rotative drilling head fixed
at the rods (respectively a controllable boring bar with injection
nozzles (for high pressure jets) and a transmitter for localizing the
position, depth and inclination of the rotative head at each point in
time) is drilling a tunnel into the soil. As injection suspension we
use a mixture made of clay (polymeren) and
water. The soil will not be displaced
but compressed into the surrounding soil.
Thereby we can go around obstacles or follow changes of the drilling
line. This kind of drilling we call pilot drilling.