Derailment Detectors on the Approaches to the Gotthard Base Tunnel Are in Operation
Following the derailment of a freight train in the Gotthard Base Tunnel in August 2023, SBB (Swiss Federal Railways) examined measures to mitigate the impact in the event of an incident. In mid-May 2026, SBB commissioned trackside derailment detectors at around ten locations on the approaches to the Tunnel.
The detectors have been installed on a particularly sensitive section before the portal cross-over points on the access lines to the Gotthard Base Tunnel. Both passenger and freight trains travel at high speed on this line, whereby high-speed switches enable cross-overs.
Derailment detectors are the only proven technology for detecting a derailment on the infrastructure side. Their aim is to prevent a collision between two trains in the unlikely event of a recurrence. However, derailment detectors cannot prevent derailments; this requires better maintenance of freight wagons and adapted liability law in railway freight traffic.
Temporary Speed Restriction Lifted
With the commissioning of the derailment detectors, the temporary speed restriction to 160 km/h around the two portal cross-overs on the approaches to the Gotthard Base Tunnel has been lifted. The restriction had been in place since the tunnel returned to operation in September 2024 and remained in force until the derailment detectors were commissioned.
Derailed freight train in the Gotthard Base Tunnel, August 2023
Credit/Quelle: SBB CFF FFS
Derailment in the Gotthard Base Tunnel Caused by Wheel Fracture
Following the derailment of a freight train in the Gotthard Base Tunnel, the Swiss Transportation Safety Investigation Board (STSB) found that the cause was a wheel fracture on a freight wagon. To prevent such incidents in future, cracks in wheels must be detected at an early stage.
The most important measure will be the introduction of significant improvements in freight wagon maintenance. The current situation is that if an accident is caused by a defect in a wagon, the railway undertaking (RU) transporting the wagon is liable, not the wagon keeper. Wagon keepers therefore have little incentive to invest more than the absolute minimum in wagon safety. According to SBB, liability legislation must therefore be amended. SBB supports the safety requirements for freight wagons issued by the Federal Office of Transport (FOT) and advocates a fair allocation of risk in railway freight traffic.
