INCHES 



i r i 



i : i« B :; ; :S:;,: - : 5 :. s .:,.i>:. : . . : 'i SMK: _ -..X't^ffii A'SSKiKS-'Xli^^Wi** ■~~~-'«Vi«^l~~»r:"ii 



Figure 3. General Electric AH-6 lamp that was unsuccess- 

 fully attempted as a substitute for original mercury vapor 

 lamp. 



ignition was obtained at the lower voltage used since none 

 of the other General Electric bulbs tested achieved ignition 

 when installed in the bathyscaph lighting system. 



Such difficulties had prevented the full visual and photographic 

 observations of which the bathyscaph is capable. These 

 advantages were not available during the 1958-59 dive series 

 off California nor during Projects NEKTON I and NEKTON II. 



To achieve the full visual and photographic potential of the 

 bathyscaph, a lighting development program was therefore 

 initiated in August 196 0. This report covers the progress 

 of that program to date. 



DEVELOPMENT CONSIDERATIONS 



The most important developmental factor of the lamp is its 

 ability to function efficiently in the harsh conditions imposed 

 by the deep-sea environment. Since pressure in the deep 

 ocean reaches 16, 000 psi, an acceptable safety margin for 

 the lamp would be its capacity to withstand 20, 000 psi. In 

 addition, the temperature often approaches 0°C. Various 

 methods of overcoming adverse environmental features of 

 the deep sea will be discussed for each of the lamps tested. 



* (See NEL Report 1096, Technological and Operational 

 Aspects of the Operations of the Bathyscaph TRIESTE 1958- 

 1961, by LT D. Walsh, USN, in press) 



