Cassia-A Vent Boom Removal

The Solution

During the concept phase, Conbit developed two lifting solutions for the Cassia-A vent boom removal.

The first concept combined the SL500 with a gantry arrangement. The second concept was based on Conbit's SL900 modular lifting system. Following an evaluation of both options, the client selected the SL900as the preferred solution.

The lifting system was designed around the SL900, supportedby 15 mt hydraulic winches for controlled handling of the boom sections. The selected solution provided a suitable approach for handling the inclined structure while working within the access and crane limitations of the Cassia-A platform.

This represented an important milestone for Conbit, as it was the first project in which the SL900 was selected for execution.

SL900 Installation Tool

A dedicated installation tool was developed specifically to support the build-up of the SL900. Part of the assembly would take place outside the reach of the platform crane once the system reached a certain height. The installation tool was therefore designed to allow the SL900 to continue building up independently.

Due to the tight project schedule, the tool had to be designed, fabricated, and tested within a short timeframe. Conbit successfully completed the development and testing, providing an important step towards the concept of a self-building lifting structure for future offshore applications.

Development & Testing

The project required close coordination between engineering, fabrication, and testing activities. With several components still under development, Conbit had to move quickly from design to fabrication and testing.

An extended Factory Acceptance Test (FAT) was conducted with Massy Wood representatives present at Conbit. This provided an opportunity for both teams to work closely together, resolve technical topics efficiently, and gain practical experience with the proposed system and installation method.

Evaluation

Although the Cassia-A project was stopped after completion of the FAT, the project provided valuable experience for the further development of the SL900.

The close cooperation during the extended FAT resulted in important practical feedback on the system, its installation method, and the supporting equipment required for offshore deployment. The development and successful testing of the dedicated installation tool was particularly valuable, demonstrating how the SL900 can be built up independently when conventional crane access is no longer available.

The project therefore contributed to the continued development and offshore readiness of the SL900, while strengthening Conbit's experience in developing engineered lifting solutions for challenging offshore environments.

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