Most of the subway tunnels were constructed with shield construction method

After the station, we began to talk about the tunnel construction. This is a very special machine, and it's called a shield machine. Most of the subway tunnels were built with such shield construction machine.

The follow of a tunnel construction:

1.     The worker are at the segment factory to prefabricate, and then transport to the tunnel construction site.

2.     Through the gantry crane, to hoisted the segment into the initial wall of the shield.

3.     The shield segment carrier to transport the segment into the tunnel.

4.     The shield machine to assemble the segment, to form a tunnel.