PAVING THE WAVES

DEME Offshore together with GICON and TUHH addresses the practical requirements of transporting, installing, monitoring and maintaining an offshore floating island with an explicit focus on the Mediterranean Sea configuration. The Transport and Installation consists of phase I, installation of the anchor pile & mooring lines and phase II; towage and offshore installation of the floating modules from marshalling port (Port of Marseille) to offshore site. Phase I will be conducted with a heavy lift vessel which is capable to install all (71) anchor piles by vibro-hammering, connect the mooring lines and perform a solo pulling & pre-tensioning activity in approx. 3 months including mob-and demobilization. Subsequently, phase II will be conducted by performing a triple body towage, meaning the towage of three pre-assembled single floaters, to offshore site. One Offshore Construction Vessel and three Anchor Handling Tugs are required to perform phase II in approx. 8 months for the full island configuration, including mob-and demobilization. It is highly recommended to reconsider the design of the rigid connectors as the offshore installation limit of 0.5m wave height causes very low workabilities, resulting in many weather delays. Conducting phase I with CSV instead of HLV results in cheaper day rates but requires more vessels,  installation days and more cost. Conducting phase I in the North Sea configuration results in longer installation days and more cost. When fully installed and commissioned, the Operation & Maintenance phase starts by conducting preventive inspection and maintenance campaigns, in combination with data from remote monitoring applications. Planned inspection and maintenance campaigns will be conducted frequently on the floating modules and mooring infrastructure to inspect and maintain or repair marine growth and potential damages with a certain level of occurrence and impact while unplanned activities are conducted depending on potential threats defined by the remote monitoring system.

KEYWORDS: HLV, towage, offshore installation, mooring system, floating installation

Alexander Jordaens is almost 4 years working for the company DEME N.V. He has started his career in ‘DEME Offshore’ as Procurement Engineer in Luxembourg where he was supporting the tender team on EPCI offshore wind tenders, and more specifically the procurement of offshore wind foundations. After, he moved to the tender team of DEME Offshore as tender engineer to support the tender management during EPCI and T&I tenders for the offshore wind business. Due to his keen interest in Innovation, he was rapidly involved in various innovative projects where he could show his motivation, interest, knowledge and experience from previous departments involved in offshore wind tenders and projects. He recently joined the business development department as project coordinator for various innovative projects such as but not limited to Space@Sea, Offshore floating PV, Offshore use of drones and Offshore Hydrogen production.