Talerddig - 2024
Summary
This episode of *Signals to Danger* investigates the 2024 head-on collision between two trains at Telford on the Cambrian Line, resulting in one fatality. Host Dan Fox explains the role of ETCS, the advanced European signaling system that replaced traditional trackside signals with in-cab controls. The investigation reveals that while the braking system functioned, leaf fall contamination caused low wheel-rail adhesion, leading to a slide. Crucially, the train’s automatic sanding system failed due to electrical faults and blocked nozzles, preventing it from restoring grip and stopping the t…
Topics discussed
Introduction and disclaimer
Sponsors and context: The Clapham Junction crash
Evolution of rail technology: From steam to electric
ERTMS, GSMR, and the need for standardization
How ETCS works: In-cab signaling and intervention
The Cambrian Line: Geography and single-track operations
ETCS implementation and the two trains involved
The evening of the accident: Timetables and movement authorities
One Juliet 25 fails to stop at the loop
One Sierra 71 approaches and the collision occurs
Aftermath: Injuries, fatalities, and emergency response
Sponsors: Whole Foods and Liquid IV
Investigation: Why did the brakes fail to stop the train?
Wheel-rail adhesion and leaf fall contamination
WSP and sanding systems: Design and intended function
Faults found: Electrical issues and driver actions
ETCS limitations: Braking curves and intervention phases
Signaling logic: Movement authorities and route reservation
Layers of defense: Testing, training, and communication failures
RAIB recommendations and safety improvements
Conclusion: Normal risks and system limitations
Outro and sponsor reads
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