

In Korea, Floating Offshore Wind Turbine (FOWT) is in the spotlight as a key strategy to cope with the government-led carbon neutrality issue.
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FOWT installation capacity in Korea is expected to reach 4.3 GW by 2030 and 31.8 GW by 2040.
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We are collaborating with the Korean Research Institute of Ships and Ocean (KRISO) to develop a floating structure and mooring design to support 15 MW wind turbine and ready to be deployed to the Korean market
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The PentaSemi design is ready to be applied to FEED stage projects in Korea
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Proven and Robust Concept with Improved Hydrodynamic Performance
The PentaSemi is a variation a proven standard semisubmersible concept commonly used in the O&G industry.
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The columns are of pentagonal shape with the side of the column aligned with the pontoon for a robust column-to-pontoon connection.
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The hydrodynamic performance responses are improved by introducing corner plates at the connection between the columns and the pontoon.

Structure Customized for Korean Shipyards
The PentaSemi hull structure is designed to be similar to typical ship and barge structures to accommodate most Korean shipyard, and in particular smaller yards that have extensive shipbuilding experience.
The hull components of the PentaSemi such as plating, longitudinal stiffeners, framing structures are similar to those used for shipbuilding and are adequate for typical block fabrication and existing schedule management strategies.
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Thorough Global Performance and Structural Strength and Fatigue Analyses
We have performed a thorough full time domain structural analysis for strength and fatigue using our software TRUST in 3 days.
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DNVGL class rules were applied.

Quay Side Integration
The Penta Semi is sized to have a quay-side draft to accommodate a wide range of marshalling sites with limited water depth along the Korean coast for turbine integration.

Mooring System
The mooring system was developed to minimize yaw motion of the hull. It consists of wire rope and chain and uses conventional and proven components and connectors.
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The mooring system can be disconnected for tow-to-port in case of heavy maintenance requirement.

Physical Model Test
We have conducted a physical model test in KRISO's wave basin in Daejeon, South Korea in May 2022 and performed correlation with numerical model, which shows very good agreement.

Design Variations
The PentaSemi was originally developed for 15 MW wind turbine but is scalable to smaller or larger turbines.
Design (e.g. columns configurations, mooring attachment point locations,...) can be customized to accommodate specific needs for operation.
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Approval in Principle
AIP was received from Korean Register (KR) on October 5, 2022.

Other Applications
The PentaSemi can be applied to different systems, such has charging station to provide power to electric tug boats and other offshore support vessels