photo: Kecko / Flickr/SBB – Gotthard Base Tunnel
The European Union Agency for Railways has published a new set of wheel checks developed after the 2023 derailment in the Gotthard Base Tunnel. UIP says the measures now reach around 500,000 tread-braked freight wagons across Europe and could put pressure on maintenance workshops.
The Gotthard accident happened on 10 August 2023, when a freight train derailed after a BA 390 wheel broke inside the tunnel. ERA’s latest JNS report puts the resulting damage to infrastructure and rolling stock at around EUR 160 million, while one tube of the tunnel remained closed for more than a year.
The investigation led the Joint Network Secretariat to review earlier European measures for broken freight wheels. Version 5.0 of the report, published on 7 August 2026, now replaces the previous JNS measures for cracks in BA 004 wheel rims and the earlier Gotthard versions published in 2024, 2025 and January 2026.
The Task Force has identified six wheel types as comparable to BA 004: BA 390, Db-004sa, RI 025, R32, BA 304 and BA 005. These wheels are subject to some of the stricter measures in the report. However, several of the new checks are no longer limited to those six types. They apply to all tread-braked freight wheels. The JNS report says visual and hammer checks alone cannot reliably detect every possible form of wheel damage, which is why the inspection regime has been expanded.
Freight Wheels Will Be Checked by Mileage and During Maintenance
One of the main additions is a mileage-based inspection of the full wheel circumference. The requirement applies to all tread-braked wheels with a nominal diameter of 920 mm. The inspection interval depends on how much material remains in the rim after wear and reprofiling. Wheels with a residual rim cross-section above 0.74 dm² can run up to 300,000 km between inspections. The interval falls to 200,000 km, 100,000 km and finally 50,000 km for the most worn wheels.
ECMs must prepare a plan for bringing their fleets into compliance by 7 October 2026. Systems for monitoring the mileage limits must be ready by 1 July 2027, and all affected wheels must have received the required inspection by the end of 2027.
A second measure links the checks to normal maintenance. From 7 October, ECMs must inspect the entire wheel circumference when brake blocks are changed, during axle inspections, heavy wagon revisions and off-vehicle maintenance. The same applies when there are signs of overheating or a fixed brake.
If inspectors find cracks or signs of thermal damage, the wagon goes to a workshop for further checks. These can include residual-stress measurements, non-destructive testing of the tread and measurement of the distance between the two wheels. BA 004 and comparable wheel types face tighter limits during these examinations.
UIP Warns About Workshop Capacity
The International Union of Wagon Keepers (UIP) represents more than 250 keepers and ECMs and around 255,000 freight wagons. In its statement on the new report, the association said implementation across the wider European fleet would "absorb substantial workshop capacity". It plans to provide fleet and maintenance data so that the timetable can be assessed against the capacity that actually exists.
UIP also wants the safety effect to be monitored. The association says the operational and economic impact of the measures is already visible, while their actual contribution to reducing broken-wheel risk still has to be demonstrated in service. Secretary General Gilles Peterhans said wagon keepers support a harmonised European approach, but the practical feasibility and operational impact need to be assessed as the measures are implemented.
Switzerland Had Already Prepared Its Own Freight Wheel Rules
The European measures also have another purpose: avoiding a patchwork of different national requirements. Switzerland introduced four national measures for freight wagon wheels in September 2025. They covered thermostability, minimum wheel diameter, regular inspections of the full wheel and hammer tests. Most were initially due to enter into force on 1 January 2026. Switzerland later postponed the full-wheel inspection requirement to January 2027.
According to the JNS report, other national safety authorities were also considering their own measures. ERA warned that separate national rules could disrupt cross-border freight traffic, and the Task Force spent another 26 meetings between September 2025 and July 2026 working on a common approach that would also apply in Switzerland.
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ERA Still Wants Better Wheel Monitoring
ERA’s own impact assessment comes out in favour of the new European measures. It compares their cost and expected safety effect with the alternatives and identifies the version 5.0 approach as the preferred option.
At the same time, the assessment recommends further work on digital in-service wheel monitoring. ERA sees potential for systems that could detect developing damage while wagons are running and reduce the cost of repeated manual inspection.