The tunnel boring machine  »Tuborine« reached the target shaft on December 14, 2011. The Herrenknecht Mixshield drove the 2,253 meter long tunnel of the new Wehrhahn Line in the North Rhine-Westphalian state capital of Düsseldorf.

Düsseldorf / Schwanau, Germany, December 15, 2011.  The state capital Düsseldorf, represented by the Department of Economy, Transport and Traffic, invested in the new Wehrhahn Line and the expansion of eco-friendly public transport.  The new 3.4km-long underground metro line will run from Wehrhahn to Bilk station in downtown Düsseldorf. Mechanized tunnelling works at the Wehrhahn Line jobsite have been successfully completed on December 14, 2011.

Tunnellers of Bilfinger Berger Ingenieurbau GmbH ordered a Mixshield with a shield diameter of 9,490mm from Herrenknecht for the construction of the Wehrhahn Line, which was accepted at the plant in Schwanau in September 2009. After the start of the tunnelling works in March 2010, the tunnel crew could successfully complete tunnelling along the first 1,298m-long section – the »southern branch«, on September 20, 2010 at 11.11am. They reached their target »Kasernenstraße« one entire month ahead of schedule. After disassembly the Mixshield  was transported to »Corneliusplatz« to start driving the second section of the »eastern branch«.

Systems provided by the navigation and guidance system experts VMT and the Herrenknecht separation plant, set up in Bilk by »Elisabethstraße« ensured smooth jobsite operations. Despite the high abrasivity of the ground, the separation plant could reach high plant availability levels in the mostly gravelly and sandy soils. Concrete segments were produced using moulds manufactured by Herrenknecht Formwork. Maschinen- und Stahlbau Dresden (MSD) delivered the segment crane and handling equipment. More than 12,000 of the 6.5t segments have been produced  and installed by the TBM in the tunnel tube.

The TBM with a total weight of 1,302 tonnes reached the target shaft  at a depth of 17 meters on December 14, 2011 after completion of the second 955m-long tunnel section between »Corneliusplatz« and »Wehrhahn«. Mayor, Dirk Elbers and the godmother of the tunnel, Astrid Elbers, as well as numerous interested citizens welcomed the TBM and tunnel crew.

The Mixshield  excavation method  proved itself with top weekly performances of up to 75 meters during the tunnelling works beneath downtown Düsseldorf and an overburden of partly only 4 meters. 170,000 cubic meters of excavated soil were removed above ground. The new Wehrhahn Line is scheduled for completion in 2015. After being opened to traffic, more than 51,000 passengers per day are expected to drive through the tunnel reaching their destinations faster and with a more eco-friendly means of transport.