Niagara Buffalo Transmission Line

THE NIAGARA-BUFFALO TRANSMISSION LINE.

READ BEFORE THE NATIONAL ELECTRIC LIGHT ASSOCIATION, JUNE 9, 1897, BY J. G. WHITE.

The possibilities of the utilization of the almost infinite power of the mighty cataract, whose thunders are audible from this building, has been dreamt of and written about ever since the days when the old French monks first attempted to convert the Indians living in this and more western regions. A few days ago the speaker received a letter from Mr. Silas P. Dutcher, formerly Commissioner of Public Works of the State of New York, in which he dwelt on his personal recollections of the predictions as to the useful development of this power which the elder Roebling was wont to make some 46 years ago, while erecting the first suspension bridge over Niagara River, the successful completion of which did so much toward securing recognition of American engineering ability as belonging to the world’s front rank. This letter spoke also of the fondness with which former State Engineer Evershed was accustomed to dwell on the possible development of Niagara’s tremendous and untiring energy. A most fitting and enduring tribute to this same engineer (Mr. Evershed) is to be seen in the splendid plant of the Niagara Falls Power Company, some of his fundamental ideas as to its hydraulic development having been adopted by the Cataract Construction Company. ‘This letter, written by the president of one of Brooklyn’s most influential trust companies, illustrates the fact that we are living in an utilitarian age, and that others than engineers and manufacturers of machinery are interested in such developments as have for some years been going on in this neighborhood.

The character of this work, as exemplified in the power-house, switchboard and other details of the plant of the Niagara Falls Power Company, is such as to deserve the thanks of this association and all others interested in electrical development, on the ground that such working exhibits of high grade installations have a tendency to raise the standard of all future work.

The poetic, imaginative and prophetic features of a transmission line from Niagara Falls to Buffalo and more distant points have been thoroughly amplified and beautifully expressed, not only by such famous engineers as above mentioned, but more recently by such eminent men in our profession as Dr. Sellers, Mr. S. Dana Greene, Mr. T. C. Martin in his lecture, ‘‘Niagara on Tap,” as well as by numerous members of the technical and general press. These features will doubtless be most aptly illustrated both in metaphor and on canvas, by the eminent electrical engineer of the Cataract Construction Company, in his lecture this evening, so that no attempt whatsoever has been made in collating this hasty sketch to accomplish the impossible task of vying with those gentlemen, even in a small way, by the slightest attempt at the imaginative.

My first personal knowledge as to the then proposed transmission line between Niagara Falls and Buffalo dates from the Autumn of 1894, when the White-Crosby Company was asked to prepare and submit detailed plans, specifications and proposal for its construction. It was then found that the engineers of the Westinghouse and General Electric companies had both recommended the construction of circuits of three wires, adapted to the three-phase system, each wire having an area of about 330,000 circular mils. Beyond this no definite plans had then been determined on. The engineers of the Cataract Construction Company at that time considered it advisable to have the line built entirely of iron poles, and, accordingly, detailed drawings and specifications were prepared and submitted, showing alternative plans. The first included two entirely independent lines of iron poles not less than 40 feet long, weighing something over 2,000 pounds each. The second consisted of lines of poles of about the same height, weighing about 1,000 pounds each, set in pairs and tied together by deep trusses, which served both as braces against the terrific wind storms which sometimes sweep across Lake Erie, and as a means of carrying part of the wires. A steel truss, fulfilling admirably this double function, was designed, which weighed about 600 pounds, the company’s right of way being 30 feet wide, and the lines of poles located 15 feet between centers. Several wooden trusses were designed for the same purpose, but, while better from an electrical standpoint, these were all so clumsy in comparison to the iron poles that preference was given to the steel truss. Various designs of poles were considered, including several built up from ‘‘rolled shapes,” final preference being given to plain tubular poles, on account of their ability to withstand equally strains from all directions, their appearance and the ease with which they can be kept painted.

Numerous designs for cross-arms were also considered, including those made from “rolled shapes,” composite arms (part wood and part steel) and those made entirely of cast-iron or of wood. The latter two were preferred, on account of the ease with which they could be designed to accommodate either wood or iron pins.

In determining the details for these alternative plans it was assumed that poles would be set in concrete and spaced 100 feet apart; that each wire would weigh one pound per lineal foot ; that the three wires composing each circuit were to be placed at the corners of an equilateral triangle having sides at least three feet long, and that the lateral strength of the line was to be not less than three times the forces produced by wind acting with a pressure at right angles with the direction of the lines, equal to 30 pounds per square foot on the projected surface of the poles, arms, insulators and wires, when the latter were covered with a coating of ice one-half inch thick.

As a matter of fact the heat generated by the current passing through the wires, together with the static effect tending to repel all particles of moisture coming in contact with the wires, this effect being quite noticeable on a 10,000-volt line, would combine to prevent the formation of any such coat of ice, unless at a time when current was off the line.

Any error thus introduced was on the safe side, and consequently not objectionable.

Full proposals with detailed plans and specifications for the construction above outlined were submitted October 11, 1894, and an amended proposition for carrying out the construction on the same general lines was submitted March 13, 1895. Nothing further developed in the matter until June, 1896, when new proposals were asked for the construction of the line on the assumption that white cedar, instead of iron poles, would be used throughout. Such proposal was submitted June 18 and accepted some days later.

In working out the details of the line as built, the same general assumed data above given were used.

When the route for the line was finally determined on, its length was found to exceed 27 miles, instead of being 25 miles, as previously assumed, and consequently the area of the wire was increased from 330,000 to 350,000 circular mils. The wire actually erected is composed of 19 strands, having a combined area of full 350,000 circular mils, and weighs nearly 6,000 pounds per mile.

In designing a transmission line the three most important factors probably are:

1. Its ability to carry its full load continuously and without interruption.

2. Cost.

3. Efficiency.

The first cost of power used to develop current for a transmission line is usually low, wherefore the efficiency of the line is not of primary, although of great, importance.

Those of us familiar with the development of the street railway motors have seen in practice an illustration of the fact that efficiency is not always a controlling factor. There has, probably, never been in general use another street railway motor so efficient as the Sprague No. 6, yet a distinct advance was made in sacrificing efficiency to mechanical strength and in subjecting track joints to what, at first, appeared to be an unnecessary, and certainly to be deprecated, wear and tear, in order to decrease the interruption to traffic.

(To be continued.)