Staying on track in summer heat and winter chills 

The weather impacting travel plans isn’t anything new. But for the UK’s railways, our varied and changing climate introduces additional challenges.  

A changing climate increases the frequency of severe weather events. Warmer air can hold more water, so rainfall is increasing on average across the world. In some places, rainfall is becoming more intense as well. 

In addition, record-high temperatures are being seen more frequently. Summer 2022 saw the UK record breaking a new all-time high of 40.3°C during a heatwave when 46 stations met or exceeded the previous national record of 38.7°C. With records highs, railways in the UK also have to endure sub-zero conditions in the winter, and even high-impact storms.  

Image: Shutterstock

During Storm Eunice in February 2022 – which struck during a week of three named storms – cancellations on the rail network was at 44.1%. 

The Office of Rail and Road (ORR) is the independent regulator responsible for safety monitoring on Britain’s railways; an area of the UK’s travel infrastructure that can be sensitive to variations in the weather.  

ORR’s role for Britain’s railways involves working with train operators to ensure safety procedures are being followed and that people can get around safely on Britain’s trains, whatever the weather.  

Paul Appleton is Deputy Director of Railway Safety at ORR and his team is busy working with operators through the winter season. He said: “Temperature range is a very interesting issue when it comes to the ability of Britain’s railways to run safely. 

“At the cold end of the spectrum, the steel on our railways contracts, which can put them under massive tension and expose any underlying flaws. When it gets hotter, the steel expands and if it gets to extreme levels of heat then that expanding rail will risk buckling and possibly derailing a train.” 

In 2022 temperature extremes weren’t hard to come by. The record maximum temperature of 40.3°C was recorded at Coningsby in July as part of a severe and widespread heatwave. At the other end of the scale, -17.3°C was the lowest temperature recorded in 2022, in Aberdeenshire in December. Train operators are often forced to impose speed restrictions to mitigate risks at either end of the spectrum.  

Part of ORR’s remit is to ensure train operators have the processes in place to manage variations in temperature; something that can be traced back to selecting the type of steel used for Britain’s railways. 

Paul said: “Rail temperature is very different to air temperature and there’s an operable range for steel railways. You can design your steel to work within a certain range, but you can’t extend that range. If you want the railways to be able to withstand 40°C summer heat, you’ll lose some of its reliability in lower temperatures during the cold winter months.” 

Winter weather 

As cold winter weather has come back into force in recent days, ORR’s focus has shifted towards low temperatures, snow, ice and the possibility of named storms.  

“With snow, the problem is pretty obvious. If there is enough of it, it blocks the railway. With ice, there’s a risk of it forming on the 3rd rail which can prevent trains from drawing sufficient power,” said Paul.  

Image: Shutterstock

Fortunately, rail operators, much like the public at large, take preventative action to mitigate the impacts of severe weather.  

In the early hours of the morning, while much of the country is still sleeping, trains take to tracks all over the country clearing leaves from the line and de-icing the surface of the 3rd rail.  

“Leaves on the line can be a big issue at this time of year. When trains run over leaves on a track, it creates a poor adhesion environment, where trains – which are obviously very heavy – struggle to get the friction required to move and stop efficiently.  

“Just one way that risk is managed is with trains being sent out with high pressure jet washers to keep leaves off the line and ensure trains have the best possible contact with the track. This will often also include applying a substance to improve grip.” 

According to Rail and Standards Board figures, poor adhesion costs the rail industry and wider society an estimated £355million every autumn. The Met Office works with many leaf adhesion services to help improve efficiencies throughout the year.  

Be prepared 

Tracks have an operable temperature range which can be sensitive in a UK climate. (Image: Shutterstock)

With steps taken to prepare railways ahead of severe weather, the public also have a role to play in keeping Britain’s railways running smoothly.  

For ORR, a ‘severely disrupted day’ of rail travel is when cancellations are at 5% or more. During Storm Eunice on 18 February, that rate was at 44.1%.  

Paul says the preparedness of the public for severe weather can help mitigate the disruption on days of severe weather.  

“After a storm, debris on the line is one of the leading causes of ongoing disruption to rail services. Of course, some of this is down to fallen trees, but we also get a lot of garden furniture and trampolines on the tracks which all has to be dealt with before services can fully resume.  

“Taking some time ahead of a storm to check for things that could be blown away would help and could also prevent delays on roads as well. 

“If you’re looking to travel after a storm, take some time to check your train operator’s website to see if there are likely to be any issues. It’s thanks to the Met Office that they know when weather conditions will be impactful enough to disrupt operations, so do also check the Met Office website or App ahead of travel.” 

The Met Office’s WeatherReady website brings together seasonal advice from expert partners  to help you stay safe and make the most of the weather all year round. WeatherReady provides simple preparedness tips anyone can do to help them prepare ahead of severe weather.

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