Rhine bridge Cologne-Rodenkirchen

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Coordinates: 50 ° 53 ′ 59 ″  N , 6 ° 59 ′ 26 ″  E

A4 Rhine bridge Cologne-Rodenkirchen
Rhine bridge Cologne-Rodenkirchen
Panorama view of the Rodenkirchen bridge
Convicted Federal motorway 4
Crossing of Rhine
place Cologne - Marienburg / Rodenkirchen - Cologne- Poll / Westhoven
construction Suspension bridge
overall length 567 m
width 52.3 m
Longest span 378 m
Construction height 3.3 m
vehicles per day 131,573 (2014)
start of building 1938/1952/1990
completion 1941/1954/1994
opening September 1941
planner Fritz Leonhardt
Paul Bonatz
location
Rhine bridge Cologne-Rodenkirchen (North Rhine-Westphalia)
Rhine bridge Cologne-Rodenkirchen

The Rheinbrücke Köln-Rodenkirchen , also called Rodenkirchener Brücke , is a 567 meter long suspension bridge that spans the Rhine at Rodenkirchen as part of the A 4 at Rhine kilometer 683.8 and connects the left and right Rhine sections of the Cologne motorway ring.

Special features are the monumental gate situation on the natural stone bridgehead at the abutments, the slimness of the horizontal stiffening girders and the tension between the girders and the portal-like pylons that frame them. In addition, the bridge, like the other urban bridges in the city area, is painted in Cologne bridge green.

Planning and construction

The bridge construction engineer Fritz Leonhardt was responsible together with Paul Bonatz (architect) and Karl Schaechterle (engineer) in the context of the planning for the Reichsautobahn Cologne - Aachen . For Leonhardt, this assignment represented the first independent construction management task. Construction of the Rhine Bridge began on March 1, 1938. The Second World War began in its construction phase at the end of August 1939. Leonhardt was drafted into military service on August 27, 1939, but two days later ordered back to the construction site because the bridge construction was considered a strategic measure. Leonhardt was able to contribute the knowledge he had gained in the USA about real suspension bridges in Rodenkirchen. First the pylons and abutments were built . The suspension ropes manufactured by the Cologne company Felten & Guilleaume were then stretched across the Rhine in order to mount the individual parts of the road reinforcement girder on them. The last girder was installed on November 11, 1940, an important date for Cologne. A total of 12,500 tons of steel were used, the construction costs for the most expensive completed structure on the Reichsautobahn amounted to 13.9 million Reichsmarks. The inauguration of the "Adolf Hitler Bridge" took place on September 20, 1941. It was the first real suspension bridge in Germany and at that time the largest suspension bridge in Europe.

The Rodenkirchener Rheinbrücke is an underground cable suspension bridge with a central span of 378 meters, which together with the two side openings of 94.5 meters each results in a total span of 567 meters. The 59.4 meter high pylons are fixed in the pillars. The first bridge was built with two directional lanes each 7.5 meters wide, a bike path in the middle of 2.8 meters and two external footpaths each 2.4 meters. The abutments with the external stairs were lavishly clad with a wall made of shell limestone . Granite was also used for the pillars up to the mean water line. Gerd Lohmer made the stone carving drawings .

Destruction and rebuilding

View from 1985, still with four lanes

After a bomb hit on January 14, 1945, the structure collapsed on January 28, 1945. The reconstruction took place according to a special design by Hellmut Homberg between 1952 and 1954 and took into account the remaining pylons; The construction costs amounted to 17.2 million DM. Material improvements and other technical optimizations, such as a reinforced concrete composite roadway, saved significantly more than 3000 tons of steel. The new motorway bridge was opened to traffic on December 9, 1954.

The steelworker Rudolf Barbré also played a key role in the construction and reconstruction .

Broadening

Lower view from the left bank of the Rhine

The steadily increasing volume of traffic on the A 4 that runs over it required a widening from four to six lanes . The building planners decided to widen the bridge on the north side of the previous bridge. The construction work took place between 1990 and 1994 and cost 184 million DM. It is a twin building with a common central column on the north side, whereby the bridge elements on the north side are not riveted but welded. The steel pylons with the maximum external dimensions of 3.6 by 4.5 meters have a height of 59.4 meters and a center distance of 26.4 meters. Three pylons are each founded on a concrete river pillar 20 meters high, 12 to 18 meters wide and 78 meters long .

The inauguration took place on December 9, 1994, exactly 40 years after the rebuilt bridge was put into operation.

construction

View of the bridge from the right bank of the Rhine

The suspension cables from 1954 have a diameter of around 50 centimeters and consist of 61 individual cables. The cable slack between the pylon and the middle of the bridge is 42 meters. The suspension ropes have a diameter of 5.4 centimeters and are spaced 10.5 meters apart. The cable tensile forces of 60 MN each are anchored  in the abutments, which are designed as box-like ballast bodies with a maximum height of 26 meters, a width of 50 meters and a length of 64 meters.

The 3.3 meter high superstructure is now a pure steel construction, consisting of a lightweight steel carriageway and a girder grid with 3.3 meter high stiffening beams and 1.65 meter high cross members. For drainage of the carriageway slab, both directions of travel are designed on the upper side with a transverse gradient of 2.5 percent towards the upper stream.

Until the renovation, the bridge had a 19 centimeter thick pre- stressed concrete deck . By replacing it with the lightweight steel carriageway, the loads on the bridge, which is now twice as wide, only increased by 50 percent, which meant that it was sufficient to add a new third cable to the two existing suspension cables. Since then, the bridge has been the only suspension bridge where the load is evenly distributed over three suspension cables. The even load distribution has been achieved with the help of the rigidity of the crossbeams, the flexibility of the suspension cables and subsequent tensioning of the new suspension cable.

Due to the large span and bridge width, the traffic load to be applied according to the regulations was reduced with the help of a special traffic load regulation by the Federal Ministry of Transport . As a result, the existing stiffening beams were also sufficient for further use. The doubling of the lane from 26.4 to 52.8 meters, the total width with pedestrian and bicycle paths is now 56.6 meters.

Further planning

Road Authority has plans for an expansion of achtstreifigen in April 2020 A 4 received between the interchanges Cologne-South and Cologne-Gremberg. This expansion was recorded as an urgent need in the Federal Transport Infrastructure Plan 2030 . For this purpose, various variants are being examined, such as (renewed) expansion of the existing structure, a replacement new building at the same location, and tunnel and bridge variants north or south of the existing bridge. The Rodenkirchen Citizens' Association spoke out in favor of preserving the listed bridge.

See also

literature

  • Roland May: Pontifex maximus. The architect Paul Bonatz and the bridges. Monsenstein and Vannerdat, Münster. 2011, ISBN 978-3-86991-176-2 , pp. 383-396, 560-563, 636-639.
  • W. Roosen, J. Haensel, R. Hornby, W. Piel: Widening and reconstruction of the Rhine bridge Cologne-Rodenkirchen, technical processing for the superstructure. In: Der Bauingenieur , 69, 1994.
  • H. Schautes, H. Runkel, P. Dünnebacke: Widening and reconstruction of the Rhine bridge Cologne-Rodenkirchen, building history and design and implementation planning . In: Der Bauingenieur , 69, 1994.
  • Helmut Signon: Bridges in Cologne on the Rhine . JP Bachem Publishing House, Cologne 1966.

Web links

Commons : Rheinbrücke Köln-Rodenkirchen  - Collection of images, videos and audio files

Individual evidence

  1. Automatic counting by the BVM
  2. He was involved in the construction of four other Cologne bridges: Deutzer Brücke , Zoobrücke , Severinsbrücke and Mülheimer Brücke .
  3. Christine Weber: Fritz Leonhardt: "Lightweight construction" - a requirement of our time. 2011, p. 71 ff.
  4. Christine Weber: Fritz Leonhardt: "Lightweight construction" - a requirement of our time. 2011, p. 83.
  5. Roland May: Pontifex maximus. The architect Paul Bonatz and the bridges. Monsenstein and Vannerdat , Münster 2011, ISBN 978-3-86991-176-2 , p. 391.
  6. a b c d Roland May: Pontifex maximus. The architect Paul Bonatz and the bridges. Monsenstein and Vannerdat, Münster. 2011, ISBN 978-3-86991-176-2 , p. 638.
  7. Klaus Stiglat : civil engineers and their work. Ernst and Son 2004, p. 60.
  8. A4plus - expansion in the south of Cologne. Project website of the State Office for Road Construction NRW (as of April 10, 2020).
  9. koelnarchitektur.de: Double is better. But now we have to think about the future of the Rodenkirchener Brücke again . March 31, 2020.