DECOMPRESSION COMPLEX 113 



1. Sufficiently large to transport ten aquanauts. 



2. Designed to ASME unfired boiler-code specifications to withstand an internal pressure 

 of 200 psig. 



3. Provided with a life-support system which could be operable internally and which could 

 maintain the ten personnel for a minimum of 12 hours. 



4. Provided with an internally controlled raising system which would allow personnel un- 

 der pressure to raise themselves to the ocean surface. 



5. Equipped with systems for communicating with surface personnel. 



6. Provided with necessary appurtenances for being lifted and handled by the surface- 

 support vessel. 



7. Provided with a system for mating the PTC with the DDC. 



DDC Functional Requirements 



The following are the functional and basic design requirements of the DDC: 



1. Sufficiently large to decompress, in relative comfort, ten aquanauts. 



2. Designed to ASME unfired boiler-code specifications to withstand an internal pressure 

 of 200 psig. 



3. Provided with a life-support system to be operated externally for decompression. 



4. Provided with a medical lock and an outer lock. 



5. Provided with an overhead flange and hatch for mating with the PTC. 



PERSONNEL TRANSFER CAPSULE 



A simplified cross-section view of the PTC is shown in Fig. 51, and its mated position on 

 the DDC is shown in Fig. 52. The PTC being lifted from the water, transferred, and mated to 

 the DDC is shown in Figs. 53, 54, 55, 56, and 57. The basic controlling dimensions of the PTC 

 were: diameter, 6 ft; height, 11 ft; entrance hatch diameter, 27 in. The cylindrical portion of 

 the unit was 8 ft long. Four pipe -type flared legs provided the necessary PTC mounted guides 

 for mating. These legs, extending below the mating flange, also provided necessary protection 

 to the mating surface during the handling of the PTC without its stand. The stand for the PTC 

 provided adequate room (5 ft) below the PTC to gain entrance through the hatch. Ballast to 

 provide negative buoyancy for the PTC was contained in two lower ballast trays at the base of 

 the stand. The upper tray was permanently affixed to the stand; the lower tray was clamped to 

 the upper tray during normal recovery operations by the crane of the surface-support vessel. 

 The emergency self-contained raising system for the PTC was, basically, a pneumatically 

 controlled, "Green-Giant" sized clock escapement mechanism as shown in Fig. 58. The ratchet 

 gear is fixed to the cable spool shaft. One end of the cable is fixed to the upper ballast tray. 

 The other end of the cable is fixed to the lower ballast tray. When the lower tray is released 

 from the upper tray, the resulting 2000 lb of net buoyancy of the PTC, its stand, and upper bal- 

 last tray provides the necessary lifting force. Were it not for the pawls and the pneumatically 

 controlled escapement arm, the PTC then would freely ascend to the surface on its cable, and 

 the lower tray would serve as an anchor. The positions of the pawls and the escapement arm 

 are controlled by the pneumatically controlled piston actuator. Each side of the actuator piston 

 can be connected by means of a three-position control valve to either PTC internal atmosphere 

 or to the low-pressure side of the He gas regulator. Thus, if both sides are connected to the 

 internal atmosphere, the piston will float and the escapement mechanism will run free, the 

 cable pay-out speed and hence the ascent rate being only a fimction of the buoyancy, dynamic 



