TABLE 5.2 POTENTIAL PRESSURE HULL CONFIGURATIONS AND W/D RATIOS 

 CONSIDERED FOR THE DSRV. [FROM REF. (1)] 



Material 



Shape 



Weight/Displacement 



Near Ag = 1.8 in. A^= 1.8 in. 



Perfect Stress-Relieved As Fabricated 



HY130(T) 



y^ — "—^ 



0.39 



0.40 



0.41 



0.42+ 



0.43 



0.42 



0.46 



0.48 



0.49+ 



0.51 



0.53 



0.54+ 



0.49 



0.47 



TABLE 5.3 ADVANTAGES AND DISADVANTAGES OF SUBMERSIBLE PRESSURE HULL SHAPES 



Advantages 



Disadvantages 



Sphere 



Ellipse 



Cylinder 



1 . Most favorable weight to displacement ratio 



2. Thru hull penetrations easily made 



3. Stress analyses more accurate and less complex 



1. Favorable weight to displacement ratio 



2. More efficient interior arrangements 



3. Thru-hull penetrations easily incorporated 



1. Fabrication easiest 



2. Most efficient interior arrangements 



3. Low hydrodynamic drag 



1. Difficult interior arrangements 



2. Large hydrodynamic drag 



1. Fabrication expensive 



2. Structural analysis difficult 



1. Least efficient weight to displacement ratio 



2. Stiffeners (internal) required at great depths 

 (1,000-ft) 



3. Structural analyses techniques difficult for 

 cylinder thru-hull penetrations 



maintaining a lower or equal W/D ratio. Such 

 is the case with the aluminum ALl/M/yVAt/T 

 and ALVIN. The latter increased its operat- 

 ing depth from 6,000 to 12,000 feet, and also 

 decreased its W/D ratio by replacing its HY- 

 100 steel hull with titanium. 



Two major factors controlling both pres- 

 sure hull shape and material are the vehi- 

 cle's projected maximum operating depth and 

 payload. Both values are derived from the 

 basic role the vehicle is expected to perform 

 and within what range of ocean depths. Ar- 



245 



