During its construction, more than 1 million cubic metres of rock and other solid materials were excavated from the tunnels using two 12.4m diameter tunnel boring machines (TBM’s). All spoil removed from the tunnel was transferred from the western worksite to the Mt Cootha Quarry via a specially designed 560 metre underground spoil conveyor.
The spoil was deposited in an unused area of the quarry, 24 hours a day, seven days a week, in line with tunnel boring machine operations. Due to the critical nature of the TBM operation it was imperative for the client to engage a proven and reliable contractor who could ensure that spreading and levelling of the spoil at the delivery end occurred without delay or disruption to minimise any impact on the TBM’s progress.
The decision was therefore easy for Transcity JV to engage AE Group to manage the earthwork operations due to our proven ability to implement innovative construction methodologies, our extensive fleet of modern and reliable plant and equipment combined with our experience in working in restricted footprints. Our dynamic approach to plant maintenance ensured almost 100% availability of our fleet keeping them operating at maximum capacity to support our clients’ needs thereby mitigating any issues that would halt the production of the TBM’s up-line.
Almost 2.2 million tonnes of material was moved without incident due to the high standards of safety awareness and attention to task management instilled in our team.
“AE Group has provided us with the resources we needed to enable the world record production that our tunnel boring machines have achieved. Both Transcity JV Management and I are delighted with the outcome, including an international Joint Venture executive who commented ‘this was the best spoil placement I have seen world-wide’
David Lansdell, Western Portal Area Manager
