Intact stability analysis of crane barge due to loading orientation effect during heavy lifting operation

Abstract

Changes in the position of the lifting load on the crane barge during heavy lifting operation significantly affect the stability of the vessel. The changes in stability during this heavy lifting operation must be analysed to prevent operational failures. This study conducted an intact stability analysis of the crane barge during lifting of topside structures in the installation phase. The analysis was performed with variations in the position of the lifted load from starboard to bow for every 15° change in the crane angle. The stability results of the Crane Barge for all variations, using both analytical and numerical methods, have met the IMO requirements. The extreme condition occurred in load case 8, with a maximum GZ value of 2.904 m at a 22° angle and an area of 103,894 m.deg. The comparison of the stability results of the crane barge during the structural lifting operation using analytical calculation and numerical methods indicates that the overall validation error values have met the ±5% requirement according to the ABS Rules. However, when considering the corrections for changes in the lifting load moment in the analytical calculation, stability error values increase significantly as the heeling angle of the vessel increases.