Quayside Mooring System Design of Prelude FLNG for Extreme Environmental Condition

Abstract

The design and analysis of a quayside mooring system for safe mooring of Prelude FLNG under extreme environmental conditions were carried out. The design of the mooring system considered the yard operation conditions and maximum wind speed during a typhoon. In order to secure the mooring safety of Prelude FLNG under an extreme environment, a special steel structure was designed between the quay and Prelude FLNG to maintain the distance from the quay to a certain extent to avoid a collision with the inclined base. The mooring safety was also ensured by installing additional new parts on the quay. A mooring analysis and mooring safety review were performed with more rigorous modeling considering the nonlinearity of the mooring rope and fender. In order to secure additional safety of the mooring system under extreme environmental conditions, a safety assessment was conducted on the failures of the mooring components proposed in the marine mooring guidelines. Based on the results of the mooring analysis, it was confirmed that the Prelude FLNG can be safely moored even under the extreme conditions of typhoons, and a worst case scenario analysis verified that the mooring system design was robust enough. The proposed mooring analysis and design method will provide a basis for the safe mooring of ultra-large floating offshore structures of similar size in the future.

Keywords

• Extreme environmental condition
• Prelude FLNG
• Quayside mooring system design
• Mooring safety