Modern marine transport requires minimum time for loading and unloading in ports and at marine terminals, a requirement often restricted by ship movements at berth. If the ship movements experienced are too large, cargo handling operations will slow down or even cease and ultimately damage to the ship and port installations may occur. In recent years changes in cargo handling methods have resulted in changes of both ship and port installations, changes which may have large economic consequences.The Permanent International Association of Navigation Congresses (PIANC) therefore commissioned a special Working Group to study the movements of moored ships in harbours with the aim to establish new criteria for acceptable ship motions in safe working conditions (i.e. when cargo handling operations have to be reduced or when a ship has to leave the berth). Further, it was the aim to assess measures for improving safe working and safe mooring conditions. The main objective in establishing criteria was to provide guidelines for port designers and port operations to minimize downtime in harbours. The Terms of Reference for the Working Group are given in Annex A.
The Working Group comprised 14 International members (see Annex A) and commenced in June 1990. The final report has been finished in the spring of 1994. This section summarizes the main findings and conclusions of the Working Group.
