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It’s just a bit of hot weather…

In fact, hot weather can cause the overhead lines to expand and sag. To avoid damaging the lines, trains must travel more slowly than normal

How does hot weather impact the railway?

Overhead power lines

Overhead lines provide the power trains draw from to run. Hot weather can cause these overhead lines to expand and sag. Trains have to slow down to avoid these lines getting damaged.


Some train services may have to be cancelled or diverted until we can repair damaged overhead lines. Most overhead lines in Britain are modern and are more resistant to the impacts of hot weather. These modern lines have auto-tension systems, which use balancing weights or springs to adjust themselves to changing temperatures. Older lines have fixed tension – making hot weather and changing temperatures more likely to affect them.


Find out how Network Rail prevents delays caused by overhead powerlines.

Buckled rails

Hot weather can cause steel rails to get up to 20 degrees hotter than air temperature. This causes the rails to expand and push against other pieces of track. This can damage the equipment that detects a train’s location and helps keep trains a safe distance apart. If this happens, Network Rail stop trains to ensure everyone is safe. Rail with no space to expand can buckle. If this happens, Network Rail must close the line for repairs before any trains can run again. Repairing the line or stopping trains can cause delays.



Find out how Network Rail prevents tracks from getting too hot.

Prolonged droughts

The ground underneath tracks can dry out and shrink during long periods without rain. This creates large pothole-like cracks. To keep everyone safe, trains cannot travel at full speed over these cracks.


How do Network Rail minimise delays caused by droughts?

  • Introduce a temporary speed restriction in areas affected by droughts

  • Frequently check affected areas and identify maintenance required for any damage caused by drought

  • Add stone to significant cracks to support tracks and machines, and realign the rails



Find out more about temporary speed restrictions.

Travel safety during hot weather

We want to ensure everyone is safe when travelling on the railway in hot weather. Please follow the below advice to keep safe this summer.

  • Carry water with you

  • Ask staff for the location of water fountains in our stations

  • Do not board a train service if you feel unwell. If you are travelling and feel unwell please get off at the next stop and seek help from station staff

  • Avoid pulling the passenger alarm between stations, as help can be more easily obtained with the train in a platform, as opposed to standing stationary on a railway line