North York Moors Railway Monitoring

Overview

This project has was conducted by Academy Geomatics Ltd in collaboration with the North York Moors National Park Authority. The goal was to establish a comprehensive, real-time monitoring system to assess the behaviour of a landslip along the North Yorkshire Moors Railway, in order to ensure the safety and longevity of this crucial transportation link.  

Optical or geotechnical surveying?

Finding a suitable location for a total station proved challenging, as there wasn’t a spot that was both clear of the train tracks and had a view of the landslip. The valley offered limited stable ground for securing reference prisms. Moreover, the dense ferns and bracken, growing over a meter tall during summer, posed a risk of blocking the line of sight. Because of that, total station monitoring was considered unsuitable and was therefore decided to use Move Solutions wireless Tiltmeters.  

Solution implementation

A series of 24 Tiltmeters were installed across three sets on 1.5m high metal poles, embedding them 1m deep into the ground.  

Mark Anderson, Director at Academy Geomatics Ltd, Move Solutions Technical Partner, also recommended the addition of sensors directly on the railway tracks due to the landslip potential impact, evidenced by a drainage ditch already being compromised by ground movement. Four Tiltmeters were positioned on the sleepers, complemented by four Accelerometers, for both static and dynamic assessments of the track. The modal analysis performed with the Accelerometers is crucial, as it helps identify issues with ballast voids or with broken culverts crossing under the track.  

In addition to Tiltmeters and Accelerometers, a Dynamic Displacement Sensor (DDS) was placed at the centre of the track area to gather more comprehensive data. Video monitoring, enabled by PTZ cameras, was integrated to correlate sensor data with visual observations, enhancing the overall monitoring strategy.

Challenges overcome

The landslip and track monitoring faced challenges in terms of power and communication due to the remote location. A custom-made setup using solar panels, a wind turbine, and a special tower was created for reliable power, with carefully placed outdoor routers solving communication challenges. An additional Tiltmeter was then added to monitor the wind turbine.  

Timeline of the project

18-12-2023

Foundations dug, concrete poured, and tower bolt cage situated.  Landslip CCTV camera installed and ethernet cable run installed.

29-01-2024

Tower installed on bolt cage.  Solar panels installed on tower.  Tilt sensor locations set out on site.

30-01-2024  

Sensors installed in relevant locations.  Move Solutions gateway and CCTV camera installed on tower.  Equipment board and batteries installed on the tower. Communications equipment trailed at the top of tower. All equipment wired up.

01-02-2024  

Sensor locations accurately surveyed.  Communications equipment moved from the tower to the top of the escarpment.  Cable protected and dug into the ground.

13-02-2024  

Wind turbine installed and wired in.  Lidar and photogrammetric drone survey undertaken.

Sensors installed

• 24 Tiltmeters on the landslip
• 4 Tiltmeters on the track
• 1 Tiltmeter n the turbine tower  
• 4 Accelerometers on the track  
• 1 Dynamic Displacement Sensor on the track  
• 1 Gateway on top of the tower  

Project outcomes

The project successfully established a real-time monitoring system capable of detecting both static and dynamic movements, providing invaluable insights into the structural health of the railway and the adjacent landslip. The data collected informs maintenance planning, enhances safety, and contributes to the long-term resilience of the railway infrastructure.