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New Schlüchtern Tunnel

The “New Schlüchtern Tunnel” project (NST) relates to the building of a second tunnel tube for the Schlüchtern Tunnel, which started operation back in 1914. The NST is located on the railway line between Frankfurt am Main and Fulda, which is the most important link for all trains travelling to Frankfurt from the north and east. The construction project comprises the tunnel roughwork including the in each case almost 1,000 m long portal zones, the engineering structures and the superstructure for a temporary twin-track operation in the new tunnel tube. The tunnel underpasses the Distelrasen mountain ridge over a distance of 3,995 m with overburden of up to 70 m. The route lies between the towns of Schlüchtern and Flieden and runs practically parallel to the “Old Schlüchtern Tunnel" (AST). Three rescue passages are to be created at 1,000 m gaps between the NST structure and the existing Old Schlüchtern Tunnel, which is currently operational but is later scheduled to be renovated. The tender and the award for the production of the main tunnel called for the application of a tunnelling machine (TBM) and a monocoque segmental lining resistant to pressurised water. The tunnel penetrates upper and middle coloured sandstone as well as tertiary formations. Underground water is to be anticipated in part-sections of the tunnel route. The TBM that is used is capable of operating in open or EPB mode. The tunnel is lined with 2 m long and 45 cm thick reinforced concrete segments with conventional reinforcement. Eight segments including a large keystone form a segmental ring. The annular gap is filled with mortar. Each segment is equipped with compression sealing frames, which seal the tunnel. The lower part of the subsequent superstructure is to be installed during the drive using precast elements. The 3 cross-passages, which are driven from the main tunnel in the direction of the existing one, are produced time-delayed to follow the main tunnel excavation. The cross-passages are driven by conventional means using shotcrete and an inner shell. Directly after the completion of the driving operations the asphalt bearing layer and the “slab track” are installed. After completing the NST train services will temporarily run through the new tunnel on two tracks and the Old Schlüchtern Tunnel will be completely renovated. During the course of this work 4 further cross-passages are to be produced so that there will then be a 500 m gap between crosspassages prior to the two Schlüchtern tunnels starting to operate as single-track tunnels as from 2013.


  • Country: Germany
  • Region: Hesse
  • Tunnel utilization: Traffic
  • Type of utilization: Railway Tunnel
  • Client: DB Netz AG
  • Consulting Engineer: DEC, Frankfurt a. M./PSP, Munich/Tunnel Consult Ettlingen
  • Construction monitoring: Schüßler Plan/ILF
  • Tunnel technical Expert: Prof. Duddeck & Partner
  • Contractor: Hochtief Construction AG, Ed. Züblin AG, Bickhardt Bau AG
  • Main construction method: Trenchless
  • Type of excavation: Shield machine(SM)
  • Lining: Reinforced concrete segments
  • No. of tubes: 1
  • Tunnel total length: 3,942 m
  • Cross-section: 10.24 m (bored diameter)
  • Contract Volume: approx.. 64 mill. Euro
  • Construction start/end: 2005 till 2009