By the early 1950s, U.S. auto sales were booming and highways were becoming heavily congested. The Interstate Highway system was still years in the future. McLean, concerned that traffic jams were delaying his drivers and raising his company’s costs, conceived of waterfront terminals at which trucks would drive up ramps and deposit their trailers aboard ships. He envisioned the vessels moving between North Carolina, New York, and Rhode Island, circumventing the heavy traffic and innumerable stop lights on highways that also served as main streets up and down the East Coast.
The industry McLean proposed to enter was more than a little antiquated. A typical oceangoing ship in the 1950s carried around 200,000 separate crates, bags, barrels, and bales. They would arrive at the dock in hundreds of separate shipments. Each item had to be removed from a truck or rail car and moved into a warehouse. When it was time to load the vessel, the individual pieces of cargo were moved out of the warehouse, placed on the dock, and assembled onto pallets that were lifted by a winch into the ship’s hold. There, dockworkers removed each item from the pallet and stowed it.
Unloading at the end of the voyage meant reversing this labor-intensive process. In consequence, moving goods across the ocean often cost 15 or even 20 percent of their value, a price so steep that many goods were not worth trading internationally. Putting truck trailers aboard ships, in theory, would cut out many of those laborious steps—and, in turn, slash costs. But the idea also had an obvious disadvantage: Trailers would take up precious and expensive shipboard space, undercutting potential savings.
McLean pondered the problem and proposed detaching the trailer bodies from their chassis and wheels and putting only the bodies—that is, metal containers—aboard the ships. This would introduce some complications, such as the need for cranes to lift the containers off truck chassis, transfer them to departing ships, and then reverse the operation when a vessel arrived at its destination. On the other hand, containers, unlike truck trailers, could be stacked, allowing each ship to carry far more cargo. Since the vessel was easily the most expensive part of the operation, the more containers that could go aboard each vessel, the less it would cost to carry each one.