Maintenance During the tunnelling process the Mechanical Division were involved with repairing and maintaining the running gear and seals while the machine was in motion. When the TBM got to the end of the first tunnel it was turned around before the second drive. At the turnaround, the TBM needed to be received from the tunnel onto a purpose-built cradle fabricated by the Mechanical Division, lowered 6 m, moved sideways by 12 m and turned 180 degrees. To do this, the TBM and back-up gantries had to be pulled apart. The biggest section turned in one piece was 2,500 tonne. The Mechanical Division have gained unique TBM experience for the turning of Alice the 10th largest TBM in the world and largest to have operated in New Zealand. The Mechanical Division performed the permanent works for four cross passages between the two tunnels, supplied and installed all form work and poured the concrete. The cross passages provide a safe exit point if an incident occurred. Alice the TBM was assembled in the Southern Approach Trench (SAT) and commenced boring in late October 2013. All 127 pieces were transported to site over a seven day period. The assembly and commissioning of the TBM took only three months, with three teams of 8 to 10 people working 24/7. A 65 tonne crane with a super heavy counterweight and a 550 tonne assist crane were used to assembled the TBM in the SAT. Assembling the TBM involved steel structures and the “Cans” Cutter Head, as illustrated below. Assembly SH1/16 Waterview Connection (continued)
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