The Bathyscaph Trieste Celebrates the 50th Anniversary of the World's Deepest Dive

Story Number: NNS100202-02Release Date: 2/2/2010 9:26:00 AM
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From Naval History and Heritage Command Public Affairs

WASHINGTON (NNS) -- Today, suspended on a steel stand, in a back corner of the National Museum of the U.S. Navy, is a huge piece of equipment, the bathyscaph Trieste, which holds the record for the world's deepest ocean dive. That historic descent was on Jan. 23, 1960 50 years ago. The massive machine is so large that when installed, 20 years after its famous dive, it was sectioned into several pieces to fit through the building's great rolling doors.

On the day the record was set, the 150 ton submersible, nearly 60 feet-long, dropped to the deepest point of the world's oceans, Challenger Deep off the Marianas in the Pacific near Guam. The descent was 6.78 miles and took over nine hours reaching the bottom at a depth of 35,840 feet. On board were Navy Lt. Don Walsh, a Naval Academy graduate, and Jacques Piccard a Swiss scientist - together, the Sailor and the scientist, Walsh and Piccard, road the Trieste into history.

The story of the Trieste dates back to 1937, when Swiss physicist and balloonist Auguste Piccard (father of Jacques Piccard who made the dive) began work on a deep sea research submersible in Belgium. But when the world was thrown into turmoil during World War II Piccard's work stalled. The plans for a bathyscaph - a word invented by Piccard - were shelved. He did not resume the project for 15 years, until he was invited to come to Trieste, Italy, in 1952, to commence the construction of his concept.

To be clear, though the Trieste looks like a submarine, it is not. The large hull of the submersible is actually a tank which held 33,350 gallons of gasoline used for buoyancy because it was lighter than sea water. The gasoline tank offset the weight of the "heavy pressure sphere" where the divers were encased. The sphere was 6 feet, 6 inches in diameter - the walls were 5 inches thick, leaving very little working space. The divers entered the vehicle from the top "sail" that stands above the tank and descended down a tube through the buoyancy tank into the pressure sphere that was then sealed shut.

Scientific and navigational instruments to equip the craft came from Switzerland, Germany, and Italy. The Trieste was fashioned in a civilian shipyard near Naples. In August 1953, the bathyscaph was placed in the water for the first time. On 11 August 1953, Professor Piccard and his son Jacques made the trial dive-to a depth of five fathoms

Between 1953 and 1956, Trieste conducted many dives in the Mediterranean. In 1955, Dr. Robert Dietz, of the United States Navy's Office of Naval Research (ONR), met Professor Piccard in London and discussed the project. During their talks, Piccard invited Dietz to Italy to see the bathyscaph. During his visit the following year, Dietz invited Piccard to the United States to discuss the bathyscaphe's future as an American submersible.

A group of American oceanographers and underwater sound specialists visited Castellamare, Italy, the following summer, 1957, and tested and examined Trieste. They eventually recommended that the craft be acquired by the United States government.

Between 1960 and 1962, after Trieste was overhauled at San Diego upon her return from Guam when in November 1962 when the submarine Thresher (SSN-593) sank off the Massachusetts coast. Trieste was brought across country to Boston, where she soon entered the search to locate the lost submarine. After 10 dives, in August 1963 she discovered the debris from Thresher, including the submarine's sail which still clearly carried the number "593.

After accomplishing her search mission Trieste returned to San Diego, where she was taken out of service.

For her part in the search, however, the bathyscaph and her commander, Cmdr. Donald A. Reach, received the Navy Unit Commendation. Subsequently, she was transported to the Washington Navy Yard where she was placed on exhibit in the Navy Memorial Museum.

Washington, D.C., is adorned with historical memorabilia. There are nearly 100 museums in the Washington metro area. But, with all that history, there is only one place where you can visit and touch the deepest diving submersible in world history, the Trieste, at the National Museum of the U.S. Navy at the Washington Navy Yard, Washington, D.C.

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