Online rules for container stacking

Abstract

Container stacking rules are an important factor in container terminal efficiency. In this paper, we investigate two concepts to increase efficiency and compare them to several benchmark algorithms, using a discrete-event simulation tool. The first concept is to use knowledge about container departure times, in order to limit the number of reshuffles. We stack containers leaving shortly before each other on top of each other. The second concept is the trade-off between stacking further away in the terminal versus stacking close to the exit points and accepting more reshuffles. It is concluded that even the use of imperfect or imprecise departure time information leads to significant improvements in efficiency. Minimizing the difference in departure times proved to be important. It was also found that the trade-off between stacking further away in the terminal versus stacking close by the exit points and accepting more reshuffles leads to improvements over the benchmark.

Evaluating impact of truck announcements on container stacking efficiency

“…We assume that there are sufficient AGVs and straddle carriers to ensure that these resources do not act as bottlenecks. The basic configuration for the stacking area was adapted from the earlier work by the same authors (Borgman et al 2010), but resized to accommodate the increased number of containers and the various container sizes. The stack configuration is now 19 lanes, each consisting of 6 segments, which in turn have 55 positions of 20 ft. Each segments is dedicated to one size of container (20/40/45ft) in proportion with the number of containers for each size.…”

“…This Direct Access when Retrieved for Trucks (DART) is a measure of the potential impact of the announcements and is expressed as a percentage of the total number of truck pick-ups. The stacking algorithms are described in more in detail in Dekker et al (2006) and Borgman et al (2010). A short description for each of the algorithms is listed in Table 1.…”

“…For the latter category few papers exist. We like to mention Dekker et al (2006) and Borgman et al (2010), who compare several stacking rules in a simulation study for an automated container terminal. This paper builds forth on their results.…”

“…In our previous research (Dekker et al 2006;Borgman et al 2010) we have looked at the performance of a number of container stacking algorithms. The main question we now face is how each stacking rule will benefit from advanced knowledge of truck arrivals.…”

“…In this paper we investigate the impact of more accurate departure time information for truck exports (containers that leave the container terminal by truck) that becomes available after the container has been stacked. This paper builds on our prior work regarding container terminal stacking (Dekker et al 2006;van Asperen 2009;Borgman et al 2010). In these studies we focus on the short term decision to allocate an incoming container to a stacking position.…”