Scheduling of the delivery of import containers in a container terminal.

摘要

The rapid growth in international trade flows over the past decade has led to an unprecedented increase in cargo volume in container terminals around the world. When import containers arrive at a terminal on a ship, they are unloaded and stored on the terminal ground for a short duration before dispatched, either to trains, over-the-road trucks, or other ships. To accommodate the increased volume, more and more import containers are stacked up in yard blocks awaiting dispatch in order to save space. This thesis focuses on the delivery of import containers from the yard blocks to over-the-road trucks.;Delivering containers from stacks requires special equipment and operators to lift and transfer them to trucks. Current practice at many ports, including the Ports of Los Angeles and Long Beach, is to service the trucks on a first-come-first-served (FCFS) basis. Using FCFS, when containers requested by trucks that arrive back to back are located far apart and/or at the bottom of some stacks, long equipment travel time and additional lifts needed to reach the requested container will result in long truck 1 turnaround time, thus resulting in longer truck queues, increased port traffic congestion and more air pollution around the port area. This thesis aims at finding alternatives to FCFS for the container deliveries to over-the-road trucks. Several alternative algorithms are selected for the study. The performance of these algorithms and FCFS are analyzed and compared using a simulation system that we develop to model the container transfer process. Statistical data outputs from the simulation form the basis for determining the best scheme for container delivery under the given yard block configuration and equipment operation assumptions, aiming at the minimization of average truck turnaround times. We expect these findings will help pave the way for a feasible implementation of a priority scheduling scheme for container delivery with reduced processing time as well as less port traffic congestion and air pollution in and around the port areas.