Stability criteria analysis for Landing Craft Utility

Abstract

Currently used Landing Craft Utility (LCU) stability criteria may not be optimal for the typical coastal transits of those vessels. Therefore, this study examines the intact transverse static and dynamic stability of the LCU in order to recommend more appropriate criteria for short-range transits. The analysis mainly uses the Program of Ship Salvage Engineering (POSSE) software and the standard Ship Motion Program (SMP) to model a stochastic sea state, simulate the LCU's loading conditions, and predict the craft's dynamic responses in certain sea state conditions. The LCU's static transverse stability is derived by the POSSE software in terms of righting arm diagrams for different loading conditions, while the SMP software determines the dynamic transverse stability. The SMP analysis is based on seakeeping theory, using sea spectra model techniques to determine the LCU's roll angle dynamic responses. Based on these simulation results, the study evaluates the currently used stability criteria and arrives at new dynamic stability recommendations and improved operational limits. These may be further refined by using hull appendage implementations in follow-on studies.