Slurry pressure balance tunnel boring machine (SPB TBM) WIRTH

Slurry shield tunnel boring machines
Bentonite slurry, consisting of a specific clay and water mixture is universally used in boring and digging operations. The slurry has numerous properties: sealing of the cutting face, reduced friction on the TBM's structure, and transport of cuttings to the separation plant outside the tunnel.

The basic principle of this TBM is to maintain the tunnel's cutting face during the excavation phase by filling the working chamber, located behind the cutterhead, with slurry.

Slurry pressure is carefully controlled by a large air bubble which is maintained by a separately-controlled air supply system. This air bubble acts as a damper by absorbing sudden variations in mucking output.

More specifications...