Lineside monitoring systems on parts of Britain’s rail network may fail to detect embankment or cutting slope movements during extreme rainfall, the Rail Accident Investigation Branch has warned following the 3 November passenger train derailment near Shap, Cumbria. The warning concerns remote condition monitoring equipment installed to trigger alerts for ground instability, which did not prevent the derailment. Geotechnical and asset engineers are being urged to review sensor siting, trigger thresholds and system performance in severe weather, particularly on high-risk slopes.

Railway managers have been warned by the Rail Accident Investigation Branch that Network Rail’s lineside slope monitoring systems may fail to give usable alerts during rapid failures, after an Avanti West Coast train derailed at around 83 mph near Shap Summit on 3 November 2025 when it struck landslip debris. Remote sensors on steel spikes at 2 m spacing recorded sub‑10 mm movements—below the 10–30 mm “green” alert threshold—before being rapidly buried, losing wireless signal and generating no alarm to control. The landslip followed heavy, sustained rainfall that overwhelmed a cutting‑slope drainage channel, and RAIB has urged duty holders to urgently review and, where needed, mitigate these monitoring limitations.

A man-made embankment on the Llangollen Canal near Whitchurch, Shropshire, failed in the early hours of Monday, creating a large breach that rapidly drained a several‑kilometre pound and triggered a major incident response. The failure occurred on a raised canal section over low-lying farmland, with water overtopping and eroding the embankment before a full breach developed, flooding adjacent fields and damaging access tracks. Canal & River Trust engineers have isolated the affected reach with stop planks and are assessing embankment stability, seepage paths and repair options under constrained access conditions.