A snowplow (also spelled snow plow, snowplough or snow plough, see miscellaneous spelling differences) is a device intended for mounting on a vehicle, used for removing snow and ice from outdoor surfaces, typically those serving transportation purposes. Although this term is often used to refer to vehicles mounting such devices, more accurately they are known as winter service vehicles, especially in areas that regularly receive large amounts of snow every year, or in specific environments such as airfields. In other cases, pickup trucks and front end loaders are outfitted with attachments to fulfill this purpose. Some regions that do not frequently see snow may use graders and other equipment for this task, but graders are nonetheless the best equipment to remove compacted snow and ice off the streets. Snowplows can also be mounted on rail cars to clear railway tracks.
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A snowplow works by using a blade to push snow to the side or straight ahead, clearing it from a surface. Modern plows may include a great deal of technology to make the job—and staying on the road—easier, such as Global Positioning System receivers, head-up displays and infrared cameras.
Large custom snowplows are mainly used at major airports in North America. These plows have oversized blades and additional equipment like a rotating sweeper broom (sometimes called jetblade) and blowers at the rear of the plow.
For sidewalks and narrow laneways small tractor plows (tracked or wheeled) are used in Canada and the United States.
When snowfalls accumulate above a certain height, snowplow operators may be seen clearing primarily designated "snow routes", often for the exclusive use of emergency vehicles such as fire trucks.
Underbody scrapers are sometimes mounted on vehicles in residential and urban settings, operating on principles similar to a road grader, but allowing greater weights and speed along with the carriage of a road treatment applicator.
Newer technology has allowed the use of articulated plow systems which can clear multiple divided highway lanes simultaneously; jurisdictions adopting this technology include Ontario Canada, along with Minnesota and Missouri in the US.[1]
The first snowplows were horsedrawn wedge-plows made of wood. With the advent of the automobile, a number of inventors set about to improve existing snowplows. In the US, patents were issued for snowplow improvements at least as early as 1920.
In 1923, the brothers Hans and Even Øveraasen of Norway constructed an early snowplow for use on cars. This proved to be the start of a tradition in snow-clearing equipment for roads, railways[2][3] and airports, as well as the foundation of the company Øveraasen Snow Removal Systems. Carl Frink of Clayton, New York, USA was also an early manufacturer of automobile-mounted snowplows. His company, Frink Snowplows, now Frink-America, was founded by some accounts as early as 1920.[4]
In many countries, railway locomotives have small snowplows permanently attached to their bogies, which also serve as pilots. With others, the snowplow forms part of the obstacle deflector below the bufferbeam. Bolt-on versions also exist, and these attach to the bufferbeam or front coupler. However, larger snowplows exist, which tend to be conversions rather than purpose-built vehicles. Steam locomotive tenders, large diesel locomotive bogies and various freight vehicles have been used, with the snowplow body mounted on the original frames. They are one-ended, with conventional coupling equipment on the inner end.
Conventional operation may see one or two locomotives running together with a snowplow at either end. This enables a snow clearance train to reverse direction quickly if it gets stuck. Alternatively, a single locomotive with bogie plows can act as a self-propelled snowplow by running light engine.