Seasonal changes, especially as winter transitions into spring with the thawing of snow and ice, pose considerable challenges to railway infrastructure. Safety, performance, and reliability can all be significantly impacted. The challenges are multifaceted and vary significantly depending on geography, infrastructure and financial resource.
In 2024, the world witnessed the warmest January globally, with an average ERA5 surface air temperature of 13.14°C, marking the 8th consecutive month of record-breaking temperatures for the respective time of year.
What does this increase in global temperatures mean for our railways, the lifelines of our economies and communities, and how is the railway industry adapting to these challenges?
During the spring thaw, railway systems face a myriad of challenges. This seasonal transition period, marked by the melting of snow and ice accumulated during the winter months, brings about a range of issues that require careful attention and proactive management.
Track Stability: One of the primary concerns during the spring thaw is the impact on track infrastructure. The freeze-thaw cycle, a hallmark of spring, can lead to significant ground movement. As temperatures rise, the frozen ground thaws, potentially causing track voiding or heave. This can result track quality deterioration, which can be hazardous if not promptly corrected.
Temperature fluctuations also affect the rails themselves. Rapid temperature changes, can lead to rail buckling or rail breakages – both of which can have severe consequences..
The ballast and subgrade are also vulnerable to the spring thaw. Water from melted snow and ice can saturate the ballast and weaken the subgrade, reducing their ability to drain water effectively. Shifting of the track bed can result in uneven horizontal and vertical alignment along the rails, posing risks to train stability, track voiding and buckling. This can cause the tracks to become unstable, leading to slow zones, operational delays, or, in severe cases, derailments.
Railway infrastructure isn’t limited to tracks; it also includes bridges, tunnels, and other structures. These too can be affected by seasonal changes. Thawing ground can shift bridge foundations and tunnel supports, while increased moisture can lead to corrosion and weakening of materials.
The spring thaw can also affect the functionality of signalling and communication systems essential for safe railway operations. Moisture infiltration and temperature changes can compromise the performance of signalling equipment, potentially leading to signal failures and communication breakdowns. Regular testing, maintenance, and weatherproofing of signalling devices are essential to safeguard the operational integrity of the railway network.
Monitoring and assessing the condition of the infrastructure is essential to identify potential hazards and address them swiftly to maintain safe operations.
Drainage Issues: During the spring thaw, the increased water flow can overwhelm culverts and drainage systems, leading to waterlogging and erosion. Inadequate drainage can also contribute to subgrade and ballast problems, further exacerbating track instability. Excessive water on the tracks can weaken the foundation, potentially causing track washouts or mudslides that disrupt train services and require extensive repairs. Implementing effective water management strategies, such as drainage improvements and slope stabilisation, is crucial to mitigate these risks and preserve the integrity of the railway network.
Vegetation Control: Spring brings new growth, which can be a double-edged sword for railways. On the one hand, vegetation can help stabilise the soil and absorb excess water. On the other, uncontrolled vegetation can obstruct signals, encroach on the track, and hide potential hazards from view.
Strategies for adaptation and resilience:
To mitigate the risks associated with seasonal changes, railway operators and infrastructure managers implement a variety of strategies. These include:
Geotechnical solutions: Implementing geotechnical improvements, such as better drainage systems and stabilised track beds, can help manage the effects of thawing and freezing cycles.
Material innovation: Using materials that are more resistant to temperature changes for tracks, ties, and ballast to reduce the impact of extreme weather.
Enhanced monitoring and maintenance: Regular inspections and maintenance are intensified during transitional weather periods to identify and rectify potential problems early.
Advanced forecasting and planning: Leveraging weather forecasting and predictive analytics enables proactive adjustments to train schedules, speeds, and maintenance plans.
Role of technology in monitoring thawing conditions
Advancements in technology have revolutionised the monitoring and management of thawing conditions in railway infrastructure.
Remote sensing techniques, such as satellite imagery, LiDAR technology, and drones equipped with specialised cameras, have become powerful tools in assessing ground conditions and identifying potential risks associated with thawing.
Satellite imagery provides a comprehensive view of the entire railway network, allowing for the detection of subtle changes in ground conditions over a large area. This data is essential for identifying regions susceptible to thawing issues, such as areas with poor drainage or underlying geological features that exacerbate thawing processes. Additionally, the use of multispectral and hyperspectral imaging enables engineers to analyse the thermal properties of the ground and assess the extent of thawing in different regions.
In addition to remote sensing technologies, ground-based sensors play a crucial role in monitoring thawing conditions in real-time.
RailSense has been at the forefront of addressing some of the challenges posed by seasonal changes to railway infrastructure through the development and deployment of innovative solutions such as VoidSense, TempSense and TrackWater.
Sensors are installed at strategic locations along railway tracks to measure parameters such as track temperature, moisture content, silt levels and flooding. The data collected by these sensors is transmitted to a central monitoring system, where it is analysed to detect changes. This enables real-time risk assessment and predictive maintenance throughout the areas they are installed.
These systems enable real-time alerting and scheduled measurements, significantly reducing the need for trackside intervention and helping railway operators adapt to the unpredictable conditions brought on by seasonal changes.
By simulating different scenarios and evaluating the effectiveness of maintenance strategies, operators can optimise their decision-making process and enhance the resilience of their networks against the effects of thawing.
VoidSense® is a sophisticated void meter and track temperature monitor designed to autonomously monitor the vertical movement of rail tracks and the temperature of the rail. This device plays a crucial role in detecting under-track voids before they lead to failures, ensuring the integrity of railway infrastructure during the spring thaw and other seasonal changes. Its real-time updates, continuous logging, and ability to send alerts directly to mobile devices and dashboards enhance operational safety and efficiency.
TempSense® is a remote track temperature monitoring system that allows for the continuous monitoring of track temperatures and provides critical alerts when temperatures reach thresholds that could affect rail integrity. By enabling rail operators to intelligently plan train speeds and monitor critical rail temperatures, TempSense substantially enhances passenger safety and operational reliability.
TrackWater enhances infrastructure resilience by monitoring and managing surface water levels, crucial during the thawing period to prevent water-related damages and ensure efficient drainage.
The integration of these advanced technologies has not only improved the efficiency and accuracy of thawing condition monitoring in railway infrastructure but also enhanced the overall safety and reliability of railway operations. With real-time data, detailed terrain models, and predictive analytics at their disposal, railway operators can proactively address thaw-related challenges, minimise disruptions, and ensure the long-term sustainability of their networks in the face of changing environmental conditions.
The path ahead is filled with opportunities to redefine how railways operate. At RailSense, we believe that by continuing to develop and implement advanced, data-driven solutions, the railway industry can ensure safer, more reliable, and efficient operations, regardless of the environmental conditions.
For more details on these solutions, visit RailSense.
- January 2024 – Surface air temperature and sea surface temperature highlights https://climate.copernicus.eu/copernicus-2024-world-experienced-warmest-january-record