Bulk carrier classes can be dimensioned to meet the maximum nautical access of specific waterways (seaways, canals, or ports), such as:
- Malaccamax. Largest vessel that can pass through the Straits of Malacca (20m draft and 300,000 DWT).
- Suezmax. Largest vessel that can pass through the Suez Canal (24m and 240,000 DWT).
- Seawaymax. Largest vessel that can pass through the canal locks of the St Lawrence Seaway (max LOA: 226m, max draft: 7.92m, 28,500 DWT). This allows for access to the Great Lakes system deep inside North America.
- Dunkirkmax. Largest vessel that can enter the eastern harbor lock in the port of Dunkirk, France (max LOA: 289m, max beam: 45m, 175,000 DWT). Dunkirk is a major bulk port, particularly for petroleum products.
- Newcastlemax. Largest vessel that can enter the port of Newcastle in Australia (max beam: 47m, 185,000 DWT). The port is among the world’s largest exporter of coal.
Several classes of bulk carriers exist:
- Valemax ships. Very large ore carriers (VLOC) with a unit capacity of 380,000 to 400,000 DWT and about 360 meters in length overall (LOA). The ships are owned or chartered by the mining company Vale (Brazil) and deployed on the iron ore trade route between Brazil and Europe, and Asia. In recent years, Chinese shipping companies also started to order Valemax-type vessels. In 2020, there were already 68 Valemax ships on the market.
- Capesize. Vessels have a capacity of between 90,000 and 200,000 DWT. A common Capesize vessel size is between 130,000 and 170,000 DWT.
- Panamax. A class of bulk carriers having a capacity of 65,000 to 89,999 DWT and meeting the maximum ship dimensions to pass through the old Panama Canal locks.
- Supramax or handymax. Bulk carriers of 40,000 to 64,999 DWT.
- Handysize. Smaller bulk carriers of 15,000 to 39,999 DWT.
- Mini Bulk Carrier. Ships of 3,000 to 14,999 DWT employed in coastal trade and to reach ports having a lower draft.
Economies of scale in the oil tanker sector are the most extensive:
- Very large and ultra-large crude carriers (VLCC/ULCC) of more than 200,000 dwt used on some main trade lanes between the Persian Gulf and Europe, North America and Asia, and between Africa and China.
- Suezmax vessels with a capacity of between 100,000 and 160,000 dwt typically found on routes to and from West Africa and in the Mediterranean.
- Aframax vessels of 70,000 to 100,000 dwt.
- Panamax vessels of 40,000 to 70,000 dwt.
LNG carriers can be grouped into different sizes:
- Small carriers of between 25,000 to 50,000 m3 are used for short-range trades, especially in the Mediterranean.
- Vessels between 120,000 to 165,000 m3. It was not until 2006 when a 150,000 m3 vessel
entered the market. In 2008, vessels of up to 165,000 m3 were delivered for the first time.
- Large ‘Q-Flex’ (210,000 to 217,000 m3) and ‘Q-Max’ (260,000 to 270,000 m3) vessels initially designed to service LNG projects in Qatar (owned by Qatar Gas). In 2010, the first vessels in the 170,000 to 180,000 m3 range were delivered, narrowing the gap between the more traditional vessels and the Qatari designs.