railway Museum The Nevada Northern Railway Museum is a railroad museum and heritage railroad located in Ely, Nevada, owned by the State of Nevada and operated by a historic foundation dedicated to the preservation of the Nevada Northern Railway. Museum ac ...

in Ely, Nevada. * Southern Pacific MW205 is on static display at the California State Railroad Museum in

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. * Southern Pacific MW206 is on static display at the Train Mountain Railroad Museum in Chiloquin, Oregon. * Southern Pacific MW208 is in operational condition at the Western Pacific Railroad Museum at Portola, California. This rotary was involved in the rescue of the '' City of San Francisco'' train in 1952. * Southern Pacific MW210 is on display at the Truckee Railroad Museum in

Truckee, California Truckee is an List of municipalities in California, incorporated town in Nevada County, California, United States. As of the 2010 United States Census, the population was 16,180, reflecting an increase of 2,316 from the 13,864 counted in the 2 ...

. *Southern Pacific MW7221 is on display in Roseville, California. *

Union Pacific The Union Pacific Railroad is a Class I freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Pacific is the second largest railroad in the United States after BNSF, ...

#900075 is on display at the Illinois Railway Museum in

Union, Illinois Union is a village in McHenry County, Illinois, United States. The population was 551 at the 2020 census. History A post office called Union has been in operation since 1852. The village was named for the federal union of the United States. ...

. * Union Pacific #900081 is on display at the National Museum of Transportation in

St. Louis, Missouri St. Louis ( , sometimes referred to as St. Louis City, Saint Louis or STL) is an Independent city (United States), independent city in the U.S. state of Missouri. It lies near the confluence of the Mississippi River, Mississippi and the Miss ...

. File:Breckenridge Rotary Snowplow.JPG, White Pass and Yukon Route rotary snowplow in Breckenridge, Colorado File:Snow Plow-1.jpg, Northern Pacific Rotary 10 steam snowplow from front end File:White Pass Snow Plow No1 Aug2011.jpg, White Pass and Yukon Rotary Snow Plow No.1 File:HenschelDampfschneeschleuderDTMBerlin.jpg, Typical German Henschel rotary steam snowplow (Austrian Federal Railways ÖBB 986.101) File:Alaska Railroad rotary snowplow.jpg, Alaska Railroad rotary snowplow near Anchorage

References

External links

Rotary snowplow list
, a listing of all surviving railroad rotary snowplows in North America.

(archived) * , February 27, 2017 {{Freight cars, state=collapsed Maintenance of way equipment Snowplows Canadian inventions