Container terminals have at least one berth that allows containerships to be served by ship-to-shore (STS) cranes, which pick up or drop off containers on the apron. In a conventional container yard relying on rubber-tired gantry cranes (RTGs), stacks are oriented parallel to the berths to facilitate operations and better use the available footprint. If straddle carriers are used for stacking and horizontal transport, the stacks are oriented perpendicularly to the berths. A conventional terminal has three systems of intra-terminal circulation:
- A. Apron to/from stacking piles, usually done by intra-terminal trucks (ITT) designed to move containers on chassis (or bomb carts) with high maneuverability (short turning radius) and 360° visibility from the cabin.
- B. Stacking piles to/from drop/pick up area, usually done with ITT, to move containers on chassis. This is particularly prevalent for yards using straddle carriers.
- C. Gate to drop/pick up area with standard trucks either bringing their own chassis, dropping a container/chassis pair, or picking a container/chassis pair. These flows are subject to clearance through the terminal gate to ensure that the valid container is being picked up or dropped off. In many RTG terminals, B and C movements are a single movement, as extra terminal trucks can go directly to the side of the RTG stacks for drop-off or pickup.
In an automated terminal with automated stacking cranes (ASCs), there is typically a separation between apron and gate activities, with the stacks oriented perpendicular to the berths. This involves two systems of intra-terminal circulation:
- A. Apron to/from stacking piles, usually done by automated guided vehicles (AGV).
- C. Gate to drop/pick up area with standard trucks.
Reefer stacks are typically located either in the central area of the yard or near the gate for quick pickup and drop-off. Empty stacks are either located pier-side (for export repositioning) or at the back of the yard (for hinterland returns). For automated terminals, empties are also stored within the ASC stacks.
Some container terminals also have on-dock rail facilities with multiple spurs, using RTGs, reach stackers, or wide-span gantry cranes.