52 METHODS OF COMMUNICATION FOR FOREST PROTECTION 



(a) Pole-steps. Steps should be used on all poles over 35 ft. high or to which 

 telephone apparatus, such as switch -boxes and test-stations, are attached. The steps 

 are of galvanized iron, 1% in. by 9 in. They should be driven alternately into the 

 opposite sides of the pole, parallel to the direction of the line, and spaced 18' in. on 

 centres. The line of the steps 1 should be parallel to the centre of inc.- poles. 



(ty Glass insulators. Glass insulators of the kind ki^own as "regular pony 

 long-distance type", weighing approximately 14 ounces each and conforming to the 

 specifications given in Appendix E, should be used on ail lines built of No. 9 wire 

 when strung on poles. No. 9 pony glass insulators may be used for all lines built of 

 No. 12 wire strung on poles. 



(c) Brackets. On a one-wire line the brackets should be placed on the same side 

 of all poles, except that at corners or curves they should be on the side of the poles 

 away from the centre of the curve, so that the line wire will pull them against the 

 poles. Brackets should be nailed to the poles with one 6-in. and one 4-in. galvanized- 

 iron wire nail. For one-wire lines the top bracket position will be used. It is not 

 necessary to shave the pole at the place where the bracket is attached. 



On straight sections of a two-wire line the brackets should be on opposite sides 

 of the poles, but on curves both brackets should be on the side of the pole away from 

 the centre of the curve (Fig. 10). 



As an additional safeguard whenever a line crosses the tracks of a railway, two 

 brackets with insulators placed 1 side by side should be .used on the first pole on each 

 side of the track. Where a line is attached to a large pole at a sharp corner two 

 brackets slightly separated will be used, in order to keep the line wire clear from the 

 pole. 



(d) Lightning-rods. Lightning-rods should be placed on poles before they are 

 set. In ordinary situations a rod should be placed on every tenth pole. 



In exposed, mountainous regions, or where the line crosses mountain ranges or 

 divides, a rod should be placed on every fifth pole. It should be the same kind of 

 wire as the line and long enough to reach from 6 in. above the top of the pole to 

 about 3 ft. below the bottom. The upper end of the wire should be bent back about 3 

 in. from the end and given several turns about itself; the lower end should be made 

 into a small coil of three or four turns, 5 or 6 in. across, at the bottom of (not round) 

 the pole. The rod should then be attached to the pole with 2 in. staples at intervals 

 of 3 ft. at a point one-fourth the distance around the pole from the bracket, running 

 in a straight line to the ground, the upper end 1 projecting about 3 in. above the ridge 

 of the pale. The wire coiled at the bottom should be bent into place or stapled at the 

 bottom of the pole so that the latter, when set, will rest on the coi-ls. 



After the pole is set and the line wire attached, an inspection should be made to 

 make sure that there is no contact between the lightning-rod wire and the line wire. 



Lightning-rods are not necessary in tree-line construction. 



5 SETTING POLES 



On straight sections poles should be set vertically. 



Ori curves or at corners the poles should be placed so that they will incline 

 outward from the centre of the curve. (Fig. 11). 



When the pull is less than 5 ft., the rake should be about 10 in. (Fig. 11) ; with 

 a pull of from 5 to 10 ft. 15 in. ; and with more than 10 ft., about 25 in. These figures 

 apply to the top of the pole after it has been set and before the line wire is attached. 

 Warped or crooked poles should be set so that the crookedness will offset the pull of 

 the line wire at the ends of long spans or on curves or corners. No attention need 

 be paid to the possibility of the line wire changing the amount of rake. Thes>? speci- 

 fications are approximate and may be exceeded without harm. Rake is sorietimes 

 necessary even though the pole is braced or guyed. 



