Winter service
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The term winter service comprises the entirety of all measures to ensure traffic safety, mobility and economic efficiency of the traffic flow in winter . Measures to combat ice and snow are being taken, especially in the road and rail sector. However, winter service is also important in aviation and shipping.
Goal and tasks
A functioning transport infrastructure is of existential importance both for the individual citizen and for the economy of every country. Winter weather conditions can, however, significantly limit the functionality of the transport infrastructure and thus cause considerable economic damage (for example through accidents or loss of time). The aim is therefore to use the winter service to maintain traffic safety on the one hand and the flow of traffic as much as possible on the other . Specifically, this means in particular the avoidance of ice build-up and the removal of ice and snow.
activities
Clearing
The snow removal is the mechanical removal of snow on traffic areas.
Different techniques can be used for clearing: If the snow is still very loose and the amount of precipitation is low, the snow can be removed with a broom or a road sweeper . For small areas, the snow is cleared manually with a snow shovel , snow shovel, snow tub or snow witch. If this is not sufficient, especially in the case of greater snow depths and areas to be cleared, motor-driven devices are used, namely snow blowers and snow plows , brooms and blowers are also used. Snow walls thrown up on the edge by the snow plow are thrown into the adjacent landscape with the side snow blower or loaded onto trucks and deposited elsewhere for melting. Pollutants such as microplastics that have accumulated in the snow can thus enter the environment unhindered.
In order to improve or even enable the visibility of the road with large amounts of fresh snow, snow signs are set up in winter time.
Clearance means that the road is almost completely cleared of snow and ice. This process is very time-consuming and costly.
During the clearance process , the fresh snow is pushed aside and the remaining snow is pegged so that it forms a solid cover. In this snow then (especially when packed snow) chips are scattered around the grip to improve. When applying the material to be spread by the spreader make spreading density and spread pattern are important parameters. This method is less expensive than the black clearance and was originally applied only in the Alpine region, particularly on secondary lines, for cost and environmental reasons, now outside the Alpine countries.
Sprinkle
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Litter materials are usually mineral granules such as crushed stone , grit, gravel and expanded clay, organic granules, for example corncob granules , grit sand or de-icing salt , ash is rarely used today . "Thawing agents" are also used. If it is slippery, grit , salt or a mixture of grit and salt is applied with a spreader . Since the 1980s, pre-wetted salt (FS) has been mainly used. De-icing salt ( NaCl , CaCl 2 , MgCl 2 ) is moistened with brine (salt solution) immediately before it is applied (usually on the spreading plate). This reduces the salt losses due to drift. The salt savings that can be achieved in this way are estimated at 20–30%. The process used is named depending on the amount of brine added; the FS 30 process (30% brine and 70% salt) has established itself. Pure brine has hardly been used in Germany so far.
De-icing salt is considered controversial. It favors the corrosion of vehicles, steel girders and concrete components and harms animals. Dogs and cats can get irritated paws and eye diseases from the de-icing salt. Even hedges can be damaged in unfavorable conditions. In many municipalities, the use of de-icing salt is only permitted under certain conditions (special risk of slipping or on inclines).
De-icing salt is also often not used in the vicinity of transmitter systems in order to prevent corrosion of earthing systems.
thawing
The functionality of the points is crucial for smooth railway operations . In order to maintain their function even in wintry weather conditions, they are kept free of snow and ice either manually with the help of a gas burner or automatically with point heating (mostly electrically operated), thus enabling the adjustment movement.
Street heating follows a similar principle . This cost-intensive special measure is only used extremely rarely on particularly endangered sections of the route (such as inclines or on bridges) and must be taken into account when the road is being built. The road surface is heated by geothermal energy or electricity and thus cleared of snow and ice.
De-icing
In order to maintain safe flight operations in wintry weather conditions, not only removing snow but also de-icing the movement areas is the task of winter service personnel. With so-called surface de - icing , the movement areas are kept free of ice with solid or liquid de - icing agents. Coarse grit, such as grit or conventional road salt, cannot be used as these damage the sensitive aircraft engines.
The aircraft must also be free of snow and ice so as not to affect flight characteristics. For aircraft de-icing, special de-icing fluids (mostly a glycol-alcohol mixture) are used, which are sprayed onto the outer skin of the aircraft. Alternatively, the aircraft can also be de-iced with the help of infrared light.
In the railway industry, so-called defrosting and de-icing systems are used to clear snow and ice from the underside of rail vehicles. This has the advantage that regularly recurring visual inspections and maintenance work on the rail vehicles can be carried out more quickly and the vehicles can thus be used again more quickly.
Winter maintenance in shipping is essentially limited to keeping waterways and ports open . There, due to ice formation, navigability can be lost and operations can come to a complete standstill. For this reason, icebreakers are used, which break the ice masses on the water and thus create an ice-free fairway for other ships.
Protect
Snow drifts are a serious danger to the safe flow of traffic on roads and railways. For protection, snow gates or snow fences are therefore mainly built in the flat and hilly areas at particularly endangered places . These reduce wind speeds and thus prevent the snow from being transported further or deposits on the road or on the railway line. In the mountains, on the other hand, avalanches and the associated snowfall on roads and railways represent a major problem. In these regions, it is therefore one of the tasks of the winter service to take measures to protect against uncontrolled avalanches (for example through avalanches ).
Combination and step-by-step approach
In order to use the various sub-instruments of winter service as efficiently and cost-effectively as possible, their combination in a meaningful sequence should be sought. De-icing salt should be used as sparingly as possible because of the high price and the often limited availability on the one hand and the potential environmental damage on the other. The use of de-icing salt is appropriate on heavily traveled downhill stretches and busy intersections of priority and secondary roads. If possible, no salt should be spread before the heavy snowfall has subsided and the roads have been cleared of the new snow cover beforehand. Roads in residential areas, provided they do not have a steep gradient, can be made sufficiently safe for traffic by clearing them with the use of gravel. In rail transport, so-called track journeys sometimes take place at night to keep the tracks clear.
Municipalities can determine that the sidewalks of certain streets are unsuitable for snow removal machines, for example due to sidewalk damage. These sidewalks may then have to be cleared by hand.
Legal position
Building contractors are responsible for clearing the roads; The clearance of footpaths is usually transferred to the residents via laws and ordinances, and from them to their tenants.
Gender equitable snow removal in Sweden
In the Swedish capital Stockholm , the red-green city government decided in 2016 to first clear the sidewalks and cycle paths and then the streets from snow. Since, statistically speaking, women walk, ride bicycles or use local public transport more often and men drive cars more often, women are disadvantaged by clearing sidewalks later. Other cities in Sweden stated that they also wanted to introduce gender-equitable snow removal.
Roof loads
In addition to clearing roads and paths, roofs often have to be cleared of snow. On the one hand, this serves to prevent dangerous roof avalanches . On the other hand, the maximum permissible snow load on the roof could be exceeded without evacuation and then collapse. There have been some such accidents in the past, such as in 2006 at the ice rink in Bad Reichenhall .
literature
- Manfred Wichmann: Street cleaning and winter service in municipal practice. Legal basis - organization - tasks. 8th edition. Erich Schmidt Verlag, Berlin 2018, ISBN 978-3-503-17643-4 .
- Günter Hausmann (Ed.): KommunalTechnik-Handbuch Winterdienst. 2nd Edition. Beckmann Verlag, Lehrte 2013, ISBN 978-3-9813013-3-5 .
- Walter Durth; Horst Hanke: Manual Road Winter Service. Kirschbaum Verlag, Bonn 2004, ISBN 3-7812-1616-0 .
Web links
Individual evidence
- ↑ DIN EN 15144 - Winter service equipment - Terminology - Terms for winter service
- ↑ Leaflet for winter road maintenance , FGSV-Verlag, Cologne 2010, page 7
- ^ Research Society for Roads and Transport: Definitions, Part: Transport Planning, Road Design and Road Operation . FGSV Verlag, Cologne 2000, p. 92 .
- ↑ Microplastics on the street - Oslo plans melting plant for winter snow masses In: deutschlandfunk.de , January 21, 2019, accessed on January 31, 2019.
- ↑ Is spreading with road salt forbidden? Retrieved March 20, 2019 .
- ↑ A source of fine dust, road salt? Pros and cons in action against snow and black ice. (PDF; 85 kB) Helmholtz Center, Munich 2005.
- ↑ a b Behind the scenes - winter preparations at the railway
- ↑ Questions and answers from the Airport Association (ADV) on the topic: Winter service at German airports ( Memento from January 23, 2016 in the Internet Archive )
- ↑ Niels Klußmann, Arnim Malik: Lexicon of aviation . Springer-Verlag, 2011, page 70.
- ↑ Jakob Kandler: Basics of an overall traffic planning under the aspect of environmental protection . Duncker & Humblot, 1983, ISBN 3-4284-5382-4 , page 36.
- ^ Röll, Freiherr von: Enzyklopädie des Eisenbahnwesens, Volume 8. Berlin, Vienna 1917, pp. 385–407
- ↑ Leaflet for winter maintenance on roads. FGSV-Verlag, Cologne 2010, page 11.
- ↑ Anett Kirchner, Rainer W. During: More and more sidewalks must not be cleared of snow by machine. Der Tagesspiegel, September 21, 2015, accessed on September 21, 2015 .
- ↑ "Women Priority" causes chaos in Stockholm. December 28, 2016, accessed January 4, 2019 .
- ↑ Silke Bigalke: Shoveling where the women are . In: Tages-Anzeiger . November 26, 2016, ISSN 1422-9994 ( tagesanzeiger.ch [accessed January 4, 2019]).
