Swiss Federal Railways (SBB) has confirmed that it will commence renovation work on the Hauenstein Base Tunnel on 3 September.
This project aims to ensure the continuity of safe and efficient rail operations throughout the tunnel for the next 25 years.
The work will include the renovation and renewal of the tunnel vault and the technical systems.
The 8.134-kilometre-long, two-lane Hauenstein Base Tunnel was built between 1912 and 1916. It is part of the Basel-Olten railway line and carries an average of around 100 freight trains and 320 passenger trains each day.
The last extensive renovation work on the tunnel was carried out between 1980 and 1987, and SBB has since carried out regular selective maintenance and renewal work. Now, a major overhaul is required. This will involve renewing and replacing the tracks including rails, sleepers and ballast, and re-laying all the cables.
In addition, the track drainage will be adjusted and improved; the tunnel self-rescue devices will be modernised; and technical systems, such as the ventilation shaft in Zeglingen will be renewed.
The project is expected to cost around 140 million CHF (146 million EUR) and will be financed via the performance agreement between the federal government and SBB.
Much of the work will take place at night and will be ongoing until autumn 2026.
At times, necessary one-lane closures will result in earlier departure times and longer travel times for long-distance traffic.
In addition, four tunnel-wide lane closures are planned in 2024, 2026, 2027 and 2028. These will each last for five weeks during the summer holiday period to enable SBB to renew the tunnel tracks. During this time, buses will run to replace the S9 trains.
Total closures are also planned on individual weekends while SBB carries out work on the switches. This work will require extensive timetable changes.
