Classification of merchant ships by size

The classification of ships by size takes into account the characteristics of the navigation area, namely the depths of straits and port waters, the dimensions of locks, and navigation conditions on artificial canals and inland waterways. The navigation conditions on ocean and sea routes are the reason why there are clear requirements for ship sizes. A two-word phrase is used to classify ships by size. The first part uses a term denoting belonging to a geographical object, while the second part uses a term denoting the maximum size or simply the size.

Dimensions of dry cargo ships (bulk carriers)

Handysize

Handysize vessels are most often bulk carriers for general cargo with a deadweight of 15,000 to 40,000 tonnes. Cargo ships larger than Handysize are classified as Handymax ships, while ships smaller than 15,000 tonnes have no specific classification and are simply referred to as coasters or coastal vessels.

Coastal vessel with a deadweight of less than 10,000 tonnes

Handysize vessels are considered the most common type of ship, as they can enter small ports and, in most cases, are equipped with cranes to load and unload cargo independently. Compared to larger bulk carriers, handysize vessels handle a wider range of so-called ‘break bulk’ cargoes. These include steel products, grain, phosphates, timber and crushed stone.

The most common standard in this category of ships are bulk carriers with a deadweight of about 32,000 tonnes and a draught of no more than 10 metres. They have five cargo holds with hydraulic twin decks and four cranes for handling cargo. Some Handysize vessels are equipped with racks on the upper deck, between which timber is loaded in stacks, which is why they are called ‘timber carriers’. Despite numerous orders from shipping companies for new types of vessels, Handysize remains the most popular and has the highest average age among dry cargo ships.

Handysize vessel

Handymax

Handymax vessels are used for bulk carriers with a deadweight of 40,000 to 50,000 tonnes. Vessels of this type are 150-200 m long and equipped with 5 cargo holds. As a rule, these are older vessels. Modern bulk carriers already have a deadweight of 52,000 to 58,000 tonnes and are equipped with five cargo holds and four cranes with a lifting capacity of up to 30 tonnes each.

Handymax-sized vessel

Supramax (Large Handymax)

Supramax bulk carriers, which are gradually replacing Handymax vessels, have a deadweight tonnage of 50,000 to 60,000 tonnes. Like their predecessors, they also have five cargo holds.

Supramax-sized dry cargo ship

Ultramax

Quite recently, another type of dry cargo ship, the Ultramax, with a deadweight of 60,000 to 65,000 tonnes, appeared on shipping lines. Their distinctive feature is not their size, but their environmentally friendly main engine. Ultramax bulk carriers are considered to be an upgrade of Supramax ships and are equipped with five cargo holds. For now, this is a small fleet.

Ultramax-sized vessel

Seawaymax

The term ‘Seawaymax’ refers to ships that can pass through the St. Lawrence Seaway, the name of the waterway from Montreal to Lake Erie, including the Welland Canal and the waterway across the Great Lakes from the Atlantic Ocean to the Great Lakes in North America.

Seawaymax dry cargo ships have a deadweight of 60,000 to 100,000 tonnes, a length of 226 m, a width of 24 m and a draught of 7.92 m. Although the canal is 235 metres wide, large cargo ships cannot leave the Great Lakes for the Atlantic Ocean due to draught restrictions in some parts of the waterway. In recent years, falling water levels in the Great Lakes have created additional problems for shipping. The famous bulk carrier Edmund Fitzgerald was built to the Seawaymax design. It set a record for crossing the St. Lawrence Seaway with a cargo of 28,502 tonnes of iron ore, while the annual deadweight of the waterway was 72,351 tonnes. In 2006, at least 28 vessels of various types were decommissioned because they were too large to leave the Great Lakes.

Seawaymax-sized lake vessel

Kamsarmax

Kamsarmax bulk carriers have a deadweight of 80,000 to 85,000 tonnes. The most common design has a deadweight of 82,000 tonnes. These dry cargo ships are 229 m long, 32 m wide and have a draught of 14.5 m, which is the maximum permissible parameter for entering the port of Kamsar, Guinea, in West Africa, one of the world's largest ports for transhipment of bauxite.

Kamsarmax bulk carrier

Panamax

Panamax bulk carriers have a deadweight tonnage of between 60,000 and 80,000 tonnes and are limited by the parameters of the Panama Canal locks.

Post-Panamax

This term applies to modern Post-Panamax dry cargo ships, which are 240 m long and 38 m wide, 6 m wider than the Panama Canal locks. Due to this characteristic, they cannot pass through this barrier. The deadweight of such bulk carriers varies from 90,000 tonnes to 110,000 tonnes.

Capesize

The term ‘Capesize’ refers to cargo ships that are unable to pass through the Suez and Panama Canals due to their large size. In English, the word “cape” means ‘headland’. Therefore, ships of this type must sail around the Cape of Good Hope at the southern tip of the African continent or Cape Horn, the southernmost point of South America.

Capesize ships have a deadweight tonnage of 160,000 to 210,000 tonnes. The majority of bulk carriers of this size are large-tonnage grain carriers and ore carriers with an average deadweight of 175,000 tonnes, a hull length of 289 m, a width of 45 m, a draught of 17.9 m and 9 cargo holds. Some Capesize vessels with a maximum width of 47 m are called Newcastlemax and are the largest vessels that can enter the port of Newcastle in Australia.

Capesize bulk carrier

Valemax (ULOC — Ultra Large Ore Carrier)

China's economic growth, with its high demand for raw materials, has led to a need for larger Capesize vessels. This has resulted in the emergence of ultra-large ore carriers with a deadweight of 400,000 tonnes, a length of 362 m, a width of 65 m and a draught of 23 m. The largest ships in this category are the Valemax series, which carry iron ore between ports in Brazil and China. Naturally, ships of this size are handled at specialised deep-water terminals.

Valemax-sized ore truck being loaded

Dimensions of container ships

Feeder

Container ships have their own size classification, as their carrying capacity varies from 500 to 22,000 containers. Their main characteristic is their capacity for 20-foot containers, which are taken as the standard unit of capacity — twenty-foot equivalent (TEU).

Feeder-sized vessels are called feeder container ships and are considered the smallest type of container ship. The capacity of such vessels is up to 1,000 TEU. They are used as carriers from major container terminals along inland waterways.

Feeder container ship

Feeder-Handy

Slightly larger container ships are called ‘Feeder-Handy’ and have a capacity of 1,000 to 2,000 TEU containers. These small container ships are mainly used for coastal shipping and transporting cargo along inland waterways.

Sub-Panamax

Container ships with a capacity of 2,000 to 3,000 TEU are classified as ‘Sub-Panamax’ types. Container ships classified as ‘Sub-Panamax’ are up to 230 m long, up to 30.0 m wide, have a draught of up to 11 m and comply with the parameters of the Panama Canal. This term is an important factor in the construction of container ships and requires the most accurate adherence to the specified dimensions.

Panamax

Panamax-sized vessels with a capacity of 3,000 to 10,000 DWT are mainly determined by the parameters of the lock chambers: width — 33.53 m, length — 320 m, height — 25.9 m. The usable length of each chamber for accommodating a ship is 304.8 m. Currently, the following maximum dimensions for vessels passing through the canal have been established: length — 294.1 m, width — 32.3 m, draught — 12 m, height from the waterline to the highest point of the vessel — 57.91 m. Vessels are only allowed to pass through during daylight hours.

Panamax container ship

New Panamax

‘New Panamax’ is a maritime term referring to a large vessel capable of passing through the new locks of the Panama Canal at full load. Opened in 2016, they have the following parameters: length — 427 m, width — 55 m, permissible draught of vessels — 18.3 m. Container ships with a capacity of 10,000 to 14,000 TEU, a length of 366 m, a width of 49 m, a draught of 15.2 m and a deadweight of 120,000 tonnes are called ‘Neopanamax’ and are limited only by the dimensions of the water barrier.

Malaccamax (ULCS — Ultra Large Container Ship)

Malaccamax container ships are built to pass through the Strait of Malacca. The designation ULCS (ultra-large container ship) is given to Maersk Triple E series container ships, which are 399 m long, 59 m wide, have a draught of 14.5 m and a deadweight of 165,000 tonnes for transporting 18,500 TEU containers. A total of 31 vessels of this design have been built. Malaccamax container ships can pass through the Suez Canal, which has no locks, with draught being the only limiting factor. The current depth of the waterway is 20 m. The maximum permissible width of a vessel is 68 m.

Magleby Maersk ultra-large container ship

Dimensions of gas carriers

A separate classification applies to gas carriers. It is based on the volumes of substances transported:

• Conventional (volume of liquefied natural gas transported from 145,000 to 154,000 cubic metres) — general-purpose gas carrier
• Q-Flex (volume of liquefied natural gas transported from 210,000 to 216,000 cubic metres) — medium-sized gas carrier
• Q-Max (Qatar-Max) (volume of liquefied natural gas transported from 263,000 to 266,000 cubic metres) — large gas carrier.

Q-Max (Qatar-Max) size gas carrier

Tanker dimensions

Tankers have their own classification by deadweight (Seawaymax, Panamax, Aframax, Suezmax, VLCC (Malaccamax), ULCC), which is discussed in a separate publication.

Aframax-sized oil tanker

In recent years, under the influence of global trade development and in connection with efforts to improve the economic efficiency of maritime transport, structural changes have been taking place in the composition of the global fleet, with an increase in the number of larger and higher-capacity vessels. In this regard, reconstruction is being carried out to improve navigation conditions and reduce transport routes on the main trunk routes of maritime transport. Thus, the parameters of ships in the categories named ‘max’ and ‘size’ change periodically, so these groups cannot be considered constant.