Electrical news and engineering . Water & Power Co. The writer has recently had occasion to make some obser-xations on a transmission line span which has some unusualfeatures. This span is 435 feet between supports and iscomposed of six 500,000 circular mil aluminum conductors,two per phase. The conductors are spaced horizontally onefoot between the two conductors of each phase and five feetbetween the conductors of difYerent phases. The circuit of which this span is a part, is kvv. at 6,600 volts, with a current per phase of ap-l)roximately 1,G00 amps. The magnetic flux se
Electrical news and engineering . Water & Power Co. The writer has recently had occasion to make some obser-xations on a transmission line span which has some unusualfeatures. This span is 435 feet between supports and iscomposed of six 500,000 circular mil aluminum conductors,two per phase. The conductors are spaced horizontally onefoot between the two conductors of each phase and five feetbetween the conductors of difYerent phases. The circuit of which this span is a part, is kvv. at 6,600 volts, with a current per phase of ap-l)roximately 1,G00 amps. The magnetic flux set up by thiscurrent draws the two conductors of each phaze together inthe central part of the span as can be observed in thephotographs. This results in a sort of truss arrangementof the two conductors, which has a marked eflfect in cuttingdown oscillation caused by wind. When the power is offthe line and the conductors fall apart, the oscillation is erraticand of magnitude, if there is. a stiff breeze blow-. The two conductors of each phase are drawn togethering. However, with power on the line, the oscillation isnot only greatly reduced but the period of oscillation is con-siderably extended. The accompanying view from a timeexposure made on a fairly windy day will give an idea ofthe steadying eflfect of the truss arrangement of the con-ductors. It is possible that in certain cases it would be desirableto construct long spans in this truss form in order to securestability. A convenient arrangement would be to clamp thetwo conductors together at the middle of the span and alsoconnect them by a jumper near each end. THK tiLRrtRiCAi. ^
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