Container vessels, bulk carriers and tankers are the three largest groups of vessels in the merchant fleet and, therefore, these market segments deserve great attention.
Depending on the size and the container carrying capacity of the container vessels, these may be divided into the following main sizes:
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Small
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Feeder
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Panamax (existing)
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Post-Panamax (existing)
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New Panamax
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ULCV – Ultra Large Container Vessel
The amount of cargo shipped in containers has increased considerably over the last fifteen years, resulting in a rapid increase in both the number and the size of container vessels during this period. In 1988, when the size of container ships increased to 4,500-5,000 teu (twenty foot equivalent unit), it was necessary to exceed the existing Panamax maximum width of 32.3 m, and thus introduce the post-Panamax size container ships. The largest container ships delivered today are of about 15,500 teu at 171,000 dwt (dead weight tonnage), based on the scantling draught.
Caused by the market mechanisms of the liner services offered involving large container vessels, these vessels are designed for higher speeds than the bulkers and the tankers. Thereby, the propulsion train including the main engine is designed for significantly higher power output for large container vessels than for bulk carriers and tankers.
Much effort is currently put into reducing energy consumption of large container ships, involving both low load optimisation, and in some cases even design for reduced speed, which in turn leads to demands for changed speed and power of the directly coupled two-stroke engines used for propulsion, while also reducing the emissions footprint compared to the past.
The reliability, the versatility and the fuel efficiency of the main propulsion engine used is therefore of paramount importance.