From National Museum of the U.S. Navy
On January 23, 1960, bathyscaphe Trieste made history by reaching the bottom of the Challenger Deep in the Marianas Trench. Inside its spherical gondola, two pilots, U.S. Navy Lt. Don Walsh and scientist Jacques Piccard sat and waited to see if they would make it to the bottom and then, perhaps more importantly make it back to the surface.
It took nearly five hours to descend the 35,797 feet. Once there, Trieste and its crew spent 20 minutes investigating the bottom. They saw several types of small fish including deep water flounder and sole, and a substance covering the ground made up of plankton and other microscopic animals. This was a huge discovery, as it was not known if vertebrate life forms (those with skeletons) could live at such extreme pressures. After their three hour ascent, it would take 52 years before another human would return.
Trieste is a deep-diving research bathyscaphe, and was launched in 1953 near Naples, Italy, by the Swiss scientist Auguste Piccard (father of Jacques Piccard). Comprised of steel, it had two distinct sections. The largest was its gasoline and water ballast tanks. This gave Trieste its buoyancy, and allowed it to freely dive independent of any ship or cable. The second chamber or pressure sphere housed the two operators and equipment.
To create a sphere capable of withstanding the pressure of the bottom of the ocean, the builders made the walls of the sphere 5 inches thick. This caused a problem, since the sphere weighed 28,660 lbs. or over 14 tons, and the resulting density was so great, it would sink. However by attaching the float chamber filled with gasoline (which is less dense than water) on top, it compensated for the dense sphere and made it buoyant.
Trieste had very limited maneuverability, other than sinking and small side to side movements. Its main objective was to reach the bottom of the ocean, and be able to come back up. To sink, it could fill its water ballast chamber, and if needed release some of the gasoline from the main tank. To achieve positive buoyancy, the pellets in the two hoppers would be released, as the pressure was too great for compressed air to blow out the salt water, like in traditional submarines.
Trieste was not designed for a long term stay. Its two operators were in the submarine for 9 hours—the time it took to descend and ascend from the bottom of the ocean. The sphere was a chilly 45 degrees Fahrenheit. The air was filtered by scrubbers, much like other submarines. The two pilots snacked on chocolate bars, as they did not have much room for anything else!
Following its 1959-60 mid-Pacific work, Trieste operated out of San Diego, Calif., supporting Navy research objectives. Modified somewhat from its earlier configuration, it was taken to New London, Conn., in April 1963 to assist in the search for the lost submarine USS Thresher (SSN-593) and to support the investigation into the cause of that tragedy. In August 1963, Trieste found Thresher‘s remains off New England, 1,400 fathoms below the surface. The bathyscaphe was retired soon after that and some of its components were used in the newly constructed Trieste II.
Trieste is now a part of the Undersea Exploration exhibit at the National Museum of the United States Navy at the Washington Navy Yard. The exhibit highlights the U.S. Navy’s involvement with undersea exploration for navigation, scientific research, strategic, and educational purposes. Often a catalyst for innovative research, by 1958 nearly 90 percent of all U.S. oceanographic ventures were funded by the Navy. Nurtured by such support, scientists explored the deepest regions of the oceans and designed increasingly sophisticated remotely operated vehicles that could observe the depths without risk to human life. Improvement of naval operations and equipment continues to be largely dependent on the discoveries made through oceanographic research. The Navy’s undersea operations have ranged from diving to the collection of scientific data, to the investigation of shipwrecks such as the Titanic.
The National Museum of the United States Navy is open Monday-Friday 9:00 am – 5:00 pm, and Weekends and Federal Holidays 10:00 am – 5:00 pm. To learn more about the National Museum of the United States Navy, visit www.history.navy.mil.