E-12 

 Gibson, this volume) . 



The sled can also be equipped with a 70 nun (100' film 

 reel) camera. This type of camera was used initially for 

 the first three camera runs. We soon switched to the higher 

 capacity 35 mm camera, so as to allow for significantly 

 longer camera tows. 



All film was developed shipboard within hours of the 

 camera's arriva-1 back on deck. The film was custom pro- 

 cessed in 50' segments in order that development time could 

 be individually adjusted to actual exposures. 



Sled Problems Encountered 



The most serious "Cheep Tow" difficulties were experi- 

 enced with the lead-acid battery power supply. A major 

 unforeseen problem arose where the sled would hang-up on 

 some obstacle and either tip over on its side or invert 

 all together despite the flotation devices. This appears 

 to have allowed the pressure compensation oil to coat the 

 battery plates, thereby greatly reducing the total amp/hour 

 capacity. The coating effect turned out to be cummulative, 

 and we were forced to retire batteries sometimes after only 

 a couple of lowerings. Toward the end of the second leg we 

 ran out of replacement batteries and had to recycle former 

 rejects. Draining of the battery acid and washing of the 

 cells did not appreciably renew the battery capacity. For 

 the latter part of Leg E-2B-79 useful camera footage was 

 terminated midway during several of the runs by premature 



