Bulk cargo ships can be divided into different types according to different loads, mainly as follows:
Coal carrier is a bulk carrier used to carry coal. Its hatch is relatively wide, making it easy to load and unload coal with a grab. In order to prevent coal from rolling in the coal bunker, many longitudinal baffles are provided at the bottom of the coal bunker. Some coal ships do not use grabs and booms, but are equipped with belt conveyors at the bottom of the coal bunker, which can be connected to shore conveyors and can load and unload coal by themselves
Ore ship is a bulk carrier specialized in loading sand. Because the ore is a heavy cargo, it has a large specific volume and a small volume, which can easily damage the hull. For this reason, the ore ship has a strong structure. The bottom of the cargo hold is mostly inclined. The cargo hold is also equipped with longitudinal baffles, which can prevent the ore from rolling longitudinally and enhance the strength of the hull.
The wooden ship is used to load and transport timber, because the timber is light in weight and bulky. Therefore, the cargo hold of the wooden ship is wide, and there are no hull components such as beams and columns in the cargo hold. Because wood is not afraid of wind and rain, it can be stored in cargo holds or stacked on deck. In order to block and enclose the timber, wooden posts are arranged on the side of the deck so that more timber can be installed.
Bulk carriers can be divided into different types according to different transportation purposes, mainly as follows:
Ordinary bulk carrier
Ordinary bulk carriers are generally single-deck, stern type, and the cargo hold section is octagonal. Due to the single type of cargo being transported, the requirements for compartment separation are not high, and the specific gravities of various bulk cargoes are quite different, the bulk carrier’s cargo compartment volume is relatively large to meet the requirements for loading light cargo. When heavy cargo needs to be loaded, the method of compartment loading or the arrangement of large and small compartments shall be adopted.
Dedicated bulk carrier
Special bulk carriers are bulk carriers designed and built according to the special requirements of some large quantities of bulk cargo on the sea transportation technology, mainly coal carriers, bulk grain carriers, ore carriers and bulk cement carriers.
Double-purpose bulk carrier
Multi-purpose bulk carrier is a ship designed and built according to the special requirements of certain specific bulk cargo or bulk cargo for marine transportation technology, and has multiple shipping functions.
Special bulk carrier
Large-hatch bulk carrier: This type of ship has a cargo hatch width of more than 70% of the ship's width, and is equipped with lifting equipment. It can load both bulk cargo, wood, steel, rubber, machinery, newsprint and containers. Wait, it is very adaptable.
Self-unloading bulk carrier: It is a transport ship with a special cargo hold structure and an automatic unloading system. It can carry out centralized operation and fast automatic unloading operations without relying on port facilities, and is suitable for transporting bulk ore, grain, coal, cement, fertilizer, etc.
Livestock ships are bulk cargo ships that specialize in transporting livestock. In order to prevent livestock from moving in the cabin, partitions are provided in the cabin of the livestock ship, and there is also a trough in the cabin for livestock food.
The grain ship is a bulk cargo ship that specializes in shipping grain. It belongs to the category of dry bulk carriers.
Cement ships are bulk cargo ships that specialize in transporting cement. It belongs to the category of dry bulk carriers.
A steel carrier is a bulk carrier that specializes in shipping steel. It belongs to the category of dry bulk carriers.
Divided by ship tonnage
For bulk carriers such as grain, cement, steel, ore, etc., they are usually divided into the following levels:
1. Handysize bulk carrier: refers to a bulk carrier with a carrying capacity of about 20,000 to 50,000 tons, of which ships with more than 40,000 tons are also called Handymax bulk carriers. As we all know, dry bulk cargo is bulk cargo by sea. These relatively small tonnage ships have strong adaptability to waterways, canals and ports, moderate deadweight tonnage, and are mostly equipped with loading and unloading equipment, which is convenient and flexible in operation. It is called 'handy type'.
2. Panamax bulk carrier: As the name suggests, this type of ship refers to the largest bulk carrier that can pass through the Panama Canal under full load, that is, it mainly meets that the total length of the ship does not exceed 274.3 2 meters, and the width does not exceed 32.30. The relevant regulations for the navigation of the canal in meters. According to the needs, adjust the size, type and structure of the ship to change the deadweight. The deadweight of this type of ship is generally between 60,000 to 75,000 tons.
3. Capesize bulk carrier: refers to a bulk carrier with a carrying capacity of about 150,000 tons. This type of ship is mainly used to transport iron ore. It is impossible to pass through the Panama Canal and Suez Canal due to size restrictions and needs to detour The Cape of Good Hope and Cape Horn are called 'cape' types in Taiwan Province. As the Suez Canal authorities have relaxed the draft restrictions for ships passing through the canal in recent years, most ships of this type can pass through the canal with full load.
4. Lake bulk carrier (Lake bulkcarrier): refers to a bulk carrier that sails through the St. Lawrence Waterway in the Great Lakes region at the junction of the United States and Canada, and mainly carries coal, iron ore and grain. The scale of this type of ship must meet the navigation requirements of the St. Lawrence Waterway. The total length of the ship should not exceed 222.50 meters, the moulded width should not exceed 23.16 meters, and any part of the bridge should not extend beyond the hull, and the draught should not exceed the maximum allowable draught in the major waters. The water surface height should not exceed 35.66 meters. This type of ship is generally about 30,000 tons, and most of them are equipped with loading and unloading devices.
5. Small bulk carrier
Small bulk carriers refer to bulk carriers with a total carrying capacity of 20,000 to 27,000 tons. Its maximum ship length does not exceed 222.5 meters, the maximum ship width is less than 23.1 meters, and the maximum draft is less than 7.925 meters.
Divided by the type of goods loaded
According to the different types of cargo carried by the ship, dry bulk carriers can be divided into ordinary dry bulk carriers, special dry bulk carriers, special dry bulk carriers, large doors and bulk carriers, etc.
1. Ordinary dry bulk carrier
Generally, bulk carriers are generally single-deck, stern type, and the cross-section of the cargo hold is octagonal. Due to the single type of cargo, the requirements for compartment separation are not high. In addition, the proportions of various bulk cargoes vary greatly, so the cargo holds of dry bulk carriers have a larger volume to meet the needs of light cargo. If heavy cargo needs to be loaded, the method of compartment loading or the same arrangement of large and small compartments shall be adopted.
The hull structure of dry bulk carriers is stronger to meet the needs of concentrated loads. Corresponding loading and unloading equipment is available at the port docks where large-tonnage dry bulk carriers are docked. Therefore, dry bulk carriers of more than 40,000 tons, especially dry bulk carriers that carry out special line transportation between specific ports, are generally not installed Lifting equipment.
2. Dedicated dry bulk carrier
Dedicated to bulk carriers are dry bulk carriers designed and manufactured according to the special requirements of some bulk and large quantities of bulk cargo on maritime transportation technology, mainly including coal carriers, bulk grain carriers, ore carriers and bulk cement carriers. They have their own characteristics.
The ship type of the coal carrier is closest to the ordinary bulk carrier, and there is no good ventilation equipment on board. To prevent the coal from heating and spontaneous combustion. Bulk grain ships have a larger capacity coefficient than ordinary bulk carriers because the bulk grain stowage factor is larger; bulk grain will gradually sink during the ship's navigation. To limit its freedom effect. Generally, the cargo hatch coamings of open grain ships are heightened and the cargo hatch size is reduced. The surface area of ??the cargo after sinking is limited to the scope of the hatch. Ore carriers do not require much cargo hold volume, because the stowage factor of ore is small; but their load is relatively concentrated, in order to appropriately increase the cargo center of gravity, improve ship performance, and facilitate cargo loading
and unloading. The double-decker city of ships is often elevated. In addition, longitudinal watertight barriers are installed on both sides of the cargo hold, so that the cut surface of the cargo hold is smaller in the shape of a bucket, and its hull structure is also stronger. There is no boom-type lifting device on the deck of bulk cement ships, but for loading and unloading cement, pneumatic or mechanical cement loading and unloading equipment is provided; in order to prevent the bulk cement from coloring and wet agglomeration, the cargo hatches are designed relatively It is small, and there is no dust chamber in the middle of the ship or an air filter on the hatch. The upper deck and cargo hatch are strictly watertight.
3. Dual-purpose dry bulk carrier
also used for bulk carrier is a ship designed and manufactured according to the special requirements of certain specific bulk cargo or bulk cargo for maritime transportation technology, and has a variety of shipping functions.
It mainly includes the following two types. ①Vehicle-dry bulk carrier: This type of ship is equipped with several layers of suspended or folding vehicle decks, equipped with light hatch covers, for loading cars. The vehicle deck generally adopts a grid patterned iron plate structure to reduce weight. When loading bulk cargo, the hatch cover can be hoisted to the deck, and the vehicle deck can be folded and hung under the main deck or folded close to the transverse bulkhead. ②Ore-spreading and oil-filling dual-purpose ships: these ships have relatively large tonnage and abundant cabin capacity. There are ore or other cargo holds in the middle with large hatch openings to facilitate grabbing up and down; the two sides are oil tanks, which can use the return journey and the off-season oil loading of ore and bulk cargo trade to improve the economic effect of the ship’s operation. In addition, according to the source of goods, the common types of ships include mine-oil combined use ships and bulk oil combined ships.
4. Special dry bulk carrier
Special dry bulk carriers mainly include the following three types.
①Large hatch dry bulk carrier: This type of ship has a cargo hatch width of more than 70% of the ship’s width and is equipped with cargo handling equipment. It can carry bulk cargo as well as wood, steel, rubber, machinery and equipment. Newsprint and containers are highly adaptable.
② Self-unloading dry bulk carrier: It is a transport ship with a special cargo hold structure and an automatic unloading system. The self-unloading dry bulk carrier adopts automatic unloading equipment, which increases the cost and weight of the ship. Therefore, it is necessary to improve the unloading efficiency to reduce the unloading fee and speed up the turnover of the ship to obtain good economic benefits. It is suitable for routes with short voyages and poor unloading port equipment.
③Shallow draft and fat large ship: It is a new type of ship that appeared in the process of the development of the ship type to large-scale. Compared with ordinary cargo ships, the ship width is increased under the condition of the same draft, and a larger draft ratio is adopted. The method increases the load capacity, thereby greatly improving the economy of ships. It is mainly suitable for ports and waterways where water is severely restricted. It is also the preferred ship type for the development of river-sea combined transport.