Application of queuing theory in the organization of bulk cargo transshipment at a container terminal

The study evaluates the effectiveness of integrating specialized transshipment equipment for handling railway rolling stock in the rear area of the marine terminal and during the loading of bulk cargo into the technological chains for processing large-capacity containers. It is noted that the problem requires a comparative assessment of operational characteristics and preliminary calculations of the performance of loading and unloading machines at the cargo fronts where they are employed. The technological process for handling fertilizers in large-capacity containers is proposed to be considered as two subsystems differing in work rhythm: ensuring transfer of cargo between the railway and the accumulation warehouse, as well as delivery for loading by internal terminal transport. To develop proposals for the optimal use of the selected type of transshipment equipment at the work fronts, a comparative analysis of the terminal’s “bottlenecks,” identified in the presented mathematical model, can be performed. It is emphasized that the proposed technology for handling bulk cargo at a sea container terminal differs from the traditional scheme for handling large-capacity containers in that the container is used only at the stage of fertilizer delivery to the ship. After the container is emptied, it must be transported through the terminal warehouse to the packing point at the manufacturing plant. Since the two processing subsystems identified in the course of the study at the marine fertilizer terminal in bulk containers require the creation of a different number of service channels for cargo flows, this case provides a classic example of solving a problem of a multi-channel queuing system with waiting, in order to calculate the number of unloading, loading, and reloading positions at each identified work front. The paper concludes that the reliability of assessing the capabilities of the terminal’s transshipment equipment will make it possible to organize a queuing system without waiting, i. e., with a given service intensity.