Maneuvring Behavior of Push Convoys in Different Barge Configurations

Ship maneuvring simulators are a useful tool for the design of inland waterways and for training of skippers. The realism of the maneuvring prediction is a key success factor. In this paper, a 6 DOF (degrees of freedom) maneuvring model is presented which is able to predict the maneuvring behavior of push convoys in different, rigidly connected configurations (number of barges, draft of the barges, and position of the pusher) and for different water depths. The coefficients of this maneuvring model have been determined based on captive model tests and the realism is exemplified with a number of fast time simulation runs, including the turning on the spot of a convoy by means of uncoupled control of rudders and propellers. Final validations were performed during real-time simulation runs with experienced skippers. Knowledge on the maneuvring prediction of inland vessels is a key factor to determine the navigability of the waterways, especially when their water depth is limited (shallow water). The quality and accuracy of mathematical models require a continuous improvement. Push convoys operating in shallow water are intensively used performing long trips or elaborated maneuvers such as turning from a river into a harbor, turning on the spot, and astern sailing. An appropriate modeling of their maneuvring capacity requires a mathematical model able to operate in four quadrants (ahead or astern motion, combined with ahead or astern propulsion). In literature, papers which deal with the creation of reliable mathematical models for this type of inland vessels and their applications are rather scarce.