HABITAT 



The underwater habitat , with some modifications , was the same as had been 

 used in the TEKTITE I program. The habitat (Figures 2 and 3) consisted 

 of two vertical steel cylinders attached to a rectangular steel base. 

 The two cylinders were connected by a crossover tunnel, and each cylinder 

 contained an upper and lower compartment designated as: crew quarters, 

 bridge, equipment room, and wet room. Each cylinder was provided with 

 three large hemispherical ports and a cupola atop the equipment room for 

 crew observation. The habitat was designed and built in accordance with 

 American Society of Mechanical Engineers (ASME) Boiler and Pressure 

 Vessel Code for Unfired Pressure Vessels. 



The base of the habitat system contained two passageways with barred 

 gates at each end. One passageway permitted access to the open ingress/ 

 egress wet room hatchway. The second passageway passed under the 

 normally closed emergency escape hatch located beneath the raised floor 

 in the crew quarters . In addition to providing a rigid attachment for 

 the twin cylinders, the base contained variable sea-water ballast tanks 

 and fixed ballast bins to hold the steel punchings and iron pigs necessary 

 to offset the displacement on the sea floor. 



The crew quarters (Figure 4, lower left) contained four built-in bunks, 

 drawer space, a sink, stove, refrigerator, and a radio and television set. 

 The bridge (Figure 4, upper left) contained the environmental control and 

 alarm panels, the communications panel, and other ancillary instriomenta- 

 tion. It served as the habitat control center and as a dry laboratory 

 for the scientists. It also contained a folding cot where the habitat 

 engineer slept. The equipment room (Figure 4, upper right) contained the 

 environmental control system, the electrical transformers and main 

 breakers, a large freezer, and a toilet. The observation cupola was 

 located above this compartment. The wet room (Figure 4, lower right) con- 

 tained a fresh water shower, a clothes dryer, storage space for scuba 

 gear, and stainless steel counters for specimen preparation and study. 



ATMOSPHERIC CONTROL 



The habitat was initially pressurized on the surface to the emplacement 

 depth pressure of approximately 2.3 atmospheres by compressed air. The 

 partial pressure of oxygen (PO2) in the habitat during all saturation 

 periods was 160 torr or millimeters of mercury (mm Hg). The specified 

 PO2 was obtained by displacing air with nitrogen after the habitat was 

 secured to the ocean floor. This resulted in a mixture of 92% nitrogen 

 and 8% oxygen. 



During the operation compressed air was continually supplied to the 

 habitat via an umbilical by low-pressure air compressors at the surface 

 support center to provide metabolic oxygen to the aquanauts and maintain 

 the PO2 between 151 and 165. The required flow rate of inlet air to the 



II-2 



