The effects of climate change and associated extreme weather have led to everything from reduction or cancellation of rail services to landslips and even derailments. Here, Terram®’s Adam Brooksbank looks at how tracks and railway slopes can improve long-term climate resilience
Over recent years, extreme weather events have steadily become more frequent. Last September saw 32% more rain than the UK average, with Wales experiencing 74% more than its long-term average.
Meanwhile, globally 2025 was the third warmest in modern history, with recent studies demonstrating an increase in the frequency and duration of heatwaves.
Extreme weather can cause serious issues on our railways, a challenge widely acknowledged by the industry, as evidenced by Network Rail’s £2.8bn investment over 2024-2029 dedicated to mitigating the effects of climate change.
As a result, resilience in the face of climate change has become a key talking point in the rail sector, and needs to be a major consideration in planning, especially in regard to track bed resilience and railway slope erosion.
So, when it comes to reinforcing rail infrastructure in the face of changing climates, what are the materials which can allow us to best cope with extremes of temperature and moisture?
Track beds
The steady increase in rainfall, and frequent instances of intense rainfall precipitated by our changing climate, pose a serious risk to the integrity of trackbeds.
The drainage systems currently in place in many areas of the UK are unable to cope with the volumes of water that are now becoming commonplace, and when they become overwhelmed, the result is unsafe levels of water infiltration. The result of this happening repeatedly is fouled ballast, leading to wet beds and mud pumping.
Similarly, extreme instances of freezing and thawing can promote moisture accumulation and degradation, which given the -10C temperatures experienced in parts of England and Scotland during 2024, is another significant consideration.
The development of wet beds represents multiple challenges, potentially compromising track geometry due to reduced stability, causing operational disruption, ‘rough rides’, and expensive remedial works.
To address these moisture related issues, geosynthetics are being adopted globally to improve trackbed resilience.
Dependent on the ground conditions, a geotextile filter and separator, such as the Terram PW1 can improve drainage and separation, reducing the size of sand blanket required, and thereby minimising the need for excavation and associated disposal of fill. In certain environments, the use of geocomposites, for example our Hydrotex range, can remove the need for sand blanket entirely, whilst providing robust defence against the negative effects of heavy rainfall.
As well as filtration and drainage capability, geosynthetics can strengthen subgrade weakened by moisture or poor filtration. A geogrid composite, such as Terram PW4-LA, can stiffen the ballast by providing reinforcement at the base, and according to a research program by British Rail can also; extend maintenance intervals, reduce elastic deflections and slow the rate of deterioration of the vertical track geometry.
Railway Slopes and Embankments
The Government describes flooding in England as a ‘systemic and growing climate risk’ with river, coastal, surface water and groundwater flooding increasing in intensity and frequency. This, alongside increased rainfall, can saturate soil, increasing water pressure and weakening embankments, potentially leading to landslips.
While the impact of escalating rainfall and flooding is one affecting railway networks globally, the nature of the UK’s steep, Victorian-era slopes make it particularly susceptible to serious issues like erosion and landslides.
Conversely, extreme hot weather is also a risk factor for slopes and embankments. Prolonged heat can result in a lack of moisture in the soil, which can cause shrinkage and track disturbances. Last summer, for example, saw train services reduced, delayed or slowed in Dorset and Devon as a result of embankment shrinkage related to the UK experiencing its sunniest spring in over a century.
This is where geosynthetics can again be utilised as a valuable mitigation tool. Geosynthetic solutions including geocells, geogrids and geotextiles can protect against the consequences of climate change in a number of regards, and chief among these is stabilisation.
Whether soil is negatively impacted by moisture or heat, installation of geocells can immediately provide slope stability by confining the fill and significantly improving resistance to wind and surface run-off. When filled with topsoil, stability is further enhanced as vegetation establishes, with the honeycomb structure of the geocell protecting plants during the early stages of germination and growth. Though not a quick fix, facilitating this vegetation in and of itself can guard against the effects of extreme hot weather.
Implementing a geosynthetic drainage layers can also not only mitigate against extreme rainfall and flooding but help to maintain a consistent level of soil moisture which will guard against the effects of hot weather and drought.
While there is no silver bullet for futureproofing railways against the effects of climate change, the inclusion of geomaterials in the planning of new or maintenance of existing railway infrastructure can offer significant support in guarding against the serious impacts of extreme moisture and heat. As we continue to experience extreme weather, the use of new and innovative materials will be a vital factor in ensuring that we keep our railways running.