Classification of a Fast-Track Multi-Body Shared Mooring FLNG Terminal

Abstract The Marine XII FLNG terminal in Congo is a groundbreaking project, being the first-ever floating multi-body, shallow water, shared permanent spread mooring redeployment of existing units. This unique FLNG terminal consists of the Tango FLNG, initially designed for a near-shore configuration in South America, and the Excalibur LNG Carrier, acting as a Floating Storage Unit (FSU). As the Classification Society, Bureau Veritas played a role in ensuring the integrity and safety of this innovative project. Firstly, it accompanied the Technology Qualification of this novel concept, which included the first-ever permanent cryogenic hose connection between the two floating bodies using multi-axial cryogenic swivels on both sides. This was a critical aspect, as the reliable and safe transfer of cryogenic LNG between the two units was essential for the terminal's operations. Secondly, Bureau Veritas independently reviewed the modifications on both units, the permanent spread mooring system (including the first-ever used nylon interconnecting ropes between the floaters), the LNG transfer system between the units, and the risers bringing the feed gas to the Liquefaction barge. This comprehensive review ensured that the integrated system met all necessary safety requirements. Thirdly, the classification society coordinated the certification of all the components that would be used in the FLNG terminal. This included verifying the design, materials and manufacturing processes of the various equipment and systems, from the flexible risers bringing the gas to the LNG transfer and cargo handling equipment, passing through the FLNG topsides changes and additions and the mooring system. Additionally, Bureau Veritas surveyed the fast-track conversion activities at the yard and followed the installation in Congo, providing on-site expertise and oversight to ensure the project's successful execution. Finally, the Class supported discussions with Flag Authorities concerning derogations to applicable international codes and the demonstration of technical diligence. The result is an in-time deployment with a dedicated project management, specialized technical resources in several countries, and direct involvement from the Bureau Veritas headquarters. This abstract describes the different activities performed by Bureau Veritas as the Classification Society and the lessons learned, highlighting what worked well and what can be improved for future fast-track re-deployment projects, including the qualification of technologies in completely new configurations.