Loads on fender structures and dolphins by sailing ships

Abstract

Fender structures and dolphins form an important part of the navigable canal. They have many functions: they must be able to guide and slow down ships, they must protect structures aft of ships against impacts from ships, and must protect ships from these structures. In addition, they must act as berthing or waiting places for ships. Fender structures and dolphins are installed where one or more of these functions are required, generally when passing nearby sluices, bridges, harbour entrances, etc. The costs of constructing and maintaining fender structures and dolphins may be considerable, thus savings in construction or maintenance costs, together with efficient operation, are very important. Up until recently schematised calculation methods, with dimensioning approach velocities and angles of the ships, obtained from practical observation, were used by the Netherlands Ministry of Public Works, Locks and Weirs Directorate, for designing fender structures and dolphins. The fender structures built meet the requirements previously laid down. However, at a time when fender structures and dolphins must be designed as economically as possible, and when ships are increasing in both size (e.g. push tows) and speed, there is a need to provide better calculation methods and more broadly based general conditions. For these reasons a study has been carried out to determine the loading of fender structures and dolphins by sailing ships. This Rijkswaterstaat Communication gives a survey of the study carried out. This Rijkswaterstaat Communication is drawn up in two parts. The first part contains an introduction to, and summary of, the study (Chapt. 1), and a determination of the data required for determining the impact forces (Chapters 2 to 5 inclusive). The second part contains the determination of the impact forces by calculations and model investigation (Chapters 6 to 9 inclusive).