Hydrodynamic derivatives investigation of unconventionally arranged pusher-barge systems

Unconventional arrangements of pusher-barge systems were studied in this paper. Pusher-barge systems consisting of 4, 6, and 8 barges with one pusher were tested in various combinations. Captive model testing was performed on the various combinations at the Hiroshima University towing tank. Hydrodynamic derivatives of the systems were obtained from the model test data by using the least-square analysis method. For asymmetric conditions, the hydrodynamic derivatives and N′_ββ were added to the force and moment equations in order to obtain better fitting of the least-square curves. Motion equations were modified to cover the asymmetric cases of pusher-barge systems with lateral force and yaw moment due to the asymmetry arrangement. Turning simulations (with 20° sudden angle change) were carried out and a comparison of advance distance and tactical diameter made. An erratum to this article can be found at