barrier
A barrier or barricade is a physical structure which blocks or impedes something.
Barrier may also refer to:
Places
* Barrier, Kentucky, a community in the United States
* Barrier, Voerendaal, a place in the municipality of Voerendaal, Netherl ...
that forces windblown, drifting snow to accumulate in a desired place. They are primarily employed to minimize the amount of
snowdrift
A snowdrift is a deposit of snow sculpted by wind into a mound during a snowstorm. Snowdrifts resemble sand dunes and are formed in a similar manner, namely, by wind moving light snow and depositing it when the wind has virtually stopped, us ...
on roadways and railways. Farmers and ranchers use snow fences to create drifts in basins for a ready supply of water in the spring.
Ski resort
A ski resort is a resort developed for skiing, snowboarding, and other winter sports. In Europe, most ski resorts are towns or villages in or adjacent to a ski area – a mountainous area with pistes (ski trails) and a ski lift system. In Nort ...
s also use snow fences in order to increase snow depth in specified areas, or for
construction site
Construction is a general term meaning the art and science to form objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and co ...
fencing or temporary sports field fencing), or a cedar or other lightweight wood strip and wire fence, also attached to metal stakes. A permanent snow fence usually consists of poles with horizontal planks running across them so that they cover just over one-half of the total fence area. The bottom 10% to 15% of the fence should be left open so that snow does not settle directly under the fence, which would reduce its effective height. Taller fences trap more snow. Taking the height of the fence as one unit, it should be placed thirty-five units or more to windward of the road or building that it is meant to protect. Permanent snow fences can also consist of lines of closely spaced shrubs, conifer trees or
maize
Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The ...
stalks.
Snow fences work by causing
turbulence
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to a laminar flow, which occurs when a fluid flows in parallel layers, with no disruption between ...
in the wind, such that it drops much of its snow load on the lee side of the fence. Thus, snow fences actually cause snow drifts, rather than preventing them. The fences are placed so as to cause snow to drift where it is beneficial, or not harmful so that the snow does not drift onto undesired areas such as roads or among buildings.
Snow fences have been reported to save lives and reduce maintenance costs. Snow and ice removal and control costs over $2 billion annually in the US. Studies published by Strategic Highway Research Program (SHRP) of
National Research Council National Research Council may refer to:
* National Research Council (Canada), sponsoring research and development
* National Research Council (Italy), scientific and technological research, Rome
* National Research Council (United States), part of ...
in 1991 showed that mechanical snow removal costs about 100 times more than trapping snow with fences.
Snow fences can also be used to trap tumbleweeds.
In Japan
In Tohoku and Hokkaido of Japan, especially in areas with strong wind and snow such as the coastal areas of the Sea of Japan and the plains, structures that lead to snow fences called "Yukigakoi" made of reeds, chives, and wooden boards have been made for a long time. Even now, the culture of making "Yukigakoi" can be seen in some areas such as Hokkaido.
As for transportation facilities, wooden fences made on railway lines in the 1880s as a measure against snowstorms began. However, at the beginning, it was difficult to predict where the snowdrift would be formed, and it was not possible to control the snowdrift well, and there was also a fire accident caused by the sparks generated from the steam locomotive due to the wooden structure, so it was unpopular. It is said that it has replaced the Railroad snow forest in Japan as well.
On the other hand, for roads, a structure called a "Blowing pool type snow fence" was studied and installed for the first time in 1961, referring to the wooden Snow fence used all over the world. Then, in 1967, the Hokkaido Regional Development Bureau Construction machinery workshop (at that time) developed a "Blow-off snow fence" that began to be installed on national roads in 1969, and later the Hokkaido Development Civil Engineering Research Institute (Currently, Public Works Research Institute Cold Region Civil Engineering Research Institute) researched "Blow-up prevention type snow fence" and installed it in 1978, and further applied "Blow-up prevention type snow fence" to "Blowing-proof snow fence" from 1981 and since 1988. It came to be installed.
In recent Japanese railways, "Blowing pool type snow fence" and "Blowing-proof snow fence" have been re-evaluated for their usefulness based on the research results and achievements on the road, so they will be used again as railway snow protection measures. Is becoming.
File:Old type snow fence in Japan-01.jpg, Yukigakoi (Old type snow fence in Japan)
File:Blowing pool type snow fence-01.jpg, Blowing pool type snow fence
File:Blow-off snow fence-01(Refrain-fixed snow plate type,winter).jpg, Blow-off snow fence (Refrain-fixed snow plate type)
File:Blow-off snow fence-02(Refrain-movable snow plate type,winter).jpg, Blow-off snow fence (Refrain-movable snow plate type)
File:Blow-off snow fence-01(Self standing type,winter).jpg, Blow-off snow fence (Self standing type-1)
File:Blow-off snow fence-02(Self standing type,winter).jpg, Blow-off snow fence (Self standing type-2)
File:Blow-off snow fence-03(Self standing type,winter).jpg, Blow-off snow fence (Self standing type-3)
File:Blowing-proof snow fence-01(winter).jpg, Blowing-proof snow fence
See also
* Snow guard, a device attached to roofs to prevent snow from falling on people below
* Snow shed, which is designed so that snow collects on top
Fence
A fence is a structure that encloses an area, typically outdoors, and is usually constructed from posts that are connected by boards, wire, rails or netting. A fence differs from a wall in not having a solid foundation along its whole length.
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