ii6 MARINE LIGHTING EQUIPMENT OF THE PANAMA CANAL. 



The corroding action of the salt water and the sea air in the tropics is such 

 that extra precautions must be taken to protect the buoys, and therefore the entire 

 inside of the buoy is given first one coat of bitumastic solution, applied cold, and 

 second, one coat of enamel applied hot. 



The exterior of the buoys which will be moored in salt water will be given one 

 coat of boiled linseed oil applied hot, and two successive coats of the best quality red 

 lead, after which they will be treated with an anti-fouling compound. 



The entire bed of what will be Gatun Lake, when the water is allowed to rise to 

 an elevation of 87 feet, is covered with a dense tropical growth which in the state of 

 decomposition causes the water to scour all ordinary paints off any kind of metal. 

 To overcome this chemical action the exterior of the buoys will first be painted with 

 red lead and linseed oil, after which they will be painted with anti-corrosive paint. 



Targets. — On the short ranges, and at certain points along the Lake channel, 

 targets will be built to mark the center line of the canal or to reference the lighted 

 buoys as the case may be. These targets will consist of a tripod 20 feet high made 

 of steel angles encased in concrete, and the upper 8 feet of the tripod will be filled 

 in from leg to leg with a plaster wall of metal lath. This furnishes a fairly uniform 

 target from whatever angle viewed, and is permanent and inexpensive. 



West Breakwater Light. — In the general scheme for lighting the canal, a harbor 

 light and fog signal station is to be built at the outer end of the West Breakwater 

 in Colon Harbor. An "L" turning inward will be made at the end of the break- 

 water and the tower built in it so that thorough protection from the waves will be 

 obtained. 



The natural bottom of the harbor at this point is mostly silt deposited by the 

 heavy rains washing down the hillsides. On this silt a pile of rip-rap for the sub- 

 foundation will be dumped, allowed to settle for some time, and levelled off by a 

 diver at elevation minus 22 below mean tide. 



The sub-foundation will consist of a reinforced concrete caisson 46 feet by 46 

 feet in plan by 36 feet high, divided into sixteen compartments by three trans- 

 verse walls running each way. 



The superstructure will be of reinforced concrete, and will contain an engine 

 on the first floor, living quarters on the second floor, and a tower rising out of the 

 center of the structure, surmounted by a lantern the focal plane of which will be 

 56 feet 4 inches above mean sea level. 



In addition to a compressed air fog signal this station will also be equipped with 

 a submarine bell. In this connection it may be stated that while there are practically 

 no fogs at the Atlantic entrance to the canal, there are frequent and heavy rains, 

 which with the aid of a fog signal will lessen the difficulty of entering the harbor. 



Illuminants. — The illuminants will be acetylene gas and electricity, the latter 

 being used in all towers and beacons convenient to a main line, and the former to 

 all buoys and inaccessible Ughts. The candle-power. of the range lights will vary from 

 2,500 to 15,000 or more, depending upon the length of the range. The most power- 

 ful lights, visible from 12 to 18 nautical miles, will be those marking the Atlantic and 



