Hydroshield Tunnel Boring Machine

Hydroshields are tunnel boring machines with a wet pumped muck conveyance system.

In the hydroshield, equilibrium is achieved through the pressure to which the water or bentonite slurry is subjected in the chamber with the excavation face. These slurries are also used to transport (by pumping or "wet way") the material crushed by the cutting crown arms in the crushing chamber to the separation equipment located on the surface.

These are the most suitable TBMs for working below groundwater levels.

In addition, they are applicable in almost all types of geology, mainly:

Water or bentonite is injected into the extraction chamber and mixed with the excavated material. The crushed mixture is extracted by hydraulic pumping to the separation plant located on the surface.

In this separation plant the excavated material is separated from the bentonite sludge to be injected back into the sludge circuit.