A new construction of the gantry cranes level luffing jib system has been proposed. Its important operating characteristics has been studied. An optimization mathematical model of these structure is built. The parameters, optimization criteria and their limitations are defined. The optimization of construction is done using the Pareto optimization procedure in MATLAB. All parts and assembled units of the gantry cranes level luffing jib system have undergone optimization in practice. The results of the optimization study of the new design are compared with those of the traditional structure.