The double shield TBM manufactured and operated by SELI for the Maeda/CRGL/SELI jv has been assembled and will be soon pushed into the launching chamber in order to produce more room and to allow the assembly of other back up gantries.The Tsuen Wan Drainage Tunnel (TWDT) will alleviate flood risk in Tsuen Wan district by intercepting excess channel flow in three stream valleys to the north of this area of Hong Kong new Territories.TWDT will require, among other structures, the construction of a 5.1 km-long, circular profile tunnel with a minimum operational internal diameter of 6.5 m lined with 300 mm thick prefabricated SRC segments.It will be excavated mainly in extremely strong and abrasive, fresh rocks, including crystal ash tuffs of the volcanic group, the Tai Po Granodiorite, and a variety of crosscutting dykes, including basalt, rhyolite, fine-grained granite, and quartz. The very high strength and abrasivity of these rocks, together with zones of blocky and closely-jointed rock, will present difficult cutting conditions for the TBM. Pre-excavation grouting will be required over much of the tunnel length to meet the specified groundwater control criteria. The TBM is equipped with a robust cutting-head to cope with the hard formations, and has probe drills to test rock and water ahead of the tunnel face. The head is equipped with 47 off 19 inch cutters and is powered by 8 off 315 KW motors. The TBM breakout torque is 6600 KNm. For more on the project click cn/19. 13/10.