TABLE 5.1 PRESSURE HULL SHAPES AND MATERIALS (Cont.) 



tlie hemisphere. Figure 5.1 shows the types 

 of combination and constructions reportedly 

 used to date. To a depth of 2,500 feet the 

 cyhnder with hemi-heads dominates, and the 

 sphere is secondary. The remaining vehicles 

 in this depth range are a combination of 

 cylinders and spheres and an inverted wedge 

 and ellipse. Below 2,500 feet only one (ALU- 



MINAUT) out of 22 vehicles uses a cylinder 

 with hemi-heads; the rest employ spheres. 



The spherical pressure hull is the most 

 weight efficient geometry but is least amena- 

 ble to efficient interior arrangements. The 

 cylinder provides an efficient utilization of 

 internal volume but is geometrically ineffi- 

 cient with respect to W/D as is a sphere. As 



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