The article discusses the 3 one-half mile long Terminal 4 tube extension through London clay, which is characterized by speedy mobilization, good equipment and an ingenious continuous mucking system. The contractor went for "fast tunneling" using three mechanized working faces. The method chosen was to use boom-type road-headers working in hydraulically jacked shields. The main problem from the contractor's point of view was how to muck out quickly enough to keep up with the rapid rate of tunneling expected. The rather novel solution adopted was to use as large mucking cars as could be gotten onto the 600mm gage Jubilee track. The mucking system also included a surge area and a conveyor. These and other aspects of the job are discussed.

  • Availability:
  • Corporate Authors:

    Morgan-Grampian Limited

    30 Calderwood Street
    London SE18 6QH,   England 
  • Authors:
    • Martin, David
  • Publication Date: 1984-5

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Subject/Index Terms

Filing Info

  • Accession Number: 00389797
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Oct 30 1984 12:00AM