128 



SUPPORT VESSEL 



SALVAGE TESTS 



DIVER TOOL TESTS 



, POWER LINE 

 yWATER LINES 

 '■ /'/INSTRUMENTATION LINE 



COMMUNICATION LINE 



Fig. 69. Sealab II operational configuration, artist's conception 



water) and completely removing all effect of the main counterweight by putting excess slack in 

 the main lowering wire behind the small counterweight. Both the auxiliary and the main coun- 

 terweight systems performed extremely well in all respects. 



DUMBWAITER SYSTEM 



During Sealab n operations, the staging vessel was positioned so that its fantail was almost 

 directly above the habitat shark cage (Figs. 68, 69). In this position, a 1/2-inch wire rope was 

 attached to the shark cage and brought up to a sheave on the 01 level of the staging vessel, 

 passed over a second sheave, and back into the water to a counterweight of approximately 500 

 lb. The counterweight served to keep the line taut at all times and to allow for wave and tide 

 motions. To transport supplies between the surface and the Sealab, a weighted container was 

 loose shackled to the taut wire and lowered and raised with a l/4-in. wire on an air-driven 

 winch. For transporting dry items, a pressure container was used which could be vented in 

 either direction to equalize its internal pressure before opening. An expanded metal cage was 

 provided for transporting wet items although it was usually found more convenient to shackle 

 the item direct to the taut wire and lower or raise it without the cage. 



Upon receiving an item at the Sealab it was necessary for one of the subjects to suit-up 

 and go out of the shark cage and bring the container inside the cage to a point where it could 

 be hoisted up through the access hatch by means of a block and tackle. In the future, this sys- 

 tem should be designed in such a manner that it could be operated without the necessity of put- 

 ting a man in the water. 



GAS STORAGE AND DISTRIBUTION SYSTEM 



A total of approximately 300,000 cu ft of gas was used for Sealab II operations, the major 

 part of this gas consisted of helium, oxygen, and helium-oxygen mix. Approximately half of 

 this gas was purchased in bulk and delivered from the vendor's tube trailer directly to Sealab 

 receivers consisting of the Sealab interior, the DDC, and, the 24 1300-cu-ft bottles movmted on 

 the Sealab. The remainder of the gas consisting mostly of helium-oxygen mixture was deliv- 

 ered in "towner" pallets. Each of these pallets consisted of 30 200-cu-ft bottles manifolded 



