Fully opened to traffic on 27 December 2020, as an extension of the Hong Kong-Zhuhai-Macao Bridge (HZMB), the Tuen Mun – Chek Lap Kok Link (TM-CLKL) provides a strategic link connecting the Northwest New Territories (NWNT) with the Hong Kong Port (HKP) at HZMB, North Lantau and the Hong Kong International Airport (HKIA) – alleviating traffic congestion along North Lantau Highway and Tuen Mun Road, and reducing travel time between Tuen Mun and HKIA by about 20 minutes.

To a larger context, TM-CLKL will be an essential element of the key transportation infrastructures that greatly enhances transport connectivity both in Hong Kong and in the Greater Bay Area.

TM-CLKL comprises a dual two-lane road and a 6-mile-long (9.7-kilometer-long) highway that includes 3 miles (4.8 kilometers) of underwater tunnel connecting Tuen Mun and the reclaimed site of HKP. For its scale and complexity, TM-CLKL is Hong Kong’s deepest, longest and largest sub-sea road tunnel and the project has the largest contract sum for government public works contract ever awarded in Hong Kong.

It is a pioneering project with several firsts, including:

  • The simultaneous breakthrough of TWO enormous 14 meters diameter tunnel boring machines. This is one of its kind in the history of HK construction, and the first in the world
  • The world’s largest tunnel boring machine (TBM) of 57.74 feet (17.6 meters) in diameter
  • The longest (3.1 miles or 5 kilometers) and deepest (164 feet or 50 meters) underwater bored tunnel in Hong Kong
  • The first time that a micro-TBM tunnelling system has been used for excavation of the cross passages
  • The first time that a 15-cell Caterpillar Cofferdam has been used for large-scale excavation works

Apart from these innovations, throughout the project’s maintenance, a technique called “saturation mode” was also introduced. This technique allowed for longer working hours in the highly pressurized sub-sea excavation chamber, or up to six hours per day from about two hours normally. In order to do this, the workers’ living chambers were filled with a compressed mixture of oxygen, nitrogen and helium, to acclimate them to working conditions. A pressurized shuttle transferred the workers to the tunnel. This drastically reduced the frequency of air compression and decompression among workers, reducing the potential risk of decompression illness.

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 to the marine environment.

TM-CLKL has been recognized with numerous awards, including:

  • HKIE Innovation Award 2020 – Grand Prize (Cat II)
  • NCE Tunnelling Award 2019 – Tunnelling Team of the Year
  • ITA Tunnelling Award 2019 – Major Project of the Year (with a budget over €500M)
  • Hong Kong Awards for Environmental Excellence 2017 – Gold Award (Construction Industry)
  • 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 appointed by the Highways Department of the Hong Kong Special Administrative Region Government to provide investigation, detailed design, contract administration, site supervision and construction management services of this mega project.


You can visit here to learn more about the project.