Swiss rail operator SBB is going to stop using wagons with LL brake blocks “as quickly as possible”. The company finds that LL brake blocks cause too many security risks and calls upon official institutions to take appropriate action.
SBB is no longer willing to transport wagons with LL brake blocks due to their supposed security risks. A wagon with such brake blocks derailed in the Gotthardt Base Tunnel in August 2023, leading to a year-long closure of the line. The Swiss Safety Investigation Board (STSB) found that the LL brake blocks led to overheating and cracks in the wheels.
Brake blocks in freight wagons
SBB explains that various brake blocks are used in freight transport. Grey cast iron brake blocks have been banned on the Swiss rail network since 2020 for noise protection reasons. Today, only low-noise, low-friction brake blocks (LL brake blocks) and composite brake blocks (K brake blocks) are in use.
LL brake blocks are the most common in Europe. However, there are numerous known incidents in which LL brake blocks have led to overheating of the wheel discs and the formation of ice, which can damage the wheel discs, says SBB.
The Swiss operator itself does not own any wagons with the LL brake blocks, but seeks to phase them out from its operations towards the end of 2025. “SBB has no influence on their design and maintenance, but bears the risk and financial consequences of derailments”, the company explains.
Maintenance methods
Even though the LL brake blocks cause a higher thermal load than the older grey cast iron brake blocks, the same maintenance methods are still used, says STSB. Subsequently, SBB argues that effective measures are needed as quickly as possible. It calls on the responsible authorities in Switzerland and on the European Union Agency for Railways to “act swiftly”. Otherwise, “the use of freight wagons with LL brake blocks must be restricted or even banned in Switzerland and Europe.”
A similar derailment to the one in the Gotthard Base Tunnel took place in northern Sweden in late 2023. Despite suspicions of sabotage and climate change causes, Swedish investigators recently concluded that a broken wheel was at fault here too.