Bathyscaphe Trieste Makes the Deepest Dive

On 23 January 1960, Navy Lt. Don Walsh and Swiss engineer Jacques Piccard descended to the deepest spot in the world ocean, the Challenger Deep near the Pacific island of Guam.

The Bathyscaphe TriesteThe Bathyscaphe Trieste
(U.S. Navy photo)

The undersea craft that took human beings on the deepest dive ever ironically was designed and built by a man who had made his name as a pioneering aeronaut—Auguste Piccard had made a number of record-breaking balloon ascents in the 1930s. There was one key parallel, however, between his air and sea exploration: he designed his undersea vessels—which he named bathyscaphes, or “deep ships”— with small spherical crew spaces slung underneath large floats that resembled balloons in both shape as well as function. It would be Auguste’s son Jacques who would help take their greatest creation, Trieste, to the very lowest spot on Earth.

Purchased by the Office of Naval Research on behalf of the Navy in 1958 through the efforts of Dr. Robert S. Dietz, who worked at ONR’s London office, Trieste was designed to go deeper than any craft before it. That capability would be put to the test in January 1960 when the small craft was towed to the central Pacific for its historic dive at the deepest spot in the ocean, the Challenger Deep, which is more than 35,000 feet deep. The dive was not just about proving the viability of human exploration in such an environment—the Navy also was interested the basic understanding of how temperature, pressure, and sound interact at great depths.

Reaching the lowest spot on Earth did not come without perils—a viewport cracked during the descent, and much of the trip was spent out of contact with the surface. But pilots Jacques Piccard and Lt. Walsh successfully reached the lowest depth of 35,814 feet and returned safely. The historic feat of reaching the deepest part of the ocean (repeated only once since, in 2012) ushered in a “golden age” of manned underwater exploration in the 1960s and 1970s, in which submersibles helped make extraordinary discoveries in biology, geology, chemistry, oceanography, and other fields.

Lt. Don Walsh and Jacques Piccard inside the bathyscaphe TriesteLt. Don Walsh and Jacques Piccard descended to the deepest spot in the world ocean in 1960, a feat not repeated again by another human being until 2012, when movie director James Cameron returned to the same spot in a small submarine.
(U.S. Navy photo)

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