A usual expression for a ship carrying petroleum, molasses, coal, cement etc, in bulk. Her construction is usually reinforced to counteract the heavy bulk weight of the cargo carried. The modern bulk carrier mostly does not have cargo derricks as she is designed to use her own unloading gear. Type of bulk carrier purpose-built for the carriage of coal. Normally with three, four or five holds, she has large hatchways to give rapid discharge by allowing the grabs access chutes.
Some colliers have conveyor belts for discharging in which case they are said to be self-unloaders.
The cargo is loaded into central hold and, if oil, into side tanks as well. Abbreviated to o.b.o. Ship designed for the carriage of liquid in bulk, her cargo space consisting of serveral, or indeed many tanks. Tankers carry a wise variety of products, including crude oil, refined product, liquid gas and wine. Tankers load their cargo by gravity from the shore or by shore pumps and discharge using their own pumps.