
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

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
Orangeville (Canada 2021 Census population of 30,167) is a town in south-central Ontario, Canada, and the seat of Dufferin County.
History
The first patent of land was issued to Ezekiel Benson, a land surveyor, on August 7, 1820. That was fol ...
, 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
Railway track ( and UIC terminology) or railroad track (), also known as permanent way () or "P way" ( and Indian English), is the structure on a railway or railroad consisting of the rails, fasteners, sleepers (railroad ties in American E ...]
. 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 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 control
Multiple-unit train control, sometimes abbreviated to multiple-unit or MU, is a method of simultaneously controlling all the traction equipment in a train from a single location—whether it is a multiple unit comprising a number of self-powered ...
s 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
Donner Pass is a mountain pass in the northern Sierra Nevada, above Donner Lake and Donner Memorial State Park about west of Truckee, California. Like the Sierra Nevada themselves, the pass has a steep approach from the east and a gradual a ...
, 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
San Francisco, officially the City and County of San Francisco, is a commercial, financial, and cultural center of Northern California. With a population of 827,526 residents as of 2024, San Francisco is the fourth-most populous city in the ...
'' 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
The White Pass and Yukon Route (WP&Y, WP&YR) is a Canadian and U.S. Class III narrow-gauge railroad linking the port of Skagway, Alaska, with Whitehorse, the capital of Yukon. An isolated system, it has no direct connection to any other rail ...
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
The Potter Section House is a historic section house in Anchorage Borough, Alaska. It is located at Mile 115.3 of the Seward Highway and Mile 100.6 of the Alaska Railroad. It is a -story wood-frame structure with a gable roof. The main facade ...
State Historic Site south of
Anchorage, Alaska
Anchorage, officially the Municipality of Anchorage, is the List of cities in Alaska, most populous city in the U.S. state of Alaska. With a population of 291,247 at the 2020 United States census, 2020 census, it contains nearly 40 percent of ...
.
*
Colorado & Southern
The Colorado and Southern Railway was an American Class I railroad in the western United States that operated independently from 1898 to 1908, then as part of the Chicago, Burlington and Quincy Railroad until it was absorbed into the Burlin ...
No. 99201 is on display at the
Colorado Railroad Museum
The Colorado Railroad Museum is a non-profit railway museum, railroad museum. The museum is located along the former Colorado and Southern Railway line on at a point where Clear Creek (Colorado), Clear Creek flows between North and South Table ...
in
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
The Denver and Rio Grande Western Railroad , often shortened to ''Rio Grande'', D&RG or D&RGW, formerly the Denver & Rio Grande Railroad, was an American Class I railroad company. The railroad started as a narrow-gauge line running south fro ...
3' narrow-gauge rotary snowplows OM and OY are owned by the
Cumbres & Toltec Scenic Railroad
The Cumbres and Toltec Scenic Railroad, often abbreviated as the C&TSRR, is a Narrow-gauge railway, narrow-gauge Heritage railway, heritage railroad that operates on of track between Antonito, Colorado, and Chama, New Mexico, in the United Sta ...
in
Chama, New Mexico
Chama is a village in Rio Arriba County, New Mexico, United States. The population was 917 at the 2020 census. The village is located in the Rocky Mountains about south of the Colorado-New Mexico border.
Geography
Chama is located on the Ri ...
. 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 ...
in
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
The Lake Superior Railroad Museum is a railroad museum in Duluth, Minnesota, Duluth, Minnesota, United States.
Opened in 1973, the museum focuses on railroading in the Lake Superior region. It is housed in the restored St. Louis County Depot.
...
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
The Oregon Short Line Railroad was a railroad in Wyoming, Idaho, Utah, Montana and Oregon in the United States. The line was organized as the Oregon Short Line Railway in 1881 as a subsidiary of the Union Pacific Railway. The Union Pacific int ...
#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
North Freedom is a village along the Baraboo River in Sauk County, Wisconsin, United States. Population was 603 as reported by the 2020 census.
Etymology
North Freedom's name is rooted in ideal of freedom alongside its position north of Barab ...
.
* 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
Ely (, ) is the largest city and county seat of White Pine County, Nevada, United States. Ely was founded as a stagecoach station along the Pony Express and Central Overland Route. In 1906 copper was discovered. Ely's mining boom came later tha ...
.
*
Southern Pacific
The Southern Pacific (or Espee from the railroad initials) was an American Class I railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was operated by various companies under the names ...
MW205 is on static display at the
California State Railroad Museum
The California State Railroad Museum is a museum in the California State Parks system that interprets the role of railroads in the Western U.S. It is located in Old Sacramento State Historic Park at 111 I Street, Sacramento, California.
Featu ...
in
Sacramento, California
Sacramento ( or ; ; ) is the List of capitals in the United States, capital city of the U.S. state of California and the county seat, seat of Sacramento County, California, Sacramento County. Located at the confluence of the Sacramento Rive ...
.
* 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
The Western Pacific Railroad Museum (WPRM) in Portola, California, known as the Portola Railroad Museum until January 1, 2006, is a heritage railroad that preserves and operates historic American railroad equipment and preserves documents, pho ...
at
Portola, California
Portola ( ) is the only incorporated city in Plumas County, California, United States. The population was 2,104 at the 2010 census, down from 2,227 at the 2000 census. Portola is located on the Middle Fork of the Feather River and was named a ...
. This rotary was involved in the rescue of the ''
City of San Francisco
San Francisco, officially the City and County of San Francisco, is a commercial, financial, and cultural center of Northern California. With a population of 827,526 residents as of 2024, San Francisco is the fourth-most populous city in the ...
'' 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
The Illinois Railway Museum (IRM, reporting mark IRMX) is the largest railroad museum in the United States. It is located in the Chicago metropolitan area at 7000 Olson Road in Union, Illinois, northwest of downtown Chicago.
Overview
...
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
The National Museum of Transportation (TNMOT) is a private, 42-acre transport museum, transportation museum in the Kirkwood, Missouri, Kirkwood suburb of St. Louis, St. Louis, Missouri. Founded in 1944, it restores, preserves, and displays a wide ...
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
See also
*
Plough (disambiguation)
A plough (or plow) is a tool used in farming for initial cultivation of soil.
Plough or The Plough may also refer to:
Science and technology
*The Plough, or the Big Dipper, an asterism in the constellation of Ursa Major
*Plough (instrument), a ty ...
*
Snow blower
A snow blower or snowblower or snow thrower is a machine for removing snow from an area where it is problematic, such as a driveway, sidewalk, roadway, railroad track, ice rink, or runway. The commonly used term "snow blower" is a misnomer, a ...
References
Further reading
*
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