By rosebell
In order to implementing the renewal of the 426m-long tunnel for Deutsche Bahn, a consortium of Porr, Feldhaus Bergbau and Heinz Schnorpfeil Bau, used a Herrenknecht Tunnel Enlargement System (TES) , so enlargement of the 160-year-old Fachingen tunnel in Germany has been completed on November 21 after that the tunneling system, named Nora, broke through the crucial wall of the tunnel.
While the consortium is also enlarging the 732m-long Cramberg Tunnel, the cross-sections of the two double-track tunnels of the Lahn Valley Railway are being enlarged by 2m.
Considering that dismantling tthe existing tracks is the first step and then a track is laid in the middle of the existing tube, the TES makes it possible to carry out tunnel renewal during ongoing rail operation. Due to that the TES serves as a protective enclosure and separates the construction work from rail traffic, rail traffic continues to run on the track throughout the construction period.
The mixed geology of clay, slate and keratophyre required blasting to loosen some material. This fell to the side of the TES and was removed by conveyor devices.
Following the break through, TES Nora was removed from the tunnel and concrete was applied to the tunnel interior.
Alongside that the narrow construction site and the ongoing rail operations created special challenges for the tunneling team, the team had to ensure there was no contamination to the catchment area of the Fachinger spring.
