Journal of electricity, power, and gas . t. spans. In arriving at the proper ten-sion at which to string the messenger wire, due con-sideration was given to the ice and sleet loads thatmight obtain, and under maximum load conditions,the tension in the messenger does not exceed the elas-tric limit. The wire was strung in the field at a ten-sion of 2200 lb. at 70 deg. F. On the standard 150ft. span, the distance between trolley and messengeris 24 in. at the bracket, and 6j4 in. at the center ofthe span. Hangers are spaced 15 ft. The standard bracket arm consists of two 2y2x2x5/16 in. angles, att
Journal of electricity, power, and gas . t. spans. In arriving at the proper ten-sion at which to string the messenger wire, due con-sideration was given to the ice and sleet loads thatmight obtain, and under maximum load conditions,the tension in the messenger does not exceed the elas-tric limit. The wire was strung in the field at a ten-sion of 2200 lb. at 70 deg. F. On the standard 150ft. span, the distance between trolley and messengeris 24 in. at the bracket, and 6j4 in. at the center ofthe span. Hangers are spaced 15 ft. The standard bracket arm consists of two 2y2x2x5/16 in. angles, attached to each side of the pole,brought together at the outer end, and supported by a 5/8 in. bracket rod. All line material is galvan-ized. The feeder is carried on a plate attached to thebracket arm and is 336,534 cm. aluminum, or theequivalent of No. 4/0 copper. Mechanical sleeves ofthe Mclntyre type are used to splice the feeder. Tapsare made by means of a two bolt aluminum clamp,that takes both the feeder and a No. 4/0 copper cable,. Double Track Overhead Construction With 13,200 VoltTransmission Lines. the latter being then soldered into a standard 7 in.,4 screw, feeder trolley ear. All poles are cedar with 9 in. tops, and are set 8ft. from face of pole to center line of track. Wheretransmission lines are carried on trolley poles, theseare 45 ft. long and set seven feet in the ground; oth-erwise poles are 40 ft. long and set 6 ft. 6 in. in theground. All poles are given two thorough brushtreatments with an approved preservative from a point18 in. above the ground to within three feet of thebutt. The preservative is applied by means of burlapfastened to the ends of long mop handles, and is kepthot by steam coils placed in the bottom of the shal-low tank over which the poles are rolled. The total mileage of electrified tracks is about105, exclusive of sidings, spurs and yard tracks. Rail Bonding. All rails are single bonded with the AmericanSteel & Wire Companys pin expanded
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Keywords: ., bookauth, bookcentury1800, bookdecade1890, booksubjectelectricity
