1,350-ft DEEP DIVER (Fig. 3.23) and the 800- 

 ft SHELF DIVER were a new breed called 

 "lock-out" submersibles. In both vehicles the 

 after portion of the pressure hull was a 

 sphere in which the pressure could be 

 brought to ambient and a hatch in the bot- 

 tom opened to allow egress of divers. While 

 not a new concept, it was the first such 

 design of this period and was addressed pri- 

 marily toward support of divers in the petro- 

 leum industry. Demonstrating the versatil- 

 ity of this concept to support not only divers, 

 but also to effect "dry" transfer of materials 

 and non-divers to an atmospheric-pressure 

 undersea habitat, SHELF DIVER locked 

 onto Perry's HYDROLAB at the 50-ft depth 

 in 1968 and transferred crewmen into the 

 habitat without them getting wet. 



On the west coast of the United States, 

 North American Rockwell Corp. introduced 

 their BEAVER MK IV, another "lock-out" 

 submersible of 2,000-ft-depth capacity. BEA- 

 VER's sophisticated instruments and sub- 

 systems provided a wide array of capabilities 

 in all aspects of undersea tasks. Particularly 

 innovative were its two mechanical arms and 

 accessories which advanced the state-of-the- 

 art in manipulative capability by a wide mar- 

 gin. 



Also on the west coast, General Motors 

 Corporation's Defense Research Laborato- 

 ries at Goleta, California, launched the 6,500- 

 ft, 3-man DOWB (Deep Ocean Work Boat). 

 Instead of viewports, DOWB (Fig. 3.24) relied 

 upon optical systems for viewing; two 180- 

 degree-coverage optical domes were in- 



Fig 3 23 TTie Perry-Unk DEEP DIVER was (he lirst modern submersible to incorporate a diver lock-out feature (Ocean Systems Inc.) 



56 



