On September 19, 1957, a curious creature containing iron pellets, gasoline, oxygen, and two humanoids visited the aquatic denizens of the deep, two miles below the gentle waves and warm breezes of the Mediterranean Sea. The mysterious mechanical interloper was the bathyscaphe Trieste, a deep-submergence vehicle originally conceived, designed, and constructed by Swiss physicist and inventor August Piccard, on a successful voyage to set a new diving depth record . Piccard coined the term “bathyscaphe” from two Greek words: “bathos”, meaning “deep”; and “scaphos”, meaning “ship”. The bathyscaphe consisted of a float chamber filled with gasoline for buoyancy (gasoline is less dense than water, and naturally wants to rise to the water’s surface) and a pressure chamber for two crew members. Piccard’s first bathyscaphe, the FNRS-2 had been constructed in 1947. Using what he learned from his early explorations, Piccard then designed the Trieste, which was built in 1952 in the town of Trieste, Italy, with the support of many local individuals, companies and institutions.
Between 1953 and October of 1957, the Trieste completed 48 dives in the Mediterranean. Its success attracted the interest of the United States Office of Naval Research, which purchased the Trieste and assigned it to the Naval Electronics Laboratory in San Diego, California.
The Trieste’s float chambers were more than 50 feet long and contained 22,500 gallons of gasoline. Water ballast tanks were added at each end of the float section. The crew’s pressure chamber was slightly over 7 feet long and contained completely independent life-support systems, including a rebreather system with oxygen tanks and a carbon dioxide scrubber. The bathyscaphe was battery-powered and operated by the French Navy during its Mediterranean adventures. Nine tons of magnetic iron pellets in ballast silos, and an electromagnetic control system, allowed the Trieste to descend and ascend. Crew members observed the underwater scenery by one cone-shaped window of acrylic glass with illumination by quartz arc-light bulbs outside the ship. Everything on the Trieste had to be designed to withstand the over 1000 atmospheres of pressure found at the extreme depths Piccard wanted to explore.