Strategic Structural Design and Refurbishment for Mooring and Ship-To-Ship Connector Foundations at a Nearshore LNG Terminal

Abstract This paper presents the structural design and implementation of the mooring and ship-to-ship connector (STSC) foundations for a nearshore LNG terminal, comprising two vessels—a 10-year-old Floating Liquefied Natural Gas (FLNG) vessel and a 20-year-old Floating Storage Unit (FSU)—moored using a split mooring system. The project faced significant challenges, including a highly compressed schedule and the inherent complexities of refurbishing aging vessels, where as-built drawings often did not capture current outfitting conditions. This paper will discuss the technical solutions, coordination strategies, and innovative approaches used to manage the structural design complexities under tight timelines, ensuring the successful integration of the mooring and STSC foundations. It will also describe the engineering judgments made to account for uncertainties using conservative design principles, as well as the rapid site instructions issued to address unforeseen discrepancies, particularly concerning outfitting elements like cable trays, ladders, and piping that restricted access to key areas.