International J-Tube Inspection Campaign & Messenger Line Installations

Case study

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Project Overview.

AISUS was tasked by an international client to carry out an internal visual inspection, high-pressure cleaning and messenger line installations on two J-Tubes on a fixed platform.

The client approached AISUS due to the suitable tooling and proven record on carrying out inspections and messenger line installations on similar scopes. The purpose of the campaign was to ensure the cleanliness of the J-Tubes and install new messenger lines for both J-Tubes in order for the client to pull umbilical through to seabed.

Visual Inspection

Experienced and competent engineers were deployed to first retrieve the existing messenger lines prior to visual inspection on both J-Tubes. Then, the team successfully lowered down the camera equipment in order for the client to gain an understanding of the general condition of sidewalls and level of cleanliness of the pipework. It was found out that some part of the J-Tubes needed cleaning.

High Pressure Cleaning

The team of engineers moved on to carry out messenger installations. The client tasked AISUS to install new messenger lines by driving the messenger lines down the J-Tubes with an in-house developed crawler system.

Due to the configuration of the J-tubes with bell mouths, AISUS designed and deployed a messenger line deployment solution to lead the new messenger line beyond the bell mouth. The messenger line was installed successfully and the crawler system recovered using a pneumatically driven air winch.


The campaign was successfully completed as both J-Tubes were successfully cleaned and inspected and a new messenger wire installed.

AISUS team successfully and efficiently integrated with the client’s team, working alongside on all aspects of the overall project. This flexible approach minimised mobilisation costs and transit times for the client, all contributing to the overall success of the project.

The inspection was deemed a great success by the client who was extremely pleased with not only the inspection campaign and messenger line installations, but also the professional and proactive approach that AISUS adapted to the scope and the high detail and quality of the inspection data provided.

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