A project in support of the Hong Kong- Zhuhai – Macao Bridge (HZMB), the Tuen Mun – Chek Lap Kok Link (TM-CLKL) will provide a strategic link connecting the Northwest New Territories (NWNT) with the Hong Kong Boundary Crossing Facilities (HKBCF) at HZMB, North Lantau and the Hong Kong International Airport (HKIA). This 9.7 km long dual two-lane highway is composed of 3.5 km of viaducts over land and sea, a 4.8 km underwater tunnel deep under the seabed at a water head of above five bars, and a toll plaza 5.4 hectares in size.

TM-CLKL is a pioneering sub-sea tunnel boring machine (TBM) project with several innovations including the world’s largest (17.6 m in width), longest (5 km in length) and deepest (over five bars water head) TBM sub-sea tunnel. This also marks the first time a mini-TBM for cross passage construction is used in Hong Kong.

As the first also the longest and deepest sub-sea tunnel in Hong Kong upon completion, the keystones of the project are the deep sea TBMs which are operated under a pressurized environment. A saturation operation, inspired by diving, was deployed to minimize decompression sickness.

A strong environmental focus was placed on the project including the relocation of over 280 endangered pitcher plants. Even the tunneling method of using TBM was chosen in part due to lower environmental impact. The design of the marine viaducts emulates seagulls in order to harmonize better with nature, and it will be the longest segmented bridge in Hong Kong upon completion.


  • Hong Kong Awards for Environmental Excellence – Gold Award (Construction Industry) (May 2017)
  • Construction Industry Safety Award Scheme 2016/2017
    • Gold Prize in Civil Engineering Sites Category
    • Outstanding Performance in Working at Height Safety Prize
    • Meritorious Prize in the Safety Team Category
  • Best Safety Enhancement Program for Working at Height-Gold Award (Jul 2016)
  • Best Presentation Sliver Award at Construction Safety Forum and Award Presentation 2016

AECOM was awarded investigation, detailed design, contract administration, site supervision and construction management services of this HK$46 billion project, which will be completed in 2020.