Summary report on fabrication, inspection and test of Alvin fixed and variable buoyancy spheres

Abstract

Fifteen aluminum alloy spheres of approximately 2 ft. diameter are used in the research submarine ALVIN for fixed and variable buoyancy. Six of them (GM Dwg.542019) are made from 6061-T6 alloy and are known as the variable buoyancy spheres (V.B.). The material of the other nine is 7178-T6 alloy. These are known as the fixed buoyancy spheres (F.B) (GMI Dwg. 542019). This report describes the manufacture, inspection, test and predicted collapse pressure of these spheres. In addition, four additional spheres, two of each type were tested to failure. Results are reported.