Solar storms, which occur due to explosions of electromagnetic energy that take place on the surface of the Sun, often have a range of effects ranging from increased visibility of auroras to certain radio communication frequencies that are interrupted for a few hours. However, in a new study presented at the National Astronomy Meeting (NAM 2022) last week, researchers believe that railway signal failures may be related to space meteorological events such as solar storms.
According to physicist Cameron Patterson of the University of Lancaster, these space weather events can induce electrical currents that interfere with the normal operation of signaling systems, turning green signals to red when no train is nearby.
He explains: “Most of us have heard at one point the dreaded words:‘ your train has been delayed due to a signal failure ’.
“While we normally connect these faults with rain, snow and line leaves, you may not have considered that the Sun can also cause rail signals to malfunction.”
By interfering with the electrical signals and causing the red lights to change to green, the researchers warned that in this way, solar storms can cause horrifying accidents.
However, Patterson noted that this would be an extreme result, and said: “We are now working to examine the case where there are trains on the line and the force that must be a storm to return a red to green signal. . ”
This, he added, is “a much more dangerous scenario that can lead to accidents!”
In rail systems, trains are located by dividing lines into small consecutive segments known as “blocks” that tend to be between 0.6 and 1.2 miles long.
Each of these blocks is linked to a signal that identifies where a train is currently in that block, which are controlled by relays that detect electrical currents in the system, which means that there is no train in the block, and therefore , the green light comes on.
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Conversely, if the relays do not detect current, the system believes that the block is occupied by a train, turning the lights red.
By inducing currents in the rail network, solar storms can cause sections of the track to be assigned a red light even when they are not busy.
In addition, the stronger the solar storm, the more likely the signals are to malfunction, increasing the delays experienced by travelers on the rail network.
Previous studies have detected induced currents with field strengths greater than 7 V / km, while extreme solar storms are expected to produce fields as strong as 20 V / km.