The airport in Hong Kong is supplied with electricity by the Castle Peak Power Station ("New Territories"). To increase the security of the supply, additional cables have to be laid. Cables cannot be laid above ground, since this would mean crossing the "Tsing Shan Firing Range". The corresponding tunnel goes through hard rock with various fault zones and expected groundwater presence and an overburden of up to 400 meters.
The Double Shield TBM started tunnelling in November 2007. The Double Shield's working principle proved of value in challenging geology with a best performance of more than 700 meters of bored and secures tunnel in one month. Working in stable rock, the TBM was supported by the grippers directly against the rock, while installing the segment rings in the shield's rear part at the same time. The S-357 took just eleven months to reach the target shaft on October 24, 2008.