signalfeil

Signalfeil, or signal fault, is a fault in a railway signaling system that prevents a signal from displaying the correct aspect or any signal at all. In railway operations, signaling systems guide train movements and ensure safety by controlling signals, track switches, and interlocking logic. A fault can occur in fixed-block or moving-block systems, in the interlocking, in cab signaling, or in the data/communication networks that connect devices.

Common causes include faulty signal heads or points machinery, broken cables, loss of power, failures in track circuits or axle counters, software faults in control equipment, and environmental factors such as weather or corrosion. Human error during maintenance or configuration can also contribute.

Detection and response: When a fault is detected, the traffic control center implements fault procedures. This may include issuing speed restrictions, blocking affected routes, and requiring trains to operate under explicit authorisation or with a safety observer. In many systems, duty holders will set the affected area to a safe state, and maintenance teams physically inspect and repair components. If a signal is stuck or unreliably displaying, conventional interlocking or fault-tolerance logic should prevent unsafe movements.

Impact and prevention: Signal faults cause service disruption, delays, and potential safety risks. Operators mitigate through redundancy, regular testing, fail-safe design, redundant power supplies, and remote monitoring. After a fault is repaired, signaling systems are tested before returning to normal operations.