Reefer vessel

Reefer ships may be categorised into three types: (1) Side-door vessels have water tight ports on the ships hull, which open into a cargo hold. Elevators or ramps leading from the quay serve as loading and discharging access for the forklifts or conveyors. Inside these access ports or side doors, pallet lifts or another series of conveyors bring the cargo to the respective decks. This special design makes the vessels particularly well suited for inclement weather operations as the tops of the cargo holds are always closed against rain and sun. (2) Conventional vessels have a traditional cargo operation with top opening hatches and cranes/derricks. On such ships, when facing wet weather, the hatches need to be closed to prevent heavy rain from flooding the holds. Both above ship types are well suited for the handling of palletized and loose cargo. (3) Refrigerated container ships are specifically designed to carry containerised unit loads where each container has its individual refrigerated unit. These containers are nearly always twenty-foot equivalent units (often called TEU) that are the "standard" container cargo size that are loaded and unloaded at container terminals and aboard container ships. These ships differ from conventional container ships in their design and power generation and electrical distribution equipment. They need provisions made for powering each container's cooling system. Because of their ease of loading and unloading cargo many container ships are now being built or redesigned to carry refrigerated containers. [Reefer ship. Wikipedia]