The Trieste was designed by Auguste Piccard and built by 2 Italian companies. The bathyscaphe launched in 1953 near the island of Capri. In 1958 the US Navy purchased the Trieste for research purposes
Trieste was more than 50 feet long. The bulk of the structure were floats filled with 22,000 gallons of gasoline. It had water ballast tanks fore and aft of the main compartment, with releasable iron ballast in two conical hoppers along the bottom, located fore and aft of the crew sphere. The crew occupied the 7.09-foot pressure sphere, attached to the underside of the structure. Crew accessed the sphere from the top deck through a vertical shaft through the structure.
Upon entering service in the Navy, some modification were made including a new crew sphere. Trieste went to the Marianas to explore the one the deepest spots in the Pacific Ocean - the Challenger Deep. On 23 January 1960 the bathyscaphe dived to a depth of 35,814 feet and reached the ocean floor. After completing its mission, Trieste returned to the United States.
In 1961 two artists Salvatore Indiviglia and Luis Llorente went to San Diego to document Trieste as it was undergoing repairs and improvements after the dive to the Challenger Deep. These four paintings depict some aspects of working on and operating Trieste during this time.
In 1963 Trieste was transported to the east coast of the United States to look for the missing submarine USS Thresher. By this point, another bathyscaphe, the Trieste II was almost complete and Trieste was decommissioned in 1966.