The Reppisch Valley and the Sihl Valley in Switzerland were linked together for the first time when the pilot tunnel on the Uetliberg tunnel project broke through on 20 February 2003. The 5m diameter Wirth TBM started excavating the 2.7km long molasse section on the “Basel” tube in May 2002. It achieved an average daily rate of 26.6m, with a recorded best of 42.6m. The tunnel will now be widened to 14.2m high and 14.4m wide, with a cross section of 160m2 using a Wirth reamer. The pilot tunnel TBM will now excavate the parallel “Chur” pilot tube. The total length of the Uetliberg tunnel is 4.4km, with the soft ground section already completed. See T&TI, November 2002, pages 24-27 for project details.
