Tailor-made technology for any geological condition.

Where shield excavation is carried out in non stable soils, a loss in stability of the tunnel face is prevented by creating a support pressure. With Earth Pressure Balance Shields, the cohesive soil loosened by the cutting wheel serves to support the tunnel face, unlike other shields which are dependent on a secondary support medium.

The machine is used as a mixshield where gravelly geological conditions indicate an unstable tunnel face or mixed geological conditions. At the tunnel face the soil is loosened all over by the cutting wheel rotating in the bentonite suspension. The soil then mixes with the bentonite suspension.

In geological conditions which indicate a stable tunnel face, e.g. in hard rock or in compacted, cohesive soils, the machine, like the smaller AVN machines, can be effectively used as a slurry shield without compressed air support.

The Single Shield TBM belongs to a category of machines which are fitted with an open shield. Tunnelling machines described as open shields are machines without a closed system for pressure compensation at the tunnel face. In other words, no excavation chamber has been defined.

Essential to the functioning of Gripper TBMs are their drilling, bracing, support and safety systems.

Double Shields are amongst the most technically sophisticated tunnel boring machines in use in tunnelling operations.

Shields with partial face excavation produce excellent tunnelling performances in a wide variety of geological conditions and in varying diameters of tunnels. They are directly controllable by the operator, simple to handle and extremely versatile in use. Furthermore, they are inexpensive to install and economical in use.

Herrenknecht supplies HDD Equipment for Maxi to Mega Rigs with max. tensile strengths of 60t to 600t. The desing of the systems has been adapted to suit an extremely wide variety of operating conditions. So ideal solutions are available for any project.