Boßler Tunnel: TBM commenced building the second Tunnel Tube

Käthchen, the tunnel boring machine (TBM), which the DB Projekt Stuttgart–Ulm GmbH is using to drive the Boßler Tunnel on the new Wendlingen–Ulm rail route, embarked on its second shield passage on April 18, 2017. The 11.39 m diameter cutting wheel began tackling the roughly 8800 m long west bore from the Aichelberg portal. In similar vein to the parallel running east tube, which was accomplished in November 2016, the 110 m long and 2480 t heavy tunnelling machine will install some 4400 tunnel rings comprising roughly 30 800 precast concrete segments. “Together with the contractor we had the ambitious aim of sending Kätchen on her second trip immediately after the Easter holidays”, commented Jörg Müller, DB project manager for the Albaufstieg contract section. “I have to thank all those involved for attaining this milestone”, Müller added. Planning foresees the TBM reaching the light of day at the other end of the tunnel above the Filstal Valley near Mühlhausen im Täle in autumn 2018.