SBB has commissioned new trackside derailment detectors on the approaches to the Gotthard Base Tunnel, following the freight train derailment that damaged the tunnel in August 2023.
The detectors entered operation during the night of 10 to 11 May 2026 and have been installed at around ten locations on the access lines to the tunnel. SBB placed them on a particularly sensitive section before the portal crossovers, where both passenger and freight trains operate at high speed.
According to SBB, derailment detectors are the only proven infrastructure-side technology for detecting a derailment. Their purpose is not to prevent derailments, but to reduce the consequences of a rare incident by helping prevent a possible collision between trains.
The 2023 derailment in the Gotthard Base Tunnel was caused by a wheel fracture on a freight wagon, according to the Swiss Transportation Safety Investigation Board. SBB says future prevention depends mainly on detecting wheel cracks earlier and improving freight wagon maintenance.
The company is also calling for changes to liability rules in rail freight. Under the current system, if an accident is caused by a wagon defect, the railway undertaking transporting the wagon is liable rather than the wagon keeper. SBB argues that this gives wagon keepers too little incentive to invest beyond minimum safety requirements.
With the new detectors now in operation, SBB has lifted the temporary 160 km/h speed restriction around the two portal crossovers on the approaches to the Gotthard Base Tunnel. The restriction had been in place since the tunnel returned to operation in September 2024.
SBB said the reduced speed did not affect passenger connections in Ticino or German-speaking Switzerland, but it did reduce timetable reserves used to absorb delays.
