Study on Under-Keel Clearance Algorithms for Very Large Ships in Restricted Waters

摘要

Under-Keel Clearance (UKC) is one of the pivotal factors that ensure the navigation safety of Very Large Ships. Nowadays, the range of UKC is determined mainly based on pilots’ navigation experience gained in specific waters (restricted waters) without sufficient consideration of impacts of multi-variables, such as types and speed of VLCC, depth of water and situations of wind and wave. This paper will analyze the components and influencing factors of UKC, investigate the impacts of various variables and develop structural equation model for accurate estimation of UKC in practice. Due to the uncertainty estimates of UKC values in restricted waters, we will propose a dynamic calculation model for UKC estimation based on characteristics of Very Large Ships and navigation conditions in restricted waters. Meanwhile, the optimal UKC value will be estimated. The reliability of the proposed dynamics calculation model and estimated UKC value will be further validated by combining the reduced-scale Very Large Ships model experiment. Achievements of this proposal are of great significance in enriching the theory and skill for Very Large Ships maneuvering and pilotage, and guaranteeing navigation safety of VLCC in restricted waters.