Note sull'episodio
On January 23, 1960, Jacques Piccard and US Navy Lieutenant Don Walsh sealed themselves into the Trieste's steel sphere, about 7 feet across with walls five inches thick, and sank toward the Challenger Deep in the Mariana Trench. The bathyscaphe was the design of Swiss physicist Auguste Piccard, who inverted his stratospheric balloon idea: a large float filled with gasoline, which resists compression, provided lift, while 18 tons of iron shot held by electromagnets in two hoppers provided weight. If power failed, the magnets released the shot and the craft rose. Built in the Free Territory of Trieste with support from pacifist collector Diego de Henriquez, it was bought by the US Office of Naval Research in 1958 for $267,000 and fitted with a new Krupp sphere forged in three sections for Project Nekton.
Towed out about 200 miles from Guam by the USS Wandank, the Trieste took 4 hours and 47 minutes to descend. At about 9,000 meters a loud crack shook the sphere: the outer pane of the acrylic viewport had fractured, but its cone shape meant pressure only seated it tighter, so they kept going. They landed on pale diatomaceous ooze at an indicated 11,521 meters, later revised to 10,916, where the cabin fell to about 7 degrees Celsius. Voice messages by underwater telephone took seven seconds each way. They reported flatfish, but fish are thought unable to live below about 8,000 to 8,500 meters, and biologists now suspect a sea cucumber. In 1963 the Trieste found the wreck of the submarine USS Thresher at 8,400 feet.
- Standard submarines use compressed air for buoyancy, which cannot work against about 1,250 kilograms of pressure per square centimeter at the bottom.
- The new sphere's specific gravity was 2.6 times that of seawater, and it weighed over 14 metric tons in air.
- External quartz arc lights worked at full depth while directly exposed to the pressure.
- The ascent took 3 hours and 15 minutes after about 20 minutes on the bottom.
- The Thresher search earned the Trieste the Navy Unit Commendation, and it was retired in 1966, its sphere reused in Trieste II.