The drill head
A so-called earth pressure balance shield is used to bore through most of the plastic and soft ground found under the city of Vienna. Located along the first then metres…
Advancing with the tunnel boring machine
The tunnel boring machine is around 120 metres long, seven metres high and is also affectionately known as the ‘mole’, it bores slowly through the soil, carrying all the necessary…
Construction methods
There are different methods for building an underground tunnel. These depend on how deep the line is, the soil it passes through and whether there are any buildings on the…
How to build an underground system?
Vienna is a densely populated city that has grown overtime, and it is suitable on geologically complicated land. Various soil formations overlap each other. The Danube and its tributaries are…