A container ship is docked at a port in Spain where it waits to be unloaded. Modern-day cargo ships are usually container ships because they transport cargo efficiently. Freight is packed in containers, which are then loaded onto ships by crane. When a ship arrives in port, the containers are easily unloaded by cranes and transferred to trucks designed to transport them.
When the costs of shipping escalated rapidly in the 1950s, studies showed that labor constituted over 50 percent of the rising costs. Dockworkers spent five days or more unloading a large cargo ship and the same amount of time reloading it.
Moreover, shipping companies paid port authorities large fees for each day they spent docked in port. American trucker Malcolm McLean offered a solution to this problem in the 1950s when he introduced the concept of containerized shipping. McLean proposed the use of standardized shipping containers to integrate truck, train, and ship transport.
In 1956 Sea-Land Service commenced containerized shipping operations between New York City and Houston, Texas. The shipment of cargo in prefabricated steel containers with standard measurements reduced labor costs and port fees significantly. The use of containerized shipping rapidly expanded, and today, ships, trains, and trucks are loaded and unloaded using huge mechanical cranes that unload and load a ship in just 24 hours.