In Poland, Herrenknecht goes straight to the point

In the fall of 2016, drilling company PPI Chrobok SA built two new pipelines in Poland using Herrenknecht’s Direct Pipe technology. The route follows the existing gas lines on a terrain of difficult nature.

With the construction of a new north-south pipeline, Poland responds to growing local demand for gas. Part of this network is part of the "Czeszów-Wierzchowice Gas Pipeline Project" located in the south-west of the country. Until now, only HDD (Horizontal Directional Drilling) technology has been used to cross rivers and roads through pipeline projects in Poland.

For decades the method proved its worth but reached its technical and economic limits in unstable terrain such as the land between Wierzchowice and Czeszów, made of sandy clay and sticky. On the other hand, the route of the two pipelines of 700 and 464 m follows the existing gas lines. Uncontrolled deviations during the drilling process were therefore not conceivable.

Given these constraints, the agent PGNiG Technologies SA and its partner PPI Chrobok SA opted for the innovative Direct Pipe technology from Herrenknecht. This method combines the advantages of microtunneling with HDD technology. In one step, the boreholes are drilled and the prefabricated pipe is placed in the trench. Thanks to the gyroscopic navigation system, which allows to locate the tunnel boring machine, the drilling team put the two pipelines with an outside diameter of 1047 mm in just a millimeter in just 13 and 16 days of drilling, despite the presence of one Ecologically sensitive pond.

Clingy clay soil is not a barrier to the Direct Pipe method. Even at very high levels of resistance to friction, the 500 t of thrust provided by the Pipe Thruster (tunnel boring machine) is more than sufficient to achieve 147 m of daily advance.