A Representative Formulation of the Container Vessel Stowage Problem and a new Non-Hierarchical LNS Solution Approach

Global containerized trade resulted in 149 million
twenty-foot equivalent units in 2020 and this number grows about
4% on a yearly basis [1]. Considering the volume of shipped
goods, research resulting in improvements of the stowage plans
can yield remarkable economic and CO2 emissions savings. With
almost 10 years of experience working closely with several
shipping companies we realized that the container vessel stowage
problem is poorly understood in the literature and lacking a
standardized definition that researchers can refer to. This work
contributes a realistic description of the problem, matched with an
extensive benchmark suite based on real-life data.
The container vessel stowage problem is complex and has several
constraints and objectives interacting with each other. While
creating a standard description, it is crucial to carefully choose
which objectives and constraints to consider to fully capture the
nature of the problem without overly complicating or simplifying
the problem. Besides basic stack capacity limits and stowage rules,
the constraints we chose include hydrostatic limits, minimum
crane intensity, lashing forces using simplified moment-based
calculations and block stowage. The objective function is a mix of
the number of containers stowed on the vessel and the amount of
free space left. More details on the selection of key aspects will be
presented.