The results presented in this section are very dependent on the
modeling assumptions made, cases studied and the quality of the
routing method used when comparing the MHE. Making unfair
assumptions or using suboptimal solution methods could lead to
biased conclusions. Also, other aspects of the MHE, such as its
costs, flexibility and scalability, needs to be considered when making
the MHE decision. In general, based on the literature and on the
authors’ experience, straddle carriers are a good storage yard MHE
for small to medium size terminals. For large terminals, straddle
carrier layouts will be affected by congestion and storage capacity.
For large transshipment terminals, Asian layouts are better suited.
On the other hand, for large terminals that handle import/export
containers the European layout is arguably better suited. In terms
of growing capacity in an automated storage yard, a logical strategy
would be to use single YCs until no additional blocks may be
added. At that point, either passing or non-passing cranes should
be implemented, depending on the relative speed of the crane on
each configuration.