Container Cargo Capacity
According to AXS-Alphaliner, the global container fleet had a total capacity of about 16 million TEU in June 2012. Container ships come in a variety of sizes and have grown increasingly larger over time. This resulted from two things: the first was the increased use of containerization - as more cargo was converted to containers, there were more containers for the ships to carry; the second was that there was certain efficiencies - like improved fuel efficiency - that could be realized with larger ships. Those efficiency improvements often reduced the operating cost.
The table below prepared by Alphaliner shows the world container fleet by size:
Because most container ship services operate on a weekly basis and calling at the same ports every week, each service uses several container ships (generally anywhere from four to twelve) of a similar size. According to IHS Global Insight, there are approximately 400 container ship services operating around the world.