Extreme temperatures are a growing concern for railway infrastructure around the world, and the UK is no exception. With climate change intensifying, the UK has experienced a series of scorching heatwaves and freezing spells in recent years, putting immense pressure on the rail system.
Just last year, the July 2022 heatwave caused widespread train delays and cancellations. The whole of the East Coast lines between Edinburgh and London were closed for hours because of the heat1.
The Global Railway Review reported that research shows that blistering heat to sudden downpours of rain increasing the risk of flash flooding also increases the risks of landslips. It is anticipated that heavy rainfall combined with higher wind speeds, hotter and drier summers and warmer but wetter winters will become the norm. If this is the case, these conditions will further impact the railways increasing the chances of falling trees, buckling, flooding and landslips2.
In this article, we delve into the issues caused by extreme track temperatures in the UK and discuss how other countries have mitigated these issues on their railways. Furthermore, we will shed light on the RailSense IoT track monitoring products, currently employed in the UK and Canada, which have shown promise in mitigating these problems.
The Impact of Extreme Temperatures on UK Railways:
Extreme temperatures pose significant challenges to the stability and safety of rail infrastructure. One of the primary concerns during heatwaves is track buckling, where rails expand and can buckle or warp due to excessive thermal stress. This can lead to derailments, delays and disruptions in the entire rail network.
UK railway tracks are pre-stressed to resist the impact of hot weather, which can cause significant disruptions however they are designed with a stress-free temperature of 27 degrees – the average summer rail temperature in the UK. The rails can struggle when air temperatures reach 30 degrees, as the rail temperature can be up to 20 degrees warmer and buckling issues can begin to arise.
Despite modern track systems being predominantly built on concrete sleepers, some parts still cannot withstand such high temperatures. The steel rails’ expansion due to heat can potentially lead to rail buckling, which is an ongoing concern.
Since train movement generates forces on the track, and with the intensity of these forces increasing as the speed of the train rises, during periods of high heat, trains are intentionally slowed down to minimise the extra stress exerted on the railway system.
As global temperatures rise, it might seem logical to replace all UK rails with ones designed to withstand higher temperatures, akin to those in extremely hot climates. However, such a move could potentially induce higher stress on the rails during the winter months, when freezing temperatures during cold spells also result in rail-related issues.
When tracks become extremely cold, the contraction of rails may cause track fractures and misalignments. These failures can lead to delays, cancellations and even accidents. The UK has experienced instances of track fractures during freezing conditions, highlighting the vulnerability of its rail infrastructure to extreme temperatures.
But the stress on the track in extreme heat is not the only issue facing the rail infrastructure in the UK. Prolonged spells of high temperatures can cause the overhead electric powerlines to expand. Once expanded they are likely to begin sagging, which further impacts train services3.
The Effects of Extreme Temperatures on Rail:
Extreme temperatures have a multifaceted impact on rail operations. Apart from the immediate safety risks, they also disrupt train schedules and create inconvenience for passengers. Track speed restrictions are often imposed during extreme weather conditions, causing delays and longer journey times. Furthermore, the maintenance and repair costs associated with temperature-induced damages escalate significantly, putting a strain on the already burdened railway budgets.
Effects on Signalling and Electrification Systems:
Extreme temperatures can also affect signalling and electrification systems. The expansion and contraction of cables and wires can cause electrical failures and disruptions in signalling, leading to reduced network capacity and potential safety risks.
Mitigation Efforts in Other Countries:
Railway networks in various countries have taken proactive measures to mitigate the effects of extreme temperatures on their infrastructure. For instance, countries like Australia and Spain have implemented advanced rail welding techniques that allow rails to better withstand extreme heat. This reduces the risk of track buckling and improves the overall resilience of the rail network.
Moreover, some countries have adopted cooling techniques to alleviate the impact of extreme temperatures. These techniques include the use of water jets, sprayed on tracks during heatwaves to lower rail temperatures and minimise the risk of buckling. Similarly, shade structures and heat-reflective materials have been employed to shield rails from direct exposure to the sun.
RailSense IoT Track Monitoring Products:
Recognising the urgency to address the challenges posed by extreme temperatures, innovative solutions such as the RailSense IoT track monitoring products have emerged. These cutting-edge technologies utilise advanced sensors and real-time data analysis to monitor track conditions continuously. VoidSense, BuckleSense and TempSense are now being used in the UK and Canada to proactively identify temperature-related issues and enable prompt intervention.
These IoT devices measure various parameters, including rail temperature, stress, and strain. By analysing this data, railway operators can detect potential risks of track buckling or fractures, enabling them to take preventive measures before any serious incidents occur. The adoption of RailSense products has shown promising results in reducing track-related failures and improving overall network resilience.
The Need for Expedited Adoption:
As global warming accelerates and extreme weather events become more frequent, it is crucial to expedite the adoption of technologies like RailSense IoT track monitoring products. These advancements provide railway operators with timely insights, enabling them to address temperature-related issues proactively. By doing so, disruptions and safety risks can be minimised, and the resilience of the rail system can be enhanced.
The effects of extreme temperatures on UK railways have become a harsh reality. Track buckling, fractures, signalling failures and delays are just some of the challenges faced due to scorching heatwaves and freezing spells. However, by learning from the experiences of other countries and embracing innovative solutions such as RailSense IoT track monitoring products, the UK can mitigate these issues.
The rail industry must prioritise the adoption of advanced technologies to safeguard against further problems as global warming takes hold. By doing so, we can ensure the reliability, safety and sustainability of the UK’s rail network for years to come.