A Grand Finale of Hong Kong’s Longest Road – TMCLKL Sub-sea Tunnels

04 August 2020

Some 7 years after the Dragages-Bouygues Joint Venture (DBJV) was awarded the Tuen Mun-Chek Lap Kok Link Sub-sea Tunnels section (TMCLK) Contract, this once in a lifetime project, has reached it’s final major milestone. With the collective effort of everyone involved in this project, all 26 Key Dates stated in the contract have now been achieved, with the Certificate of Completion issued in June 2020. All the project works are now substantially completed, and all site areas handed over to our Client to carry out electrical & mechanical installations.

The 7-year construction journey covers a 16.5-hectare reclamation for the North Landfall of the tunnels, the construction of a dual two-lane sub-sea tunnel of approximately 5 km long between Tuen Mun Area 40 and the Hong Kong-Zhuhai-Macao Bridge Hong Kong Boundary Crossing Facilities, and a 500-meter cut-and-cover approach tunnel for the South Landfall. To construct these deepest and longest sub-sea road tunnels in Hong Kong, Dragages-Bouygues team had to combat numerous technical challenges induced by a compressed air environment as the majority of construction work was undertaken below sea level, while managing strict environmental standards in terms of marine ecology, water quality, noise pollution and waste management. Thanks to the extensive experiences in Tunnel Boring Machine operations and compressed air works of Dragages-Bouygues, several technical firsts and in-house innovations were deployed in the project. For example, the world’s largest tunnel boring machine was driven in a freshly reclaimed land, incorporating some advanced TBM technology like MOBYDIC – a TBM cutter disc monitoring system, TELEMAC – a robotic arm for changing cutter discs, mini TBMs for constructing cross passages, and saturation diving to facilitate hyperbaric interventions for carrying out maintenance and changing cutter tools on the cutter head. Last but not least, Hong Kong’s first double TBM breakthrough happened within a 15-cell Caterpillar-shaped cofferdam.

The state-of-art technologies, high efficiency and safety standard exhibited in this complex project has earned Dragages-Bouygues the most prestigious prizes in the construction industry, including the International Tunnelling and Underground Space Association (ITA) Tunnelling Award (Award for Major Project of the Year (500 millions Euros)), New Civil Engineer (NCE), Tunnelling Awards (Innovation in Design & Delivery, Tunneling Team of the Year), and the HKIE Innovation Award 2020 (Category II – An Innovative Application of Engineering Theories).

“In the last 7 years, our Dragages-Bouygues team has delivered an extraordinary project – using innovative solutions to overcome complex engineering challenges, improving the safety and working conditions on site, and ensuring the highest quality product is delivered to the satisfaction of our client. The dedication of everyone involved in the project is beyond imagination and I would like to thank each and every one of them sincerely for their contribution.” said Wes JONES, Managing Director of Dragages Hong Kong.

The sub-sea tunnel is expected to open to the public at the end of this year. It will strengthen both the local and regional transportation network by serving as an alternative route to the airport, and will further enhance the cross-boundary network between Hong Kong, Macao, Shenzhen and Zhuhai.