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:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/08919526
• 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:
  • Engineering News-Record
  • Volume: 195
  • Issue Number: 10
  • Publisher: McGraw-Hill, Incorporated
  • ISSN: 0891-9526

Subject/Index Terms

• TRT Terms: Costs; Design; Granite; Power; Specifications; Tunneling machines; Waterjets
• Uncontrolled Terms: Requirement
• Subject Areas: Construction; Design; Energy; Finance; Highways; Vehicles and Equipment;

Filing Info

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