Following the breakthrough of its 8.6m diameter Herrenknecht TBM in April, the WSKE –Wientalsammler project is claiming a world record for a large shield drive having clocked up the impressive advance of 36m in one day.
Site manager Arthur Gobl told T&TI that this advance was obtained whilst the shield was closed and operating in EPB mode. He said that it rightfully deserved the title of fastest shield drive greater than 7m diameter working in closed mode.
The contractor JV of Porr Tunnelbau and Bilfinger Berger drove the machine 2.6km through clay and sand. Rings of five pre-cast segments plus a key, designed by D2-Consult, were used to line the tunnel that will be used as a tank sewer for wastewater.
Gobl said the city of Vienna was the client in the form of MA 30 Wienkanal and was also funding the US$69M project through the agency EbS – Entsorgungsbetriebe Simmering. Of this, the tunnel component accounts for US$44M.
Tender award was in December 2003, with construction starting soon after in May last year. The machine was launched in Spetember 2004 from a 22m diameter shaft. Gobl described how this meant the TBM was installed in stages to suit the available space, with each significant advance of the machine giving space in the shaft for the next installation.
With the tunnel works now complete, the project is expected to run until April 2006, by which time Gobl told T&TI they aim “to make the river Wienflub the cleanest city river in Europe”.
