Initial Situation
SBB uses HFO systems (hot box and stuck brake detection) to measure the bearing and wheel temperatures of passing trains on open tracks. Stuck brakes or overheated wheel bearings damage rolling stock and can lead to axle or wheel failure, resulting in derailment. If temperatures exceed defined limits, an alarm is triggered. On track sections where a train cannot be stopped at short notice, such as in the Gotthard Base Tunnel, this alarm may arrive too late for optimal operational intervention. Earlier detection makes it possible to remove at-risk trains from service before they reach critical sections, thereby avoiding track blockages.

The SCS Contribution
To achieve this, SCS combined historical HFO measurement data from several checkpoints and developed a model that evaluates temperature development on an axle-by-axle basis to derive the risk of an impending stuck brake alarm.
Result
The study demonstrated that imminent stuck brakes can be detected based on consecutive HFO measurements even before a limit is exceeded. This allows affected trains to be removed from service before critical track sections, preventing disruption to subsequent operations.
1:1,000,000
Targeted maximum false alarm rate per analyzed axle.
1 Checkpoint Ahead
Prediction of a possible alarm at the next HFO checkpoint.



