Delays on the railways could be caused by solar storms, say scientists

Researchers from Lancaster University said a storm could affect electrical circuits and change signals from red to green.

Solar storms could potentially change railway signals from red to green, scientists say (Chris Radbourn/PA) (PA Archive)

UK scientists have claimed some train delays could be caused by “space weather” after they found solar storms have caused malfunctions in railway signalling systems.

Research from Lancaster University will be presented this week claiming solar activity can cause electrical currents flowing on Earth to interfere with signals, turning them from green to red even if there are no trains nearby.

Signals operate like traffic lights and detect whether a train is currently standing on a particular section of the line, in order to stop any potential collisions.

Even moderate solar storms can offset the balance of electrical currents which control train signals, the researchers said, but stronger solar storms cause more signals to malfunction, which in turn can increase the amount of time a train can be delayed.

Cameron Patterson, a PhD student at Lancaster University and one of the scientists investigating the phenomenon, said: “Most of us have at one point heard the dreaded words, ‘your train is delayed due to a signalling failure’, and while we usually connect these faults to rain, snow and leaves on the line, you may not have considered that the sun can also cause railway signals to malfunction.”

The team of scientists investigated the impact of space weather on the South-North line from Preston to Lancaster and a West-East line from Glasgow to Edinburgh.

Mr Patterson added that his next project is to look at how strong a solar storm would be needed to change a red signal, when a train is on the line, back to green to indicate that the line is clear, which he described as “a far more hazardous scenario potentially leading to crashes”.