Ideal X carried the first commercially successful container shipment in 1956.
The vessel, a converted oil tanker, sailed from Newark, New Jersey, to Houston, Texas, on 26 April 1956. It carried 58 truck bodies loaded as standardized containers, demonstrating that cargo could be transferred between trucks and ships without individually handling each item.
The experiment was organized by American trucking entrepreneur Malcolm McLean, whose company Sea-Land Service developed the operation. Standardized containers greatly reduced loading time, theft, cargo damage, and dock labor compared with the older break-bulk system.
Ideal X was not the first vessel ever to carry cargo in containers; earlier container experiments had occurred in several countries. Its voyage is remembered because it proved the commercial potential of a large-scale, intermodal container system. The ship is therefore linked with the beginning of modern container shipping, while later purpose-built container vessels rapidly expanded the idea worldwide.