Background

The Teignmouth section of the Great Western Mainline is one of the UK’s most iconic railway stretches, running along the dramatic red cliffs between Dawlish and Teignmouth. While visually stunning, this coastal route faces continuous threats from erosion, geological instability, and extreme weather events.

Cliffs rising up to 50 metres, made of weak sandstones and breccia formations, are particularly vulnerable to slumping, root-driven slab failures, and water erosion. Regular inspections are critical to maintaining both passenger safety and service reliability on this strategically important line.

Historic events, such as the 2014 Dawlish storm, which washed away a 40-metre section of seawall and closed the line for 59 days, highlight the necessity of proactive inspection and maintenance on this challenging route.

Method

GeoAccess combined rope access techniques, walkthrough inspections, and advanced drone surveys to monitor and maintain the route effectively.

The complex geology from Permian sandstone near Dawlish to breccia cliffs approaching Teignmouth requires specialist understanding and flexible inspection strategies. Traditional walkovers provide valuable ground-level insight, but cliff instability and difficult access points demand more innovative solutions.

Our drone technology offers a safe and efficient way to assess inaccessible cliff faces. Using high-resolution imagery, thermal cameras, and AIVR mapping tools, drones allow precise monitoring of cliff conditions. Positioning accuracy down to the 5-chain (100m) railway segments enables detailed analysis and data consistency for long-term monitoring.

By integrating monthly and bi-monthly walkovers with aerial drone assessments, GeoAccess delivers a comprehensive inspection approach that balances traditional expertise with cutting-edge innovation.

Innovations & Solutions

• Drone integration keeps personnel away from hazardous cliff edges and active rail lines, enhancing safety.
• Thermal and high-definition imagery detects structural weaknesses invisible to the human eye.
• Accurate geolocation through AIVR ensures inspection data is precisely tied to railway chainage for better tracking of erosion and instability.
• Rope access vegetation clearance complements aerial surveys, ensuring visibility of geological features for both ground and drone-based inspections.
• Daytime working avoids unnecessary night possessions, improving safety, efficiency, and sustainability.

Results & Conclusion

Using drones, rope access, and structured walkover inspections, GeoAccess has enhanced the resilience and safety of the Great Western Mainline’s coastal section.

Key outcomes include:

• Improved safety by reducing time spent on or near active railway lines.
• Faster, more efficient inspections, reducing disruption to Network Rail operations.
• Enhanced monitoring of cliff instability through combined drone and ground-level approaches.
• Long-term sustainability, ensuring this vital coastal route remains resilient against climate and geological challenges.

By continuously innovating inspection methods, GeoAccess provides Network Rail with a future-ready solution for coastal erosion monitoring and railway safety along one of the UK’s most exposed and iconic mainline routes.