This study focuses on an analytical approach to calculate four crane lifting forces for heavy ship hull blocks considering elongations of lifting slings. Four-crane-lifting is a redundant problem. For lifting analysis, the Euler angles are defined to represent the inclination of a hull block. In addition to the force and moment equilibrium equations, a compatibility condition is introduced to determine four unknown lifting forces. For verification of the method, ship hull blocks with field measurements data are analyzed and the results show that the information obtained by the current method could be useful for engineers to conduct similar lifting work at shipyards.