On June 27, 2024, SBB confirmed the date for the full reopening of the Gotthard Base Tunnel as September 2, 2024. This follows extensive testing and trials, including the operation of empty trains to verify new installations, especially the tracks, and the interaction of various systems. The second phase, starting mid-August, will see northbound trains resuming regular service in the west tube.
The tunnel was closed on August 10, 2023, following the derailment of a freight train at a critical point in the west tube, where the gate separating the two tubes is located. The incident not only destroyed eight kilometers of ground and overhead infrastructure but also damaged the large gate, prolonging the restoration process. The initial work involved clearing the derailed train and debris, completed by September 2023, followed by a thorough damage assessment and reconstruction.
In the meantime, on August 23, 2023, Swiss railways managed to partially reopen the east tube, which was undamaged, allowing some freight traffic and limited passenger train service on weekends. With the activation of the winter timetable in December 2023, the frequency of freight trains increased. SBB estimates the cost of this operation at 150 million Swiss francs, with a 20% margin of error, 140 million of which is covered by insurance.
SBB used the closure of the west tube to carry out numerous planned interventions. Regardless of the incident, multi-day maintenance windows had been scheduled long in advance. This event prompted the railway company to find solutions to prevent future occurrences or at least mitigate their consequences.
To this end, SBB states that "measures to promptly detect train maintenance needs, through data collection on status and images and enhancing train control systems, are necessary to prevent such events. To minimize the consequences and promptly detect a derailment, SBB is considering installing specific detectors along the route, at track changes inside and before the Gotthard Base Tunnel. However, due to the time required for planning and installation, as well as the complex integration into existing systems, SBB believes these measures can be implemented in the medium term."
The first measure, to be implemented when the tunnel reopens, will be the temporary speed limit of 160 km/h for track changes near the portals before the Gotthard Base Tunnel. This limit "will reduce the time reserves useful, for example, to recover from a delay." However, passenger trains will continue to travel at a maximum speed of 230 km/h inside the tunnel.
Since the incident, the Swiss Safety Investigation Service (SISI) has drafted the final report on the cause of the August 2023 derailment, which has yet to be published. In an interim report, SISI established that the cause was the breaking of a wheel disc. SBB notes that its fleet does not have wagons with this type of axle, but this equipment is used in Switzerland by other operators in international transport. Therefore, the Swiss Federal Office of Transport (FOT) has called on European railway authorities to require all freight car holders using vehicles with similar wheels to inspect and, if necessary, withdraw them from service.
