MARINE LIGHTING EQUIPMENT OF THE PANAMA CANAL. 



By Jambs Pattison, Esq. 



[Read at the twentieth general meeting of the Society of Naval Architects and Marine Engineers, held in 



New York, November 21 and 22, 1912.] 



In accordance with the plans of the eminent army engineers who are 

 carrying the work to completion, the Panama Canal will be lighted through- 

 out by automatic unattended lights, each having a distinctive characteristic. 

 At the entrances and through Gatun Lake a double row of about sixty 

 automatic acetylene lighted buoys will mark the channel. The channel 

 will be further defined by powerful, rapid-flashing range-lights, one set at 

 either end of each successive tangent, thus permitting vessels going in either 

 direction to take their range over the bow. The center lines of each range 

 are set apart sufficiently to enable the largest vessels to pass one another in 

 safety. Through the Culebra cut, or wherever the proximity of the banks 

 permits, beacons will be used instead of buoys (see Plate 46). 



WGHTED BUOYS. 



A brief mention of the various types of buoys in general use to-day may 

 be of interest in leading up to the description of the particular system adopted 

 by the Isthmian Canal Commission. 



It is generally conceded by lighthouse authorities that the lighted buoy 

 is the greatest aid to navigation produced during recent years. It is inex- 

 pensive both in first cost and maintenance, and produces a highly efiicient 

 light of from six to fifteen miles visibility which will bum without attention 

 and with absolute reliability for long periods, even up to a year or more if 

 desired. 



The use of oil as an illuminant for lighted buoys is now obsolete, and 

 the electric light is yet quite impracticable for this purpose, so that to-day 

 buoys are lighted with gas only — either oil-gas or acetylene. In the case of 

 the oil-gas buoy, the nature of the illuminant renders its light weak and 

 inefficient unless aided by an incandescent mantle, which, of course, is an 

 added source of unreliability to be avoided. Oil-gas also loses a considerable 

 amount of illuminating power by compression, owing to condensation of the 

 heavy hydrocarbons. 



Acetylene, a product of recent years, is, in this country, rapidly super- 

 seding oil-gas, its properties rendering it especially well adapted for buoy 



