Electrical and systems contractors are already at work in the tunnels which form 38% of the West Rail route following the completion of tunnel boring and excavation last year and installation of most of the track.
West Rail's southern section comprises two major tunnels, the 5.5km drill and blast Tai Lam tunnel, and the 3.6km Kwai Tsing tunnels, comprising three sections running between Tsuen Wan West Station and Mei Foo Station along the West Rail southern section.
The £168M Kwai Tsing tunnels comprise a 1.7km drill and blast section just north of Mei Foo which broke through in October 2000 and the 1.78km twin bore Tsing Tsuen section to the Tai Lam tunnel, completed last year by contractor Dragages Zen Pacific using the same earth pressure balance shield tunnel boring machine for both bores.
The Tsing Tsuen section passes through a mixture of granite and soft ground mixed with granite boulders. While the first bore took eight and a half months to complete, the second began in early 2001 and finished last July.
KCRC West Rail construction manager Howard McKay says the faster progress on the second bore reflected the fact that the contractor's TBM teams had refined their tunnelling techniques.
Contractor DragagesNishimatsu broke through on the £159.2M Tai Lam tunnel in April last year after a two year programme. The French/Japanese consortium split work along national lines with Dragages working from the northern end and Nishimatsu from the south.