Bulk carrier
A bulk carrier or bulker is a merchant ship specially designed to transport unpackaged bulk cargo, typically grain, coal, ore, forest products, steel coils, or cement, in its cargo holds.
Since the first specialized bulk carrier was built in 1852, economic forces have led to increased size and sophistication of these ships. Today's bulk carriers are specially designed to maximize capacity, safety, efficiency, and durability.
Today, bulk carriers make up 21 percent of the world's merchant fleets, and they range in size from single-hold mini-bulk carriers to mammoth ore ships able to carry 400,000 metric tons of deadweight. A number of specialized designs exist: some can unload their own cargo, some depend on port facilities for unloading, and some even package the cargo as it is loaded. Over half of all bulk carriers have Greek, Japanese, or Chinese owners, and more than a quarter are registered in Panama. South Korea is the largest single builder of bulk carriers, and 82 percent of these ships were built in Asia.
On bulk carriers, crews are involved in operation, management, and maintenance of the vessel, taking care of safety, navigation, maintenance, and cargo care, in accordance with international maritime legislation. Crews can range in size from three people on the smallest ships to over 30 on the largest.
Cargo loading operations vary in complexity, and loading and discharging of cargo can take several days. Bulk carriers can be gearless or geared.
Bulk cargo can be very dense, corrosive, or abrasive. This can present safety problems that can threaten a ship: problems such as cargo shifting, spontaneous combustion, and cargo saturation. The use of old ships that have corrosion problems—as well as the bulk carriers' large hatchways—have been linked to a spate of bulk carrier sinkings in the 1990s. These large hatchways, important for efficient cargo handling, can allow the entry of large volumes of water in storms and accelerate sinking once a vessel has listed or heeled. New international regulations have since been introduced to improve ship design and inspection and to streamline the process for crews to abandon ship.
Definition
The term bulk carrier has been defined in varying ways. As of 1999, the International Convention for the Safety of Life at Sea defines a bulk carrier as "a ship constructed with a single deck, top side tanks and hopper side tanks in cargo spaces and intended to primarily carry dry cargo in bulk; an ore carrier; or a combination carrier." Most classification societies use a broader definition, by which a bulk carrier is any ship that carries dry unpackaged goods. Multipurpose cargo ships can carry bulk cargo, but can also carry other cargoes and are not specifically designed for bulk carriage. The term "dry bulk carrier" is used to distinguish bulk carriers from bulk liquid carriers such as oil, chemical, or liquefied petroleum gas carriers. Very small bulk carriers are almost indistinguishable from general cargo ships, and they are often classified based more on the ship's use than its design.A number of abbreviations are used to describe bulk carriers. "OBO" describes a bulk carrier that carries a combination of ore, bulk, and oil, and "O/O" is used for combination oil and ore carriers. The terms "VLOC", "VLBC", "ULOC", and "ULBC" for very large and ultra-large ore and bulk carriers were adapted from the supertanker designations very large crude carrier and ultra-large crude carrier.
History
Before specialized bulk carriers were developed, shippers had two methods to move bulk goods by ship. In the first method, longshoremen loaded the cargo into sacks, stacked the sacks onto pallets, and put the pallets into the cargo hold with a crane. The second method required the shipper to charter an entire ship and spend time and money to build plywood bins into the holds. Then, to guide the cargo through the small hatches, wooden feeders and shifting boards had to be constructed. These methods were slow and labor-intensive. As with the container ship, the problem of efficient loading and unloading has driven the evolution of the bulk carrier.Specialized bulk carriers began to appear as steam-powered ships became more popular. The first steam ship recognized as a bulk carrier was the British collier John Bowes, built in 1852. She featured a metal hull, a steam engine, and a ballasting system which used seawater instead of sandbags. These features helped her succeed in the competitive British coal market. The first self-unloader was the lake freighter Hennepin in 1902 on the Great Lakes. This greatly decreased the unloading time of bulk carriers by using conveyor belt to move the cargo. The first bulk carriers with diesel propulsion began to appear in 1911.
Before World War II, the international shipping demand for bulk products was low—about 25 million tons for metal ores—and most of this trade was coastal. However, on the Great Lakes, bulk carriers hauled vast amounts of iron ore from Minnesota and Michigan's northern mines to the steel mills. In 1929, 73 million tons of iron ore was transported on the Lakes, and an almost equal amount of coal, limestone, and other products were also moved. Two defining characteristics of bulk carriers were already emerging: the double bottom, which was adopted in 1890, and the triangular structure of the ballast tanks, which was introduced in 1905. After World War II, an international bulk trade began to develop among industrialized nations, particularly between the European countries, the United States and Japan. Due to the economics of this trade, ocean bulk carriers became larger and more specialized. In this period, Great Lakes freighters increased in size, to maximize economies of scale, and self-unloaders became more common to cut turnaround time. The thousand-footers of the Great Lakes fleets, built in the 1970s, were among the longest ships afloat, and, in 1979, a record 214 million tons of bulk cargo were moved on the Great Lakes.
Categories
Size categories
| Name | Size in DWT | Ships | Traffic | New price | Used price |
| Handysize | 10,000 to 35,000 | 34% | 18% | $25M | $20M |
| Handymax | 35,000 to 59,000 | 37% | 18% | $25M | $20M |
| Panamax | 60,000 to 80,000 | 19% | 20% | $35M | $25M |
| Capesize | 80,000 and over | 10% | 62% | $58M | $54M |
File:Capesize bulk carrier at Suez Canal Bridge.JPG|thumb|right|Post-deepening of the Suez Canal, a capesize bulk carrier approaches the Egyptian-Japanese Friendship Bridge|313x313px
Bulk carriers are segregated into six major size categories: small, handysize, handymax, panamax, capesize, and very large. Very large bulk and ore carriers fall into the capesize category but are often considered separately.
Categories as per regions
Categories occur in regional trade, such as Kamsarmax, Seawaymax, Setouchmax, Dunkirkmax, and Newcastlemax also appear in regional trade.- "Kamsarmax": Maximum length overall 229 meters refers to a new type of ship, larger than panamax, that is suitable for berthing at the Port of Kamsar, where the major loading terminal of bauxite is restricted to vessels not more than 229 meters.
- "Newcastlemax": Maximum beam 50 meters, and maximum length overall of 300 meters Refers to the largest vessel able to enter the port of Newcastle, Australia at about 185,000 DWT
- "Setouchmax": About 203,000 DWT, being the largest vessels able to navigate the Setouchi Sea, Japan
- "Seawaymax": LOA 226 m max / 7.92 m draft. Refers to the largest vessel that can pass through the canal locks of the St. Lawrence Seaway
- "Malaccamax": LOA 330 m / 20 m draft / 300,000 DWT, Refers to the largest vessel that can pass through the Straits of Malacca.
- "Dunkirkmax": Maximum allowable beam = 45 m / LOA 289 m. max for the eastern harbour lock in the Port of Dunkirk
Handysize and Handymax ships are general purpose in nature. These two segments represent 71% of all bulk carriers over and also have the highest rate of growth. This is partly due to new regulations coming into effect which put greater constraints on the building of larger vessels. Handymax ships are typically 150–200 m in length and 52,000 with five cargo holds and four cranes. These ships are also general purpose in nature.
The size of a Panamax vessel is limited by the Panama canal's lock chambers, which can accommodate ships with a beam of up to 32.31 m, a length overall of up to 294.13 m, and a draft of up to 12.04 m.
Capesize ships are too large to traverse the Panama canal and must round Cape Horn to travel between the Pacific and Atlantic oceans. Earlier, Capesize ships could not traverse the Suez and needed to go around the Cape of Good Hope. Recent deepening of the Suez canal to 66 ft permits most Capesize ships to pass through it.
Capesize bulk carriers are specialized: 93% of their cargo is iron ore and coal. Some ships on the Great Lakes Waterway exceed Panamax dimensions but they are limited to use on the Great Lakes as they cannot pass through the smaller St. Lawrence Seaway to the ocean.
Very large ore carriers and very large bulk carriers are a subset of the capesize category reserved for vessels over. Carriers of this size are almost always designed to carry iron ore.
In October 2022, Mitsui O.S.K. Lines 's bulk carrier Shofu Maru arrived in Newcastle on its maiden voyage, becoming the first bulk carrier to be partially powered by hard sail wind power propulsion technology. A five percent fuel savings was anticipated.