Dry Bulkship Transport
Bulkships transport huge volumes of cargoes such as iron ore, coal, grain, salt, aluminum, and copper ore without packing or packaging.
These vessels are called "bulkers," "dry bulkers," "bulk carriers," or "dry bulk ships," since they transport "dry cargo" in "bulk." Bulkships vary widely in size and configuration, depending on the cargo they carry and the characteristics of the ports where they call.
VLOC stands for "Very Large Ore Carrier". This class of ship is a recent development, reflecting the trend toward larger vessels in pursuit of economy.
The "Capesize" is the largest class of bulkship that can carry any type of cargo, such as iron ore and coal in main. They are called "Capesize" ships as they cannot pass through the Panama Canal and have to go around the Cape of Good Hope to sail between the Pacific and Atlantic oceans.
"Panamax" is the name of the largest class of ships able to transit the Panama Canal. These vessels are up to 900 feet (about 274m) long with a breadth of up to 106 feet (about 32m). The Panama Canal was expanded in 2016 and can now accommodate larger vessels than ever before. However, as of today, the term "Panamax" still means the maximum size able that can navigate the Panama Canal before its expansion.
Ship classes smaller than the Panamax include the word "handy" in their names. This reflects the convenience of being able to call at most ports around the world. Handy bulkers are equipped with their own cranes, allowing them to load and discharge cargo even at ports without loading/discharging facilities, and can transport a wide variety of commodities.
|Standard deadweight tonnage||Main cargoes|
|Very Large Ore Carrier (VLOC)||250,000||Iron ore|
|Capesize||180,000||Iron ore, coking coal|
|Panamax||82,000||Iron ore, coking coal, thermal coal, grain|
|Handymax||58,000||Thermal coal, grain, salt, cement, steel|
|Small Handy||28,000||Steel, cement, grain, ore|
Bulkships have "topside tanks," triangular ballast tanks (filled with water to stabilize the vessel) fitted at both shoulders/wings of the cargo holds. These help the ship maintain the proper trim no matter how much cargo is on board. The sides on the lower part of the hold are designed with a hopper configuration to maximize loading/discharging efficiency by preventing cargo from accumulating in the corners. Some bulkers have cranes for loading/discharging, while others rely on shoreside equipment. In general, vessels larger than Panamax do not have cranes. There are hatch covers at the top of the hold, which are opened only during loading/discharging.
— Dedicated Bulkships by Cargo —
Generally, an optimal type of bulkship is chosen based on cargo volume, port scale, facilities, and equipment. But some dedicated bulkships are designed and constructed to transport a specific cargo in the safest, most economical, and most efficient manner.
Iron ore has a high specific gravity, so the cargo hold is designed to be narrow, with the cargo heaping up in the center. These large vessels without cranes represent the mainstream in economical, efficient transport of iron ore.
These vessels transport coal for thermal power generation. They are designed to match the water depth and discharging equipment at a dedicated berth for a power station. The wide-breadth type (80,000-90,000DWT) is the mainstream, as this configuration allows the ship to load a large volume of coal and still navigate safely in shallow waters.
This type of vessel is specially designed to carry woodchips, the raw material for paper. The specific gravity of woodchips is low, so the hold is designed to maximize cargo capacity. In addition, wood chips do not shift very much in transit, eliminating the need for topside tanks.