Optimisation in liner shipping: Challenges in mega vessel's cargo-mix and loading operations

The goal of this thesis is to develop decision support tools, to optimise the planning of certain activities within the liner shipping industry. With the emergence of mega-vessels, the planning of vessel and terminal activities are becoming more and more vital for the liner shipping industry. This thesis considers two specific problems where optimisation methods can be used to help with the planning.

The rst of these problems aim to improve the utilisation of the vessels, and the second aim to improve terminal productivity to minimise the time spent at ports for vessels. For large vessels to achieve economies of scale, it is crucial they be fully utilised. E.g. It requires a 91% utilisation for an 18000 TEU vessel to be cost-effective over a fully loaded 14000 TEU vessel.

When determining a load configuration (stowage plan), it is of utmost importance to ensure the vessel do not capsize or break. For this, the weight distribution of the containers on the vessel plays an essential role. A stowage plan must also conform with the cargo already loaded on the vessel, the cargo to be loaded while also ensuring the vessel can still be utilised to its maximum in downstream ports.

Given the growth in the size of newly built vessels, this task is becoming harder and harder, as well as more important. We study this problem and develop an adaptable framework to help with dierent kinds of what-if analysis. While the voyage cost per container is decreased for the mega-vessels, the handling cost is increased.

Hence, terminals are under pressure to increase productivity and minimise the turnaround time for the vessels. The design of the mega-vessels, however, makes this hard. These vessels are both higher and wider, requiring cranes to reach further away from the quay and deeper into the vessel. As an effect of the inherent design of the vessels, the (un)loading time per container is thus increased, compared to smaller vessels.

With more mega-vessels coming shortly it is also expected that yard congestion will be an increasing problem. Without any significant improvements it is therefore not expected that productivity will increase, and even maintaining the current level will be a challenge. Decreasing the time spent at port is a shared goal between the liner and the terminal.

For the liner, the operating costs are decreased, while the terminal can plan the use of their container-handling equipment better, so it can be used for another vessel. We investigate such a collaboration and how the sharing of data can be used to optimise the terminal-side planning while ensuring the liner also beneffits from this.

The results are prototypes of decision support tools, that can be used to automatize the planning of these activities.