The tunnel was closed in August last year after a broken wheel caused a freight train to derail, causing extensive damage.
The Gotthard Base Tunnel, the main rail connection between Switzerland and Italy and a key goods transport route, will reopen on Monday more than a year after an accident forced its closure.
The accident took place on 10 August last year when a Swiss Federal Railways (SBB) freight train derailed due to a broken wheel.
The derailment caused the train to crash into the gate separating the western and eastern tunnels, causing severe damage.
An investigation after the crash revealed that hairline fractures in a wagon wheel caused the accident when pieces came away, causing the carriage to jump the tracks.
And the clean-up operation was also problematic.
« It took several weeks just to remove the train and clear the accident site. Afterwards, all the materials had to be brought into the tunnel. Temperatures in the tunnel were almost 40 degrees centigrade. Precautions had to be taken to protect the workers, » said Beat Deuber, the Head of Infrastructure Systems for SBB.
SBB estimated last year that repairing the damage would cost in the region of €135 million, but the company said this week that the final price was 150 million Swiss francs (€159 million).
The closure of the tunnel has been a major headache for the rail freight sector since the incident.
Several weeks after that accident, SBB reopened the undamaged eastern tunnel for the exclusive use of freight trains, with around 100 passing through every day.
But re-routing freight trains has been an enormous task for rail freight operators, especially Italian ones, both in terms of costs and capacity availability.
Just days after the Gotthard Base Tunnel accident, the Frejus Railway, the main rail connection between Italy and France, was closed due to a landslide. It’s not expected to reopen until 2025.
The closures of both the Gotthard Tunnel and the Frejus line cost rail freight operators active on these routes millions of euros.
« We have carried out clarifications on the infrastructure side and we will develop measures to be able to recognise derailments at an early stage, » said Beat Deuber.
Taking almost 17 years to complete after decades of planning, the Gotthard Base Tunnel is the longest railway tunnel in the world, stretching 57 kilometres under the Swiss Alps.
It’s an essential link between Switzerland’s German and Italian-speaking cantons and cost 9.7 billion Swiss francs (€10.3 billion) to construct.