Ravenna Bridge

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Ravennabrücke is the name of a viaduct of the Höllentalbahn in the Black Forest . It leads over the Ravennaschlucht , which flows into the upper Höllental .

Former building

Old Ravenna Bridge
Old Ravenna Bridge
First Ravenna Bridge in 1900
Convicted Ravenna Gorge
overall length 144 m
Number of openings 4th
height 37 m
building-costs 338,870 gold marks
start of building 1885
completion 1887
planner Robert Gerwig

From 1885 the Ravenna Bridge was built as a bridge with three brick sandstone pillars and a steel framework superstructure according to plans by the railway pioneer Robert Gerwig . The bridge described a slight arc of 240 m radius, the speed of the trains was limited to 15 km / h and the axle load was limited to 16 t. It was more than 37 m above the bottom of the stream, at a gradient of 1:20. The four openings had a span of 35 m each. The weight of the iron components was 255,500 kg and the total cost was 338,870 marks .

The old Ravenna bridge was demolished after the new one was built. But the old abutments are still there.

Current structure

Coordinates: 47 ° 55 ′ 3 ″  N , 8 ° 4 ′ 27 ″  E

Ravenna Bridge
Ravenna Bridge
Ravennabrücke with Hofgut Sternen and Galgenbühl
Convicted Ravenna Gorge
overall length 224 m
Number of openings 9
Arrow height 4.20
Pillar strength 4.50 m
Arch thickness (vertex) 20 m
height 36 m
building-costs 1.7 million Reichsmarks
start of building August 9, 1926
completion 1927
opening December 14, 1927
location
Ravennabrücke (Baden-Württemberg)
Ravenna Bridge

Due to increased requirements in train traffic - heavier locomotives and higher speeds - today's Ravennabrücke, a masonry stone viaduct with nine arches and an arch width of 20 m, was built from August 26, 1926 , and the route was straightened and shortened by 38 meters. The new bridge is 36 meters high, 224 meters long and overcomes a gradient of 12 meters. Some of the pillars had to be anchored up to 30 meters deep in the ground; the foundations for this stand on gneiss and were made from rammed concrete . This was necessary because the soil surface consisted only of rubble, clay and boulders. The vaults are made of granite , the pillar shafts of granite layered masonry with a core of concrete. The floors and pillars were protected against weathering by walls with natural stone. Any rot on the top of the bridge should be prevented by a combination of soaked jute fabric , bitumen and another protective cover reinforced with wire nets.

The material was brought to the construction site in special trains at night so as not to disturb the traffic on the route. The inauguration of the bridge took place on December 14, 1927 after the bridge was completed on December 10 and loaded with two locomotives on a trial basis.

The Ravenna Tunnel, which immediately follows the bridge, was originally 85 meters long. It was partially slit and is therefore only 47 meters long today. Previously, the road that was on top of the tunnel was relocated by 20 meters (today's Bundesstraße 31 ). The demolition work on the tunnel was also carried out during ongoing operations.

Luis Trenker's Freiburg cameraman , Sepp Allgeier , documented the entire construction, from the preparations, the excavation of the foundations, the manufacture of the stones, concrete work, construction of the arches to the load test, the first pull and the blasting of the old viaduct. The documentary received was shown on May 11, 1995 on Südwestfernsehen in the series Eisenbahn-Romantik . The film from 1926 was provided by Wilhelm Tröndle. His father was the site manager and responsible for the entire construction.

During the Second World War , the bridge was the target of Allied air raids, but was not hit because of the use of blocking balloons . On April 21 and 22, 1945, shortly before the end of the war, it was blown up by German pioneers . Shortly after the demolition, a motorcyclist reportedly came from Freiburg with the order not to blow up. The explosive charges for this had already been brought in in 1941. The blasting destroyed pillars three to five and vaults 3 to 6, which corresponds to a length of over 100 meters. The Löffeltal road bridge and the Hirschsprung tunnel were also blown up. As a result, a loaded food train was trapped between the blasting sites. When the population reached the train, they were shot at by low-flying planes. Until the reconstruction in 1947/48, travelers had to walk between the Höllsteig and Hinterzarten stations through the Löffeltal before a primitive shuttle service with wood gas-powered trucks could be set up.

From October 16, 1946, it was rebuilt under the supervision of the French occupation forces , also with the use of about 80 German prisoners of war from Offenburg who were obliged to do forced labor , for one million Reichsmarks , so that large quantities of logs that had to be delivered from the Black Forest as reparations could be transported away. The festive reopening took place on December 22nd, 1947, before continuous traffic on the Höllentalbahn started again a day later. Before that, however, the load-bearing capacity of the bridge had been tested with four steam locomotives.

The Ravennabrücke is the only heated bridge operated by Deutsche Bahn.

Since 2010 there has been a Christmas market under the illuminated viaduct on Advent weekends.

In January 2017, a base jumper jumped off the bridge and was seriously injured.

Ravenna bridge as a breeding place for the rock tern

The rock tern has been breeding at the Ravenna Bridge since 2014 .

literature

  • Gasteiger: The new construction of the Ravenna crossing at km 22 4/7 of the Höllentalbahn. In: Die Bautechnik , Volume 6, Issue 38 (September 4, 1928), pp. 559–577.

Web links

Commons : Viaduct over the Ravennaschlucht  - collection of pictures, videos and audio files

Individual evidence

  1. horst-jeschke.de: Viaduct of the Höllentalbahn , accessed on November 8, 2009
  2. ^ HM Poppen & Son: Freiburg im Breisgau. The city and its buildings. , Freiburg im Breisgau 1898, page 139
  3. a b c d e f g h i The new viaduct over the Ravenna in: Freiburger Zeitung of December 14, 1927
  4. a b c Notice board at the foot of the bridge
  5. a b c Ravennabrücke. In: Structurae
  6. a b c d e f Annika Lindenberg: The little book from Höllental . 3. Edition. Maienstein, Kirchzarten 2001, DNB  124971865 , p. 71 ff .
  7. http://www.eisenbahn-tunnelportale.de/lb/inhalt/tunnelportale/4300-ravenna.html
  8. SWR-Fernsehen: Eisenbahn-Romantik - Episode 142: Construction of the Ravenna Viaduct , accessed on January 11, 2010
  9. a b c d R. Naumann: Construction site Ravenna Viaduct . In: Nature and Technology . No. 20 , 1947, ISSN  0174-9625 ( archive.org ).
  10. a b Roland Weis: 75 years ago, German soldiers blew up the Ravenna Bridge in Breitnau. Badische Zeitung, April 22, 2020, accessed on May 3, 2020 .
  11. Hans-Wolfgang Scharf, Burkhard Wollny: The Höllentalbahn. From Freiburg in den Schwarzwald 1987, ISBN 3-88255-780-X , p. 129
  12. ^ A b Hans-Wolfgang Scharf, Burkhard Wollny: The Höllentalbahn. From Freiburg in den Schwarzwald 1987, ISBN 3-88255-780-X , p. 133
  13. ^ Wilhelm Karst: The last route walker . In: The time . No. 40 , October 1, 1993 ( zeit.de [accessed May 3, 2020]).
  14. Peter Stellmach: Breitnau: Höllental: Christmas market in the Ravennaschlucht: only here you can get Rothaus punch. Badische Zeitung, November 18, 2014, accessed on December 11, 2016 .
  15. David Weigend, Oliver Huber, Julia Dreier: Southwest: Höllental: Seriously injured: Base jumper jumps from Ravennabrücke. Badische Zeitung, January 30, 2017, accessed on January 31, 2017 .
  16. Bettina Maier: Population development of the rock tern Ptyonoprogne rupestris in southern Baden-Württemberg (Germany) in 2017 . The Bird World 138: 123–140.