Two standard capacity measures can be used to assess container yard capacity:
- Static capacity. The total capacity of the yard at any given point in time, in terms of how many TEU equivalent can be stored, considering its physical and equipment characteristics.
- Dynamic capacity. The capacity of the yard over a defined period of time. It is contingent on dwell time, which is the average amount of time a container spends in the yard before being picked up for inland distribution or loaded onto a ship. Dynamic capacity (TEU per ha/year) = static capacity * (365/Dwell time)
Container terminals can exhibit significant variations in stacking density (static and dynamic) on the same surface, depending on the type of container yard equipment. The most common are rubber-tired gantries (RTGs) and straddle carriers, which are associated with average stacking densities of 500-800 TEU per hectare of yard space. At any given time, a container yard using RTGs should be able to store about 800 TEU per hectare. If containers remain in the yard for an average of 4 days, the dynamic capacity of this yard is around 72,500 TEUs per ha/year.
The available terminal footprint and the complexity of terminal operations determine the choice of stacking density and the related static and dynamic capacity. Low densities offer lower capital investment and a quick turnaround, but consume more yard space. In contrast, high densities are logistically more complex and require careful operations to avoid undue container rehandling.