Twin-crane scheduling during seaside workload peaks with a dedicated handshake area

To enable the efficient division of labor in container yards, many large ports apply twin cranes, two identical automated stacking cranes each dedicated to one of the transfer zones on the seaside and landside. The use of a handshake area, a bay of containers that separates the dedicated areas of the two cranes, is a simple means to avoid crane interference. Inbound containers arriving in the transfer zone of one crane and dedicated to a stacking position of the other crane’s area are placed intermediately in the handshake area by the first crane and then taken over by the second crane, and vice versa for outbound containers. Existing research only evaluates simple heuristics and rule-based approaches for the coordination of twin cranes interconnected by a handshake area. For this setting, accounting for precedence constraints due to stacking containers in the handshake area, we derive exact solution procedures under a makespan minimization objective. In this way, a comprehensive computational evaluation is enabled, which benchmarks heuristics with optimal solutions and additionally compares alternative crane settings (i.e., without workload sharing and cooperation with flexible handover). We further provide insights into where to position the handshake area. Our results reveal that when planning is too simple (i.e., with a rule-based approach), optimality gaps become large, but with sophisticated optimization, the price of a simplified crane coordination via a handshake area is low.

Mixed Integer Programming Models on Scheduling Automated Stacking Cranes

Automated deep-sea container terminals are the main hubs to move millions of containers in today's global supply chains. Terminal operators often decouple the landside and waterside operations by stacking containers in stacks perpendicular to the quay. Traditionally, a single automated stacking cranes (ASC) is deployed at each stack to handle containers. A recent trend is to use new configurations with more than one crane to improve efficiency. A variety of new configurations have been implemented, such as twin, double, and triple ASCs. In this paper, the authors explore and review the mixed integer programming models that have been developed for the stacking operations of these new configurations. They further discuss how these models can be extended to contemplate diverse operational constraints including precedence constraints, interference constraints, and other objective functions.

Automation of Handling Systems in the Container Terminals of Maritime Ports

Automation of handling systems in the container terminals of maritime ports has become one of the most important changes that happened in maritime transport since the first voyage of a container vessel in 1956. Nowadays, new automated terminals are being built in the world. Most of them are located in Europe, then in North America and the Far East. Automated guided vehicles, automated straddle carriers or automated stacking cranes have replaced handling devices that were manipulated and were controlled by port workers in the container terminals. The basic goal of the paper is to focus on the advantages of this progressive system that is based on the increase of the output of the container terminals, the reduction of downtimes or accidents during handling of containers.