
Sure Sphere is a filthy piece of literary swill but it also a vital component of any submersible. As you may remember from geometry, for any given volume, a sphere has the smallest surface area, or for any given surface area, a sphere will have the greatest volume. From a practical standpoint for a deep-sea submersible, this means less surface for pressure to act upon. Thus the choice for the 'large' compartment to hold humans on a deep diving submersible is a sphere.
The first deep-diving sphere was the aptly named Bathysphere of Barton and Beebe, making its first unmanned test in 1930.
The Bathysphere was made by the Watson Stillman Hydraulic Machinery Company in Roselle, New Jersey. Made of cast iron, it could hold two people. The "walls" measured one and a half feet thick and were made of a single casting of the finest open-hearth steel. The Bathysphere and its cables cost Barton $12,000.

The deepest diving sphere was the one that hung below float filled chamber filled with gasoline. In 1960 the Trieste bathyscaphe descended to 10,900m in the Mariana Trench. Big enough to hold just to people
The pressure sphere was built by the Krupp Steel Works of Essen, Germany, in three finely-machined sections (an equatorial ring and two caps). To withstand the high pressure of 1.25 metric tons per cm² (110 MPa) at the bottom of Challenger Deep, the sphere's walls were 12.7 cm (5 inches) thick (it was overdesigned to withstand considerably more than the rated pressure). The sphere weighed 13 metric tons in air and 8 in water (giving it an average specific gravity of 13/(13-8) = 2.6 times that of sea water). The float was necessary because the sphere was dense: it was not possible to design a sphere large enough to hold a man which would withstand the necessary pressures, yet also have metal walls thin enough for the sphere to be neutrally-buoyant.



Craig is temporarily a post-doctoral fellow at the Monterey Bay Aquarium Research Institute who is looking for a permanent position. He spends most of his time balancing his overwhelming geekdom with normalcy so he can function in the real world. Luckily his wife likes his geekiness.
Peter Etnoyer is a Graduate Research Associate at the Harte Research Institute for Gulf of Mexico Studies, Texas A&M University-Corpus Christi. He studies deep corals and ocean fronts, and he loves to be on the water.
Kevin Zelnio is a Graduate Student Researcher at Penn State studying the ecology of hydrothermal vent and methane seep communities. He raises awareness of the plight of the spineless through folk music.




Having problems commenting? (UPDATED)