In this paper, we develop sinkage coefficients for ships in shallow open water, or harbour approach channels with minimal transverse restriction. These sinkage coefficients may be used for under-keel clearance management by ports, pilots, and deck officers. The coefficients are calculated using slender-body shallow-water theory applied to 12 published hull forms. Results are condensed into sinkage coefficient ranges for container ships, oil tankers, bulk carriers, and membrane LNG carriers. Limitations on use of the coefficients are suggested, based on ship and navigation channel dimensions. Examples are given for container ships, bulk carriers, and LNG carriers in Australian ports. |