Designing constraints in evaluation of ship propulsion power

Preliminary ship owners' assumptions for new ship consist of deadweight (for container vessel load capacity TEU), speed shipping line and others. Taking it as a base, in early stage of design one has to select propulsion type. This goal needs definition of principal dimensions of a vessel, which are the base for further calculations of hull’s resistance and evaluation of necessary power of main engine (engines) to fulfil shipping requirements. Selection of main dimensions of vessel is limited by rules regarding buoyancy, stability, hull strength, manoeuvring capability, and limitations related to seaways or harbours characteristic. In this paper is presented the methodology of calculation of principal parameters of a vessel, necessary for calculation of displacement in relation to vessel’s type, volumetric coefficients, Froude number, and others values affecting ship’s dimensions. It is about midship section coefficient, waterline coefficient, prismatic coefficients and hull feature and area coefficients. Those values are necessary for calculation of hull resistance. In the table are presented comparison of results of calculations above mentioned values and movement resistance and propulsion power of three container vessels representing different load capacity and one bulk carrier. There are also presented different calculation methods of transverse midship section coefficient and wet area coefficient, for 5000TEU container vessel.