CASE STUDIES

Fire Water Lift Caisson: Ultrasonic & Remote Visual Inspection

Overview

AISUS were contracted to conduct a comprehensive inspection of a Fire Water Lift Caisson to assess its structural integrity. The task involved both Visual and Ultrasonic inspection, as well as High-Pressure Cleaning to remove marine growth, scale, and debris. The use of advanced remote inspection technologies, including the AISUS ‘SIRIUS’ ultrasonic scanner, enabled a detailed evaluation of the caisson’s condition.

 

 

 

The Requirement

The client required an urgent inspection to confirm the Caisson’s safety and structural integrity. This project included a multi-stage inspection process that left no details overlooked.

The initial internal visual inspection assessed the overall condition of the caisson, to ensure no obstructions were present and to ascertain the extent of High Pressure (HP) jetting required.

AISUS then conducted a Remote Visual Inspection and Ultrasonic Testing (UT) to highlight any areas of concern and anomalies. The inspection covered the full length of the Caisson, from the top through the splash zone and down to the termination grille.

 

 

 

The Challenge

  • Significant buildup of marine growth on the sidewall was present, which needed removed to enable clear UT readings
  • The caisson had varying diameters along its length, requiring AISUS specialised equipment to ensure secure and consistent fitting of the ultrasonic scanner.

The Solution

AISUS deployed a series of strategic steps to ensure the success of the inspection. Including a Preliminary Visual Inspection to assess cleanliness and identify any debris, foreign objects, or buildup inside the caisson. This step was crucial for determining the effectiveness of the cleaning process.

AISUS adjusted the HP jetting pressure to ensure adequate cleaning and to minimise any potential damage to coating or parent material.

After cleaning, the AISUS ‘SIRIUS’ ultrasonic scanner was deployed to collect wall thickness data across the full length of the caisson. The wall thickness data was autonomously collected in a predetermined grid, providing valuable insights of the caisson’s structural condition. The tool’s centraliser ensured secure fitting even in areas where the diameter of the caisson varied. The motorised probe arm maintained consistent standoff distance from the caisson material, ensuring reliable readings.

 

Results

AISUS were able to provide a comprehensive inspection of the fire water caisson, offering detailed insights into its current condition and identified areas that may require attention.

The high-pressure jetting effectively removed marine growth and debris, allowing for a clearer visual inspection and more accurate ultrasonic readings.

The ultrasonic data revealed areas of internal wall loss, as well as detailed thickness measurements. Additionally, the Remote visual inspection identified a total of 27 holes within the caisson.

The data presented as C-scans, provided a clear visual representation of the caisson’s internal condition, enabling informed decision-making regarding future maintenance and any necessary remedial repairs

 

 

Benefits

  • Integrated Service: All tasks completed within a single service.
  • Cost-Effective: Prevented further marine growth that could halt operations or damage tools.
  • Increased Safety: Fully remote inspection eliminated the need for a large team.
  • Expert Team: Delivered precise and reliable results, providing personalised support to maintain high standards, quality, and safety
  • Streamlined Reporting: Secure access to comprehensive reports for inspection data

 

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