Vessels designed to carry cargo packed in standardized, sealable, and reusable containers, that are made to fixed dimensions (usually either 20 or 40 feet in length) and designed to stack and lock together. They are also characterized by the lack of cargo handling gear, which is located on shore terminals rather than aboard ship. Container ships require large hatches in the deck for stowing the cargo; belowdecks typically is a cellular grid of compartments opening to the weather deck and designed to receive the containers and hold them in place until unloading is achieved at the port of destination.