Underground Singapore 2011
Cutterhead of Single Shield TBM
Ventilation was also designed with care, in order to ensure the methane/air mix would remain below the explosion point: this was achieved with powerful blowers (52 m3/s) and housing part of the electrical circuits in an ATEX enclosure. As it was planned to dismantle the machines inside the tunnel, they were designed with a sacrificial skin allowing this operation without the need for a cavern
Disassembly of Shield with Sacrificial Skin
The main characteristics of the two TBMs are as follows: Table 2 – Single Shield TBM Data Type of Tunnelling Excavation Diameter Length of TBM + Back Up Number of 17” disc cutters Total power Drive unit power Nominal / Unlocking Thrust Nominal / Unlock Torque Variable speed Shield weight Total weight
110
Single Shield TBM Ø9.9 m extendable up to 10,1 290 m with California switch 69 (+2) 8 000 kVA 5 000 kW 130 000 kN / 180 000 kN 25 000 kN.m / 30 000 kN.m 0 to 5 rpm 1 150 Tonnes 1 850 Tonnes