“Abstract

Yard equipment upgrades are vital for port decarbonization, yet the coexistence of legacy and new yard cranes creates challenges in coordinating operations and allocating limited electrical power. This paper studies the integrated container allocation and conflict-free scheduling of multiple yard crane types, including slipline rail-mounted gantry crane (RMG), hybrid diesel-electric RMG, cable rubber-tyred gantry crane (RTG), and diesel-powered RTG, under power capacity, interference, and safety-distance constraints. We propose a mixed-integer linear programming (MILP) model that minimizes energy cost, carbon penalty, and makespan penalty. Because general-purpose solvers struggle with large instances, we develop a tailored logic-based Benders decomposition (TLBBD) algorithm with several enhancement strategies. Numerical experiments based on data from a real port demonstrate that TLBBD significantly outperforms Gurobi, an existing LBBD method, and real-world scheduling schemes, obtaining optimal or near-optimal solutions within 15 minutes for instances with five cranes and 100 containers. Sensitivity analyses on cable RTG cable length, yard crane layout, and carbon tax further illustrate the practical applicability of the proposed approach.”

 

The full report is accessible via: https://doi.org/10.1016/j.tre.2025.104581

For related publications, please see Resources – UK National Clean Maritime Research Hub

“Abstract

Stacking strategies determine which yard block to allocate the container and which bay and column in the block to stack the container. They play an important role to ensure yard efficiency and reduce vessel berthing time and truck waiting time. This paper models and analyses the impact of stacking strategies on the container terminal operations by a two-stage approach. We consider common stacking rules including random stacking rule and distance-based priority assigning rule. In the first stage, the individual operations of handling equipment are modelled by travel time models considering uncertainty in operations. The effects of stacking rules on individual operations, such as Automatic Guided Vehicle (AGV) traveling times, landside yard crane operation times and seaside yard crane operation times, are estimated. In the second stage, we use a semi-open queuing network to model the interactions between individual operations, and the results of the first stage are used as inputs in the second stage network. We analytically examined the handling times of the relevant equipment under different stacking strategies and their sensitivity to yard density. Finally, we use simulation method to verify the effectiveness of the results of our model. The results can offer insights into which stacking strategies are more suitable under different criteria and circumstances such as balancing workload, increasing yard utilization and reducing congestion for external trucks.”

Zhang, X., Jia, N., Song, DP., & Liu, B. (2024). Modelling and analyzing the stacking strategies in automated container terminals. Transportation Research Part E: Logistics and Transportation Review, 187, 103608. DOI: 10.1016/j.tre.2024.103608

Please use the DOI link above to access the full report.

For related publications please see Resources – UK National Clean Maritime Research Hub