Heavy rain and flooding can short-circuit power supplies and disrupt signalling systems – the railway’s traffic light system – which is why we closely monitor weather forecasts and act fast when flood warnings are issued. Flooding can also block lines, wash debris and mud onto the track, or even wash away the ballast – the stones that hold the track in place – making it unsafe for trains to run until repairs are made.
Landslips are a serious risk, especially on embankments and cuttings, even after the rain has stopped. They happen when water saturates the soil, weakening its structure and causing it to slide.
High winds can also bring your journey to a halt. Fallen trees and wind-blown debris – including garden items like trampolines – can damage trains and electrical equipment. By putting in place speed restrictions, we enable trains to safely run, albeit a little slower.
When the temperature drops, even the lightest shower of rain or dusting of snow can freeze and become compacted on the rails, turning into dangerous ice. Not only does this freeze around the electric rail and create an insulating effect preventing trains from drawing power and being able to move with any speed – in the worst cases, it stops them from being able to move at all.
Snow and ice also causes points - which allow trains to move between tracks – to freeze solid, or get jammed with compacted snow. When this happens, trains can’t safely run over them.
The couplers that join carriages together can also become iced up, making it difficult to join them together, or split them apart, reducing the number of trains we have available.
The more times trains stop and start in ice and snow, the more likely it is that they won’t get enough power to get going again, and by running the Winter Weather Timetables, we enable trains to stop and start less which means they are less likely to get stuck.