A concept was developed by the Seabasing Innovation Cell within the Center for Innovation in Ship Design (CISD) at the Naval Surface Warfare Center Carderock Division (NSWCCD). The study was undertaken during February–May 2003 with funding provided by the Office of Naval Research (ONR). The concept was developed in summer 2003 with further CISD funding and has been chosen for the 2004 Senior Year Design, Build and Test project by Florida Atlantic University’s (FAU) Ocean Engineering Department. The concept, known as the Deep Water Stable Craneship (DWSC) consists of two entities, a catamaran craneship and a detachable spar, which when connected form a self-deploying, open ocean capable trimaran. The spar can be rotated through 90 degrees, from horizontal to vertical, using seawater ballast. When vertical, partial de-ballasting ‘lifts’ the catamaran clear of the water surface allowing the system to operate as a spar and take advantage of the superior seakeeping afforded by the small waterplane area. The concept was inspired by the “ONR owned” and “Scripp’s Institute operated” FLIPSHIP, and was developed as a potential solution to the Seabasing goal of transferring containerized cargo at sea between large and small vessels in seastate four (significant wave-heights 1.25–2.5m). Current crane operations at-sea are limited to seastate two (significant wave-heights 0.1–0.5m), largely due to pendulation of the load. This paper presents the development of the concept, its performance and alternative uses. In addition, a 1:15 scale ‘demonstrator’ is discussed as is a proposal for a FLIPSHIP-II.

This content is only available via PDF.
You do not currently have access to this content.