A broken wheel is the likely cause of last week’s derailment in the Gotthard Base Tunnel, public broadcaster SRF reported Sunday, citing information from the Swiss Transportation Safety Investigation Board (STSB).
A Google translation of the SRF report says automatic equipment showed the train was “sound” as it entered the 35.5-mile tunnel from the south at Biasca, so the STSB assumes the wheel disc broke in the tunnel. All the fragments of the wheel have been recovered. The cause of the wheel fracture is still to be determined; a metallurgical examination is planned.
STSB spokesman Christoph Kupper told the Keystone-SDA news agency that the train could have continued for several kilometers after the wheel broke, with the derailment finally occurring at a switch at the multifunction station in the tunnel, where crossovers exist for trains to move from one tunnel tube to the other. Twenty-three of 32 cars derailed, according to a Bloomberg report; a damaged gate (visible in the photo above) is a significant issue for repairs as it must be operable for safety reasons before the tunnel’s other tube can be used.
Repair work in the tunnel is challenging because the temperature is 40 degrees Celcius (104 Fahrenheit) and the accident site can only be reached by a lengthy walk.
The tunnel, the world’s longest rail tunnel, will remain closed until at least Wednesday [see “Derailment closes Switzerland’s Gotthard Base Tunnel,” Trains News Wire, Aug. 10, 2023]. Swiss National Railways continues to operate passenger trains via the historic Gotthard line, with trips taking about an hour longer and capacity reduced by about 30% because that route cannot handle bilevel equipment. SBB said all scheduled trains operated on Saturday.
The tunnel handles nearly 70% of all freight moving through the Swiss Alps, Bloomberg reports, and its closure has led major Swiss grocers such as Coop and Migros to move transport from rail to road. This brings its own challenges; on Saturday, the backup to pass through the Gotthard Road Tunnel was reported at 1 hour, 40 minutes.
— Updated at 7:15 a.m. with additional details.
Would never have guessed the temperature is so high in there…
What our resident expert should have added is that European freight trains are typically lighter and shorter than U.S. ones due to lighness of the rail sytucture, and the capacity limitations of the couplers and draft gear used. As a result, they rum more trains, more frequently.
The derailed freight train was traveling from Italy to Germany and had been checked for any problems with the wheels or cargo shortly before entering the Gotthard Base Tunnel.
Dr. Güntürk Üstün
Hoping that this incident will not happen again.
Dr. Güntürk Üstün