. Electrical world. igh, towering above a turbulent river at the more than paper engineering is demanded in the solu-tion. Nothing short of a careful investigation on the ground is likelyto be of much use. In open country the simplest way to prevent contacts of powerand signalling circuits is, of course, to run the two lines sufficientlyfar apart so that if either one falls down it will in all cases clearthe other. Such lines should not approach one another nearer thanthe distance equal to the height of the taller pole line. Telephoneand telegraph wires should be kept off the
. Electrical world. igh, towering above a turbulent river at the more than paper engineering is demanded in the solu-tion. Nothing short of a careful investigation on the ground is likelyto be of much use. In open country the simplest way to prevent contacts of powerand signalling circuits is, of course, to run the two lines sufficientlyfar apart so that if either one falls down it will in all cases clearthe other. Such lines should not approach one another nearer thanthe distance equal to the height of the taller pole line. Telephoneand telegraph wires should be kept off the cross arms or poles of thepower line, excepting the private signalling circuits of the powercompany. Even these open up the possibility of serious shock, anoisy private telephone line and the burning out of buildings if theconstruction is not maintained in excellent condition, and it is anopen question if such circuits are not better off on a pole line oftheir own. Whenever high-tension and signalling lines approach. FIG. I.—TELEPHONE WIRES UNDER HIGH-POTENTIAL WIRES. one another nearer than the height of the taller poles, the damagemay be reduced by bracing or guying the poles of the taller linewith extra care. When it is absolutely necessary to carry signallinglines on the same poles with power circuits, extra precautions shouldbe taken to reduce the liability of a break-down to a minimum, suchas the use of wires of ample mechanical strength, widely spacedcross arms, short spans, double or extra heavy cross arms, extraheavy pins, insulators and poles carefully supported. The high-potential wires should be at least three feet above the telephone ortelegraph line. At times it becomes necessary for high-potential and signallingcircuits to pass over or under one another en route. Extraordinaryprecautions are necessary to prevent crosses in such cases. Thepoles supporting the cross over span should be specially selected,braced and guyed, and the wires of the crossover span shoul
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectelectri, bookyear1883
