By using a drone to capture the majority of the data, significant time, cost and safety savings can be made. Once survey control had been put in place on the ground, our dedicated UAV team was able to rapidly survey the entire site – tracks and all – without the need for ‘boots on ballast’ or closure of the line.

Flying from a position of safety, our award-winning Vogel R3D is the only UAV-based survey solution verified as able to capture data to Network Rail’s Band 1 accuracy level of sub-5mm.

To ensure nothing was missed, we then terrestrially laser-scanned at ground level to capture the underside of the bridge, the supports and the surrounding topography. The point clouds from both surveys were then combined into one point cloud database and from that a topographical survey of the site and a BIM model in Revit of the viaduct and its supports were extracted.

> How the Vogel R3D system works

As well as helping with design and asset management, the model and accompanying 360/panoramic imagery has a range of other benefits from site visualisations to logistics planning.

For example, on this project we mocked up a theoretical scaffold bridge in the model to show how the scaffold would look. We factored in how the water level of the river may affect the integrity of the scaffold – something the client was extremely interested in understanding.

We conducted a costing exercise of how much it might cost to paint the bridge, using the model to calculate the exact surface area, the volume of paint required, how long it would take to do and what the cost implications for this would be. This feeds into 4D Construction Sequencing, providing an intelligent visual of the project timeline.

We also showed the animated fly-through to both Network Rail and BAM Nuttall, during which an environmental expert spotted an invasive species – something that could have taken weeks to manually search for.