Discussion on “some power transmission economics”, at Niagara Falls, N. Y., June 28, 1907

This paper describes a construction suitable for power transmission where the utmost reliability is not necessary, but where cheapness is needed to make the installation feasible. It is desirable in all such discussions to give some clue of what is understood by “reliable” or “satisfactory” operation. In listening to statements of satisfactory operation of transmission lines, it will be found that “satisfactory operation” is a flexible expression; for what may seem to one engineer under certain conditions as satisfactory, may to another engineer, seem very unsatisfactory. For instance, the chief engineer of a large city told me a few days ago that in his city the power has not been off the low-tension bus-bar in fifteen years. In such a case a number of shutdowns averaging one shutdown per year, of five minutes or less duration, would be unsatisfactory operation; because if it should happen there probably would immediately be a legislative committee to investigate why it happened that some thousands of citizens were caught by the failure of the power in elevators midway between the floors of office buildings. In another instance, in a transmission line supplying power to a mining district, it may be perfectly satisfactory operation if the number of shutdowns averages not more than two per month, with perhaps a total duration of an average of twenty minutes per month. That may be perfectly satisfactory in that case.