Fig 15 1 Though its bow equipment rack prohibits head-on hull collision, ASHEFIAHs unprotected downward-looking viewports were susceptible to contact with sharp pinnacles. 



(Gen Dyn ,'Elec Boat) 



the brass battery boxes exploded and the 

 vehicle descended. A 450-pound emergency 

 weight was dropped and SP-350 surfaced. 



Submersible: DEEPSTAR 4000 Date: 25 

 October 1966 Reference (1) 



Incident: The vehicle was to take core 

 samples; the dive was made with DS-4000 in 

 a heavy (75-lb) trim condition, i.e., after the 

 descent weight was dropped the vehicle was 

 still negatively buoyant. Trim weights could 

 be dropped to achieve neutral buoyancy if 

 desired. With the vehicle on the bottom at 



687 



