The ratio of empty containers to heavy containers in container yard is not fixed, but should be different under various conditions. For a terminal mainly engaged in transit business, the ratio of empty containers to heavy containers is very small. The proportion of an inland port will be relatively large. At the same time, it will also be affected by local logistics conditions. For example, Ningbo has a special freight station (freight forwarders can directly pick up empty containers here), and the proportion of empty containers and heavy containers in their docks is lower than that in Wenzhou (there is no special freight station).

Container throughput refers to the maximum quantity that a port can load and unload goods for a ship with its modern equipment in a certain period and under certain conditions. Comprehensive reflection of the production capacity of terminals, warehouses, railways, workers, machinery and other links should be adapted to the port throughput task.

Storage capacity refers to the number of containers that can be stored in the dock yard (empty container storage area, heavy container storage area and dangerous goods storage area). It comprehensively reflects the amount that a container can store in a certain period of time and under certain conditions.

Throughput capacity, also known as port capacity, refers to the maximum amount of cargo that a port can load and unload for a ship in a certain period of time (year, month and day) under certain technical equipment and labor organization conditions, according to reasonable operation flow and advanced loading and unloading technology, that is, the maximum throughput, expressed in tons. It is the sum of the throughput of all berths in the port, in tons.