capability of 35,000 feet at ,51 weight to displacement ratio. The smooth 

 hydrodynamic shape of the hull will make the ascent of the 370-pound 

 vehicle carrying a 150-pound payload with an integral buoyancy of 30 pounds 

 after release of ballast at the bottom of the ocean a fast operation. For 

 oceanographic missions, Benthos will be launched and retrieved, like DIVEAR, 

 by sliding on an inclined ramp at the stern of the boat. For ASW missions, 

 it will be launched from shipboard or submarine torpedo tubes. Although 

 free-diving capsule Benthos relies solely upon its buoyancy for return to 

 the ocean's surface, the addition of an electric or closed cycle thermal 

 power plant will convert the free-diving capsule into an oceanographic or 

 ASW vehicle with unsurpassable operational depth capabilities. If Benthos, 

 when proof tested this summer, withstands the hydrostatic pressure at its 

 design depth, the repeated pressure cycling, and the tube launchings, then 

 the approach used in the design and fabrication of its deep submergence 

 hull can be considered a success, and the five to one increase in cost 

 over DIVEAR justifiable, when one considers the exceptional performance 

 parameters achieved. 



GUIDEPOSTS FOR FUTURE DEVELOPMENTS 



The glass and ceramic construction materials, although already proven 

 applicable to small and intermediate size and oceanographic free-diving 

 capsules, must also be found useful for the construction of large oceano- 

 graphic buoys and vehicles in order to maintain their position as desirable 

 materials for deep submergence hulls. At the present time, the capability 

 of the glass and ceramic industry to produce large glass or ceramic mono- 

 lithic external pressure shells of spherical or cylindrical shape is 

 severely limited. Monolithic spheres, of approximately 4 feet diameter, 

 and monolithic cylinders of monocoque or rib- stiffened design of 2 feet 

 diameter and 5 feet length are considered today the practical limits of 

 monolithic glass or ceramic hull construction. Large investment in glass 

 or ceramic furnaces, holding tanks, molds and grinding equipment would 

 probably raise the capability of the industry to produce monolithic spheres 

 or cylinders of twice the size that they are capable of today. Assuming 

 that the money ($5 to $10 million) can be invested immediately, the ability 

 to produce monolithic shapes of twice the size possible today will in turn 

 become a new size limitation on glass or ceramic hulls that will be 

 exceedingly difficult anu expensive ($10 to $50 million) to overcome. It 

 is obvious then that steps have to be taken today to develop construction 

 techniques which will permit the design and fabrication of spheres and 

 cylinders larger than the future size limit imposed by the fabrication 

 capability limitation on monolithic construction. 



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