Cargo capacity is expressed in the number of 20-foot equivalent unit (teu) containers that the ship can load to its full potential. In just a few decades we have gone from ship sizes of 1,500 teu to today’s units of up to 22,000 and more.
In general, 3 types can be identified according to a dimensional criterion:
- Panamax vessels: with a width of less than 32.25 metres so as to be able to transit the Panama Canal.
- Post-Panamax vessels: which are too large to transit the Panama Canal.
- Suezmax vessels: with a maximum draught of 19 metres so as to be able to transit the Suez Canal.
Along with container ships designed for long distance routes, there is also the local transport fleet with so-called feeder ships which normally carry a few hundred containers.
In fact, these smaller ships are designed to reach shallower waters, which is economically disadvantageous for large ships.