Mastering Dam Inspection with Unmanned Underwater Drones

​Introduction
Unmanned Underwater Drones (UUDs) have revolutionized the field of dam inspection, providing an efficient and cost-effective means to assess the structural integrity of these critical infrastructures. When conducting a dam inspection, a UUD pilot must follow a series of precise procedures to ensure that the dam's concrete face, spillway, and draw-off tower are thoroughly examined. In this article, we will explore the correct procedures for a comprehensive dam inspection and highlight key points to watch for during the inspection process.

1. Pre-Inspection Preparations
Before starting the inspection, it is essential to gather all necessary information about the dam, including its design, construction history, and previous inspection reports. Understanding the dam's unique characteristics and potential problem areas is crucial. Additionally, obtain all required permits and permissions for the UUD operation.

2. Safety First
Safety should always be a top priority in any inspection. Ensure that the UUD is in optimal condition, and that all systems and sensors are functioning correctly. Verify that all safety protocols are in place and that the pilot and inspection team are adequately trained for the operation.

3. Deployment and Navigation
Carefully deploy the UUD into the water, making sure it is securely connected to the pilot's control station. Navigating the UUD to the inspection location should be done with precision and care to avoid collisions and minimize disturbances to the dam's surroundings.

4. Dam Concrete Face Inspection
(i) Close Visual Inspection (CVI):
Begin by approaching the dam's concrete face and conducting a close visual inspection. Look for signs of cracks, spalling, erosion, or any other visible damage. Use high-resolution cameras and specialized sensors to capture detailed images and data.
(ii) Depth Assessment:
Gradually descend the UUD to explore the underwater portion of the dam's concrete face. Pay close attention to areas near the base, where water pressure and erosion are most significant. Document any irregularities observed during this phase.

5. Spillway Inspection
(i) Approach with Caution:
Carefully navigate the UUD towards the spillway, which plays a critical role in flood control. Inspect for any debris or structural issues that may obstruct the spillway's function.
(ii) Water Flow Analysis:
Monitor the flow of water through the spillway to ensure it is functioning as designed. Any signs of blockage or unusual flow patterns should be documented.

6. Draw-Off Tower Inspection
(i) Structural Integrity:
Inspect the draw-off tower for signs of corrosion, degradation, or damage to the structure. Pay special attention to the tower's foundation and any access hatches.
(ii) Sensor Data:
Utilize specialized sensors to measure water levels and temperature around the draw-off tower. Changes in these parameters could indicate potential issues.

7. Data Collection and Analysis
Throughout the inspection, gather a wealth of data, including images, videos, and sensor readings. After the UUD has completed its inspection, return it safely to the surface. Back at the control station, analyze the collected data thoroughly to identify any areas of concern or deterioration.

8. Reporting
Compile the findings into a comprehensive inspection report, which should include a summary of the dam's current condition, potential problem areas, and recommendations for any necessary maintenance or repairs. This report is a critical tool for dam operators and maintenance teams.

Conclusion
Unmanned Underwater Drones (UUDs) have ushered in a new era of dam inspection, making it safer, faster, more cost-effective, and more thorough than ever before. By following the correct procedures and keeping an eye out for key issues, UUD pilots can contribute to the ongoing safety and security of critical infrastructure. Properly executed dam inspections are essential to ensure these structures continue to serve their vital functions effectively and safely.

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