A new Japanese pipe jacking machine called the Iron Mole is described. Made by Komatsu the device drills a pilot hole ahead of its main cutter through which excavated material is conveyed to the arrival pit. The pilot tube acts as an accurate guide for the cutter and concrete pipes of the main drive. The penetrating pilot head is articulated to enable deviations from the intended line to be corrected. A hydraulic cylinder is used to push forward the pilot jack head, then the head and pilot pipe are pushed forward the same distance by the jack in the starting pit and the process repeated till the pilot head is pushed out into the arrival pit. The head is removed leaving a 200 mm diameter tube on the line of the main pipe run. As the pilot hole is enlarged by a screw discharge typecutter head, the debris falls inside the head and is carried to the arrival pit by a screw conveyer. The mole can jack pipes from 250 mm diameter up to 900 mm diameter. As the mole advances the pilot tube with its auger is gradually removed at the arrival pit whilst the main pipes are being jacked in from the launching pit; the normal maximum span between launching and arrival pits is about 50 M. (TRRL)

Media Info

  • Features: Figures; Photos;
  • Pagination: p. 20-21
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00389484
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Oct 30 1984 12:00AM