CASE STUDIES

Preparing for Redundancy: External Caisson Cleaning and RVI

Overview

AISUS was contracted by a North Sea operator to carry out external high-pressure jetting and remote visual inspection on two sea water lift caissons. The work formed part of the preparation for making the caissons redundant, with the key objective being the removal of marine growth, scale, and corrosion products, followed by a detailed assessment of their condition to ensure safe removal.

 

external caisson cleaning

 

Requirements

The project utilised our external system, AURIGA to remove marine growth, surface scale, and corrosion build-up. Once cleaning was complete, a comprehensive visual inspection was conducted to verify cleanliness and identify any external anomalies that could present risks during caisson removal.

Pre-cleaning observations focused on the extent of marine growth, the presence of corrosion and scale, and any visible distortion or buckling of the structure. Post-cleaning assessments examined the presence of external wall loss or holes, the condition and elevation of any remedial repairs and signs of structural distortion.

 

external inspection system

 

Challenge

  • A significant challenge of the project was the need for accurate inspection results. This was critical in guaranteeing the caisson’s readiness for redundancy.
  • The work had to be carried out in the splash zone, a challenging environment due to constant wave action, making precision cleaning and inspection more complex.

Solution

AISUS deployed its external Inspection system, AURIGA, with the HD Spyball providing high-resolution imagery that allowed for the accurate identification of anomalies and potential defects. The halo ring, ensured consistent cleaning coverage whilst technicians were required to continuously monitor live camera feeds to detect guides and obstructions. This approach allowed the team to operate efficiently, even within the challenging conditions of the splash zone.

 

caisson marine growth cleaning

 

 

Results

The operation successfully removed marine growth and corrosion, restoring the caisson surfaces to a clean and sound condition. The RVI provided clear and detailed imagery, with no anomalies identified. This combination of effective cleaning and accurate inspection allowed the operator to proceed confidently with redundancy planning.

The project demonstrated AISUS’s ability to deliver safe, efficient, and innovative offshore cleaning and inspection solutions, even in challenging environments.  

 

Benefits

Reduced Personnel Needs: A small three-person team was required, minimising risk and optimising efficiency.

Accurate Data Collection: The combination of HP cleaning and visual inspection provided a thorough and reliable dataset ensuring the caissons were ready for redundancy

Expert Team & Innovative Technology: We deliver reliable and precise results while ensuring high standards of quality and safety

Integrated Service: All tasks complete within a single scope

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