Optimization and evaluation of tandem quay crane performance

摘要

To meet the challenges of mega-vessels, i.e. those vessels that have capacity of 18,000 Twenty-foot Equivalent Units (TEUs) or more, tandem lift quay cranes have become more and more popular in container terminals. Theoretically these cranes may double the productivity of loading and unloading operations at the quayside. However, many factors in real operations affect the throughput of such cranes. The existing performance evaluations of these cranes involve yard operations which may end up with inaccurate results. They also do not consider hatch covers, intra-bay crane movements, and the time needed by the crane to change spreader between tandem lifts and single lifts. We propose a method to plan the operations of tandem quay cranes to handle the containers in a 40-foot bay. This includes grouping containers into tandem lifts and sequencing all lifts (tandem and single) in a 40-foot bay to optimize crane performance. Our evaluation of crane performance is based on the quay crane systems only and we use real vessel stowage plans to show what can be achieved by these cranes in real operations.