A foro tunnel boring machine (tbm) in the atlas copco series is described in this paper. The working part of the machine consists of the rotating cutterhead which forms the front assembly. The front and rear gripper systems form the remaining two assemblies. The front gripper consists of a split, ring shaped steel structure which is in contact over the full 360 degrees of the bore cross section. The rear gripper system houses the rear thrust cylinders and pivotally attached, a cross member which contains the rear gripper cylinders. Details of how these assemblies work are given. The rear grippers are individually controlled, but can also be operated together. Thrust control is achieved by an automatic system in response to drive motor current, and can be overrided by the operator. Steering in both the horizontal and vertical planes can be made at anytime while the rear grippers are pressurized. All hydraulic functions are derived from solenoid operated hydraulic valves which can either be controlled by the operator or automatically activated via a system of relays. The disc cutters are made of alloyed hardened steel with shock absorbent properties. Safety measures have been incorporated into the machine in the form of a dust shield and overhead protective roofing. This machine has been used to complete the 7.5 km saltsjotunnel in Stockholm. (TRRL)

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    LONDON,   United Kingdom  EC2A 2HD
  • Authors:
    • Smith, M
  • Publication Date: 1989-6


  • English

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Filing Info

  • Accession Number: 00499158
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Sep 30 1990 12:00AM