leg stiffening attachment. The tripod legs may be removed when the 

 vehicle is to be towed. To maintain a stable picture platform the 

 towing vane or rudder of 1/2" marine plywood was attached as shown 

 in photographs and drawings (figs. 2 and 10). 



An access port 3" x 3" was cut at the lower rear of the 20" 

 pipe section and eight I|./l6" standard studs were installed for clamping 

 the control-cable stuffing tube (fig. 1). This port allowed the drive 

 control electrical cable to be disconnected from the vehicle assembly 

 by means of a quick disconnect plug. The access port was sealed with 

 1/8" standard rubber plumber's gasket material. At the center of the 

 lower flange a 5" hole was cut and six equally spaced holes were drilled 

 around the perimeter to clamp and seal the main drive shaft housing. 

 To seal the shaft housing 1/8" standard rubber plumber's gasket mater- 

 ial was used. Two plates l/2" x U" x 6" were welded fore and aft of 

 the c^ assotibly for attachment of tail assembly (fig. l). 



A. standard 1/8" Schrader tank valve, used when pressurizing 

 the vessel for deqj water work was centered with and 1" above the 

 access port. The upper chamber may be filled with air from any con- 

 venient source either compressed air bottles or an automobile tire 

 pump. The valve was equipped with an l/B" pipe cap which sealed the 

 vaLve and prevaited external water pressure from overcoming internal 

 air pressure. The upper chamber was tested to 12^ p.s.i. (pounds per 

 square inch) internal pressure. Pressurized to I4O p.s.i. the unit 

 can descent to 50 fathoms. 



Lower Chamber 



The camera vessel was made from an I8" length of standard 8" 

 steel pipe (figs. 3 and 6) and vias not pressurized. Circular rings 

 of 5/8" steel vieve machined for "0" ring seals and welded to each end. 

 The camera viewing port was a circular plate of lucite l/2" in thick- 

 ness drilled to fit eight evenly spaced 5/l6" studs. A brass clamp 

 ring 1/2" X 3/16" mth stud nuts was used to hold the window tight 

 against a 5/l6" x 6-1/2" "0" ring seal thus assuring water-tight integ- 

 rity. The rear cover was a circular plate of 3/8" brass plate with a 

 stuffing tube for the camera cable. In a similar manner this plate 

 with eight 5/l6" studs, nuts, and "0" ring sealed the rear of the 

 vessel. 



The camera housing was held in place in the cradle with four 

 tb.umb screws through eyes on the housing (fig. 3). The supporting 

 frame was fabricated from one piece of 2" x 12" channel iron cut to 

 form a cradle. Angle irons running the lengt-h of the camera housing 

 were welded to the cradle to form a slide arrangement to hold the 

 camera housing. At each end of the cradle steel shafting was welded 



