Feasibility and Design of the ClubStead: A Cable-Stayed Floating Structure for Offshore Dwellings

The ClubStead is a novel type of offshore floating platform, which provides comfortable and safe ocean-going dwellings for communities of a few hundred people. The prospect of large, unclaimed ocean spaces has encouraged people to consider developing sea-going settlements. A number of attempts have been made on former oil platforms or cruise ships. But these structures are not designed for permanent living at sea and fall short of meeting dwellers’ expectations. Efforts to build large, spacious floating living facilities have struggled to balance cost-effectiveness and structural integrity. This paper describes an innovative, cost-efficient solution to maximize space on offshore structures. To control the cost, the submerged volume of the floater is minimized. To maximize comfort, the available living surface area is also maximized, while the motions of the platform are limited. The proposed solution is based on the principles of tensegrity, which are commonly used on bridges. Cable stays are tensioned at the top of towers to support the weight of both light and cantilevered top-sides. The floater is column-stabilized with four submerged columns. A feasibility study was performed for the design of a Clubstead based off the coast of California. The platform is dynamically positioned and can house up to 270 people. Due to its primary function, as a floating living facility, the architectural design and the engineering studies are intertwined. Iterations are necessary to determine the global characteristics of the ClubStead. The buildings and living spaces are arranged by an architect, within specific offshore-related constraints. The resulting payload is calculated and thus used in the design basis to perform the engineering analysis. The feasibility study focuses on survivability and passenger comfort to assess the novel design. The survivability analysis is based on structural strength and motion predictions in a 100-year storm. Passenger comfort is evaluated in operational conditions.