Lötschberg repair works to start next week

2 September 2020

Starting Monday 7 September, Swiss rail operator BLS will begin the remedial works to prevent further sand and water ingress into the Lötschberg Base Tunnel. This will involve renovating the east bore of the 14km twin-bore section while allowing the majority of passenger services to continue.

The work was recently approved by Switzerland’s Federal Office of Transport and will involve excavating a cavern next to the damaged site to house a 2,000m3-capacity settling tank. As mountain water flows into the tank, the sand carried will settle to allow the filtered water to be discharged to the Raron portal. All the sand deposited will be taken out of the tunnel by rail car during regular maintenance shifts. BLS says it anticipates that the work will be successful in preventing future water and sand ingress.

During the US$16.2m remedial works, which will result in complete closure of the east tube from 7 September to 23 December 2020, scheduled passenger traffic will be diverted through the west tube. The final phase will see the east tube closed on weekdays from 11 to 29 January 2021 when the main work is expected to be completed. The staggered construction programme is designed to allow uninterrupted passenger services during Christmas and the winter sports season. Much of the freight traffic will be rerouted along the mainly open-air Lötschberg mountain line or diverted into the Gotthard tunnel.

The remedial work follows the emergency measures instigated in February and March 2020 when sand was washed into the eastern bore, forcing its closure. A similar but less significant incident in the western bore on 13 March 2020 has seen no further recurrence.

The Lötschberg Base Tunnel is one of the three key components of the New Rail Link through the Alps (NRLA). The Gotthard Base Tunnel and the Ceneri Base Tunnel (currently under construction) are the other two.