Caisson Management

Project Overview

In 2025, a major North Sea operator contracted Altrad to conduct comprehensive visual and ultrasonic (UT) wall thickness inspections on the caisson before reinstating the pump.

The Challenge

Following the failure of a firewater lift pump on an offshore asset, it was crucial to assess the extent of the damage and initiate repairs or replacements to ensure the safety and integrity of the asset.

The Solution

To ensure it was fit-for-purpose and not a potential dropped object, Altrad performed a series of visual and ultrasonic inspections of the internal diameter of the caisson. Our experts remotely deployed camera systems to provide data on the general condition of the sidewalls and levels of cleanliness.

Following the initial visual inspection, Altrad’s High-Pressure (HP) remote jetting package was used to remove all marine growth and scale. After a final visual inspection, our specialist ultrasonic inspection tooling was utilised to map the wall thickness of the caisson and highlight any further areas of corrosion or wall defects.

The Results & Benefits

This was the first time we had performed this task on this platform. Care had to be taken when using high pressure jetting to ensure no damage was inflicted to the caisson during cleaning operations. Our remote HP jetting units allow for variable pressure adjustment.