When it gets icy, slippery and winter cold, it's just around the corner: the melting point depression. This physical-chemical effect is used every year by winter services to make our roads safer. In order for water to remain liquid at sub-zero temperatures, it is enough to dissolve another substance in it. The road and freeway maintenance departments like to use an abundant mineral here: salt.
1600 tons of it stored by the district of habberge at the habfurt and ebern sites. Just a grain on the cold stone compared to the 24.000 tons used by the schweinfurt state building department during extreme winters. However, this de-iced state and federal roads in as many as four counties. But no matter how much and who uses it, the winter services all work with the same method.
The road salt is enriched with a solution of salt and water called brine before it is spread on slippery roads. This has two effects: on the one hand, only moistened salt can thaw snow and ice (the aforementioned physical-chemical effect), and on the other hand, it prevents the otherwise dry material from being blown away by wind and cars.
That's enough for now
With 1,600 tons in the bunker, alfons schanz feels well prepared for the winter in the habbergen mountains. "The preparations are of course completed", says the head of the civil engineering department, who is responsible for 321 kilometers of county roadways.
The county makes its roads safe with six of its own gritting vehicles and three contracted from an external contractor. When it's really slippery and there's a lot of snow, everyone goes out at the same time, explains schanz. The snowplows are now also equipped with on-board computers. The spreading quantity and pattern can thus be precisely adapted to the respective road conditions: "it is adjusted so that the salt does not land next to the asphalt", says schanz. That is important for the different widths of the roads.
The men at the tram master's office in zeil have been working with GPS and computer systems for a long time. For about five years now, the vehicles of the public works department in schweinfurt have been equipped with high-tech systems that can calculate the amount of salt spread to the gram. The GPS device installed in the unimog also records every kilometer driven and where and in what time it was cleared. "The data is then automatically sent to a server for recording", explains workshop manager herbert kern. Together with his colleague edwin schonunger and the head of the tram maintenance department, hartmut pianski, he makes the rounds in zeil and inspects the vehicles and the salt storage system. Those who are assigned to winter road maintenance, female: soon it will really start again. "Last week, we were already out of the woods" says scheuringer.
New warehouse for 12.000 salt
800 tons of salt are currently stored in zeil, and another 700 tons in ermershausen. In addition, a new warehouse is being built in eltmann, with space for 12 .000 tons of road salt. It should be ready and in use this year, says pianski. If you include all the storage facilities, including the one soon to be completed in eltmann, the state construction office has 22,000 tons of salt at its disposal in the counties of habberge, rhon-grabfeld, bad kissingen and schweinfurt. A total of twelve vehicles will take it to the road when it gets icy. According to pianski, the cost of winter road maintenance for a season is 346. 000 euros.
The construction office is not solely responsible for the approximately 350 kilometers of state roads in the habberge district. The district's snowploughs drive part of the route for the schweinfurt authorities. In return, the building authority takes over a part of the district roads. Alfons schanz is pleased with the cooperation, which has optimized the routes of the two winter road services. Schanz cites wagenhausen and grebhausen as an example: "if the state uses the B26, it stands to reason that a vehicle would drive there and spread the road." His county vehicles grit the state highway between zell am ebelsberg and unterschleichach, for example.
Around the clock
Oh yes, and then there is the freeway A70. The freeway maintenance department in knetzgau is responsible for the section between bergrheinfeld and bamberg harbor. Four trucks with spreaders are always on standby there, because they have to look after the 52 kilometers of highway around the clock. 1200 tons of salt are available for this purpose. "That's enough for the winter, says strabenmeister alfred bauer.