Canal bridge Eberswalde
Coordinates: 52 ° 51 ′ 11 ″ N , 13 ° 48 ′ 16 ″ E
| Eberswalde bridge canal | ||
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 Photo by Hermann Rückwardt |
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| Convicted | Oder-Havel Canal | |
| Subjugated | Berlin-Szczecin Railway | |
| place | Eberswalde | |
| building-costs | 248,000 marks | |
| completion | 1912 | |
| closure | 2007 (demolition) | |
| location | ||
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The canal bridge Eberswalde , structurally correct bridge canal Eberswalde , was a hydraulic structure of the Oder-Havel canal , in which the canal was led by means of a trough bridge over the double-track railway line of the Berlin-Szczecin Railway . The successor structure has been a railway tunnel under the canal since 2008.
planning
The Berlin-Szczecin Railway also had to be crossed during the construction of the Berlin-Stettin large shipping route , later referred to as the Oder-Havel Canal. The plan provided for a place about two kilometers north of Eberswalde. However, since the difference in height between the upper edge of the rail and the water level was insufficient, further line variants were examined. On the one hand, the canal could have been swiveled to the south, which, however, would have required a very long and high dam. On the other hand, a relocation of about four kilometers to the north would have been possible in order to be able to lead the railway over the canal. Both variants were not pursued because of the expected extremely high construction costs and instead the railway was lowered.
Before construction began, the upper edge of the rail of the railway rising to the north was 30.43 meters above sea level (NN). Since the water level of the apex position is 37.10 meters above sea level, there was only a height difference of 6.67 meters. However, a height of at least 8.42 meters was required for the overpass structure. This height resulted from the required clearance height of the railway of 4.90 meters, the water depth of 2.70 meters, the construction height of the trough floor of 0.70 meters and the seal of 0.12 meters. As a result, the runway had to be lowered by 1.75 meters. The traffic on the railway was operated on two tracks before construction began, but a steady increase in traffic was expected and a later four-track expansion of the railway line was to take place. A subsequent expansion of the bridge structure was considered almost impossible due to the expected high costs and problems. The structure was already planned as a four-track underpass.
Construction work
The tracks were led through two openings, each with a clearance of 7.90 meters, separated by a 1.20 meter thick central pillar. In order to achieve a high level of stability, the foundations of the abutments and the central pillar were heavily widened and provided with iron inserts. The entire structure was made of rammed concrete. In order to prevent the formation of cracks as a result of the different setting of the structure, approximately 2 centimeters thick asphalt-filled expansion joints were installed. The structure of the bridge trough was made up of 38 continuous, riveted steel girders. They were connected by riveted flat irons running across and stamped with concrete to stiffen them in the gaps. The girders had different heights depending on the location and load in the structure. The height varied between 570 millimeters and 850 millimeters. In the towpath walls, the girders together with the steel insert and the concrete body formed a reinforced concrete girder on three supports. To prevent them from being torn off, the towpath walls were connected to the trough floor by strong shear bars.
To seal against seepage, the building was designed with 1.5 millimeter thick lead plates on the water side. The lead plates were soldered at the edges and protected against destruction by several layers of bitumen and roofing felt. In the towpath walls, the lead seal was protected against external attacks by a 0.75 meter thick attachment wall. The trough floor was still covered with 8 centimeter thick wooden planks. At the expansion joints, the lead plates were bent over like a bead and stuffed with asphalt fiber putty to prevent them from being compressed. At the connection to the canal support , the structure was surrounded by a clay pack that reached down about 4 meters and into which the lead seal reached 1.20 meters. The parapet walls were made of red hard-burning bricks, the towpath was covered on the top with small plaster. For better guidance of the ships, friction wood was attached to the towpath walls. The width of the fairway was 27 meters.
For the construction work, the terrain cut was first extended to four tracks and deepened on the side of the third and fourth track. Now a working track has been connected to the Britz station and the Stettin - Berlin track has been moved from track two to track four. The central pillar was then concreted up to the level of the support. After that, the Berlin - Stettin line could be moved from track one to track three and the eastern abutment built. Parallel to this work, a makeshift wooden abutment was built to the west of the tracks. Then the delivered, one-piece girders were placed and half of the eastern half of the bridge trough and the towpath walls were concreted after the required formwork had been attached.
After relocating the tracks, the western abutment was built and then the entire structure was completed by 1912. After the canal was filled, there was a leak in the structure at one point, producing 23 drops per minute. The structure was not drained. Attempts were made to repair the damage by silting up clay. The success came almost immediately. The drops decreased and finally stopped completely. The finely divided clay had followed the threads of water and sealed the spot. Rumor has it that the bridge was sealed with pork bellies, bear fat or whale blubber; this was never planned or carried out.
The total construction costs amounted to 355,000 marks, of which 248,000 marks went to the actual bridge construction. Building materials were brought in from Bralitz (gravel), Kratzwiek (cement) and Lauchhammer (steel girders). The 95-year history of the canal bridge ended with its demolition in 2007 as part of the enlargement of the canal. Before that, the canal was laid in an arch about 250 meters to the north ( new route ) and provided with a tunnel structure for the railway.
literature
- The bridge canal of the large shipping route Berlin-Szczecin over the Berlin-Szczecin Railway. In: Zentralblatt der Bauverwaltung , Volume 32, 1912, No. 67, p. 429ff.
- Connection of clay seal with masonry or other seals. In: Zentralblatt der Bauverwaltung , 40th year 1920, No. 32, p. 200.
Footnotes
- ^ Report from WSA Eberswalde on the rumor of bacon on the occasion of the demolition work
- ↑ Federal Waterways and Shipping Directorate: 100 Years of the Havel-Oder-Wasserstraße , 2014, page 64: Canal Bridge Eberswalde
