Adjusting to Giants: How Terminals Can Better Utilize Ultra Large Container Vessels (ULCVs)

By Michael Kugler

Ultra large container vessels (ULCVs), which are container ships with a cargo capacity of up to 24,000 TEU (twenty-foot equivalent units), are increasingly sailing the world's oceans. Ships with medium cargo capacity become less common than they were a few years ago. Smaller ships with a maximum cargo capacity of 14,000 TEU, on the other hand, continue to be used to reach smaller terminals and less navigable waters like the Baltic Sea. Some ports specialize in transshipment, which involves transferring containers from ULCVs to smaller ships.

Simulating the future annual throughput

Many terminal operators are currently wondering if their terminal can handle the growing number of ULCV calls and future growth. We regularly receive such requests as well. With the help of our simulation software, CHESSCON, we can usually conduct relevant calculations within a few weeks. In principle, terminal operators seek answers to some very important questions arising, when looking into future growth of the terminal:

• Will the terminal be able to handle increasing ship sizes, and increasing number of such ships?
• What is the top-notch throughput my terminal could handle, possibly considering terminal expansions or equipment fleet renewal?

This is where we, as the CHESSCON simulation team, step in and use our simulation to answer those questions. For this, we utilize the terminal's input data, a vessel schedule provided by the shipping lines which might be applicable in a few years, and our own assumptions to create, e.g. a future vessel schedule to be tested, derive developments in vessel sizes or call sizes of each vessel visit.  

One-Year Simulation Focusing on Waterside Operation, Quay Cranes & Container Storage Capacity

In such simulations, we often start with a rough overview. Initially, we roughly model the terminal in the CHESSCON Capacity tool and enter all the information such as the vessel schedule, ship sizes, the number and size of cranes, length of the quay wall, etc. We also factor in various dynamics such as "bad weather" or "delayed ships."  

To analyze the container storage capacity, we include varying container dwell times into our models. This is especially important if container dwell times are subject to major increase. For example, during the COVID-19 crisis, many terminals were fully occupied due to extended dwell times. Based on these inputs, we conduct a one-year simulation using the CHESSCON Capacity tool.

In such a coarse simulation the precise internal yard processes are not considered yet. The focus of such one-year simulation is on waterside operation, quay cranes and container storage capacity. Despite the enormous amount of possible input data, the actual simulation of such a scenario takes no longer than a few minutes.

The next step: Detailed Simulation  

In the next project phase, we usually conduct a detailed simulation, although some projects may directly start with this phase. Here, we depict the terminal with all the quay cranes, road networks, storage areas, RTGs (rubber-tired gantry cranes), prime movers, etc. Depending on the overall goal of the simulation study, we choose a simulation period between one shift or even up to one week. To act stress on the terminal model, peak shifts with very high workloads are assumed as the basis scenario for the simulation. Here too, we factor in vessel delays or delays due to bad weather. The key questions in this more detailed simulation are:  

• What do the processes behind the quay cranes look like?  
• Are the existing horizontal transport devices and stacking equipment sufficient for the operations?
• Are there traffic jams?  
• How many vehicles does the terminal need to keep their quay cranes continuously working?
• What are the options to convert the terminal from manual operation to automated stacking cranes (ASC)?

Not Only the Container Handling Equipment Can Be Stretched to Their Limits

In such simulations, one should consider various factors beyond the equipment used, such as the terminal operating system (TOS). The "human factor" should also be taken into account, including realistic break times or detours. Furthermore, each terminal operator follows own strategies in terms of how many automated guided vehicles (AGVs), automated stacking cranes (ASC), trucks or straddle carriers to deploy per quay crane, but this can vary significantly.

Our clients regularly seek our consultation to test different types of horizontal transport working at their terminal, while reducing or increasing the number of equipment deployed. Our goal is to provide robust guidance to terminal operators to answer those questions, and to support decision makers when it comes to procurement of new equipment or a change of overall terminal strategy.

Where Is the Utilization Limit, and How Can It Be Extended?

I have reported on this general simulation process to illustrate how terminal operators can better address strategic challenges using simulation scenarios and thus plan their options in a timely manner. We always recommend that terminal operators ask themselves early on where the actual utilization limit of their terminal lies and what measures and efforts can raise this limit. Should the quay wall be extended, should taller cranes or more transport devices be acquired? Or could these measures have little positive effect or even create other bottlenecks? Which directions for automation are feasible, and what performance may be expected from a move towards automation?