The water damaged two of the four tunnel boring machines, but no workers were injured.

This mass then formed a waterproof wall through which the tunnel boring machines could run without the surrounding water and rock penetrating.

The crossing under the main railway station is not done by the tunnel boring machine, but by manual digging.

As such, even though it cost less than using a tunnel boring machine, the plan drew heavy criticism from area residents and businesses.

Some of the sections under the airport required the use of a tunnel boring machine.

Herrenknecht AG - makers of the tunnel boring machine used.

Construction began in the second half of 2007, and the tunnel boring machine started to operate in 2009.

It is applied immediately behind the tunnel boring machine, to create a natural load-bearing ring and minimize the rock's deformation.

Stage Two is being built using tunnel boring machines.

There was local debate whether the tunnel should be built using a tunnel boring machine or by drilling and blasting.