Norway: The new Ulriken Tunnel – drill and blast or TBM?
4 June 2014 • Author(s): Hans-Egil Larsen, Project Manager at Jernbaneverket
The line between Arna and Bergen in Norway is one of the most heavily trafficked sections of single-track railway in Europe, with approximately 130 trains passing daily. This section is a bottleneck for rail traffic to and from the station and freight terminal in Bergen. The Norwegian National Rail Administration (Jernbaneverket) is currently carrying out a competitive tender procedure for the construction of the new Ulriken Tunnel between Arna and Bergen as part of the Arna–Bergen double-track project. Two alternative construction methods are envisaged: conventional drilling and blasting or the use of a tunnel boring machine (TBM). On the closing date for tenders at the end of February 2014, tenders had been received based on both methods, and the choice of method will be decided during the negotiations with the contractors. It is estimated that the total investment in the project will be NOK 3 420 million. Hans-Egil Larsen, Project Manager at Jernbaneverket provides more details.
More about the project
Essentially, the laying of double-tracks between Arna and Bergen comprises two projects: a new tunnel between Arna and Fløen, and a double-track from Fløen to Bergen with a new signalling and interlocking system. The new interlocking system at the station in Bergen will also have the capacity to control the station in Arna. In addition, the existing tunnel tube will be upgraded when the new tunnel is completed, and Arna station will be modified and upgraded.
The existing tunnel was completed in 1964. The Ulriken Tunnel is currently one of the most heavily trafficked sections of single-track line in Europe1. The project came about mainly because the current section between Arna and Bergen is a bottleneck that limits the capacity for passenger and goods traffic on the Bergen Line.