General cargo is cargo that has been packed in crates, boxes or bags, or cargo coming in pieces.
Cargo is loaded and discharged by the vessel’s own derricks or by shore based cranes.
The conventional general cargo ship has several tweendecks, so that the cargoes for the various destinations can be reached and discharged without having to remove cargo for otherdestinations first.
Under the influence of cargo-palletization the “open freighter” was fitted with two or even three hatches side by side.
Both types of vessels, the general cargo ship and the open freighter, are becoming rather obsolete, since general cargo is more and more transported by vessels that have been designed to carry general cargo is containers.
Dry Bulk Carrier
A bulk carrier isocean-going vessel used to transport bulk cargo items such as ore or food staples (rice, grain, etc.) and similar cargo. It can be recognized by the large box-like hatches on its deck, designed to slide outboard for loading. A bulk carrier could be either dry or wet. Most lakes are too small to accommodate bulk ships, but a large fleet of lake freighters has been plying the Great Lakes and St.Lawrence Seaway of North America for over a century.
A tanker is a ship designed to transport liquids in bulk.
Tankers can range in size from several hundred tons, designed for servicing small harbours and coastal settlements, to several hundred thousand tons, with these being designed for long-range haulage. A wide range of products are carried by tankers, including:
• hydrocarbonproducts such as oil, LPG, and LNG
• Chemicals, such as ammonia, chlorine, and styrene monomer
• fresh water
Different products require different handling and transport, thus special types of tankers have been built, such as "chemical tankers" and "oil tankers". "LNG carriers" as they are typically known, are a relatively rare tanker designed to carry liquefied natural gas.Among oil tankers, supertankers were designed for carrying oil around the Horn of Africa from the Middle East; the FSO Knock Nevis being the largest vessel in the world. Knock Nevis was formerly the ULCC "Jahre Viking".
Apart from pipeline transport, supertankers are the only method for transporting large quantities of oil, although such tankers have caused large environmental disasters whensinking close to coastal regions, causing oil spills. See Exxon Valdez, Braer, Prestige, Torrey Canyon, Erika, for examples of tankers that have caused oil spills.
Cargo that has been containerized is carried by container ships.
Containers are most often measured in Twenty Feet Equivalent Units (TEU’s) and are stowed in a cellular arrangement is Rows, Bays and Tiers.
The rowsrun abeam, or athwartship; the bays run fore to oft and the tiers are horizontal layers. Thus, each container can easily be found. Container ships are sometimes equipped with their awn gantry cranes that load and discharge the container. Container ships may cary general cargoes, liquid cargoses or refrigerated cargoes.
The advantages of carrying cargo in containers are: short lay time because ofefficient and rapid cargo handling; few stevedores are required; less pilferage because the cargo has been stored in locked containers.
Roll-on/roll-off (RORO or ro-ro) ships are designed to carry wheeled cargo such as automobiles, trailers or railway carriages. This is in contrast to lo-lo (lift on-lift off) vessels which use a crane to load and unload cargo.
RORO vessels havebuilt-in ramps which allow the cargo to be efficiently "rolled on" and "rolled off" the vessel when in port. While smaller ferries that operate across rivers and other short distances still often have built-in ramps, the term RORO is generally reserved for larger ocean-going vessels.
A coaster carrier cargo along the coast or on seavoyages. Trans-Atlantic voyages are quite common.