Ship Handling Simulation
The Department of Hydraulic Engineering in Coastal Areas of the BAW’s Hamburg office is the consultant and advisor for the Federal Waterways and Shipping Agency. It provides consultative input on, amongst other things, the fairway dimensions required to adapt coastal waterways to navigation by large ships (e.g. Lower Elbe and Outer Elbe, Lower Weser and Outer Weser, as well as the access route to Stralsund and the Peenestrom waterway). The results obtained from ship handling simulation play a significant role today when the dimensions of fairways are determined. The use of ship handling simulators is considered a valuable tool in fairway dimensioning projects and is recommended (e.g. by PIANC WG II-20, 1992; PIANC WG II-30, 1997) when critical boundary conditions are concerned (e.g. where fairway dimensions have to be minimized), although the limits of such use are yet unknown. The BAW is mainly commissioned by the Waterways and Shipping Offices to provide expert consultancy in contract award procedures for simulation projects and on the verification of the design approaches. Evaluations of existing ship handling simulation software, which was originally designed for nautical tasks, showed that the mathematical approaches used for the simulation tools and relevant for fairway dimensioning (e.g. regarding squat or bank effect) fail to meet the technical requirements of the WSV. In view of the rapid increase in the sizes of container ships and the long planning periods required when coastal waterways have to be adapted to the new vessels, professionally verified navigability analyses will be required for large container ships navigating in the Weser or Elbe estuaries or the Kiel Canal, for instance.
The urgency of the task is obvious, all the more so because in the future the focus will be on the economic exploitation of existing or adapted waterway infrastructure which means that the modular simulation software will continuously have to be further developed and also implemented.
In Germany, the use of ship handling simulators in the field of inland navigation began only in 2008. The BAW Karlsruhe procured its own simulator in 2009. Based on this commercial simulator which was developed for training the nautical staff of seagoing vessels the calculation kernel was expanded to include methods to calculate ship-induced waves and predict the movement of inland vessels in extremely shallow water while taking account of current fields. The characteristics of the stern and bow rudders were also adapted in order to meet the technological requirements of inland navigation vessels. Further developments such as an expansion of the collision model to simulate sliding wharves, squat and bank effect are being worked on.
There are two different approaches the BAW can adopt when carrying out tests in the framework of projects commissioned by the WSV. In order to ensure that the simulation results are as unbiased as possible, the simulation runs are closed-loop controlled which ensures that the model ship follows a predetermined track. Thus, the performance and capabilities of the “shipmaster” are constant across all tests and the results obtained from the individual simulation runs can be compared. The navigability of the area when observing the predetermined track and the number and intensity of the ship manoeuvres that had to be undertaken during the simulation run provide an indication of the safety and level of ease of navigation of the particular test reach.