the next (Figure 44). Gradually ascending through 
several such stations, diving personnel undergo 
decompression and simultaneously make use of 
heretofore enforced idle time. This system is 
attractive only under special conditions of terrain. 
Plans to expand one nonmilitary undersea test 
range include a series of habitats from nearshore to 
shelf depths, including this use of decompression 
staging. 
Figure 44. Artist’s concept of a decompression 
Staging system. (Westinghouse photo) 
f. Personnel Transfer Capsule/Deck Decom- 
pression Chamber This system, first used for 
commercial saturation diving, allows divers to live 
in a deck decompression chamber (DDC) (Figure 
45). A single small chamber, the personnel transfer 
capsule (PTC), transports divers from deck 
chamber to the worksite. The divers enter when 
Figure 45. A personnel transfer capsule/deck 
decompression chamber system. (Westinghouse 
photo) 
VI-112 
the PTC is mated with the DDC, both being 
pressurized equally. The PTC is lowered by a 
crane. The system’s pertinent features are: 
—Divers live and sleep above water. 
—The PTC has horizontal mobility within the 
range of its surface support platform and full 
vertical mobility. 
—Both chambers can mate at any pressure from 
atmospheric to maximum rated pressure to trans- 
fer divers. The system can be mounted on a dam, 
drilling platform, barge, or ship. 
Possible alternate means of operation include 
(1) two PTCs mating with adjoining compartments 
of one DDC or (2) PTC serving two or more DDCs. 
For safety reasons, a DDC should consist of not 
less than two self-contained pressure vessels; two 
main chambers and an entry lock are the most 
practical. 
g. Vehicle with Diver Lockout The system is a 
two-compartment vehicle with one compartment 
exposed to ambient pressure (Figure 46). The 
system is valuable for a series of short, widely- 
spaced dives (e.g., photographing and marking 
damaged spots on a submarine telephone cable). 
Such a system could be used where weather 
restricts deployment of normal surface support 
methods. Currently, storage batteries are the 
power source for the vehicle, limiting mission 
duration to a few hours and restricting speeds to 
less than five knots. 
Figure 46. A submersible vehicle with diver 
lockout. The diver lockout hatch is located 
aft on underside of hull where open hatch 
cover is visible. (Perry Submarine Builders 
photo) 
