WET SUITS 299 



The third subject was BMl W. D. Meeks. The Team 3 subject training was incomplete 

 because their suits had malfunctioned to various degrees during the Team 1 and Team 2 evalu- 

 ations. The suits were not worn during the Team 3-stay in Sealab 11. 



Field Engineering 



The field-engineering work was concerned mainly with charging and maintaining the silver- 

 zinc batteries, maintaining the suits, familiarizing the surface staff members with the heated 

 suit program, conducting liaison with the subjects on the bottom to instruct and assist them, 

 and perhaps most important of all, to take care of the legion of seemingly small problems in- 

 variably associated with accelerated research and development programs. 



The first problem encountered in the field was poor fit of the chin area in both the wet 

 suits and the snag suits. This was nearly universal and occurred in all but two suits. The chin 

 areas of the suits were too tight, causing both upward forces and forces directed toward the 

 back of the head. The chin area is critical, both for comfort and safety. The suit parts were 

 returned to the Clothing Plant, altered, and returned by air express. The value of field engineer- 

 ing was demonstrated to be essential in this instance. The program might very well have ended 

 here without it. 



Most of the subjects found it difficult to put their swim fins over the boots. The boots are 

 slightly bulkier than standard l/4-in. neoprene boots because of the added hard sole. Dr. 

 Sonnenburg found it impossible to wear his super-extra-large Duck Feet over the heated boots, 

 and extremely difficult to wear them over any other boot. To solve this problem, the writer 

 provided a pair of altered super-extra-large Duck Feet with 2-in. nylon webbing and buckles 

 rather than the fixed rubber strap. It would be well if the fin manufacturers provided swim 

 fins for size 13 and 14 feet which are covered with 1/4-in. boots. But they do not. 



Battery charging and maintenance accounted for a significant fraction of engineering time. 

 Silver-zinc cells require careful attention during the charge cycle, unless automatic scanning 

 chargers are employed. None were available. The cells are generally charged at constant 

 current until the end-of-charge voltage is attained. They can be ruined if current is main- 

 tained after the end-of-charge voltage has been reached. 



An attempt to charge the cells was made aboard the Sealab 11 staging vessel, but it was un- 

 successful and had to be abandoned. Power-line surges due to heavy electrical equipment in 

 the circuit together with an inadequate patch-board for connecting the cells were the principal 

 obstacles. An arrangement was made to have the cells charged at the Battery Maintenance 

 Shop at the Naval Electronics Laboratory at Point Loma. The cells were charged at 6 amps 

 until the normal end-of-charge voltage (2.05 volts) was achieved. But these cells did not pro- 

 vide power to a suit the very next morning. The voltages measured at that time were between 

 1.52 volts and 1.83 volts. Most readings were about 1.58 volts. The open-ciruict readings 

 should have been 1.86 volts. 



The problem turned out to be the resistance of the underwater electrical fittings, which 

 was greater than the resistance of the cells. This difference in resistances resulted in voltage 

 drops across the connectors had spurious voltage readings. The cells were then charged at 3 

 amperes to the end-of-charge voltage. This procedure, however time consuming, was a solu- 

 tion. The batteries did not deliver full capacity during the first discharge, even though they 

 were partially developed by Yardney prior to shipment. They had been put through one charge- 

 discharge cycle. Development of a silver-zinc cell consists of several charge-discharge cycles 

 until full capacity is achieved. The high resistance of the electrical connectors caused erro- 

 neous voltage readings during the development cycles, and the cells were not fully developed. 



The pressure-compensating fittings had to be removed and washed after each use. Potas- 

 sium hydroxide forms a salty deposit which can be removed by vigorous washing in freshwater. 



Three of the suits worn by Team 1 members were flooded because valves were left open. 

 This was attributed to the nonavailability of the subjects for indoctrination and training. The 

 sea water was removed by applying a vacuum to the suit parts. Flooding of these suits vitiates, 



