TamSoil 281AC is a soil conditioning foam with anti-clogging properties specifically developed to be used on a tunnel boring machine (TBM). It acts as a soil conditioner for various types of soil conditions, especially clayey soils showing tendencies to cohesion problems as well as adhesion to metal surfaces. TamSoil 281AC gives the excavated soil the necessary plastic properties and reduces significantly soil stickiness at the cutterhead, working chamber and screw conveyor. TamSoil 281AC also creates a homogeneous and compressible spoil in order to reduce the cutterhead torque and secure a constant earth pressure in the working chamber during the excavating process.