at the yard, are off-loaded at the quay, and loaded onto a vessel by quay cranes. Both reclaimers and cranes move along a single rail track and therefore cannot pass each other, and handle one object at a time (a stockpile in the case of a bucket wheel reclaimer and a container in the case of quay or yard cranes). Furthermore, in coal terminals as well as container terminals maximizing throughput, i.e., minimizing the time it takes to load and/or unload vessels, is the primary objective, and achieving a high throughput depends strongly on effective scheduling of the equipment.

However, there are also significant differences between the scheduling of bucket wheel reclaimers in a coal terminal and the scheduling of quay and yard cranes in the container terminals. The number of containers that has to be unloaded from or loaded onto a vessel in a container terminal is much larger than the number of cargoes that has to be loaded onto a vessel in a coal terminal. As a result, the sequencing of operations (e.g., respecting precedence constraints between the unloading/loading of containers) is much more challenging and a primary focus in crane scheduling problems. On the other hand, containers 