The Cologne north-south city railway is currently one of the largest urban development projects in Germany and simultaneously counts as one of the largest archaeological excavation sites in a European metropolis. The track construction work in the new tunnel is mostly completed up to the area around the collapsed archives.
The intention of this measure is to close a gap in the track during the second phase of construction, which will serve as the link of the Cologne north-south city railway to the bank of the Rhine.
For the planned commissioning in December 2015, the eastern branch, which runs from the future Bonner Wall station to the Rhine bank, two curved track connections still have to be installed as a gap closure in the tunnel. Along the four curved points, approx. 60 m of Vignoles-tracks have to be embedded in concrete on the bi-block sleepers in the existing tunnel structure. The rails of the track system will be installed on a highly elastic bearing (HES) provided by the customer. The greatest challenge during this project is the precision of the point systems to be manufactured as a fixed carriageway and the placement of the concrete with a transport route of up to 500 m into the tunnel.
The concrete was transported using the existing mobile concrete mixer from HERING Bahnbau. To accomplish that, the drum was filled with a concrete pump on the ramp outside the tunnel and easily pulled over the track route to the installation site with the two-way excavator. The work was successfully concluded in July 2015.