GENERAL DESCRIPTION 



The design of the vehicle was dictated by operational and 

 performance requirements determined from early experiments for use 

 as a fishing gear research tool. Some basic considerations were 

 ease in handling, maneuverability, and a useful working range down 

 to 50 fathoms. It was found desirable to provide both horizontal 

 and vertical scanning mechanisms for the television camera. Of 

 importance was the ability of the unit to hover, to be placed on the 

 bottom for extended periods of time, or to be moved through the water 

 at speeds up to 3 knots. Practical considerations of time and avail- 

 able funds limited the selection of certain mechanical and electrical 

 devices and materials used in the fabrication. 



PRESSURE VESSELS CONSTRUCTION 



Upper Chamber 



Two sealed pressure vessels were constructed: the upper 

 double chamber housed the vertical and horizontal control mechanism, 

 and the lovfer cylindrical chamber housed the television camera (fig. l). 



The upper double chamber was constructed of standard 20" x 

 3/b'^ X 10" length and standard 10" x 5/l6" x 10" length mild steel 

 pipe. These pipes were closed at either end with plates and flanges 

 which formed a water-tight compartment housing the control mechanism. 

 Wall thickness for lA" hold do-vm studs on the inside edge of the 20" 

 by 10" pipe section was gained by welding in a circular ring of 1/2" 

 by l/2" key steel. The ring flange faces were then machined to insure 

 positive seating and sealing of the gasket material. The cap joint 

 was gasketed with 1/8" standard rubber plumber's gasket material. A 

 loop of 1/2" round cold rolled steel was welded to the extreme top of 

 the cap to effect a mount for supporting the vehicle (fig. 1) . To 

 prevent the possibility of leaks through the hold do\m nuts on the cap, 

 close fitting l/l6" copper washers were used. End plates and flanges 

 were fabricated from 3/8" hot rolled steel. All closed joints were 

 electrically welded inside and out. Three tapered leg mounts of 3/8" 

 plate were welded at equidistant intervals to the lower flange. A 

 1/2" hole was drilled at each leg mount tip for securing the removable 

 tripod leg with l/2" by 13" standard bolts. The tripod legs were con- 

 structed of standard 1-1/2" galvanized steel pipe 31" in length 

 (fig. 1). Circular pads of l/2" by It" steel plate were welded to the 

 bottom ends of the legs for use of the vehicle in bottom observations. 

 In the upper ends of the legs l/2" steel discs were welded in the sides 

 of the pipes. One-half inch holes were drilled and tapped to provide 

 means of securing legs to leg mounts. Three standard studs 3-3/8" by 

 1" were welded midway between the leg support plates for cross brace 



