Lift the camera and lower carefully over the 

 side, using the retrieving line to lower the 

 camera untU it is suspended in a vertical posi- 

 tion from the oceanographic wire. Great care 

 must be taken during this operation not to 

 compress the sliding sleeve and fire the camera 

 inadvertently. When the camera is in the ver- 

 tical position and ready for lowering, secure 

 the end of the retrieving line to the shackle at 

 the top of the frame. Lower the camera to 

 the waterline and set the meter wheel to zero. 

 Commence lowering. 



7-10 Obtaining the Bottom Photograph and 

 Core Sample. — Lower the camera slowly until 

 the apparatus is well clear of the ship. When 

 the camera approaches the sonic depth, measure 

 the wire angle. Using the method described in 

 section 6-7 determine the approximate amount 

 of wire to be payed out to reach bottom. Slow 

 the winch down to prevent violent contact 

 with the bottom. Stop the winch the instant 

 contact is signaled by means of the ball breaker 

 or dynamometer. This is to prevent the wire 

 from being laid on the bottom with resultant 

 kinking and damage. The picture and core 

 having been taken at contact, now commence 

 hoisting slowly until the camera is well clear of 

 the bottom then increase to normal hoisting 

 speed. Again, slow the winch as the camera 

 approaches the surface. When the camera is 

 at the platform unfasten the retrieving line, 

 swing the camera to a nearly horizontal posi- 

 tion, and bring it aboard. Care must be 

 taken not to raise the bottom end to the 

 horizontal as this will disturb the core sample. 



7-11 Removing the Core Sample and Re- 

 cording the Data. — The core sample is re- 

 moved, the data recorded, and the core stored 

 in the same manner as described in section 

 6-20, 6-21, and 6-24 for Phleger cores. All 

 data are recorded on the M-sheet. In addition 

 to the data required for the core, the following 

 information pertaining to the photograph 

 should be recorded in the Remarks column. 

 Record the type of film used, the type of flash- 

 bulb, lens, stop and shutter speed, and number 

 of the picture. If necessary use more than 

 one . line of the log sheet, writing across the 

 columns. 



7-12 Removing the Camera and Securing 

 the Camera Assembly. — If operations are in 

 shallow waters (such as less than 100 fathoms) 

 and the camera is to be lowered again, it may 

 be removed from the case, the film advanced, 

 the shutter trigger cocked, and then reinserted 

 in the case. The old flashbulb is removed 

 and a new one placed in the housing. If the 

 housing is tight, use a strap wrench to loosen 



it. A new core liner is placed in the coring 

 tube and the core catcher and cutting edge 

 replaced. The core catcher, cutting edge, 

 and coring tube must be thoroughly washed 

 clean of aU sediment before using again. The 

 camera is then ready for another lowering. 



If operations are in deep waters and the 

 camera is to be lowered again, it is recom- 

 mended that the film be removed from the 

 camera and a new reel used for each lowering. 

 Thus loss of several valuable photographs is 

 prevented should some accident occur to the 

 camera. 



Whenever photographic laboratory facilities 

 are available aboard ship, it is advisable to 

 develop the film as soon as possible. Thus, 

 necessary adjustments in stop and shutter 

 speed can be made. After the negative has 

 been developed and prints made on glossy 

 paper, the information recorded on the log 

 sheet should also be recorded on the back of 

 the print. Negatives and positives should be 

 kept together and forwarded with the log sheets 

 and core samples at the end of the cruise (fig. 

 7-5). 



If the camera is not to be used for a day or so, 

 the following procedure should be carried out. 

 Remove the camera from the pressure case, 

 insert a desiccator bag, and secure the cover 

 plate. Remove the used flash bulb, insert a 

 desiccator bag in the glass housing, and replace 

 the housing. Remove the batteries from their 

 case, place a desiccator bag in the case, and 

 recap. Place the camera in its shipping box and 

 store the coring tube and parts. Secure the 

 camera frame to prevent damage. It is desir- 

 able to secure it in some overhead location 

 where it will be out of the way of traffic and 

 protected from the sun. The camera box must 

 be kept in a safe dry place. 



7-13 Maintenance ofthe Single-Shot Bottom 

 Contact Camera. — It is most important to 

 watch for pressure leaks if the camera is to 

 remain in proper operating condition. Leaks 

 will cause damage to the camera and short 

 circuits in the electrical system. All 0-rings 

 must be kept in good condition. They should 

 be replaced if there are any indications of wear, 

 cuts, or chafing. If short circuits develop, the 

 electrical cable should be replaced and a careful 

 watertight connection to the spark plug con- 

 nectors made. 



The watertight connection is made in the 

 following manner. Attach the cable to the 

 connector. Cover the connector and about 

 8 inches of the cable with a layer of tightly 

 wound rubber tape. Cover the taped area and 

 about an inch of exposed cable with a layer of 



76 



H. O. 607 



