We are proud to announce that we are now the official UK Repair and Maintenance Centre for Autel!
Click to find out more

How the ASIO Drone Enhances Safety and Efficiency in Spillway Tunnel Inspection

November 22, 2023

How the ASIO Drone Enhances Safety and Efficiency in Spillway Tunnel Inspection

The customer, Group E, required a meticulous inspection of the tunnel’s concrete structure and potential blockages without human entry. The inspection scenario undertaken at Rossens Dam in Switzerland, pertaining to a high-risk confined space – the spillway tunnel.

Rossens Dam, Lake of Gruyère, Switzerland

The infrastructure posed significant challenges due to it is over 8-meter diameter, presenting a high level of difficulty. The objective was to optimise inspection speed and cost-effectiveness, focusing on the importance of efficiency and safety.

The inspection was successfully completed within a single day, highlighting the efficiency and expertise required to fulfill the customer’s specific requirements and ensure the integrity of the spillway tunnel.


ASIO Explore – Post-processing software

Using the ASIO drone, Groupe E completed a visual inspection of the spillway tunnel within 24 minutes, achieving a thorough assessment of the concrete walls and identifying potential blockages.

This inspection was significantly faster and cost-effective compared to traditional methods, reducing inspection time from several days.

How Flybotix Achieved This Result:

The ASIO drone is equipped with advanced software, navigated the confined space efficiently, capturing high-resolution imagery of the tunnel. The drone’s agility and maneuverability allowed it to cover the entire surface, providing a detailed visual inspection without human intervention.

Cost Savings during Inspection:

By utilising the ASIO drone, the need for expensive scaffolding or rope access, costing up to 40,000 CHF and 10,000 CHF respectively, was eliminated. Additionally, there was no requirement to lower the reservoir’s water level, saving an estimated 280,000 CHF and preventing immeasurable environmental water loss.

8-meter diameter | 24 min | $280,000 saved per inspection

Spillway Tunnel – Photogrammetry


  1. Time Efficiency: The ASIO drone completed the inspection in a fraction of the time it would take using conventional methods, minimising downtime for the spillway’s functionality.
  2. Cost Savings: Significant cost savings were achieved by eliminating the need for costly infrastructure and water level adjustments.
  3. Safety: By keeping humans out of the confined space, the risk to personnel was eliminated, ensuring a safer inspection process.
  4. Environmental Impact: The ASIO drone reduced water waste and minimised the environmental impact associated with lowering the reservoir’s water level.


ASIO’s drone solutions, is designed for confined space inspections by offering unparalleled maneuverability, high-resolution imaging, and advanced software capabilities. This allows for efficient and comprehensive visual inspections in challenging environments, such as the spillway tunnel at Rossens Dam.


  1. Safe Inspection: ASIO drone eliminate the need for human entry, ensuring safety by keeping personnel out of hazardous confined spaces.
  2. Efficient Maneuverability: ASIO drone can navigate complex structures with agility and precision, reaching areas that are difficult or impossible for humans to access.
  3. Cost-Effective: ASIO drone reduce inspection costs by minimising the need for expensive infrastructure and lowering associated operational expenses.
  4. Increased Frequency: The efficiency and speed of ASIO drone allow for more frequent inspections, optimising asset performance and longevity.

Related Products

Like what you read in the case study above? Check out the product(s) below for more information or to download the relevant product datasheet (where available)