Trieste Dive
The Trieste Dive refers to a significant milestone in ocean exploration, marked by the descent of the bathyscaphe Trieste into the Challenger Deep, the deepest known point in the Earth's oceans. Developed by Swiss inventor Auguste Piccard, the Trieste was designed to withstand immense underwater pressure, with a sturdy sphere that could endure up to 16,000 pounds of pressure per square inch. After extensive development and testing, the Trieste was acquired by the United States in 1958 and subsequently prepared for its historic dive, which took place on January 23, 1960. Piloted by Jacques Piccard and U.S. Navy Lieutenant Don Walsh, the Trieste successfully reached the ocean floor at a depth of 35,800 feet, providing valuable insights into the existence of life in such extreme conditions. This dive not only demonstrated the potential of manned submersibles but also paved the way for future oceanographic research and exploration initiatives worldwide. The Trieste's journey has influenced various applications, including military uses, marine archaeology, and ecological studies, highlighting the ongoing interest in our planet's underwater mysteries.
Trieste Dive
Date: January 23, 1960
Submersible deep ocean dive. The bathyscaphe Trieste dove to the deepest point on the ocean floor.
Origins and History
The two-thirds of Earth’s surface that is water has remained largely a mystery because of the human inabilities to withstand submarine pressure and to breath underwater. Bathyscaphe research is an attempt to create a vehicle for manned exploration of the ocean depths. In 1931, Auguste Piccard, a Swiss professor, made his first balloon ascension into the stratosphere. He determined that the same physical principles could be used to develop a balloon that would descend to the bottom of the ocean. He developed and tested the FNRS-2 in 1948, successfully diving to forty-six hundred feet. For ten years, he refined and tested his bathyscaphe with the assistance of the Belgian, Swiss, French, and Italian governments. In 1958, the Trieste was purchased by the United States and put under the Office of Naval Research. Piccard’s son, Jacques Piccard, was retained as the pilot. Increased funding resulted in Project Nekton, a plan to descend in a manned bathyscaphe to the deepest point on earth, the Challenger Deep in the Mariana Trench off the coast of Guam.
Project Nekton
For the descent, it was necessary to build a sphere strong enough to withstand sixteen thousand pounds of pressure per square inch and heavy enough to sink. The sphere of the Trieste was seven feet, two inches in diameter. It was supported by a float of thin sheetmetal that held thirty-four thousand gallons of gasoline. Gasoline was chosen to fill the float instead of air because it is lighter than water, does not mix with water, and is not highly compressible. The float had slits along the bottom that allowed seawater in as the gasoline compressed or was ejected. A porthole of six-inch-thick plexiglass provided a view of the ocean floor. On Saturday, January 23, 1960, at 8:23 a.m., the Trieste, manned by Piccard and Lieutenant Don Walsh of the U.S. Navy, began its descent seven miles down to the floor of the Challenger Deep. For the first 26,000 feet, they traveled at 200 feet per minute through the twilight zone, into the black stillness of the abyssal zone, and finally past the normal sea floor into the trenches of the hadal zone. Iron ballast was released to slow the descent as they approached the bottom. At 1:06 p.m., they landed on the trench floor at 35,800 feet. As the Trieste settled, Piccard saw a foot-long flatfish scurry across the ocean floor, answering the question of whether life exists at that level. The water temperature was 36.5 degrees Fahrenheit. At 1:26 p.m., eight hundred pounds of ballast was released, and the bathyscaphe began its three-and-a-half-hour elevator-like ride from night to predawn to daylight.
Impact
Submersible research has steadily increased, with vehicles being built worldwide. In addition to their many military applications, submersibles are used for oceanographic exploration, marine archeology, tourist adventures, oil and mineral exploration, sonar and volcanic research, and marine ecology studies.
Additional Information
Auguste Piccard’s 1956 book Earth, Sky, and Sea discusses the construction of the Trieste. Seven Miles Down (1961), by Jacques Piccard and Robert Dietz, covers Project Nekton.