Numerical software package SWAMS – Simulation of Wave Action on Moored Ships

Abstract

Container ships traffic has increased significantly in recent years as well as the ship dimensions, therefore the need for port expansion and construction of new ports. Portugal is no exception to this global phenomenon and there are plans to expand some of the major Portuguese ports (eg Sines and Leixões). These large ships require depths and widths of the entrance channels relatively large and it is inevitable that waves enter the ports. These waves can cause serious problems in port operation as a result of excessive movement of the ship. The costs associated with berth downtime are enormous. For container ships, horizontal movements must be very small due to crane operation constraints. Excessive movements can also cause ship collisions with berth or with other ships or the breakage of mooring lines, all with serious economic losses. From the above it becomes clear how important it is the ability to know the sea conditions that lead to excessive movement of ships. This knowledge would bring a huge asset to the port operational management and it could point out ways of mitigating these problems. This paper describes the development of an integrated tool made of several numerical models able to characterize the wave climate and its effects in ports, particularly in terms of movements of ships moored to a port terminal. The validation of this tool is presented in the form of some simple test cases. Additionally an application to a real harbour situation is also presented. The information obtained from this tool is a major help in port management and it can significantly increase the competitiveness of our ports.