MOLE WITH WATER JETS CHEWS UP GRANITE WITH EASE

A tunneling machine fitted with a 56,000-psi water jet system that weakens rock at the face may reduce the cost of hard-rock boring by as much as 30 percent. In driving through solid granite with a compressive strength of 25,000 to 40,000 psi, a 7-foot diameter bore was advanced at a rate of 8.7 feet per hour. Energy requirements, however, are greater for jetting than for mechanical boring. The waterjet system requires 1,000 hp, supplied by four 250-hp, high-pressure intensifier pumps.

  • Availability:
  • Corporate Authors:

    McGraw-Hill, Incorporated

    330 West 42nd Street
    New York, NY  United States  10036
  • Publication Date: 1975-9-4

Media Info

  • Features: Photos;
  • Pagination: p. 10
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00126482
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 16 1975 12:00AM