THE FREJUS TUNNELS: 100 YEARS OF DRILLING PROGRESS

This article shows the progress which has been made in tunnel construction by comparing the first Frejus railway tunnel linking Piedmont and Savoy 100 years ago with the motorway tunnel being constructed to the east and almost parallel to it. A description is given of the equipment including compressed air drilling rigs used in the 1860'S. Agreement was made in 1972 to build the present tunnel, which is 12833 M long, 11.6 M wide and 8.5 M high, driven mainly through calcareous schist. The cost was estimated to be $96 M. An unusual feature is the tunnel sole sloping at 0.56% gradient over its full length from the Italian to the French portal. Three ventilation shafts are provided, and its capacity will be 1800 veh/hr at 80 kph maximum speed. Hydraulic rigs were used for the French section. A detailed description is given of the massive gantry-type structure, used in the Italian section, capable of performing both tunnel driving and roof bolting operations, having six booms carrying hydraulically operated hammer drills. The working schedule for tunnelling operations is given, and the entire tunnel surface was gunited. Finally a comparison is made of the labour and machines used and progress made in constructing the first and second Frejus tunnels. (TRRL)

  • Availability:
  • Corporate Authors:

    Foundation Publications Limited

    7 Ongar Road
    Brentwood CM15 9AU, Essex,   England 
  • Publication Date: 1979-10

Media Info

  • Features: Figures; Photos;
  • Pagination: p. 41-51
  • Serial:
    • GROUND ENGINEERING
    • Volume: 12
    • Issue Number: 7
    • Publisher: EMAP CONSTRUCT LIMITED
    • ISSN: 0017-4653

Subject/Index Terms

Filing Info

  • Accession Number: 00309786
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Aug 5 1980 12:00AM