APPENDIX 



Human Factors Considerations in Self-Contained Diver Heater Design 



by F. B. Barrett 



BACKGROUND 



A limited human factors analysis of self-contained diver heating 

 systems was conducted to determine inan/equipment interface requirements. 

 The analysis was accomplished primarily through in-water test trials of 

 several heater mock-ups and through discussions with combat swimmer 

 personnel and appropriate Navy diving authorities. Equipment compatibil- 

 ity tests were also conducted during Swimmer Delivery Vehicle (SDV) 

 operations by personnel using Navy Mark 6 underwater breathing apparatus. 



PRELIMINARY CONSIDERATIONS 



An analysis of underwater breathing apparatus (UBA) currently In 

 use by Navy tactical swimmers and probable future configurations was 

 conducted to determine possible locations for diver heater components. 

 The major requirement placed on the analysis was to minimize the re- 

 strictions imposed on the swimmer and his mobility. 3 a result of this 

 analysis, three heater mock-ups were fabricated for in-water test and 

 evaluation (Figures 33, 34, and 35). A brief description of the mock-ups 

 is contained in Table 7. All of the mock-ups were fabricated from wood 

 and weighted for neutral buoyancy; the leading edges were faired to 

 reduce hydrodynamic drag. The chest and wing tank mock-ups were con- 

 figured to be compatible with the presently used Mark 6 UBA. The chest 

 unit appeared to be compatible with all known types of Navy UBA's. Some 

 UBA's have enclosed back packs that make adaptation of the back pack 

 wing tank units very difficult. 



A mock-up of the heater control panel was fabricated ?nd Is shown 

 in Figu.e 36. The basic unit was 2 x 3 x A inches (5 x 8 x 10 cm). The 

 control handle was 2 inches in diameter with pronounced knobs. Small 

 diameter LEDs were simulated. 



TESTS 



The chest and wing tank mock-ups were tested in a swimming pool in 

 conjunction with the Mark 6 UBA. The apparatus shown in Figure 37 was 

 used to determine the mock-up drag characteristics. Divers were pulled 

 through the water at 1-knot speeds while submerged. Considerable varia- 

 bility in the results was noted; however, the drag was verified as being 

 a fraction of 1 pound. 



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