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New Ebensfeld-Erfurt Line Silberberg Tunnel

The new Ebensfeld-Erfurt line (NBS) is an element of the transport project German Unity Rail No. 8 upgraded/new line from Nuremberg to Berlin. It represents the link between the upgraded Nuremberg-Coburg and Bebra- Erfurt routes running on to the new Erfurt-Leipzig/Hal le line. The 7,391 m long Silberberg Tunnel extends from construction km 57.0 + 05 to 64.3 + 96 and affects the communities of Altenfeld, Gehren, Gillersdorf. Großbreitenbach and Möhrenbach. The excavated cross-section of the twin-t rack tunnel varies between 130 and 180 m² with an effective cross-section of 92 m². Tunnelling start s with driving the intermediate point of attack headings near Möhrenbach and Altenfeld - 352 and 760 m long respectively, from the ends of which the actual main excavation takes place. The intermediate points of attack later serve as emergency exits. The rescue concept foresees a total of eight emergency exits set at a maximum of 1,000 m apart, which lead to the outside for example via drivable parallel tunnels (total length 3.213 m), a 22 m deep shaft and a 70 m long accessible tunnel. For operat ional reasons during the construction phase an optional temporary ventilation shaft is produced that is 80 m deep. The drives, which are located in clay-slit slates, quartzites and greywackes as well as sandstones and vulcanites, are mainly tackled by drill+blast but partly by excavator with divided face. Depending on the excavation class the supporting agents normally used in conventional tunnelling such as SN, Swellex, self-drilling and face anchors as well as lances, support arches and reinforced shotcrete of varying thickness are applied. In addition a crown floor vault and/ or a face wedge is foreseen for certain sections. Undercutting industrial plants and residential areas as well as special protective measures for the environment and waterways places high demands on the driving operations. The inner shell, which is between 35 and 95 cm thick, is produced from in situ concrete and executed with an umbrella seal or an all-round seal that resists water pressure - depending on the requirements of the project. The route is to be provided with a slab track so that it will be capable of coping with speeds of up to 300 km/h.


  • Country: Germany
  • Region: Thuringia, Großbreitenbach/Ilm District
  • Tunnel utilization: Traffic
  • Type of utilization: Twin-Track Railway Tunnel with ICE Traffic
  • Client: DB Netz AG, RB Südost
  • Test engineer: Prof. Duddeck und Partner GmbH
  • Contractor: Bilfinger Berger AG, Wayss & Freytag Ingenieurbau AG, Max Bögl Bauunternehmung GmbH & Co. KG, Bickhardt Bau AG
  • Main construction method: Trenchless
  • Type of excavation: Drill-and-blast
  • Lining: Concrete formwork
  • No. of tubes: 1
  • Tunnel total length: 7,391 m; 4,395 m (various tunnels), 22 m/80 m (shafts)
  • Cross-section: 130 to 180 m²
  • Construction start/end: 2009 till 2012