Rail services around Britain are expected to be severely disrupted next week, with trains running slowly to reduce the risk of track and equipment failing in extreme heat.
Blanket speed restrictions are likely to be put in place around the south-east of England, with the air temperature forecast to possibly surpass the highest ever recorded in Britain, which was 38.7 in 2019.
Network Rail’s emergency weather action teams are meeting on Friday to examine detailed forecasts, and will be expected to limit train speeds for safety if temperatures pass 35C.
Passengers will be informed that trains are likely to run with severe delays, particularly on main lines in and out of London, where a 60mph speed limit would have a significant effect on fast services.
It means intercity trains to Scotland, Wales and the furthest points of England could be disrupted as much or even more than London and the south-east – the regions forecast to experience the hottest temperatures.
Rails, overhead lines and points are all susceptible to extreme heat. Steel rails can get as hot as 55C on a 35C day, and are more likely to buckle when used by trains travelling at higher speeds. Overhead lines can sag, while other railway equipment failure is likelier in the heat. Line-side fires are also a risk, and the railway’s incident response teams will be on high alert.
A Network Rail spokesperson said: “Passengers need to be prepared for extreme temperatures next week, and to take a bottle of water on the train when travelling. There will be disruption, so plan ahead, be prepared, and check before you travel.”
Local speed limits can be put in place at temperatures above 30C, but blanket restrictions are likely to be put in place from Sunday to Tuesday on current forecasts.
In 2019, many trains were cancelled and passengers advised to avoid travel in a July heatwave during which a record temperature of 38.7C was recorded in Cambridge.
Network Rail receives detailed weather reports from specialist forecasters that pinpoint each square mile of railway, and will examine them on Friday before announcing any speed limits.
Transport for London, meanwhile, said it had a comprehensive hot weather plan in place to protect its infrastructure and keep services running.
Mark Evers, TfL’s chief customer officer, said: “During this hot weather, we advise customers to ensure they have water with them when they travel, offer a seat to those who may need it and that they may wish to travel at quieter times when possible.”
Trains on about 40% of the tube network are now air-conditioned, as well as London Overground and Elizabeth line trains. TfL has introduced industrial-sized fans and chiller units to pump cold air into the older underground lines.
