The 80m long TBM, Xiaolongnu (Little Dragon Girl), started work on the first of two 1.1km tunnel drives in mid-August to form part of Hong Kong’s US$1.06bn Kowloon southern rail link.
The tunnel is being built under a US$260M design and built contract awarded to a joint venture between Australia’s Leighton Asia and John Holland, Britain’s Balfour Beatty and Kumagai Gumi of Japan, by the Kowloon-Canton Railway Corporation (KCRC). Gammon Construction was a member when the project was bid, but it has since merged with and become incorporated into Balfour Beatty.
The slurry TBM, which was built by Germany’s Herrenknecht at its plants in both Germany and Guangzhou in southern China, was named following a competition held by the rail company. Speaking at the inauguration ceremony on 22 August, KCRC chief executive James Blake said: “The name is most befitting because the machine will do her work with the agility and effect of a super kung fu fighter, yet with a feminine touch of tenderness and softness as she tunnels her way through soft ground and hard rock.”
Xiaolongnu will excavate twin running tunnels under Canton and Salisbury Roads in the heart of the Tsim Sha Tsui tourist district. The TBM will run southwards from West Kowloon Station at Canton Road to a retrieval shaft in Salisbury Road.
The 7.99m diameter Mixshield is expected to bore through geology comprising granite that varies between completely and moderately decomposed. The TBM has 2,400kW of cutterhead power and 12,620kNm of cutterhead torque at its disposal. T&TI was told the TBM has a total thrust available of 53kN.
Thomas Ho, Gammon’s chief executive, said: “A mixed shield slurry tunnel boring machine has been selected to provide maximum control and capability in the anticipated geological conditions.” Ho added: “Real time monitoring of adjacent structures and noise control will be an integral part of the works.”
About six months is programmed for the excavation of each drive. Tunnelling of both bores is expected to be completed in January 2008. The Kowloon southern link also includes another section of tunnel which is being built by cut and cover techniques. The 3.8km will connect the KCRC’s east and west rail networks.
