finally installed on TRIESTE. The first is a lamp developed 

 at NEL which contains a small General Electric 150-watt 

 incandescent bulb designed for use in wingtip lights of high 

 performance aircraft. The lamps are housed in a pressure- 

 resistant case with a Plexiglas window and are designed on 

 a unit basis so that they can be rapidly replaced by a SCUBA 

 diver. The lamp bulbs have a life of approximately 100 

 hours and are arranged in clusters of five units to a cluster. 

 The plastic window is protected by a thin layer of water and 

 a piece of heat resistant glass between the bulb and the win- 

 dow, so that heating of the window is not a problem. The 

 second type of lighting is an Edgerton 300-watt unit which 

 is an ordinary projection lamp bulb enclosed in a Pyrex 

 sock, with an external reflector behind the whole unit. 

 These lamps proved extremely useful in the early test dives 

 and it is anticipated that more will be installed. In addition, 

 investigations are still being carried out to develop a more 

 efficient, higher intensity lighting system. 



8. CONTROL SYSTEM 



To achieve a 24-volt basic power system, the motor 

 and lighting circuits had to accept larger currents. Since 

 the hull connectors were only capable of handling a maximum 

 of 10 amperes per wire, an external control system opera- 

 ting through a system of relays was constructed. This 

 system is contained in a pressure- compensated, oil-filled 

 box located just aft of the conning tower. The relay system 

 is actuated by control circuits from inside the sphere and, 

 thus, the heavy current demands are met without high 

 currents being carried by the hull connectors themselves. 

 In operations, the relay control box proved to be efficient 

 and reliable. 



FLOAT STRUCTURE 



Several of the tubes and pipes within the float were 

 found to be in deteriorated condition during overhaul of the 

 float and were replaced at the Naval Repair Facility in 

 San Diego. In addition, the end tank of the float, where the 

 towing force is applied, needed additional internal bracing 

 to distribute towing stresses more equally. The internal 

 bracing was installed and some deteriorated metal replaced, 

 achieving considerably more strength in this area. The 



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