Signalman 1 & C - Historic Naval Ships Association

OperationTo start the light, close the remote manual switch,then turn the starter counterclockwise on the rear ofthe starter unit. (See fig. 2-3.) Release the starterswitch as soon as the lamp arcs. Be sure the starterswitch returns to its previous position; otherwise, thehigher current required to start the lamp may damageelectrical components.Initially, the lamp burns only at about 25 percentof designed intensity. It takes 2 to 3 minutes to reachmaximum brilliance.The light should not be elevated or depressed morethan 10 degrees for extended periods of time becausethe life of the lamp is reduced considerably at extremeangles. Operate the shutters the same as you would theincandescent lamp shutters. To turn off the lamp, openthe remote manual switch.MaintenanceThe 12-inch mercury-xenon arc searchlightshould be inspected and checked monthly. All screws,especially those of the reflector clamps, focusingmount, and lamp support, should be examined forlooseness. All screws and fastenings should bechecked after ship's guns have been fired.Trunion and yoke bearings should be lubricatedwith grease; see the MRC for the type of grease.Replacement of the lamp must be performed asexplained in the applicable manufacturer's manual,observing all precautions given.When the return action becomes sluggish, theshutter bearing and links should be lubricated. Thelubricant should be used sparingly and should not beallowed to contact the envelope of the mercury-xenonlamp. Should the shutters remain sluggish, replace theshutter springs.The reflector and glass cover should be cleaned asrequired by the MRC.When considered necessary, the cover of theballast box should be removed and the five resistorsexamined and tightened in their sockets. Wiringshould be checked and terminal screws tightened asrequired. The packing glands at the cable entrancesshould be kept secure and watertight.Focusing is performed by means of a slidingplunger at the rear of the focusing box on top of thesearchlight.Maintenance is basically the same for themanual-starting and automatic-starting, 12-inch,mercury-xenon searchlights. For detailed differencesin the construction and operation of these two types,see the applicable manufacturer's manual.Electrical maintenance should be left to theelectricians unless a member of the signal gang isqualified to do it by the engineer officer.Figure 2-3.—Starter unit for 12-inch mercury-xenon searchlight.2-4