The effect of containerisation on ships and shipping has been far reaching. A container can be lifted on or off a ship in a fraction of the time taken to load or discharge conventional cargo. As containers are of a standard size, a ship can be built to carry just containers. Its holds have guides for the containers to be slotted in easily. Because containers are loaded very quickly, time in port is kept to just a few hours, compared with days or weeks with a conventional cargo liner. Operators of container ships have built on this rapid turnround, and made sure their ships were as large and as fast as possible. As a result, one modern container ship can do the work of perhaps 20 conventional cargo liners.

Container ships can be easily recognised. They usually have many containers stacked high on their decks. Most have no cargo gear, relying entirely on the huge cranes at the big ports they serve. The superstructure is placed amidships or three-quarters aft in the bigger ships, right aft in others. To free deck space or as many containers as possible, the superstructure is built short but high. Its height also allows those navigating the vessel from the bridge a clear view over the container stacks on deck.

Effects of containerisation

The effect of containerisation on ports and on seafarers has also been momentous. To survive, ports have to provide the enormous cranes needed to unload container ships, stacking grounds for the containers, and vehicles to carry them and load them on and off trucks or railway wagons. As container ships have grown bigger, ports have had to deepen their channels and provide extra quay space and facilities to maintain their share of container traffic. The dock labour force has been massively reduced and, with far fewer ships needed, seafarers have also lost opportunities to work. Those who have benefited have been mainly consumers, for whom goods are available more quickly and more cheaply, and the shipowners who had the courage to invest enormous sums in containerisation.