For driving the Eurasia tunnel beneath the Bosphorus, Turkish-South Korean construction consortium Yapı Merkezi Insaat ve Sanayi AS/SK Engineering & Construction ordered a specially developed 13.6 m-diameter Herrenknecht TBM Mixshield. Named Yildirim Bayezid after the sultan who drove the expansion of the Ottoman Empire in the 14th Century, the TBM is on its way to Turkey to begin excavation of 3.34 km of the 5.4 km tunnel from a launch shaft in Istanbul on the Asian side at end-2013. Extensive geological and hydrogeological preliminary investigations showed water pressures of up to 12 bar. The inner diameter of the tunnel will be 12 m, housing two traffic lanes in each direction on two levels.

This new link between Europe and Asia will initially be operated for 26 years by the JV ATAS, and subsequently handed over to the government of Istanbul. Click tr/30 for tunnelbuilder archive. Visit www.avrasyatuneli.com/en/. 35/13.