102 HANDLING CHARACTERISTICS 



52. Move the remaining switches, one at a time to on. (Except the switches for the water 

 heater, stove and radiant heaters in the entry.) 



53. Check all systems to insure that they are working properly on normal power. 



54. Using the same procedure, switch back to alternate power. Alternate power will be 

 used during lowering. 



55. Lower the TV camera tripod to the bottom and check it out for proper operation. 



56. Complete the final loading of equipment into Sealab. 



57. Place the automatic oxygen system in a "service for use on the bottom" condition by 

 opening the following valves in sequence: H9, H3, H2(2). Then energize the Krasberg oxygen 

 sensor. 



58. Prepare to charge Sealab by opening internal valves D3(2), E3, and E4 or E5. 



59. Remove the strongback from the main access hatch. Stow it in Sealab. 



60. With all necessary systems operating on alternate power, vacate Sealab and secure the 

 conning-tower access hatches. 



61. Take Sealab draft readings. 



62. Open vent valves A2, A3, A6, and A7 of ballast tanks 1 and 3. 



63. Open flood valves CI and C3 of ballast tanks 1 and 3. Then open vent valve AlO and 

 master vent valve Al. Sealab, if properly ballasted, will submerge to approximately the 

 9000-lb mark, near the mid-height of the conning tower. 



64. Close flood valves CI and C3 and vent valve Al and AlO when tanks 1 and 3 are com- 

 pletely flooded. 



65. Take Sealab draft readings. 



66. Open the equalizing valves Bl and B2 and vent valves A4 and A5 of ballast tank 2. 



67. Open external valves Dl, D2, and E2 and charge Sealab through the gas- supply line of 

 the umbilical cord to Sealab depth plus 5 psi. A pressure gage will be attached to the gas- 

 sampling hose in the atmosphere control van to read out the pressure. The charging will be 

 done as follows: (1) Charge to approximately 28 psi* with air. (2) Complete the charge with 

 helium. 



68. Check for pressure in the conning tower by opening and closing C4. 



69. Take marks on the lowering wire. 



70. Inspect the complete counteiweight system to insure that it will function properly. 



71. Flood the conning tower by opening its vent valve A8 and its flood valve C4. Sealab will 

 now completely submerge and will impose a tension load of approximately 9000 lb on the low- 

 ering line. Leave valves Al, A8, arid C4 open to prevent any damage to the conning tower dur- 

 ing lowering. 



72. Prepare to plumb Sealab on short stay as it becomes negative. 



*The exact pressure will be decided by the exact Sealab test depth. 



