Remove the camera from the carrying case 

 and cock the shutter trigger. Place the un- 

 loaded camera in the pressure case so that it is 

 seated firmly on the banana plugs. 



Now test the firing circuit by moving the 

 sliding sleeve up so that the U-magnet passes 

 over the microswitch. The test lamp should 

 light and the camera shutter trip. If they fail 

 to do so, make a check for short circuits. When 

 the system is operating properly, remove the 

 test lamp and camera (fig. 7-3). 



Figure 7-S. 



Exploded view of underwater camera 

 a.ssembly. 



Attach brass foot plate (when needed) and 

 the coring tube to the sliding sleeve. Insert 

 a length of plastic liner, a core catcher, and 

 cutting edge as described in section 6-15. 

 Once the coring tube is assembled, be carejul not 

 to trip the firing circuit. 



Put a photoflash bulb into the socket. Coat 

 the 0-ring of the glass housing with a very thin 

 even layer of stopcock grease, and fasten it in 

 place. The housing should be tightened slightly 

 by hand. Do not use a wrench or other tool to 

 tighten it. 



Load the camera with film. Set the lens 

 opening and shutter speed. Recommended set- 

 ting for plus X film is 1/50 second at f9, and for 

 super XX is 1/50 second at fll. Variations to 

 these settings may be desired owing to slight 

 differences in cameras. The first few lowerings 

 should reveal whether changes in settings are 

 needed. 



Cock the shutter trigger of the camera and 

 insert the camera into the pressure case in the 

 same manner as during the circuit test. Check 

 the cover plate to insure that the 0-ring is 

 properly seated. Coat the 0-ring with a very 

 thin even layer of stopcock grease. Bolt the 

 cover plate to the pressure case. The operator 

 must be cautioned that only a small amount of 

 pressure must be applied in tightening these 

 bolts and this pressure must be evenly applied 

 around the plate. If too much pressure is ap- 

 plied, the 0-ring will be flattened and its intended 

 purpose defeated (fig. 7-4). 



Front of underwater camera pressure case. 



The camera assembly is now ready for attach- 

 ment to the oceanographic wire. The proce- 

 dures described above must be carried out before 

 each lowering. If the camera assembly has not 

 been used for several days, it is strongly recom- 

 mended that a test lowering be made without 

 the camera to inspect for leaks. A lowering to 

 500 meters will usually reveal any leakage. 



7-9 Rigging for Lowering. — The camera 

 assembly is shackled to the oceanographic wire. 

 It is recommended that if available, a bottom- 

 signalling device such as the ball breaker be 

 used. Attach the ball breaker to the ocean- 

 ographic wire and rig as described in sections 

 6-57, 6-58, and 6-59. Shackle the camera 

 assembly to the ball breaker. It is advisable 

 to splice a length of manila line around the 

 frame just below the photoflash bulb housing 

 to use as a retrieving line. 



H. O. 607 



75 



