2824 HYDROGRAPHIC MANUAL PagE 16 



side from the anchor cable, the rope sling also serves to indicate the direction of the current as the 

 ship approaches the anchored buoy. 



(B) LIST OF MATERIALS FOR ONE-BARREL BUOY 



Amaant 

 Description Size required 



Lumber (see 281).. 2" by 4" by 16' 5 pieces. 



Do.... 2" by 4" by 10' 1 each. 



Do l"by 4" by 16' 4 pieces. 



Barrel, G. I. ._ 55 gallon 1 each. 



Car coupler (scrap) 180 to 200 pounds 1 each. 



Eyebolt with shoulder and nut, G. I ?4" by 5" _ 1 each. 



Bolts ^"by7" 3 each. 



Rods, tie, threaded on both ends H" by 32" 2 each. 



Nuts, hexagonal H" - Teach. 



Washers... IH" by ^-ie" (^Ae" hole) 7 each. 



Washers 2J4" by Me" C^'ie" hole) 2 each. 



Washer plates, iron _ 3" by 10" by H" drilled 2 each. 



Counterweight plate, iron 3" by 15" by ^" drilled 1 each. 



Shackle, G. I H" 1 each. 



Screen, wire, black. medium mesh, 1 yard wide 2 yards. 



Cloth, muslin, various colors '. 1 yard wide 2 yards. 



Rope, Manila 3" 15 feet. 



Nails 12 d. and 20 d. 



Tacks carpet. 



Standard enameled buoy plate or muslin signal notice 1 each. 



(C) METHOD OF CONSTRUCTION, ONE-BARREL BUOY 



The one-barrel buoy is designed so that it may be built on board ship, including the special parts 

 required; washer plates, counterweight plate, and threaded rods. 



A clear deck space approximately 35 feet long is needed, and two sawhorses, or boxes, are required 

 to support the buoy frame while it is being built. 



The first step in the construction of the buoy is to prepare the two vertical frame members, each 

 of which is made of two 16-foot pieces of 2- by 4-inch lumber. Each pair is spiked together with a 

 5- or 6-foot overlap, so that the overlapped length will extend 12 to 18 inches above and below the 

 barrel when the frame is attached. The two pieces of lumber must be in alinement when they are 

 nailed together in order to obtain a symmetrical construction. Two ^ie-inch holes are drilled through 

 the overlapped portion of each frame member through which to insert the two tie rods, one just 

 above and one just below the barrel which is placed between and with its axis parallel to the frame 

 members. 



On the sawhorses, with the barrel between the two vertical members, the two tie rods are inserted 

 with washers and nuts on both ends and the nuts are drawn tight to hold the barrel firmly in the center 

 of the frame. Two wooden cross braces of 1- by 4-inch lumber, grooved to fit over the chimes of the 

 barrel, are next nailed between the vertical members, two at the top and two at the bottom of the 

 barrel. These serve to hold the barrel in place and prevent it from slipping out. 



The upper and lower ends of the projecting vertical members are next drawn together by long 

 wood clamps. This must be done carefully so that their junctions are on the centerline of the frame. 

 The lower ends are sawed off evenly and two ^le-inch holes are bored through them to correspond to 

 the holes in the washer plates. The washer plates are placed outside and the counterweight plate 

 between the vertical members and the bolts- are inserted and drawn tight. The upper ends of the 

 vertical members are trimmed to equal length and beveled to fit the mast which is placed between 

 them. A ^le-inch hole is bored through the three pieces of lumber at this point and a bolt inserted 

 and drawn tight. 



The clamps may now be removed and horizontal cross braces of 1- by 4-inch lumber are nailed 

 on both sides of the frame 5 feet above its bottom and 4 feet below its top. Crossed diagonal braces, 

 one brace on each side, of 1- by 4-inch lumber are nailed on the upper and lower parts of the frame 

 between the horizontal cross braces and the barrel. The upper diagonal braces are also nailed to the 

 mast which is stepped on the top of the barrel and nailed to the cross braces previously placed there. 



The eyebolt is inserted through a ^^le-inch hole bored through one of the vertical members of 



