Single deck ships designed to carry homogeneous unpacked dry cargoes such as sugar or cereals. Such ships have large hatchways to facilitate cargo handling, hopper sides and wing tanks.The latter are used either for the carriage of grain, other bulk cargoes or water ballast. Bulk carriers, or bulkers as they are sometimes called, are built in a wide range of sizes and are generally gearless, although smaller vessels may have their own gear.