Urgent alert after landslide detectors failed to avert Glasgow train derailment

Sensors on a slope above the west coast main line in Cumbria were not connected to a control room and unable to send alerts after being buried by debris, the UK Department for Transport’s Rail Accident Investigation Branch (RAIB) reported n Friday.

Four passengers and crew were injured when an Avanti West Coast train travelling at 83mph hit landslip debris near Shap summit between Penrith and Oxenholme at 6.10am on November 3.

The RAIB said Network Rail should take “urgent steps” to mitigate the risk of such equipment being unable to detect landslips “in some circumstances”.

The “urgent safety advice” it issued also provided further information that drew parallels with the fatal derailment at Carmont, near Stonehaven, in 2020 when a ScotRail train hit debris from a drain overwhelmed by heavy rain.

The RAIB said its preliminary examination of the Shap incident “found that a drainage channel, which runs across the cutting slope above the washed-out material, was unable to accommodate the volume of water which was present.

“This led to the slope material below becoming saturated, initiating the landslip.”

Landside sensors have been deployed across the rail network following the Carmont crash.

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The RAIB said the sensors to detect ground movement were recording data and reporting to its “online monitoring service” but had not been formally entered into operational use so was not sending alerts to the Network Rail control centre.

It said some four hours before the incident, the sensors began to show minor movement, but at about 4.30am, when the landslip is thought to have occurred, “the two sensors in the path of the debris were tipped over and subsumed by the material sliding down the slope.

“It would appear that this occurred too quickly for them to determine and transmit their movement and to generate an alert.

“RAIB has further concluded that the sensors’ wireless signal was also unable to pass through the layer of material which covered them.

“This is based on them being able to re-establish a connection and report a variety of alert levels as the site was cleared.”

A rail industry source told The Scotsman: “Clearly, infrastructure maintainers need to learn from this incident and perfect the equipment, so that if reporting stops for any reason trains are immediately cautioned in the area.”

A spokesperson for Network Rail Scotland said: “Immediately after the Shap incident we examined our sensors and processes and found no interventions are currently required in Scotland. This will be kept under review.

"Remote monitoring forms part of a much broader approach to managing the risk of adverse weather, alongside measures such as speed restrictions, physical inspections and real-time monitoring by our team of meteorologists.

“We have strong contingency plans should any device go offline and we continually test and enhance our systems as technology evolves.

"We have invested significantly in weather resilience, committing £1.9 billion between 2024 and 2029 to renew Scotland’s railway infrastructure.

“Around £400 million of this will strengthen the network against extreme weather, including more than £100m for earthworks, £100m for drainage and lineside infrastructure, and over £40m for bridges and tunnels."