Method of laying pipes in the ground

A method of laying pipes in the ground comprising:

• a. digging a departure pit and an arrival pit spaced apart from the departure pit;
• b. providing a propulsion jack in said departure pit, the propulsion jack being adapted to press and propel pipes to be laid in;
• c. pressing a pilot head into the ground in said departure pit in a direction towards said arrival pit by means of a pilot jack coupled thereto and then pressing said pilot head further into said ground, wherein the pilot jack is placed into a contracted state by the pressing force of said propulsion jack;
• d. pressing pilot pipes successively into the ground by said propulsion jack, said pilot pipes being in a following relationship with said pilot head;
• e. measuring the position and posture of said pilot head at the departure pit during the pressing and laying-in of the pilot head;
• f. controlling the straight advance of the pilot head based on said measurement;
• g. bringing a multistage head into abutment against the rearmost end of the laid-in pilot pipes after the latter are laid in;
• h. pressing the rear end of said multistage head and laying in the multistage head by said propulsion jack;
• i. connecting pipes to be laid in to the rear end of said multistage head, said pipes being larger in diameter than said laid-in pilot pipes;
• j. propelling said pipes in succession into the ground by said propulsion jack;
• and
• k. collecting said laid-in pilot pipes in the arrival pit.