Austria
Hungary
Bosnia-Herzegovina
Bulgaria
China
Germany
Italy
Croatia
The Netherlands
Poland
Romania
Russia
Serbia
Slovakia
Slovenia
Czech Republic
Turkey
-payr-2280.jpg?t=1782737398130&s=0.5&f=webp "© RCG/Payr")
Summer heat affects more than just people. Railways also feel the impact of rising temperatures, particularly where steel, ballast, technology and timetables must perform reliably every day. What may appear stable and immovable at first is, in fact, a finely tuned system: rails expand, overhead lines react to temperature changes, and points and signals must continue to function safely in extreme conditions.
This is particularly relevant for rail freight. When heat puts pressure on infrastructure, it affects not only individual trains, but entire transport chains.
-payr-1900.jpg "© RCG/Payr")
Why is extreme heat a problem for rails?
Rails are made of steel. Steel has one key property that becomes crucial in summer: it expands when heated and contracts when temperatures fall. Rails are usually either welded together or joined with fishplates. This allows for smoother running, less wear and tear, and greater passenger comfort. However, it also means that the rail cannot simply expand freely.
When temperatures rise sharply, high compressive forces build up in the track. Under normal conditions, this is accounted for; the rails are installed and tensioned in such a way that they can withstand significant temperature fluctuations. However, in extreme heat, the stress can become so great that the track shifts sideways. This is known as track buckling.
A deformed track cannot remain in operation. First, specialists have to check whether the affected section is safe. Depending on the situation, this can lead to speed restrictions, closures or diversions. It is a common misconception that if the air temperature is 35°C, the rails are too. In reality, rails exposed to direct sunlight can heat up significantly more.
Overhead contact lines and locomotives are affected too
It's not just the track itself that's under strain. Overhead contact lines react to temperature changes, too. They must be kept correctly tensioned to ensure locomotives are reliably supplied with power. Extreme heat can necessitate additional checks and precautionary measures.
-payr-1900.jpg?t=1782738517550&s=0.5&f=webp "© RCG/Payr")
Locomotives are affected too, as their cooling systems, electronics and mechanical components are placed under greater strain. This can lead to damage and, in some cases, locomotives being taken out of service when they are exposed to extreme heat. This is why additional maintenance and inspection measures are often required during periods of high temperatures. Safety remains the top priority.
For operations, this means that temporary restrictions may be put in place on individual sections of the network. This may involve reducing speeds, adjusting services, rescheduling transports or working with partners to stabilise operations. This is particularly complex in rail freight because every train is part of a wider supply chain.
While rail is weather-resistant, it is not weather-independent
Rail is one of the most robust transport systems in Europe. At the same time, however, it forms part of an open infrastructure that is exposed to wind, rain, snow, frost and heat every day. The challenge lies in ensuring that rail freight remains reliable even as extreme weather events become more frequent.
And that is precisely what is happening. Heatwaves in Europe are becoming more frequent, intense and long-lasting. Climate change is no longer an abstract issue for the future; its effects are already visible in day-to-day operations in the form of extreme temperatures, heavy rainfall, flooding, storms and drought.
For rail, this means two things. Firstly, infrastructure, rolling stock and operational processes must adapt to changing climate conditions. Secondly, since the transport sector contributes significantly to greenhouse gas emissions, the modal share of rail freight in Europe must increase, and sustainable rail freight must be strengthened.
No mode of transport is immune to heat, including rail. However, it remains one of the most important ways of making Europe’s freight transport more climate-friendly, efficient and future-proof.