The tunnels were constructed using earth pressure balance tunnel boring machines (TBMs) and pre-cast tunnel lining segments. The internal diameter of the tunnels is 5.75 metres. The project included traffic diversion and intersection signalization.

The work included secant pile headwalls at three stations, jet grouting headwalls at four stations, nine cross passages between tunnels, and an extensive instrumentation system to monitor for settlement. We used a jet grout system to densify the ground to keep existing utilities in operation during construction.

Kenaidan built the launch shaft for the TBM under a separate contract, which included the excavation of a 60-metre-long x 20-metre-wide x 17-metre-deep access shaft for the TBMs.