supporting the decompression complex and 10-inch wide flange beams were 

 used as primary support members. The 25 by 50 foot catamaran deck area 

 contained a 12 by 12 foot well through which the diving bell was 

 operated. The water depth below the well at the mooring was approxi- 

 mately 25 feet. 



The decompression complex consisted of a skid-mounted MK IV Personnel 

 Transfer Capsule (PTC), a gantry handling system, a MK III Deck 

 Decompression Chamber (DDC), designed and built by Reading and Bates, 

 Incorporated, and a decompression console. 



The PTC was a 66-inch diameter sphere with two double-door hatchways 

 located on the bottom and side, the side hatch for mating and easy sur- 

 face entry, the bottom hatchway for locking divers in and out. An 

 umbilical attached through various penetrations contained compressed 

 air, communication and gas sample lines. An on-board air and oxygen 

 supply was available through high pressure bottles racked on the bell's 

 exterior. Other equipment included internal and external pressure 

 gauges, gas control valves, and a two-way communicator. The PTC was 

 lowered and raised via a 7/8-inch strength cable. 



The handling system consisted of an overhead pneumatic winch containing 

 the PTC strength cable and a fairlead/alignment bracket attached to the 

 underside of the gantry for raising and lowering of the PTC. The 

 hydraulically operated gantry allowed fore and aft movement of the PTC 

 from the deck well to a wheel track between the skids, positioning it 

 so that hand winches could snub it against the DDC mating flange, where 

 a tube-turn clamp allowed pressurized transfer into the DDC. A diesel 

 driven air compressor with a capacity of 100 CFM at 125 psi provided air 

 to either or both locks of the DDC, the pneumatic winch, or two 200 SCF 

 receiver tanks for storage. The hydraulic rams operating the gantry 

 required 220 volt, 3-phase power from an external source. 



The double lock decompression chamber consisted of a main chamber 12 feet 

 in length, with a diameter of 84 inches. The outer chamber or entry lock 

 was 5 feet in length, with a diameter of 54 inches. Side hinged pressure 

 hatches are located at the entry lock end, between the entry lock and 

 main chamber, and at the main chamber end. The main chamber has an 

 extended flange with a tube-turn hub and tube-turn locking device, which 

 is mated to a similar hub on the PTC flange for pressurized transfer of 

 personnel. Pressurized transfer of personnel and supplies could also be 

 accomplished through the entry lock into the main chamber. Several 

 through-hull penetrations were provided for gas, water, and electrical 

 lines . Each chamber lock contained adequate view-ports , oral-nasal masks 

 for O2 or mixed gas input , two-way communicators , and overhead lights . 

 The main chamber, shown in Figure 11, contained four bunks (the fifth 

 crew member rested or slept on an air mattress in the aisle) and a coil 



11-10 



