Hi,
Container capacity can be either the theretical capacity of the ship or based on and average weight of each container.
The nominal capacity of the CMA-CGM vessels is 13880teu, meaning if every container on board was empty and 20' in size then that is what they could carry.
The average weight for a loaded container is 14tonnes, so based on every container being 14t then they could carry 9932teu (Twenty Foot Equivelent Units)
Some lines quote the nominal capacity for their vessels ie CMA-CGM, MSC, while Maersk Line especially base capacity on loaded units at 14t.
regards
Andrew
Containership Admin