New A45 bridge is shifted sideways: 40,000 tons drive on grease
Over these two days, approximately 40,000 tons of steel and concrete will move exactly 20.59 meters southwest into their final position. A project that stands out even within the large-scale replacement construction program for the Sauerland Line.
Preparations have been in full swing for weeks. To ensure the massive structure could be moved at all, the six piers were raised by approximately two centimeters . Teflon plates coated with special grease are placed between the foundation and the pier heads. This allows the entire bridge half to glide almost frictionlessly along a sliding track – centimeter by centimeter, for approximately 20 to 30 hours.
The transverse launching is taking place while traffic is moving . While the southern superstructure has been completed for some time and is supporting traffic, the northern section of the bridge, constructed parallel to the bridge, is now being pushed into its final position. This is a technical milestone for those responsible. "The transverse launching, including the piers, is an innovative process that is unique on this scale in Germany," says Elfriede Sauerwein-Braksiek, Director of the Autobahn branch in Westphalia. Safety is the top priority: "We have specifically identified risks and comprehensively safeguarded them in all project phases."
According to Autobahn GmbH, the bridge shifting brings several tangible advantages:
- Time savings during construction: auxiliary pillars or additional scaffolding are no longer required – this speeds up the entire construction process.
- Safety during assembly: Because the moving takes place close to the ground, dangerous work at great heights is avoided.
- Less noise and dirt: There is no need to build or later demolish complex additional structures.
- Material savings: Around 13,000 cubic meters of concrete and 730 tons of steel can be saved – a contribution to greater sustainability on the construction site.
However, no one on site will be able to observe the maneuver. The entire construction site will be closed for the duration of the shifting. The bike path between the Wilnsdorf industrial area and the Rinsdorf district will also be closed on June 3 and 4. A complete no-stopping ban will be in effect along the L907, which runs under the bridge, on both days.
The Rinsdorf Valley Bridge was built in 1967 and was ultimately beyond repair. Construction of the replacement bridge began in September 2017, with the southern section of the bridge initially being erected on site. The demolition of the existing structure followed in February 2022—an event that also attracted national attention, as a bridge demolition at this height was unprecedented.
The northern superstructure, which was now to be moved, was constructed parallel to the piers, sideways. The incremental launching method was used: Prefabricated steel components were welded together in the incremental launching cellar and gradually pushed onto the piers using a launching device. Due to the great construction height, wind forces and vibrations had to be calculated in detail and absorbed by temporary stabilization.
The bridge is located between the Siegen-Süd and Wilnsdorf interchanges and spans the Rinsdorf Valley at a height of up to 71.9 meters. The structure measures 485.5 meters in total. In the immediate vicinity, the shorter Rälsbach Valley Bridge is being replaced in parallel. The goal is to minimize disruption to road users by consolidating the construction phases.
Exactly when both halves of the bridge will be fully opened to traffic has not yet been determined. What is clear, however, is that with the transverse launch, the project is now entering its decisive phase – and at the same time, it sets an impressive example of engineering precision in German bridge construction.
auto-motor-und-sport
