Landslip Along Shropshire Railway Corridor

In March 2024, a landslip occurred beneath a stretch of railway between Shrewsbury and Wolverhampton, UK.

Railway slips happen when the ground below the tracks becomes unstable. This often occurs because of heavy rainfall, soil erosion, or weathering of the rocks. These factors can cause the soil beneath railway lines to shift or collapse. Experts believe that about 5,000 tonnes of material moved following the collapse near Oakengates on the 8th of March.

Work to restabilise the railway embankment involved excavating the displaced material to create a new profile for the slope. The project required 12,000 tonnes of stone to reduce the gradient and strengthen the embankment (Network Rail, 2024). Finding and placing this material could have easily cost over £600,000. This does not include the cost of disrupting rail services.

Interferometric Synthetic Aperture Radar (InSAR) is a remote sensing method that uses satellite images. It helps monitor ground movement by comparing satellite radar images of the Earth’s surface taken at different times.

In the case of railways, InSAR can find small ground movements. It does this by analysing the phase differences in high resolution radar images.

This method shows tiny changes in elevation, even as small as a millimetre. This helps detect ground movement under and around tracks early. This movement may signal a possible landslip. Early detection allows for timely maintenance and prevention measures.

Implementing InSAR monitoring as a pre-emptive maintenance method can present many business benefits for rail infrastructure stakeholders:

1. Improved Safety: InSAR monitoring detects ground movements early. This helps prevent landslips and keeps passengers and cargo safe.

2. Cost Savings: Finding and preventing landslips early can greatly lower costs. This includes emergency repairs, track closures, and accident-related expenses, like in this UK incident.

3. Improved Reliability: Regular monitoring keeps railway infrastructure in good shape. This leads to fewer disruptions and more reliable service schedules. As a result, customer satisfaction and trust increase.

4. Regulatory Compliance: InSAR monitoring can assist in meeting regulatory requirements for infrastructure maintenance and safety, avoiding potential fines and legal issues.

5. Data-Driven Decision Making: The ongoing data from InSAR helps make better maintenance and investment choices. This improves resource use and long-term planning.