Nearby Schwerin in the north of Germany several ducts for new cables had to be laid trenchless. The contractor Stoldt-Bau GmbH from Gadebusch decided to release the complete pipe laying project in Grabow with their new HDD machine TERRA MINI-JET MJ 1400.
The 40 m (132 ft) long bore at the B 5 in Grabow was quite challenging, especially during the pilot bore. The depth of the machine pit was limited by existing pipes and cables. Therefore it was obvious, that the bore had to start with enough pitch (inclination). The theoretical depth under the heavy traffic road was 3.0 m (10 ft).
At the target pit the drill head had to come out at a depth of 1.35 m (4.5 ft). Therefore the drill head was drilled down to a depth of 3.10 m (10 ft), then corrected to the left and then drilled downwards with a pitch of 12 %. The target was reached after 3 hours and a total drilling fluid consumption of 1’100 ltr (290 gal).
Due to its compact design. The TERRA MINI-JET MJ 1400 with the power pack and the mixing+pumping station can be transported on a car trailer.