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Optimizing the time factors in ports and consequences for externalities

Book - Dissertation

Real-world container terminals usually consist of several quays with different water depths which are time-varying parameters based on the tidal conditions. However, most of the existing techniques in literature were designed for a single quay terminal, considering the water depth as a fixed parameter. Tides always have an impact on terminals operation in container ports, specifically during the arrival and departure of the vessels. By scheduling and reducing the tidal impacts on different aspects, the terminal operators are able to manage the vessels’ mooring time and increase terminal productivity. While some quays can accommodate all sizes of vessel, others are able to allocate only ships with the lower drought. Drought limitation is one of the main factors impacting on the decision to allocate a quay to a ship alongside the berth. If a ship’s drought exceeds the acceptable level for both arrival and departure, then it is not possible for the ship to be moored in terms of under-water tidal limitations. In that case, such vessels have to wait for permitted sea level conditions or will be redirected to other quays where water depth is not a restrictive element. Moreover, on-the-water tidal limitations affect quay crane assignment and scheduling processes. As tide conditions can cause a significant variation in real drought alongside the berths, assigning and unmooring of the vessels in the quays will be affected by tidal conditions. Due to higher complexity of the integrated problems of the BAP, QCAP, and QCSP, most of the existing techniques were used to tackle these problems individually. In order to overcome the mentioned limitations and drawbacks, this research presented a new model (named TMB-CAS model) for the BAP in multi-quay terminals under tidal restrictions (TMB) considering quay crane scheduling and assignment problems (CAS). In the proposed TMB-CAS model, not only under-water restrictions (for mooring vessels without accident by the ground), but also on-the-water restrictions (for loading/unloading different bays of vessels by quay cranes) were taken into account. Moreover, the TMB-CAS model considers the impact of real-time weight of the vessels on the drought and free space. In order to solve the proposed TMB-CAS model, a combined heuristic-metaheuristic algorithm based on Heuristic information and Knowledge Based Simulated Annealing (named HKBSA) was proposed. The proposed methodology has been successfully tested on a set of numerical instances systematically generated from close to real-world container terminals, as well as on the Port of Shahid Rajaee, Iran. The obtained simulation results for the real case study for the Port of Shahid Rajaee clearly demonstrate the performance of the proposed method to be applied for the berth allocation and scheduling in real ports. According to the obtained results, the proposed HKBSA algorithm results in improvement rates of 42.5%, 59%, and 33.5% in the waiting cost, delay cost, and the total objective function, as compared with the real allocation and scheduling decisions at the port of Shahid Rajaee.
Number of pages: 183
Publication year:2021
Keywords:Doctoral thesis