Mobile offshore base: Hydrodynamic advancements and remaining challenges

Abstract

SeaBasing is one of three core operational concepts of the 21st century US Navy. The most capable SeaBase, labeled the Mobile Offshore Base (MOB), would require a 2 km length to accommodate conventional take-off and landing long-range cargo aircraft. Such a platform is definitely a very large floating structure (VLFS). The first part of this paper highlights fundamental technology advancements from a 1997–2000 research program that examined the full spectrum of SeaBase design and analysis issues. Multiple studies in industry and academia made significant hydrodynamic advancements, including a model that interfaces hydrodynamic pressure fields to finite element structural analysis models. A second series of studies examined the large (km) scale structure of ocean waves. Third, the first probabilistic- (and performance-) based design methodology for US marine structures was drafted, and initial feasibility studies and demonstrations of multiple module dynamic positioning were completed. The final sections of the article describe real Navy VLFS structures such as waterside security barriers and amphibious logistics floating piers, and present remaining challenges.