KHI Receives Order for Four Slurry TBMs for Circle Line Section in Singapore - sg/15Kawasaki Heavy Industries (KHI) has won an order from Taisei for four slurry-type shield TBMs for delivery between April and June 2005. The TBMs will be used to excavate running tunnels as part of contract 854 to build a section of Stage 4 of the Circle Line covering 6.3 km of twin bored tunnels, 320 m of cut-and-cover tunnels, 13 cross passages, the Adam and Farrer underground stations, provisions for the future Bukit Brown and Thomson Road stations, and commuter facilities. The internal diameter of the twin tunnels is 5.8 m. The tunnels lie entirely within the Bukit Timah granite formation, which consists of residual soils composed of sandy silts to silty clays, highly fractured and fresh granite rock. All tunnel horizon, all kind of ground conditions such as soft ground, mixed face conditions to fresh granite are expected.The TBMs will be equipped with a 6.72 m-diameter cutterhead holding 39 disc roller cutters plus 4 centre cutters. Each machine weighs 395 tons for a length of 10.1 m (115.6 m including the back-up system). The main drive power is 1,500 kW (6 x 250 kW) with a AC 6.6 kV, 3-phase, 50 Hz power supply. The maximum rotation speed of the cutterhead is 4.5 rpm and the maximum thrust force is 56,000 kN (20 shield jacks). Bolted and steel bar reinforced precast concrete segments (grade 60), 1.4 m wide and 275 mm thick, will be erected for lining (5 segments plus one key). The slurry transportation system will be supplied by Aktio Corporation and Toyo Industry from Japan. The slurry treatment plant will be supplied by Kankyo Engineering Corporation. Segments will be supplied to the TBM using railbound cars pulled by battery operated locos. Excavation will start at the end of May 2005 for completion in September 2006. Visit www.lta.gov.sg, www.taisei.co.jp/english and www.khi.co.jp/products/plant/index.html 49/04.