This article presents an approach of numerical modelling of I-beam crane jib, with using the finite element method particularly the most loaded elements at different speeds. One of the possible methods for use in the design process of hoisting dynamics modelling and its effects on the load-carrying structure for the marine jib crane is shown. For proper modelling, the impact of the load and hoisting speed on the load-carrying structure jib, dynamics simulations of hoisting the load using Matlab-Simulink software were carried out and in the field of finite element method. To carry out such a simulation, hybrid calculations had to be applied, where the response from the phenomenological model based on solving a system of differential equations of motion in Matlab-Simulink was used to stimulate the crane I-beam jib during the FEM simulation, which permits to determine dynamic properties of the load-carrying structure for two example different hoisting speeds. The basic strength parameters for a typical light marine jib crane, obtained in the case of static calculations and using the proposed approach between the two computing environments were compared.