Container ships, port cranes and self-unloading Liberty ships

When could container ships reasonably have been introduced?

The 1950s are suggested because suitable cranes and ships existed. Their large carrying capacity is qualified by their dependence on port cranes, while Liberty ships could unload themselves.

The 1950s are proposed as a reasonable introduction date for container ships because suitable crane technology and ships were available. An approximate capacity comparison puts about 70 modern container ships alongside the entire Liberty-ship production programme. That estimate concerns carrying capacity. Cargo handling changes the comparison because Liberty ships could unload themselves, while the container ships considered here depend on external equipment. A large cargo capacity is useful only if the vessel can deliver that cargo at its destination.