Pierside Mooring for Cruise Ships

A method of estimating the number and size of mooring fixtures required to secure a ship at a pier in steady winds ranging from 30 to 60 knots is presented for cruise ships ranging in size from roughly 50,000 to 250,000 gross registered tons (GRT). The method requires physical characteristics of the ship, calculation of wind force coefficients, mooring line capacity, and either the actual or assumed average vertical angle of mooring lines, excluding the spring or longitudinal lines. Changes in water level can be considered by varying the average vertical angle of the mooring lines. The method discusses and extends the spreadsheet EMOOR, a planning and preliminary design tool for evaluating ship moorings at piers and wharves, to suggest the number of mooring lines and the size and number of breasting bollards necessary to safely moor cruise ships. Static mooring analysis results for six cruise ship mooring design projects are compared with the prediction of mooring line requirements from EMOOR. Guidelines for achieving optimum mooring efficiency for planning and design of new berthing facilities or the expansion of existing facilities for larger vessels are also identified. The information presented here is for general use and intended to assist port planners and designers with a starting point for providing safe and efficient pierside moorings. Data or results contained herein cannot be extrapolated or interpolated for application to other vessels or circumstances. The methods outlined here should be used only as a precursor to final project design, including a formal mooring analysis based on specific ship parameters and governing site conditions and constraints.