By rosebell
Following passing its Factory Acceptance Test, the Herrenknecht mixshield TBM with 4.9m diameter, that is going to be deployed on the SuedLink grid expansion project in Germany, is ready for the project.
The grid expansion project is due to transport electricity over 700km from Brunsbüttel in Schleswig-Holstein, northern Germany, to Großgartach in Baden-Württemberg, southern Germany, whereas linking the wind power regions of northern Germany with the industrial locations of Bavaria and Baden-Württemberg in southern Germany is the aim of electricity highway.
A key section is the 5.2km tunnel under the Elbe River for transmission system operator TenneT. In order to constructing the tunnel from Wewelsfleth in Schleswig-Holstein to Wischhafen in Lower Saxony, the Arge Tunnel ElbX consortium, comprising Porr GmbH and Wayss & Freytag Ingenieurbau, will operate the TBM.
Six 525kV underground cables and the associated building, safety, control and monitoring technology as well as rails for the tunnel vehicles required for maintenance and repairs, will be the contents of this tunnel.
Considering existence of challenges geology of clay, peat, sand, and gravel as well as stones and boulders, the TBM was designed to face this conditions.
The mixshield is sealed against the water pressure 20m beneath the Elbe with a multiple sealing system and the TBM is slated to line the tunnel with prefabricated concrete segments to create an inner diameter of 4m.
According to Herrenknecht project manager Johannes Faißt: “The ElbX tunnel with its heterogeneous subsoil, high water permeability and the water pressure under the Elbe is a special challenge that spurs us and our technologies on.”
While the scheduled date for launching this machine is end of the current year, now it will be dismantled and transported to Schleswig-Holstein for reassembly.
