Grunwald Bridge
Coordinates: 51 ° 6 ′ 34 ″ N , 17 ° 3 ′ 9 ″ E
| Grunwald Bridge | ||
|---|---|---|
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| Official name | most Grunwaldzki | |
| use | Road bridge | |
| Crossing of | Or | |
| place | Wroclaw | |
| construction | Suspension bridge | |
| overall length | 186.5 m | |
| width | 20 m | |
| Number of openings | a | |
| Longest span | 126.6 m | |
| Clear width | 112.5 m | |
| start of building | 1908 | |
| completion | 1910 | |
| planner | Richard Plüddemann , Alfred von Scholtz , R. Weyrauch and M. Mayer (architect) | |
| location | ||
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The Grunwaldbrücke ( Polish most Grunwaldzki , until 1945 Kaiserbrücke or Freedom Bridge ) is a suspension bridge over the Oder in Wroclaw .
history
At the end of the 1880s, the idea of a 35 m wide diagonal street between the Ohlauer Vorstadt and the Scheitniger Park was born , which would better connect the northeastern districts of Wroclaw to the old town. The purchase of the corresponding land dragged on over several years, so that the first section of the new road connection, called Kaiserstraße, between Stadtoder and Tiergartenstraße could not be opened until the beginning of the 20th century. The first preliminary draft for a new bridge on the Oder, which was created in 1902 and which was supposed to connect the street Am Ohlau Ufer with the new Kaiserstraße, came from Richard Plüddemann , who was the city councilor for building construction at the time . He envisaged a suspension bridge with two river piers and the stone pylons erected on them. In December 1904 an architectural competition was announced. The jury consisted of Plüddemann, Lord Mayor Georg Bender , City Planning Officer for Civil Engineering Alfred von Scholtz , Oberstrombauirektor Friedrich Hamel, City Councilors Leizus and Simon (all from Breslau) and the renowned architect Karl Hofmann (Darmstadt). On April 5, 1905, the choice fell on the article with the keyword “Gespannt” by the two architects Martin Mayer and Robert Weyrauch (Hamburg / Berlin), who received the prize endowed with 2,000 marks (approximately € 12,800). Plüddemann's basic idea was expanded to include a more spacious solution without intermediate pillars, with bank pylons and a significantly larger span .
The further planning was taken over by the two building department heads Plüddemann and von Scholtz, assisted by the employees Karl Klimm , Brugsch and Günthel. In 1908, work began on the bridge according to its design. The main contractor for the steel construction was the steel construction company Beuchelt & Co. in Grünberg in Lower Silesia . Scholtz was in charge of the project management and the city architect Günther Trauer was in charge of construction . In September 1910 the load tests of the completed bridge took place, whereby 24 tram cars with a weight of 12 tons each were used. The construction costs including ancillary construction costs amounted to 2,810,000 marks (corresponds to about 16,380,000 €). On October 10, 1910, the bridge was opened in the presence of Kaiser Wilhelm II . At that time, the bridge was praised as the second longest suspension bridge in Germany, as the Blue Wonder (the 147 m long Elbe bridge near Dresden-Blasewitz) was still classified as a suspension bridge . According to today's criteria, the Kaiserbrücke would be regarded as the longest suspension bridge (in the broader sense) in Germany.
Until 1924 the bridge was called Kaiserbrücke . Between 1924 and 1933 it was called the Freedom Bridge. In 1933 it was given the old name Kaiserbrücke back.
In the last weeks of the Second World War, Breslau was declared an imperial fortress and the broad and straight Kaiserstrasse was converted into a makeshift runway by the German defenders . For this reason, all non-structural parts of the bridge pylon on the right bank of the Oder that rose above the bearings of the drawstrings were removed in order to reduce the height of the hurdle for the aircraft. In addition, the bridge was badly damaged by the air raids, so that it had to be temporarily supported on four grounded barges and wooden scaffolding and was temporarily only released for pedestrians and military transports. In the autumn of 1945 the bridge was given the name most Grunwaldzki, which is still valid today, in memory of the victory of the Polish-Lithuanian-Ruthenian troops near Grünstelde . In the spring of 1946 the temporary support was so damaged that the bridge had to be closed to all traffic. From autumn 1946 it was rebuilt under the direction of R. Siwiński. The spire helmets and the reliefs of imperial crowns were removed from the left pylon and the right pylon was restored analogously. For the endurance test, again 24 trams, each weighing 12 t, and a 15 t road roller were used . The bridge was reopened on September 5, 1947.
In 1956, 1982, 1990 and 2005, extensive repair work was carried out on the bridge. It has been registered as an individual building monument since 1976. To this day, it is the longest suspension bridge in Poland and the only one that can be used regularly by vehicles.
The centenary of the bridge was celebrated with large fireworks.
Bridge under construction (1909)
Opening of the bridge
(October 10, 1910)
Oblique aerial view of the bridge
One of the pylons
Trams on the bridge
description
The Grunwald Bridge is a four-lane road bridge with two tram tracks installed flush with the road and sidewalks on both sides. Until October 2011, when the north-west bypass of the Wroclaw motorway was opened, the national road No. 8 ran over the bridge, since then the national road No. 98 (an alternative route). Although part of the national road, the bridge is managed by the city of Wroclaw, which has taken over the road construction work in its urban area.
The bridge has a span of 126.6 m. This made it the largest suspension or chain bridge in Germany at the time . It was originally called a suspension bridge, as there were almost no wire rope suspension bridges and only a few chain bridges in Germany, and suspension bridges were usually referred to indiscriminately. This name is retained to this day, although it should be classified more as a chain bridge.
However, it differs from a chain bridge - and is probably unique in that respect - in that it does not have chains made of eye rods , but rather four wide drawstrings (two next to and one above the other) serve as carrying chains on both sides. These drawstrings in turn consist of several layers of steel strips riveted together . At that time, after lengthy considerations and studies carried out on the model, the drawstrings turned out to be the cheapest solution. In the tops of the pylon towers, large steel bearing structures with rounded saddles divert the belts from the ascending to the descending direction. The tension straps are not guided and fastened diagonally into the anchor blocks, even if they are different than usual, but diverted into the vertical just above the ground with large steel saddle structures and then fastened vertically in the anchor blocks.
The distance between the upper and lower tension straps is regulated by special fastening constructions of the 24 hangers on each side, which compensate for the different length expansion of the straps lying above in the sun or in the shade. With the tension straps that lead from the pylons on the banks to the anchor blocks, small framework connections serve as spacers and vibration dampers. The hangers also consist of riveted steel profiles and not just round bars.
The pylons are designed as large portals in the Wilhelmine style . Its towers, made of clinker masonry and clad with granite blocks , stand on concrete foundations and are connected by stone arches. Today they end with the encasing of the bearings for the drawstrings at a height of 19.5 m. Originally they wore masonry helmets and were 25.5 m high, but the helmets were not renewed after the war. A stone relief with the Wroclaw city coat of arms, influenced by Art Nouveau , is attached to the pillar shafts . The relief with the imperial eagle on the other tower was removed after the war. The connecting arches originally bore the name of the bridge as well as a stylized imperial crown on one side and the Hohenzollern coat of arms on the other. Both have been removed, including the indicated roof of the arch. As a result, the portals today convey a sober and strangely compact impression.
The center distance between the pylon towers and the side anchorages is 23.45 m. An anchor block made of reinforced concrete is built into the ground on both banks for both tension straps. Each block is 29.1 m wide, 13.2 m long and extends 10.85 m deep underground. They are supported in the ground on the one hand by the foundations of the pylons, on the other hand they extend 6.5 m above the axis of the anchorages. The anchor blocks have a mass of 135 t each, but since they are partially in the groundwater, this mass is not fully effective.
The total length of the structure is 186.5 m. The clearance between the pylon towers is 112.5 m, the clearance height required was 3.98 m above the highest navigable water level.
The hangers carry the 1.8 m high cross members, which are arranged at a distance of 4.75 m, which are connected to the longitudinal and intermediate cross members, as well as the two stiffening girders arranged between the hangers.
The stiffening girders are lattice girders with almost parallel straps that follow the light, upwardly curved parabola that describes the roadway.
The bridge is a total of 20 m wide, with the stiffening girders having a center distance of 18.9 m. Originally the carriageway was 11 m wide and the two walkways each 3.5 m. During a modernization after the war, the sidewalks were narrowed in favor of a four-lane road.
Wrought iron gas and water pipes, which have since been replaced with modern material, were led through round openings in the cross members. Various pipes for the cables of the Reichspost, the fire brigade and the power supply were hung under the footpaths. A mobile scaffold for inspection and maintenance of the underside is suspended under the bridge.
The construction process was just as unusual as the construction of the bridge. In the case of a suspension bridge, the pylons are usually built first, then the supporting cables and the hangers are installed and then the bridge deck and stiffening girders are suspended in sections. At the Kaiserbrücke, the foundations of the pylon towers and the anchor blocks were first built. While the scaffolding for the towers was being erected, half of the stiffening girders were installed on both banks, at a lateral distance of only 4.8 m so that they could fit through the pylon scaffolding. With the support of two provisional pillars built in the river, the halves were then pushed in and riveted. Above the river, they were pulled apart into their final position and the completely prefabricated cross members that were transported by ship were installed. After the pylon towers had been completed in parallel, the tie rods and hanging rods were installed on specially designed scaffolding and finally connected to the cross members and stiffening girders.
Web links
- Historical photographs of the bridge (Polish)
- most Grunwaldzki Numerous photos (from the time of construction to the present day); on Wroclaw.fotopolska.eu
Individual evidence
- ↑ Pharus-Plan Breslau , small edition, M 1: 14000, Pharus-Verlag, Berlin 1930 ( Memento of the original from February 21, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ The longer hanging bridge structures in Poland are cable-stayed bridges .
- ↑ Birthday of the Kaiserbrücke in Breslau (Most Grunwaldzki - 100-lecie) uploaded by Martin Breslauer, on YouTube
- ↑ The information in the description is based on the report by Günther Trauer: The Kaiserbrücke in Breslau
- ↑ In fact, there was no imperial crown of the German Empire from 1871 to 1918
- ↑ Total length: 6.5 + 23.45 + 126.6 + 23.45 + 6.5 = 186.5 m
literature
- Agnieszka Gryglewska: Architektura Wrocławia XIX-XX wieku w twórczości Richarda Plüddemanna. Oficyna Wydawnicza PWr, Wrocław 1999, ISBN 83-7085-386-2 , pp. 58–59, 63, 218–219
- Klaus Klöppel: Breslau - Lower Silesia and its millennial capital. Trescher Verlag, Berlin 2014, ISBN 978-3-89794-256-1 , p. 104
- Maciej Łagiewski : Mosty Wrocławia. ZNiO Wydawnictwo, Wrocław 1989, ISBN 83-04-02937-5 , pp. 25-27
- Magistrate of the royal capital and residence city of Breslau (ed.): The Kaiserbrücke in Breslau. , Breslau 1910 ( digital copy by DJVU, digital library of the University of Breslau)
- Günther Trauer : The Kaiserbrücke in Breslau. In: Deutsche Bauzeitung. XLV. Vintage. N ° 1 (dated January 4, 1911) pp. 6-8; N ° 2 (dated January 7, 1911) pp. 15-19; N ° 3 (dated January 11, 1911) pp. 26-32; N ° 6 (from January 21, 1911) p. 47–50 ( digital version of these numbers PDF 25.56 MB) and N ° 10 (from February 4, 1911) p. 82–88 ( digital version (PDF 35.3 MB) , each in btu, Brandenburg Technical University Cottbus)