Design of an on-board installation system for a TLP FOWT

Abstract

This research investigated the feasibility of designing an on-board system for the installation of fully assembled Tension Leg Platform Floating Offshore Wind Turbines (TLP FOWTs). The study aimed to identify a potential design that would enhance the overall feasibility of such installations, which required a combination of a literature review, a design methodology, and a concept evaluation.

The main research questions guided the study, focusing on the essential design elements and systems needed for the installation process. Key insights from the literature review helped form a basis for answering the first four sub-questions, while the subsequent sub-questions were addressed through concept development and analysis. The most crucial design decisions revolved around the connection between the installation deck and the ship and the selection of the actuating system.

Multiple concepts were developed, all incorporating a three-beam parallelogram configuration. A load analysis established an installation method and indicated three critical scenarios during the whole procedure. Force analysis, based on the load analysis, revealed two designs as the most feasible. This analysis provided crucial information on the direction and magnitude of forces within the system, guiding further refinement. Further specification of these designs addressed critical parameters, including the dimensions and structure of the beams, the size of the actuating system, and the integration of water ballast.

The study identified two potential solutions. One concept featured an additional framework within the three-beam configuration, optimising force distribution and introducing compressive forces in the actuating system, making a hydraulic cylinder the best choice. The other concept consisted of a simpler three-beam configuration, where the actuating system faced only tensile forces, making a winch system the most suitable solution.

The design methodology structured the development of these concepts, with analyses providing critical insights for further refinement. This iterative process highlighted the advantages and challenges of each concept.

In conclusion, this thesis contributed significantly to the current understanding of TLP FOWT installation by proposing potential solutions for the on-board installation system and identifying future research directions. Through its systematic approach and iterative design process, this research laid the groundwork for further advancements in the installation of TLP FOWTs.