Turkish contractor í–ztas has signed a contract for the supply of a refurbished Lovat RME136SE series 19500 earth pressure balance TBM that will be employed in the construction of the Gürpinar and Firuzkoy tunnels in Istanbul. The TBM will undergo a complete refurbishment at Lovat's facilities in Toronto. The 3.5 m-diameter mixed face TBM will first bore the 5,227 m-long Gürpinar tunnelpredominantely located in Gürpinar formation, mainly anticipated to consist of hard to stiff over-consolidated plastic clay with some weak sandstone, siltstone, claystone and tuff. A small portion of the tunnel alignment will be in a formless landslide complex consisting of water saturated sand layers. A faulted zone is likely to be encountered, in which greater water inflow is expected. The entire alignment is below the groundwater level, with a maximum groundwater height above the tunnel invert of 60 metres.The TBM will then bore the 3,770 m-long Tahtakale-Ambarh wastewater tunnel in Firuzkoy through three distinctive formations: the Kusdili formation, consisting of very soft to firm sandy silty clay, the Ceylan formation, consisting of limestone with marl fragments and clay layers, and also through the Gürpinar formation as described above. Groundwater levels will vary from one to 48 metres below the surface, with the entire alignment below the groundwater level. The TBM is scheduled to be delivered to Istanbul prior to year's end. Visit www.lovat.com and www.oztas.com.tr 23-24/07.