How Space Storms Could Disrupt Train Signals and Trigger Serious Accidents

Electrical systems in railways across various countries, including the UK, are vulnerable to space weather phenomena. The most alarming possibility is a signal malfunction where a red light could inadvertently turn green, potentially leading to tragic train accidents, warns Cameron Patterson from Lancaster University, UK.

“This can disrupt the signaling systems which are vital for railway safety,” he states. “Proactive measures are essential to mitigate these risks, and it’s critical to communicate this urgently.”

The sun continually releases light and charged particles. This solar wind creates auroras. During solar storms, the sun can emit larger quantities of particles, which may impact the Earth’s magnetic field.

While satellites are particularly at risk, solar storms can also disrupt electrical systems on Earth, inducing unexpected currents in railway tracks due to shifting magnetic fields. This is particularly concerning as many rail systems utilize direct current to determine the presence of trains.

“When geomagnetically induced currents are introduced, they can create anomalies, leading to erroneous signals, such as green lights turning red,” Patterson explained at a recent European Geosciences Union meeting in Vienna, Austria. “Trains travel at high speeds, making it crucial to have advance warning to prevent accidents.”

Patterson cited a notable case from July 1982 in Sweden, where a signal was impacted by solar storm activities, and geomagnetically induced currents were correlated with the signal errors.

He believes more incidents may be overlooked as engineers rarely attribute these anomalies to space weather. Often, by the time they investigate, the solar storm has passed, leaving them unable to find clear causes. Studies in Russia have indicated similar correlations between solar storms and signal irregularities.

A red light erroneously turning green poses the greatest threat, but the reverse scenario can also create significant disruptions, especially if a train is immobilized and its electrical systems fail, potentially endangering passengers who leave the train.

Fortunately, the likelihood of these incidents is low. Such potent solar storms capable of causing these issues are estimated to occur once every 30 years, although a significant storm could strike at any moment, potentially leading to widespread power outages and chaos.

Certain countries have adopted alternative signaling systems using magnetic sensors to monitor train wheels; however, their susceptibility to geomagnetically induced currents remains uncertain.

Many railway systems may also be exposed to disruptions from solar storms, impacting transformers, systems aiding train tilting around curves at high speeds, radio communications, and satellite navigation critical for precise train positioning.

Patterson is collaborating with Network Rail, the Railway Safety Standards Board, and a British engineering firm to enhance system resilience. Initiating dialogue around this issue has been challenging, but their commitment is strong.

Magnus Wike from the Swedish Institute for Astrophysics shares concerns that solar storm-related signal anomalies might go unnoticed. “There may be brief disruptions, but without clear cause analysis, the system returns to normal,” he explains.

Wik mentioned that Sweden modernized its railway system in the 1950s after signal anomalies during geomagnetic storms in the 1930s. He emphasized that the 1982 instance of signals fluctuating between green and red was less severe in impact.

“The Swedish Transport Agency likely lacks insights into whether such events could reoccur,” he states. “We discussed the possibility of researching historical geomagnetic disturbances alongside error logs, though it’s not an official undertaking.”