31 March 2000
Secretary for the Treasury commissions KCR West Rail Tunnel Boring Machine "Mulan"
The largest Tunnel Boring Machine (TBM) ever used in Hong Kong is commissioned today (31 March) by Secretary for the Treasury Ms Denise Yue for the construction of West Rail's Tsing Tsuen Tunnel.
With the adoption of this machine, disturbance on road traffic and the surrounding community will be significantly minimised, compared with the conventional cut-and-cover tunnelling method.
The TBM is capable of working through both soft ground and hard rock, and therefore is ideal for the mixed type of soil conditions along the route of the 1.78-km long Tsing Tsuen Tunnel. TBMs previously used in Hong Kong were for one type of soil condition only, and this is the first time a mixed-ground TBM is used in Hong Kong.
The giant machine weights about 1,500 tonnes and has a diameter of 8.5 metres and a total length of more than 100 metres.
At the ceremony, Secretary for the Treasury Ms Denise Yue threw a bottle of champagne at the giant machine "Mulan", named after the famous lady in Chinese history who disguised as a man and stood in for her elderly father in battles and won many victories.
Also officiating at today's ceremony is KCRC Chairman and Chief Executive Mr K Y Yeung.
Mr Yeung said that a major benefit of the TBM is that it is environmentally friendly.A launching shaft and a reception shaft are the only key land requirements throughout the construction.
"Without this machine, the tunnelling would have to be done by cut-and cover method, which would mean that we would have to dig up busy roads, causing major traffic and environmental disruption," Mr Yeung said.
Measures will also be taken to ensure the machine be operated in an environmentally friendly manner.The launching shaft, with a dimension of 140 metres long and 30 metres wide, will be fully covered with acoustic material to mitigate noise generated from the delivery of the excavated spoils.
In addition, a water treatment plant is built at the site for immediate treatment of spoils before transporting them to designated sites for further disposal.A noise barrier will also be installed on the side of residential area as part of the mitigation measures.
Advancing at an estimated average rate of 11 metres per day, it will take about 6 months to complete the first bore of the tunnel.During a 3-month re-set period, the machine will be taken back to the launching shaft for the construction of the second bore, which will take about 5 months.