Public Funding for Intelligent Moorings Limited

The Intelligent Moorings project **"**Quarter Scale Testing of the Intelligent Mooring System for Floating Offshore Wind Platforms" is a joint UK and US collaborative project comprising Intelligent Moorings, the University of Exeter, PCCI, Inc, and Ocergy Inc together with a range of further support from the ORE Catapult, the US Navy and NREL. Intelligent Moorings is developing the IMS load reduction mooring systems based on pressurised rope technology, the University of Exeter provide modelling and the Dynamic Marine Component Test Facility (DMaC), PCCI are bespoke moorings specialists managing the sea trial deployment, Ocergy will provide platform interface support and end user feedback, the US Navy provide the WETS test facility, the ORE Catapult LCOE studies, NREL data acquisition and ABS Product Design Assessment and Certification support. The project undertakes coupled modelling, interfaces with platform design requirements and scales up an existing IMS design to meet quarter scale loads for the NREL 15MW reference turbine. It designs and builds an IMS system for deployment and test at the US Navy WETS test site to prove the operational performance of the IMS system can deliver significant LCOE reductions. Mooring systems are critical sub-systems for floating installations, warranting safe station keeping and hydrodynamic stability. The moorings must withstand ultimate load conditions, as well as cyclic fatigue loading. Floating installations in water depths exceeding 50m will be required to access much of the global offshore wind resource. Conventional mooring designs rely on adaptations from the oil and gas sector that can meet the required integrity and safety margins but lead to CAPEX intensive designs. The capital cost of moorings is driven by extreme (peak load) conditions, whilst revenue is generated under normal operating conditions. If peak loads can be mitigated, the cost of mooring systems and associated structural elements, as well as deployment and installation costs, can be significantly reduced. The IMS provides innovative non-linear responses based on hydraulic load damping mechanisms. It includes a water-filled bladder housed in a braided rope and connected to an accumulator, functioning like a shock absorber. Increased mooring loads result in the pressurised rope extending and reducing the volume of the internal bladder. Active control of the pressure provides intelligent stiffness variations that can be tuned to reduce peak loads and control platform dynamics.