Internal Stack Survey and External Inspection at North Yorkshire Mine
High-Risk Asset Inspection Delivered Safely with Advanced Drone Technology
DJM Aerial Solutions recently completed a comprehensive internal and external stack survey for a mining operation in North Yorkshire. The structure, a 90-metre-high masonry stack, required a full defect assessment as part of a scheduled condition survey.
Using the Elios 3 confined space drone for the internal stack survey, and our Matrice platform for external inspection, we delivered high-resolution data covering the entire structure—safely, efficiently, and without scaffolding or rope access.
Why This Stack Required a Dual Survey Approach
The masonry stack, which has been in operation for decades, forms a critical part of the mine’s exhaust infrastructure. The asset was due for structural review, focusing on:
Internal concrete and masonry degradation
Cracking, spalling, and mortar joint condition
External surface integrity and vertical alignment
Evidence of water ingress or structural movement
Due to the height, internal confined space conditions, and external exposure, traditional inspection methods would have required significant scaffolding, manned access, and extended downtime. The site opted for a combined drone survey solution to minimise risk and cost.
Internal Stack Survey with Elios 3
For the internal portion of the stack, we deployed the Elios 3 drone, purpose-built for confined space inspections. Operating in a GPS-denied, vertical environment, the drone captured stabilised 4K video, high-resolution stills, and spatial awareness data via its onboard LiDAR.
Internal Inspection Focus:
Visual condition of the lining
Cracks and structural displacement
Mortar deterioration and joint separation
Soot accumulation or blockage evidence
Mapping of internal geometry for comparison to design drawings
All findings were defect-tagged in real time and compiled into a visual inspection report within 48 hours of survey completion.
External Stack Survey with Matrice UAV
The external stack survey was carried out using our Matrice 300 RTK drone, equipped with a zoom-enabled visual sensor and thermal imaging. We captured overlapping high-resolution imagery for photogrammetric analysis, defect tagging, and full elevation review.
External Inspection Outputs:
Cracks and surface erosion on outer masonry
Weather-related degradation (freeze-thaw damage, efflorescence)
Vegetation or root intrusion
Loose masonry or displacement
2D orthomosaic for documentation and visual comparison
Aerial imagery stitched and rectified to grid
Benefits of Combining Internal and External Drone Surveys
This integrated approach ensured a 360° assessment of the stack’s condition, delivered with:
No scaffolding or working at height risks
No confined space entry for personnel
Minimal operational disruption at the mine
Rapid data turnaround and engineering-ready reporting
Detailed defect documentation for long-term planning
Why This Approach Works for Masonry Stack Structures
Tall stacks—particularly those constructed from masonry—are prone to structural fatigue, thermal cycling effects, and weather-related deterioration. Routine inspections are critical for:
Verifying continued safe operation
Informing maintenance planning
Complying with regulatory requirements
Avoiding catastrophic failure
Our use of internal drone technology (Elios 3) and external aerial capture (Matrice 300) allows us to inspect every accessible surface, inside and out—without the cost, risk, or delay of traditional methods.
Frequently Asked Questions About Drone Surveys
An internal stack survey uses a confined space drone to inspect the inside of a vertical structure like a chimney or flue, without manned entry.
The 90m stack required a full defect review of both internal and external masonry conditions to plan maintenance and avoid long-term structural issues.
We used the Elios 3 for the internal stack survey and the Matrice 300 RTK for external visual and thermal inspection.
Yes. We identify cracking, spalling, weather damage, mortar joint failure, and displacement using stabilised imagery and LiDAR scanning.
No. Our internal stack surveys are performed with drones from outside the structure, eliminating confined space risks entirely.
The structure was a 90-metre-high masonry stack at a mining facility in North Yorkshire.
Yes. You receive high-resolution imagery, video, defect tagging, and optional LiDAR point cloud or 3D model output.
No. Our drones can fully assess vertical and hard-to-reach surfaces without access platforms or scaffold erection.
Energy from Waste, mining, manufacturing, cement, chemicals, and industrial processing facilities all benefit from drone-based stack surveys.
We are based in the North East and operate nationwide across the UK with fast mobilisation for planned and emergency inspections.
Deliverables Provided
4K visual footage of internal and external surfaces
Annotated inspection reports
LiDAR-based point cloud of internal stack geometry (optional)
Full image set for review and archiving
Highlighted areas of concern with defect tagging
Ready to Survey Your Stack?
Whether your structure is concrete, steel, or masonry, our internal stack survey and external drone inspection services provide fast, high-value results with no compromise on safety or accuracy.
Contact DJM Aerial Solutions today to discuss your stack inspection requirements.