As Hong Kong’s deepest, longest and largest sub-sea road tunnel, this project has the largest contract sum ever awarded in Hong Kong, a reflection of the project’s scale and complexity.
This dual two-lane sub-sea tunnel will run between the western New Territories and Lantau Island. The world’s largest Tunnel Boring Machine (TBM) of 17.6 metres in diameter and two identical mix-shield TBMs of 14 metres in diameter are used to construct the road tunnels. These state-of-the-art machineries are equipped with in-house innovations – namely MOBYDIC, SNAKE and TELEMACH – which enable real-time geological mapping of rock faces, and robotic detection of damaged components on the cutter head to reduce manual inspections under hyperbaric conditions.
Working under a compressed-air environment is the key challenge of this project. The project team has proposed to use a saturation technique for maintenance works on the TBMs’ cutter heads, which will maximise the health and safety of workers, while also enhancing work efficiency.
Sustainable measures are in place during and after construction, such as recycling excavated materials from the north reclamation as backfilling of the launch shaft or returning it as public fill. The two ventilation buildings will attain a Hong Kong BEAM Plus Gold rating upon completion. Wind turbines will also be built in both buildings for renewable power generation.