@article{ref1,
title="Modeling "wrong side" failures caused by geomagnetically induced currents in electrified railway signaling systems in the UK",
journal="Space Weather",
year="2023",
author="Patterson, C. J. and Wild, J. A. and Boteler, D. H.",
volume="21",
number="12",
pages="e2023SW003625-e2023SW003625",
abstract="The majority of studies into space weather impacts on ground-based systems focus on power supply networks and oil and gas pipelines. The effects on railway signaling infrastructure remain a sparsely covered aspect even though these systems are known to have experienced adverse effects in the past as a result of geomagnetic activity. This study extends recent modeling of geomagnetic effects on DC signaling for AC-electrified railways in the UK that analyzed &quot;right side&quot; failures in which green signals are turned to red. The extended model reported here allows the study of &quot;wrong side&quot; failures where red signals are turned green: a failure mode that is potentially more dangerous. Railway lines using track circuit signaling, like those modeled in this study, are separated into a number of individual blocks. This study shows that a relay is most susceptible to &quot;wrong side&quot; failure when a train is at the end of a track circuit block. Assuming that each train is positioned at the end of the block it is occupying, the results show that the geoelectric field threshold at which &quot;wrong side&quot; failures can occur is lower than for &quot;right side&quot; failures. This misoperation field level occurs on a timescale of once every 10 or 20 years. We also show that the estimated electric field caused by a 1-in-100 years event could cause a significant number of &quot;wrong side&quot; failures at multiple points along the railway lines studied, although this depends on the number of trains on the line at that time.<p /> <p>Language: en</p>",
language="en",
issn="1542-7390",
doi="10.1029/2023SW003625",
url="http://dx.doi.org/10.1029/2023SW003625"
}