Weissenstein Tunnel

The Weissenstein Tunnel is a long, single-track railway tunnel on the Solothurn–Moutier railway line, built by the former . It passes under the 1,395-meter-high Weissenstein as a Jura crossing.

Location and construction

The north portal is located at Gänsbrunnen at an elevation of 722 meters above sea level, and the south portal is at 659 meters above sea level at Oberdorf.

The tunnel has a one-sided gradient from north to south of 18 ‰, with only a short section on the northern side being level. In addition, the tunnel is straight except for the last 120 meters at the southern exit, which had to be curved with a 300-meter radius.

Construction of the tunnel began at the south side at the end of December 1903. After initial hand drilling at the adit, compressed air percussion drills from ''Bechem and Reetmann'' were used, allowing an average breakthrough of 4 meters per day. In contrast, only 292 meters of tunnel were drilled by hand from the north side. On September 23, 1906, the breakthrough occurred 3,406 meters from the south portal. The deviations were 49 mm laterally and 11 mm vertically. On August 1, 1908, the tunnel was opened along with the Moutier to Solothurn West section.

Operation

Today, the line and tunnel are operated by BLS, and the Weissenstein Tunnel is traversed in both directions by SBB on an hourly basis, taking around 4 minutes.

Renovation

Starting in 2014, an assessment was made to determine whether the estimated investment for the renovation, ranging from 100 million CHF (for 25 years of service) to 170 million CHF (for 50 years), was worthwhile for the federal government, or whether a replacement offer with a better cost-benefit ratio would be possible, as required by Swiss federal law in such cases.

In February 2017, the Federal Office of Transport (FOT) decided to renovate the tunnel, responding to the concerns of the affected regions. Their concerns were given higher priority than economic considerations. The renovation is expected to cost around 85 million CHF, to be funded by the federal government through the railway infrastructure fund. The tunnel will be renovated to allow another 25 years of operation.
The construction work was initially planned to begin in 2020 but was postponed for a year to allow for the simultaneous renovation of the entire line. The tunnel was scheduled to be renovated from 2021 to 2022. Due to a legal dispute, the renovation date was postponed several times. After the legal dispute was concluded in May 2023, the renovation work began on 4 March 2024, which will take longer than originally planned due to the brittle rock, and it is now expected to be completed by June 2026 after the previous date being pushed back by 3 months.

Bibliography

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References

External links

* {{commons category-inline, Weissensteintunnel

Railway tunnels in Switzerland
Tunnels in the canton of Solothurn