During the design stage of tunnel construction, the tunnels will be divided into different
sections. At each section, there will be a launching shaft at the starting point and a
retrieval shaft at the destination. The depth of the launching shaft and the retrieval shaft depends on the rail level of the tunnel alignment.

The TBMs to be used in the Express Rail Link project are supplied by German or Japanese manufacturers, sourcing parts from all over the world and assembling either in the Mainland or in Japan. They are then transported to Hong Kong by sea and delivered to the site. Since the size of the components to be transported is substantial, road closures are required at night for transporting the TBM components to the site and then reassembled in the launching shaft.

TBM is an efficient and powerful machine – the permanent tunnel walls will be constructed immediately after excavation by installing precast segmental lining. This reduces the loss of underground water and the risk of settlement.

Launching shaft work site – the site of Kowloon Southern Link Tunnel workers have to undergo rigorous training

In addition to the main shield of the TBM, there is a string of trailers which include the control room, electronic panels, compressed air tank, grouting tank and electric cable reel. When TBM works, about twenty people will operate and monitor the operation of the TBM underground, while around ten people will provide support for tunnelling logistics at ground level.