The planned Semmering base tunnel (SBT) is currently one of the most important large-scale infrastructure projects in Central Europe. It forms part of Austria’s new southern railway, which serves as the central axis for trans-European routes from the Baltic coast to the Adriatic. With a total length of 27.3 km, the SBT links the country’s Lower Austria and Steiermark regions. Austrian Federal Railways (ÖBB), which is responsible for awarding the contracts, has now commissioned the “ATF” consortium consisting of Implenia (technical lead) and Swietelsky, to do the work on the 13 kilometre long middle section (Lot 2.1). The two partners each have a 50% stake in the consortium. This section will be built using both TBM drilling (8.6 kilometres) and mining methods (4.3 kilometres). It involves 26 cross passages, an emergency stop station and two 400-metre ventilation shafts to supply the entire construction site. The contract for Lot 2.1 is worth EUR 623 million (around CHF 770 million; Implenia’s share: CHF 385 million).
One of the main challenges in this major project is dealing with the geological conditions in the drilling zone. Added to this is the need to supply the construction sites with building materials and take away excavated matter – always with a view to finding sustainable solutions for people and the environment. Implenia’s many years of experience, and particularly the expertise gained from the successful construction of the NEAT base tunnel, will be very useful in this new project. Implenia took the technical lead on three of the five lots within the NEAT project – Sedrun, Bodio and Faido. The Bodio and Faido sections were handed over on schedule to the client in September 2013 after approximately twelve years of construction. For Implenia, winning the Semmering contract marks a major milestone as it continues to builds up its infrastructure business in Western Europe. Construction works started at the beginning of January 2014 and will last around ten years.