Ranna line

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Art Nouveau house above the exit of the Viehbergstollen (2007)

The Rannaleitung is a 45 kilometer long drinking water pipeline that supplies the city of Nuremberg with water .

Drinking water supply for the city of Nuremberg

The city of Nuremberg took over the drinking water supply in 1856. Before that there were around 1200 wells in the city, which were not always of good quality. The result was in 1854 a cholera - epidemic . The first municipal waterworks was the Schwabenmühle. Between 1885 and 1896, the water extraction systems that still exist today were connected to the grid in the area of Fuchsmühle (near Brunn ) and Krämersweiher as well as in Erlenstegen . The increasing demand for water in the city was due to the fact that the population of Nuremberg increased tenfold between 1800 and 1899 as a result of increasing industrialization .

Construction of the line

With the help of this water pipeline , the construction of which began in April 1905, a large part of the drinking water required in Nuremberg flows freely, without a single pump, from the spring water works near Ranna , a district of Auerbach in the Upper Palatinate , in cast iron pipes and several tunnels to Nuremberg . The line was put into operation on July 18, 1912 by Mayor Georg Ritter von Schuh . The seven-year construction project cost 9.5 million gold marks . Around 350 liters of drinking water are currently flowing through the pipe every second. The Ranna I spring version is one of the largest in Germany with a natural outlet.

600 construction workers with 20 supervisors, five site managers and three engineers moved 75,000 cubic meters of earth and 17,000 cubic meters of dolomite stone and gravel for the construction of the spring catchment. When it was commissioned, the city of Nuremberg had 72,000 cubic meters of water per day. This amount was later no longer sufficient (in 1928 more than 100,000 cubic meters of water were used for the first time), so that another spring intake, Ranna II, was necessary. This was handed over to the company in 1934.

The line runs through six mountain tunnels , crosses the railway embankment of the Nuremberg – Pegnitz line three times and crosses the Pegnitz underground six times . One of these tunnels is the 2,495 meter long Viehbergstollen , which runs under the Großviehberg district of the city of Hersbruck . On this stretch the tunnel has a gradient of 80 centimeters, it is 177 centimeters high and 154 centimeters wide and has a 50 centimeter thick concrete wall. A 500-meter-long seepage water pipe has also been laid in the western part to prevent damage from the sulfur-containing seepage water from the mountain.

At the western exit of the tunnel near Kühnhofen there is a limestone house with Art Nouveau ornaments.

In 2012, 100 years after it was put into operation, almost the entire gray cast iron pipe was still originally in the ground. It was only replaced by steel pipes in a few places. Every ten years, the gray cast iron pipes with a wall thickness of 2.5 centimeters are metallurgically examined. They are still in very good condition today. According to experts, they can last for another 100 years.

So far there has only been one massive disturbance: During the water disaster in Nuremberg on June 7, 1950, a four-fold line break at Lauf , Rückersdorf , Behringersdorf and Wetzendorf caused water shortages for a week. The other areas of Nuremberg water production could not meet the demand, so that the bottleneck had to be kept within limits with water trucks. A pumping station had been installed to increase the transport capacity , but it was put into operation without a trial run and the gray cast iron pipes could not withstand the increased pressure.

In October 2012, federal highway 14 near Rückersdorf was completely washed away by a four-meter-long crack in the cast pipe . The road and the drinking water pipe had to be closed for several days.

Web links

Commons : Rannaleitung  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b Rudolf Weber: 100 years of drinking water from Ranna. In: weber-rudolf.de. May 22, 2012. Retrieved January 20, 2016 .
  2. ↑ Water history on the homepage of "n-ergie" as well as article Sparkling stories in the magazine " Meine N-ERGIE" , autumn 2012. Accessed on January 20, 2016 .
  3. ↑ Hersbrucker Zeitung of March 20, 2010
  4. ↑ a b Nürnberger Nachrichten of May 22, 2012, page 10: Nuremberg's water vein has been pulsing for 100 years
  5. ↑ Clemens Fischer: B14: Total block after pipe break canceled. The route to Nuremberg can be used on a single lane from Monday morning. In: nordbayern.de. Verlag Nürnberger Presse Druckhaus Nürnberg GmbH & Co. KG, October 21, 2012, accessed on October 3, 2017 .