Photo: Dr. Jean-Paul Rodrigue, 2019. Location: Long Beach Container Terminal (LBCT).
An important component of container terminal automation concerns horizontal movements, which includes flows between the docks and the stacking yards. Automated Guided Vehicles (AGV) are able to carry containers between dockside and the stacking yards using various sensors and positioning systems to properly navigate. They are almost exclusively electric with a charge of about 6 to 8 hours and a power down mode when not in use. Charging is usually achieved by swapping their batteries with a charged pack, while the uncharged pack is being recharged.
Automated Stacking Cranes (ASC) are able to automatically load containers from both ends of the stacking yard. On the quayside, containers can be brought and retrieved by AGVs while on the gate side they are usually brought and retrieved by chassis and trucks. Each stacking yard contains at least two ASC; one for quayside operations and the other for gate side operations. During low activity cycles, such as nighttime, ASCs usually reposition containers in light of the anticipated activity, such as an inbound ship to be loaded with a series of containers that are easier to retrieve sequentially.