GeoAccess: Earthwork examinations

Rob Fisher

It is a late December morning. The sky is a leaden-grey, the temperature is in single digits, it is starting to rain and the wind makes it feel a lot colder. A GeoAccess earthwork examiner starts up the GISmapp application and opens up the record of the first of many earthwork assets to be inspected. They beckon to their vegetation management team “lets go”, and so begins another day of earthwork examinations. Across England and Wales dozens of our earthwork examiners do the same.

No drones and certainly no robotic dog here; this is Human V1.0 and the accompanying Mk 1. Eyeball. It is niche and highly specialised work, requiring a special type of person; there are fewer than 100 earthwork examiners working across England, Scotland, and Wales during any given examination season. As sole framework contractor responsible for earthwork examinations in Network Rail’s Southern, Wales, and Western Regions, GeoAccess employs the majority. We select the very best, looking for that special blend of knowledge, experience, perception, and intuition.

Early-warning system

The 2023/24 season will see our earthwork examiners inspect over 15,600 individual five-chain lengths, comprising cuttings, embankments, and rock slopes. Ahead of this, enabling works to clear vegetation will be undertaken, alternative access points to reduce the need for line blocks and possession will be determined, and sites requiring rope access will be identified.

The process of inspection remains largely unchanged since the early days, a detailed visual assessment that requires a keen eye. Not just for the obvious signs of slope instability but the subtle, less discernible features and other factors, notably the condition of drainage, retaining structures and, more recently, outside party slopes. Our earthwork examiners are the early-warning system, often calling in issues that may pose a risk to the safe running of trains, or an urgent defect that requires prompt action, not just for earthworks, but also structures and dangerous trees, particularly following storm-events.

While technology is available for other methods of inspection, such as LiDAR surveys and producing 3D digital twins, the scale and number of assets to inspect means that from a practical, feasibility, and compliance standpoint, applicability is reserved for special inspections of problem assets. As the technology improves, along with Big Data handling, machine-learning, and AI, the problems of scale will eventually be overcome. In the interim, our earthwork examiners provide feedback on the GISmapp application such as improvements to enhance the user-interface to allow greater efficiency, and data checks for erroneous or conflicting information prior to completing an exam to ensure quality and compliance are maintained to a high standard.

We work closely with Jeremy Benn Associates (JBA), developers of GISmapp and the maintainer of the Earthworks Database, to seek continuous improvement and efficiencies. A new chapter of collaboration with JBA will begin shortly as we look to the latest in innovation and technology to elevate earthwork examinations to a new level for the 21st century. A successful trial with One Big Circle, developers of the AiVR platform, means we can now capture video with our drones and have it precisely geo-located to ELR, mileage, and side of the line. Going forward, we will use video surveillance on the Cornish Main Line between Dawlish Warren and Teignmouth to monitor the vulnerable rock formations that form the cliffs as a supplement to our regular foot patrols of the section.

Rapid response

At time of writing (April 2024), GeoAccess has attended 373 earthwork incidents since the summer of 2020, when our records began. The Network Rail Southern Region accounts for 51% of the total (Wales 30%, Western 13%, others 6%). With the number of named storms and associated high-intensity rainfall events increasing each year, climate change is having a significant impact on earthworks. January 2023, a period of prolonged wet weather, saw the southern half of England receive above average rainfall. Consequently, 25 earthwork incidents occurred during that month (the highest total for a single month), of which 19 occurred in the Southern Region. The upward trend continues, for the period January to March 2024, GeoAccess has responded to 60 incidents, compared to 46 for the same period in 2023.

A strategic review of our rapid response service is currently underway, which will include a review of records to identify weather-related earthwork ‘hot spots’ across the regions we work in. This will help us to provide additional earthwork examiners when severe weather is forecast to impact those areas, in anticipation of multiple incidents occurring.

What next for GeoAccess?

Growth of the business, through continuous learning, innovation, and collaboration, and being our best, is at the forefront of everything we strive for. The coming months look to provide some interesting and exciting opportunities in respect of collaborative working with past and current partners, not just in earthworks but other disciplines for which we are strongly positioned.

This year will see significant recruitment as the upcoming 2024/25 earthwork season will be our biggest to date. In response to the increase in numbers of earthwork examiners, one of our priority internal projects is the continued expansion of our learning and training platform, GeoAccess Academy, including developing VR training for earthwork inspections in partnership with Techcare Digital.

Beyond 2024 may well see our gaze extend towards Europe.

Image credit: GeoAccess