In passenger vessels, various appendages are generally attached to the hull. These appendages are employed to guarantee high comfort and good maneuverability, and the twin shaft type is usually adopted to provide a redundancy in propulsion systems and a high-speed performance in shallow draught since these vessels usually operate in harbors or water channels. Therefore, appendage design requires full technical consideration of hydrodynamic performance aspects such as resistance, propulsion, sea keeping, and maneuvering performance, and strength and structural performance aspects including noise/vibration. In general, it is difficult to establish the dimensions or design of appendages in the early design stage since the detailed design of the vessel is not still fixed.
In this view, appendage design should be carried out with a full preliminary investigation; otherwise, many negative problems would be caused, such as an increase of resistance, a reduction of self-propulsion performance, a possibility of creating harmful cavitation, a delay in the construction schedule by manufacturing problems, among others. Consequently, special attention should be paid to appendage design during the entire design process through sufficient technical investigation and a survey of the reference vessels, and the optimal design of appendages should be performed in accordance with the design progress of the vessel.
This paper investigates the design characteristics of some appendages such as the side thruster, the shaft-strut, and the stern wedge based on the design experience accumulated at Samsung, on CFD, and on model test results for the Ro-Ro Passenger Ferry (hereinafter referred to Ro-Pax) and the cruise vessel(Rhyu et al. 2003). The object of this paper is to suggest some practical and valuable design guidelines for such appendages.