1 Herrenknecht, 1 Lovat for Istanbul LRT and MetroThe Otogar-Bagcilar LRT system project in Istanbul consists of three double-tube tunnels. The first double-tube tunnel will be constructed from Otogar to Bagcilar, approx. 3,200 m for the LRT, then a second one from Bagcilar to Yildiztepe shaft (1,600 m) and the third one as a short tunnel from Bagcilar towards Ikitelli direction (85 m), where these two double-tube tunnels will serve to the future Yenikapi-Ikitelli metro project. The total length of these three double-tube tunnels will be 2 x 4,885 m.Two EPB TBMs, one Herrenknecht and one Lovat RME257SE, will each bore one of the double-tube tunnels, namely 4,885 m. The Gülermak-Dogus JV signed a contract with Lovat at the 2005 World Tunnel Congress and 31st ITA General Assembly held in Istanbul last month. The outer diameter of the tunnel is 6,300 mm, its inner diameter is 5,700 mm. The Herrenknecht machine is new. The Lovat machine was used before on the Molino Dorino-Rho Fiera section on Red Line 1 of the Milano metro. The cutterhead diameter is 6,490 mm for the Herrenknecht TBM and 6,570 mm for the Lovat. The total installed power is 963 KV for the Herrenknecht machine and 1,692 KV for the Lovat, the thrust force is 32 kN for the Herrenknecht, 54 kN for the Lovat. The Herrenknecht machine will be equipped with one main cutter, 96 scrapers and 40 scraper bucket. The Lovat cutting wheel will bear one main cutter, 68 scrapers and 42 block ripper teeth. The mucking-out system consists of locomotive and muck cars. The geology is soft ground predominantly consisting of clay, silt and sand. Under the supervision of Lovat, the RME257SE TBM will be refurbished and ready to bore by 13th September, 2005. The Herrenknecht in late October. Site mobilisation and preliminary design works are under progress.The project includes one surface and three underground stations. They are approximately 100 m in length and 25 m, 35 m and 45 m deep. Underground stations will be constructed by the cut-and-cover method. Bagcilar station will be constructed as a two-basement station, with one station serving for the Otogar-Bagcilar LRT and the other for the future Yenikapi-Ikitelli metro project. Yenikapi is the main crossing point for all the Istanbul LRT and metro network. Visit www.herrenknecht.com, www.lovat.com and www.gulermak.com.tr 24/05.