302 WET SUITS 



Water leakage into the insulating foam was experienced due to pin holes, tears, and human 

 error. Although there was some criticism of the battery pack, umbilical cable, and power- 

 control boxes, these components did not malfunction at all. The rubber suits stood up quite 

 well to the rigors of repeated donning, diving, and doffing. The snag suits, although objection- 

 able, experienced only zipper failures and some seam splitting.- 



The resistance wires failed in the various suits from minor to major degrees. Suit parts 

 were dissected and examined for wire failure as well as ozone cracking, pin holes, tears, and 

 moisture in the foam. 



Nearly all of the boots and mitts malfunctioned electrically. More wire breaks occurred 

 in the "uppers" of the boots than in the soles. Wire failure in the mitts seemed less systematic. 

 The boot and mitt wire design simply did not allow enough stretch, and the wires were severely 

 strained. Of seven boots examined for wire breakage, there was a total of ten breaks in the 

 soles and about 31 in the uppers. Five mitts were examined. Eighteen breaks occurred in the 

 palm side, while 12 occurred on the dorsal side. 



Two jackets and two trousers were also examined. Wire breaks occurred mainly in or 

 near areas of high suit material extension: hood, sleeve, upper back, and leg (especially the 

 knee area). 



Breakage of the resistance wires was evidently followed by electrical arcing and metal 

 corrosion. Arcing resulted in scorching of the foam rubber, while corrosion contributed to 

 further wire failure. 



Fourteen out of 16 suit parts had moist or wet latex foam due to pin holes or tears in the 

 outer skin or because gas valves were left open during sea-water immersion. Tears occurred 

 in suit parts not protected by snag suits. Valves were left open only by Team 1 subjects who 

 were not made available for thorough training. 



Thirteen out of 18 suit parts displayed ozone cracking to various degrees. All mitts, three 

 out of eight boots, and all jackets and trousers suffered ozone cracking. 



No delamination of the insulating sandwich material was evident in any suit part examined. 

 The copper "feed" wires were all intact, as were the soldered connections to the underwater 

 electrical connectors. All potted solder joints were in good condition. 



The rubber suit seams were in excellent condition. None of the Velcro closure material 

 suffered from any apparent wear or damage. There was only minor separation of the stretch 

 nylon liner material from the inner latex sMn. 



Ozone cracking can be minimized by applying a layer of neoprene latex to the skin material 

 prior to suit fabrication. Some snag and abrasion resistance without a separate snag suit can 

 be realized through the addition of an outermost layer of stretch nylon. This will result in a 

 stiffer suit, but it is the price one must pay for durability and speed of donning and doffing. 



The resistance-wire problem requires a complete redesign of the wire configuration as 

 well as more durable wires. The stranded wires (7/42 Advance) do not have adequate flex- 

 fatigue characteristics. Many more finer filaments of higher modulus alloy should be em- 

 ployed. They should be coated with an insulating material which will not bind them all together. 



RECOMMENDATIONS FOR FUTURE WORK 



The principle of supplemental heating in a pressure-compensated wet suit has been demon- 

 strated conclusively to be worthwhile for saturation diving. With the inclusion of a constant- 

 volume feature, these suits also will be extremely useful for deep diving from the surface. It 

 would seem appropriate to continue the development of such suits until they are operationally 

 acceptable. 



