UAV Survey of Historic Wades Bridge

Location:
Wade's Bridge, Aberfeldy, Perthshire 

Clients:

• Perth and Kinross Council

• WSP 

Industry:
Local Authority / Historic Infrastructure / Asset Management 

Background
Wade's Bridge, originally called Tay Bridge, is a historic five-arch, Category A listed structure in Aberfeldy, Scotland, that was designed by architect William Adam. Completed in 1733 for Lieutenant General George Wade, it was built using chlorite schist from a nearby quarry as a vital link in a strategic military road system. 

Malcolm Hughes was selected for this project due to our specialist experience in complex surveying environments, our ability to combine UAV, laser scanning, and traditional survey techniques, and our proven record of delivering accurate, defensible data for historic and sensitive structures. Services requested on this project were: UAV photogrammetry, Terrestrial laser scanning, Integrated survey control, Topographic survey. 

Challenges

The project required a solution capable of capturing fine structural detail across a complex historic structure with difficult access, varying elevations, and strict non-intrusive requirements. Accuracy was critical, as the data needed to support long-term condition comparison without reliance on frequent repeat surveys or on-site inspections. 

In addition, multiple survey techniques had to be seamlessly integrated within a single, consistent control framework to ensure the data was robust, defensible, and future proof. 

Value to Client:

• Reduced need for repeat site visits and specialist access 

• A permanent, objective baseline record of the bridge's condition 

• Improved safety by minimising on-site inspections 

• Lower whole-life costs through reduced survey repetition.

Client deliverables: 

• Interactive, photorealistic 3D model of Wade's Bridge 

• ±5 mm accuracy suitable for measurement and condition assessment 

• Topographic survey data referenced to OS National Grid and Datum 

Our Approach 

Malcolm Hughes developed an integrated survey strategy that combined complementary technologies to produce a single, highly accurate, digital asset. Alongside the bridge model, the team delivered a detailed topographic survey of the surrounding area, capturing levels, infrastructure, drainage, and boundaries to support future design and maintenance requirements. 

Data is captured using combination of terrestrial laser scanning, calibrated ground photography, and UAV-based aerial photogrammetry. High-resolution laser scans produce dense point clouds with millimetre-level precision, while overlapping imagery from both ground and aerial platforms ensures full spatial and surface coverage. Survey and ground control points are established and tied to the project coordinate system to maintain positional accuracy and alignment across all datasets. The laser scan and photogrammetric data are then combined, processed, and georeferenced to create a detailed 3D model that includes both precise geometry and high-quality textured surfaces. These models are suitable for measurement, analysis, and seamless integration into CAD, BIM, or asset management workflows. 

Stakeholders can now explore the bridge virtually, gaining a clear and consistent understanding of its condition and behaviour over time. The digital model supports collaborative decision-making and provides confidence that all parties are working from the same trusted dataset. 

Added value: 

• Secure web-based access to the model via a simple link, enabling remote review by all stakeholders 

• A reusable digital dataset that can be revisited and re-analysed without further site surveys 

Summary

This project demonstrates Malcolm Hughes' ability to deliver technically robust, non-intrusive survey solutions for complex and historic infrastructure. More than a one-off survey, the output is a long-term digital asset that supports safer operations, better planning, and informed asset management, delivering lasting value well beyond the initial commission. To enquire about a similar project please get in touch with our team of experts who will be able to advise you.