Location

Hong Kong

Client

Highways Department, HKSAR Government

Contract Value

HK$1,000 million

Construction Period

2003 Q2 - 2008 Q2

The Highways Department of the HKSAR Government has awarded Gammon, in conjunction with Skanska International, the contract for the construction of Nam Wan Tunnel and West Tsing Yi Viaduct.

Valued at HK$1 billion, the contract covered a 1.4-kilometre viaduct in West Tsing Yi linking to the existing Cheung Tsing Highway and a 1.2-kilometre highway tunnel in Tsing Yi Island, with two parallel tunnel tubes, each comprising three lanes. It formed part of Route 8 and provided linkage between the eastern part of the New Territories and Chek Lap Kok International Airport. The project was scheduled for completion in 2008.

From a tunnelling point of view three major challenges existed. The first was to obtain all necessary permits, to construct the portal and the first 20 metres of tunnel. The second was to maintain a high production rate. The logistics was particularly challenging. When tunnel excavation was in full swing, a truck left the site every 100 seconds from 8 a.m. to 7 p.m., each fully loaded with rock materials. The third, and perhaps greatest, challenge was to maintain a low accident rate. Tunnelling operations were particularly prone to accidents and the site team responded by vigorously addressing all safety issues.

The project also included a large ventilation building and substantial E&M works.