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A method is developed for determining the meridional contours of a toroidal shell which will produce no hoop stress resultants in the curved portion of the shell when subjected to internal pressure. The meridional membrane force will remain tensile. The resulting specialized toroidal pressure vessel design may eliminate the possibility of buckling failures found to be of critical concern in many other types of noncircular tori. Methods for finding the internal volume and surface area of such a pressure vessel are also presented.

No pressurizing gas is introduced into the propellant tanks of the Centaur vehicle during engine firing. The consequent pressure decay causes the propellants to boil, and the resulting gas bubbles change the effective density of the propellants. For liquid hydrogen in the Centaur, this change is 1.4% and would show up as an error in any level sensing propellant utilization system. A perforated capacitance probe shows a net 1/2% error because the bubble population is not the same inside and outside the probe. However, a manometer type capacitance probe senses propellant mass without a bubble induced error. This paper outlines the theoretical background for this effect, and presents the results from medium-scale tests in a general form applicable to vehicles other than Centaur.

The tensile and shear properties of eight soft solders were determined at several loading rates at 78, −100, −320, and −423 F. In general it was found that the tensile and shear strengths increased with increase in loading rate and decrease in temperature. Large decreases in ductility, as measured by elongation and reduction in area, and decreased tensile and shear strengths for some of the solders at cryogenic temperatures are indicative of their low temperature embrittlement. A discussion of the experimental data and literature values is given and recommendations are made concerning the application of solders for cryogenic service.