Conceptual Design of a Modular Floating Multi-Purpose Island

Abstract

The design of a modular floating multi-purpose island inherently involves interaction within a group with a large range of backgrounds such as engineering, architecture, sociology, climate modeling, and more. A heuristic design approach was adopted for future island developers to make a first conceptual design. Four major design considerations were distinguished to discretize the design space: module size, module shape, module principle, and module connection and mooring. For each consideration a set of evaluation criteria were defined. This article describes the heuristic conceptual design procedure that was applied to the design of a modular floating island for offshore energy, offshore accommodation, aquafarming, and offshore transport and logistics. Two reference installation scenarios with a different respective focus of functionality, located in the North Sea and in the Mediterranean Sea, were created as a basis for the design. The first step of the design procedure consisted of a participatory process involving stakeholders and experts to rate design options for each category of design considerations based on the evaluation criteria and with regard to the installation scenario. As a result, all design configurations could be associated with an overall rating. In a second step, the most favorable designs identified during the participatory design procedure were investigated numerically to assess force distribution throughout the island when exposed to wave and current loads. The numerical results indicate that contrary to initial estimates during Phase 1, wave forces on an island consisting of quadrangular modules do not significantly exceed those experienced by triangular base shapes. As quadrangular modules can be shown to provide a higher Ground-Space-Index, this gives them a distinct advantage. As a result of the design process for this application, a barge-like, square structure with a base size of 45 m was chosen as the base module.

Pathways to sustain atolls under rising sea levels through land claim and island raising

“…For example, rather than abandoning islands, can islands and their infrastructure be designed to be raised with SLR, potentially avoiding the need for migration? Similarly, floating islands (Proetzel 1983, Souravlias et al 2020, Drummen and Olbert 2021, Flikkema et al 2021, Tamis et al 2021 might be explored with similar benefits.…”

Seakeeping criteria of a moored and articulated multibody floating platform in head seas

“…We see that the motion limitations for the energy hub and aquafarming modules are less strict. For further details of the floating concept, see Drummen and Olbert (2021).…”

Hydrodynamic Sensitivity of Moored and Articulated Multibody Offshore Structures in Waves

“…These tests comprised three body shapes and different coupled configurations. It was concluded that the cuboid module shape scored best, and its dimension was defined based on the inherent advantages regarding modularity, building ease and transport and installation effort [11]. Table 1 lists properties of such a floating module at its basic design stage.…”

“…Additional benefits are lower transportation, fabrication, and installation costs and the potential expansion of practical VLFS systems [10]. Nevertheless, size, shape, and joint design to connect the basic modular units should be carefully investigated to meet a mix of specific requirements [11]. Riggs and Ertekin [12] used two-dimensional and three-dimensional approximate hydroelasticity theories to predict the dynamic responses of a MFS consisting of different number of modules in regular waves, where a linearized stiffness matrix represented the connecting system.…”