City Rail Link – C6

Automated track and groundwater monitoring ensuring safe micro-TBM stormwater tunnelling beneath live KiwiRail lines.

About CRL Contract C6

The City Rail Link (CRL) consists of twin 3.4 kilometre long tunnels up to 42 metres below the city streets to create an underground rail line linking Britomart and the city centre with the existing western line near Mt Eden and is key to delivering the Auckland Plan, the City Centre Master Plan, the Long Term Plan and the Integrated Transport Programme.
The Contract C6 involves stormwater diversion works in Mt. Eden for the construction of a new underground stormwater tunnel between Water and Nikau Streets, which replaces an existing pipe that would be in the way of the CRL tunnels.

What we’ve delivered

Sixense has been selected to install and monitor groundwater and structure deformation sensors during micro TBM works for the construction of the new stormwater tunnel.
Deformation monitoring included deploying Sixense’s patented Cyclops system to monitor KiwiRail railway tracks in real-time, which included calculation of track parameters, such as gradient, cant, twist, vert and horz. Groundwater monitoring was conducted wirelessly using a proprietary site-wide radio datalogging system.
Geoscope was used to display data and generate reports, where any sensor reading exceeding set thresholds will automatically generate alarms that are distributed to all stakeholders.