TERRA-JET 8522 S TERRA-JET 8522 S drills 170 m (560 ft) upwards A HDPE pipe OD 355 mm (14“) had to be laid in a hilly forest. The height difference for this 170 m (560 ft) long HDD bore was 23 m (76 ft). The maximum depth to the surface was 14 m (57 ft). Due to the high depth, this bore had to be done trenchless. The contractor Iwashita Sangyo from Hachiken Nishi-Ku, Japan decided to use his horizontal directional drilling (HDD) machine TERRA-JET 8522 S for this pipe laying job. Iwashita Sangyo has a long HDD experience. They own several HDD machines, the oldest TERRA-JET is more than 12 years old, and still in operation regularly. They used a three finger head for the pilot bore through the hard ground layers. I:\MS\Baustelle\englisch\TJ 8522 S\bau-169e (TJ 8522 S in Japan).doc 1/2 LN-29.09.2011

TERRA-JET 8522 S 1 2 3 4 5 6 Pic 1: View onto the starting point of the 170 m (560 ft) long bore. Pic 2: The three finger head is assembled, because the pilot bore drills through hard ground layers. Pic 3: The TERRA-JET 8522 S during the pilot bore. Pic 4: The 170 m (560 ft) long HDPE pipe OD 355 mm (14“) is assembled to the backreamer 520 mm (20“) Pic 5: The HDPE pipe 355 mm (14“) is pulled in. Pic 6: After 170 m (560 ft) the backreamer 520 mm (20“) and the HDPE pipe OD 355 mm (14“) reach the TJ 8522 S. The bore is successfully finished. TERRA AG, Hauptstrasse 92, 6260 Reiden, Switzerland, phone:...