• The largest, longest, and deepest sub-sea road tunnels in Hong Kong

  • Awards received at the Construction Industry Safety Award Scheme 2016/2017 Award Presentation Ceremony: Civil Engineering Sites Category Gold Award, Outstanding Performance in Work-at-height Safety Prize and Safety Teams Category Merit Award

  • Hong Kong’s deepest, largest, and longest sub-sea road tunnels.

  • Entrance of the sub-sea tunnel

  • Cross passages excavated using a pipe jacking technique

  • 48 cross passages excavated using mini TMBs in less than 24 months – a FIRST in Hong Kong’s tunnelling projects

  • The world’s largest TBM – 17.6m in diameter

  • Northern Landfall – Aerial view of reclamation area – August 2017

  • Unique caterpillar-shaped launching shaft was formed using a diaphragm wall, eliminating the use of strutting which maximized both cost and operational efficiencies

  • TBM tunnel breakthrough under water in November 2015

  • World’s largest scale changeover of TBM cutter head from 17.63m to 14m

  • Internal view of Northbound Tunnel – September 2017

  • Northbound Tunnel – Installation of precast panel for overhead ventilation duct – August 2017

  • Southbound Tunnel – Installation of precast panel for overhead ventilation duct – January 2017

  • Internal view of southbound tunnel – November 2016


Tuen Mun-Chek Lap Kok Link – Northern Connection Sub-sea Tunnel Section


View Project Website


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.

Client Highways Department, Hong Kong Government
Project Design and construction of a dual two-lane sub-sea tunnel of about 5km and reclamation of about 16.5 hectares of land
World’s largest TBM 17.6m in diameter
HK’s deepest sub-sea road tunnels 50m below sea level
HK’s longest sub-sea road tunnels Approximately 5km long x 2 tubes
HK’s greatest no. of cross passages for road tunnels 52
Year 2013
Video Tuen Mun-Chek Lap Kok Link