ABSTRACT
Proper shaft alignment is vital for safe operation and efficient performance of a vessel. Hull deflections had infrequently been considered in shaft alignment procedure, due to the time-consuming task of creating a detailed 3D model. Recently, in extension to the existing ESA regulations, ABS released notations concerning shaft alignment procedures, and suggested that 1D beam theory FEM can provide acceptable hull deflection estimates. In the present work, the hull deflections of a typical 10K containership are calculated utilizing 1D beam theories and compared with 3D FEM results from previous work. A Graphical User Interface was developed to calculate sectional properties semi-automatically. Bending, shear stiffness and load distributions from the ship’s loading manual are used as input, and the 1D FEM is solved for representative loading conditions. Conclusions are drawn comparing the accuracy of the 3D and 1D approaches, discussing the respective restrictions and highlighting the key parameters for accurate modeling.
