This thesis covers the topic "Strength calculation and optimization of the ship crane". The introduction states in general about the cranes, their distribution and more details about the ship crane and the purpose of its use. By inspecting the existing constructional designs of ship cranes and the requirements which need to be fulfilled, new constructional design of the ship crane is made in the second chapter. After determining the critical position of the crane in the form of a load, calculation of the inside diameters of cylinders is made and depending on them the required number of cylinders has been selected. The strength calculation of the characteristic parts of the crane is shown in the third chapter. The calculation of the stresses and total deformations was made using the Ansys Workbench 19.0 software package. Numeric calculation has proved that previously design of crane is rated to be unsatisfactory with requirements imposed on the strength and that crane needs to be strengthened. After the structure reinforcement has been added, a reconducted analysis has been made and the crane has met all the requirements imposed on the strength. In order to confirm the results, the basic analytical calculation has been made and compared with the results performed with finite element method. After designing the boat crane and preforming the strength calculations, it is necessary to calculate and analyze the motion of the designed crane construction which is done in the fourth chapter. Boat crane is designed with hydraulic cylinders and rotation around the shaft using a hydraulic motor. Therefore, it is necessary to create a scheme of hydraulic system of the crane to calculate the power and the flow of the hydraulic pump that drives all the hydraulic actuators. A description of all characteristic hydraulic elements in the system and the speeds of lifting are also presented. Optimization of designed crane is made in the fifth chapter. After reinforcing the structure in the third chapter, no material exploitation was taken into account and reinforcements were added only with the goal of reduction the equivalent stresses and the maximum total deformation of the crane. Due to the possible oversizing of the reinforcements, the optimization was performed by the response surface optimization method. Optimization was performed with the goal of minimizing the mass and it has been found that the construction was oversized and the mass was reduced by almost 14 kg.