POLE-LINE CONSTRUCTION 



63 



span. The sag in the wire at the time it is made fast to the brackets should corre- 

 spond to the temperature at that time. 



TABLE D SAG OF A No. 9 B. W. G. GALVANIZED-IRON WIRE IN A POLE LINE 



NOTK. If a strong wind is blowing, the sag value should be increased. Interpolate for temperatures 

 and spans not given. When any other size than a No. 9 B. W. G. wire is used, it will be necessary to com- 

 pute the sag required. Instructions for doing this will be furnished by the district inspector. 



Sag may be handled in the following manner: After a half-mile reel of wire has 

 been pulled out, linemen, who follow, carry the wire up each pole 011 their shoulders 

 and place it between the bracket and the pole. When this has been done over the entire 

 half mile, the line is stretched by means of a Buffalo grip and stretcher-block until it 

 is taut, or until the two or three linemen who are on the poles along the half-mile 

 stretch pass along the signal to stop. About two minutes' rest is then required for 

 the line wire to " creep " along the entire distance. It should then be loosened or 

 stretched tighter, according to the signals of the men on the poles, who can sight from 

 the bracket of one pole to the brackets of the adjacent poles and determine when the 

 proper amount of slack has been provided, 



7 TYING IN WIRE 



On straight lines the wire should be tied to the inside of the insulator, so as to 

 bring it between the insulator and the pole. On curves and corners the wire should be 

 tied to the insulator on the outside, so that the strain will be against the bracket and 

 the pole. 



On pole-line construction the tie wire (the wire used to fasten the main line to 

 the insulator) should be of the same size as the line wire. The method of tying wire 

 to a glass insulator is shown in Fig. 22. 



In making the tie great care should be exercised to avoid twisting the wire so 

 tightly that the main line will be burned. 



Linemen should be cautioned against nicking the line wire in making ties, 

 especially when this is hard-drawn copper. The latter should always be tied by hand. 

 Pliers, connectors 1 , or other tools should be used only with iron wire. Linemen should 

 also be cautioned against leaving the endte of the tie wire protruding, lest through 

 twisting of the pole a contact be made. 



(a) Tying galvanized-iron wire. There are two methods of tying galvanized-iroii 

 wire. The regular tie (Fig. 22) should be used on all poles except where there are 

 sharp dips or changes in level in the line .wire, or in crossing railway rights of way, 

 or on spans from 250 to 500 ft. in which cases the " figure 8 " should be used (Fig. 23). 



