This paper discusses the technical aspects of modeling the cage retention system for industrial fish farming in a pond using pull chains. The purpose of this work: substantiation of the parameters of the holding ropes, the length of the chains and the required mass of the anchors by calculating the tensile forces in the ropes and the reaction of the anchor supports when solving the dynamic problem in an unsteady setting. Dynamic system was developed that takes into account wind, wave and inertial loads acting on all elements of the system: cage, holding ropes, chains, anchors. The force acting on the surface of the cage from the wind is received. For this, a solid-state cage model was developed with equivalent windage. The tensile forces in the ropes and the reaction of the anchor supports in three planes are obtained. The lengths of the chains are selected, ensuring the absence of tearing forces acting on the anchors. Moreover, the calculations were performed in a non-stationary setting with a gradual increase in load. The simulation duration was 60 s. During this time, one resonance phenomenon was revealed: a significant increase in the breaking strength in the rope at 37 seconds of calculation.