Built by The Marinship Corporation during World War II as Potrero Hills, she was later purchased by Malcom McLean's Pan-Atlantic Steamship Company.[1] [2] [3] In 1955, the ship was modified to carry shipping containers and rechristened Ideal X. During her first voyage in her new configuration, on 26 April 1956,[4] the Ideal X carried 58 containers from Port Newark, New Jersey, to Port of Houston, Texas, where 58 trucks were waiting to be loaded with the containers.[5] It was not the first purpose built container ship: the Clifford J. Rodgers, operated by the White Pass and Yukon Route, had made its debut in 1955.[6]
In 1959, the vessel was acquired by Bulgarian owners, who rechristened her Elemir. The Elemir suffered extensive damage during heavy weather on 8 February 1964, and was sold in turn to Japanese breakers. She was finally scrapped on 20 October 1964, in Hirao, Japan.