Source: UNCTAD (2000) Review of Maritime Transport.
Major ship size groups include:
- Handy and Handymax: Traditionally, the workhorses of the dry bulk market, the Handy, and the more recent Handymax types are ships with less than 60,000 dwt. The Handymax sector operates in a large number of geographically dispersed global trades, mainly carrying grains and minor bulks, including steel products, forest products, and fertilizers. The vessels are well suited for small ports with length and draft restrictions and also lack transshipment infrastructure. This category is also used to define small-sized oil tankers.
- Panamax: Represents the largest acceptable size to transit the Panama Canal, which can be applied to both freighters and tankers; lengths are restricted to a maximum of 275 meters, and widths to slightly more than 32 meters. The average size of such a ship is about 65,000 dwt. They mainly carry coal, grain and, to a lesser extent, minor bulks, including steel products, forest products, and fertilizers.
- Capesize: Refers to a rather ill-defined standard that has the common characteristic of being incapable of using the Panama or Suez canals, not necessarily because of their tonnage, but because of their size. These ships serve deepwater terminals handling raw materials, such as iron ore and coal. As a result, “Capesize” vessels transit via Cape Horn (South America) or the Cape of Good Hope (South Africa). Their size ranges between 80,000 and 175,000 dwt.
- VLOC / ULOC: Very Large Ore Carrier / Ultra Large Ore Carrier. A specific bulk carrier class above 200,000 dwt designed to carry iron ore. The largest ships of the ULOC class, above 300,000 dwt, carry iron ore between Brazil and global markets (mostly Europe and Asia). Due to their size, there is only a comparatively small number of ports around the world with the infrastructure to accommodate such vessel size.
- Aframax: A tanker of standard size between 75,000 and 115,000 dwt. The largest tanker size in the AFRA (Average Freight Rate Assessment) tanker rate system.
- Suezmax: This standard, which represents the limitations of the Suez Canal, has evolved. Before 1967, the Suez Canal could only accommodate tanker ships with a maximum of 80,000 dwt. The canal was closed between 1967 and 1975 because of the Israel – Arab conflict. Once it reopened in 1975, the Suezmax capacity went to 150,000 dwt. An enlargement to enable the canal to accommodate 200,000 dwt tankers is being considered.
- VLCC: Very Large Crude Carriers, 150,000 to 320,000 dwt in size. They offer good flexibility for using terminals since many can accommodate their draft. They are used in ports that have depth limitations, mainly around the Mediterranean, West Africa and the North Sea. They can be ballasted through the Suez Canal.
- ULCC: Ultra Large Crude Carriers, 320,000 to 550,000 dwt in size. Used for carrying crude oil on long haul routes from the Persian Gulf to Europe, America, and East Asia, via the Cape of Good Hope or the Strait of Malacca. The enormous size of these vessels requires custom-built terminals.