Details of the Niagara Falls-Buffalo Transmission Line

THE NIAGARA-BUFFALO TRANSMISSION LINE By J. G. White of the J. G. White and Company, New York

Members of the National Electric Light Association and Its Guests, Ladies and Gentlemen:

Before taking up the subject of this paper as given on the programme of this meeting, I crave your attention to a few words of apology, or, more properly speaking, of explanation. Some weeks ago, I notified the president and secretary of your association that it would be impossible for me to comply with their courteous request to prepare a paper on the Niagara-Buffalo Transmission Line, for several rea sons, principal among which were the facts that, up to date, no measurements had been made to deter mine the exact capacity, induction , power factor, efficiency, or other similar attributes of the line, and that I was so occupied with an unprecedented amount of work in connection with my regular duties as to make it impracticable to find time to arrange in presentable form even the few facts obtainable with reference to this line. You can readily imagine my surprise, therefore, upon receiving the programme of this meeting a few days since, to see that the mere fact that there was nothing to say on this subject, deserving the attention of this association, had been disregarded in making up the schedule of these sessions. Under these circumstances, the blame for occupying the time of this meeting with facts too well known and too dry to deserve its attention, must attach to your officers.

The possibilities of the utilization of the almost infinite power of the mighty cataract whose thunders are audible from this building, has been dreamed 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, I 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 forty-six 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 upon 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 a 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 of 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 those above mentioned, but 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 whatever has been made in collating this hasty sketch to accomplish the impossible task of vying with these 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 proposals 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 upon. The engineers of the Cataract Construction Company at that time considered it advisable to have the line built entirely of iron poles, and detailed drawings and specifications were accordingly prepared and submitted, showing alternative plans. The first included two entirely independent lines of iron poles, not less than forty feet long, weighing something over 2,000 pounds each. The second consisted of lines of poles of about the same height, weighing 1,000 pounds each, set in pairs and tied together by deep trusses, which served both as braces against the terrific wind storms that 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 about thirty feet wide, and the lines of poles located fifteen 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 with 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 rains 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 one hundred feet apart; that each wire would weigh one pound per linear 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 thirty 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 sub mitted October 11th, 1894, and the amended proposition for carrying out the construction on the same general lines was submitted March 13th, 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 should be used throughout. Such proposal was submitted June 18th, and was 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 upon, its length was found to exceed twenty-seven miles, instead of being twenty-five miles as previously assumed, and the area of the wire was consequently increased from 330,000 to 350,000 circular mils. The wire actually erected is composed of nineteen 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:

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

2d. Cost.

3d. Efficiency.

The first cost of power used to develop current for a transmission line is usually low; therefore 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 Number Six, 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.

First cost, within reasonable limits, should always be considered secondary to good construction, so that you will probably concur in awarding first place, as a factor in problems of this nature, to the avoiding of interruptions. This is surely of primary importance in lighting work, and it is easy to conceive of circumstances where the unexpected shutting-off of power might have more serious, or, possibly, more fatal, results than could ever arise from sudden deprivation of light. Entering into this problem of sure and continuous operation, we have the same two factors entering that usually confront us in connection with any electrical installation ; namely, insulation and mechanical strength. In low-tension plants of all kinds, the insulation is usually accomplished with ease, and any probable defects are likely to be of minor importance, but, on such a line as that under discussion, the importance of these two factors is practically equal, and they are mutually interdependent. This has been practically illustrated by the experience afforded by the present line. With units of an ordinary size, a short circuit on a line carrying 10,000 volts, even if through a defective insulator, a wooden cross arm and a wooden pole, would make itself manifest at the power station by the opening of a circuit breaker, the blowing of a fuse, or some similar method. With the huge generators that furnish power for the line, the effects are different. Of what importance to a 5,000-horse-power dynamo is the current that would leak down a wooden pole, even when wet? Nevertheless, this same current is sufficient to char or burn the pin under a defective insulator. During one night last fall, while an attempt was being made to operate the line on temporary insulators, the best obtainable at the time-the ends of no less than five of the large cross arms used on this line were burned entirely off, and this, too, without any manifestation having been made at the station that anything unusual had occurred. This naturally raises the questions whether it is possible to procure insulators that can be depended upon to maintain the insulation on a circuit carrying 10,000 volts or over, and whether it is not good practice to have fewer poles, and, consequently, fewer weak spots in the form of insulators. There are two sides to this question, and both deserve serious consideration in designing any transmission line. Let us assume that poles are set one hundred feet apart, and allow a sag in wires between supports of twenty inches, or one-sixtieth of the length of the span. We find that the area of the wire in use on this line is .267 of one square inch, and that its tensile strength, even assuming a high value for soft copper, is about 10,000 pounds. Allowing the same deflection, --one-sixtieth of the length of the span--this determines the maximum safe distance between poles as 178 feet, allowing a factor of safety of four, and shows that the cables might be expected to break if the span were lengthened to 712 feet, not allowing for wind pressure or extra load due to ice.

Assuming a tensile strength of 8,000 pounds per square inch for yellow pine, we find that the larger cross arms used on the line, which are twelve feet long and nearly five inches wide by six inches high, would support a load of 270 pounds on each end without bracing, and of 360 pounds on each end with the steel angle braces used, and this, too, with a factor of safety of ten--an unnecessary margin, when we consider that the arms are all specially selected heart, long-leaf Georgia pine. Similarly, these cross arms would have the same factor of safety carrying three power cables on each side with spans 177 feet long if without braces, and 266 feet long with braces. Besides giving this added strength, the braces used on this line prevent such vibration and oscillation as usually take place with the ordinary strap iron braces; such oscillation being the cause of many of the petty troubles on ordinary lines. These braces were each made from a single piece of steel angle, two and one half inches by two inches by one-fourth inch, bent to shape and forming, when finished, a truss eighteen inches deep and five feet in extreme length, their weight being a little over twenty pounds each. Assuming again, that poles are set one hundred feet apart, we find that twelve wires, with cross arms, insulators, etc., would present an area to the wind aggregating about sixty-seven square feet, and that, consequently, each pole would be subjected to a side strain, when wind pressure was thirty pounds per square foot, of about 2,010 pounds. A sound fifty-foot cedar pole, eight inches diameter at top and eighteen inches diameter at butt, eight feet being rigidly in the ground, would be capable of withstanding, before breaking, a side pressure, near its top, of only about 4,900 pounds when a layer two inches thick had decayed around its circumference.

With spans of one hundred feet, the pole would therefore have a factor of safety of only about two and one-half inches when new, while the wires would have a factor of safety of about seven and the cross arms of about twenty-six. The advantages of having cross arms amply strong are so evident, and the possible reduction in cost such an insignificant part of any ordinary line carrying much copper, that it would seem foolish to reduce the size of these in order to bring their strength down to correspond with other parts of the line.

It is evident from the above that the weakest point of this line, mechanically, is the pole, in spite of the fact that, as advised by one of the prominent members of your executive committee, final decision was made in favor of spacing the poles seventy-five feet apart on straight, and proportionately closer on curved, parts of the route. The only reasonably safe and practicable method of decreasing the number of weak spots furnished by the insulators, would be to use poles larger than eight-inch tops, or to brace the poles to withstand this wind strain . Fifty-foot poles, having tops greater than eight inches, are now hard to find, and although thirty-five-foot poles were used on a part of the company's private right of way, nevertheless, many fifty-foot, and even a few sixty-five foot, poles were required to avoid obstructions and for crossing railroads and highways. The only feasible plan, therefore, would seem to be to brace the poles laterally, which can readily be done if set in pairs, but which would be very difficult to accomplish in a satisfactory manner with a single line. This naturally brings us back to the question, "Are insulators such insurmountably weak links in such a chain, and is it not possible to get insulators that can be depended upon even when supporting wires under a pressure of 10,000 volts?" This can be most satisfactorily answered by again narrating the experience with this line. During the past eight months, insulators have been sent to Niagara Falls by four of the works which are among the first six in this country in the production of porcelain for electrical use. Of a sample lot of ten received a few days ago for test from one of these factories, one had broken in transit, eight broke under the strain of electrical pressure varying from 16,000 to 36,000 volts, and the last broke under 40,000 volts' strain. This latter would seem to be a minimum safe test limit for any insulator expected to sustain a regular strain of 10,000 volts, and is a test that any mechanically-good, well-vitrified insulator of ordinary design will pass. As several previous lots from the same factory showed even poorer results, the manager of that company states that he hopes within a few weeks to be able to furnish insulators that will stand a 40,000-volt test. It is only fair to state that these insulators were of a smaller type than, and different design from, those in use in the Niagara line. Several lots of somewhat similar insulators from another factory gave about the same results.

Several thousand insulators, of a diameter almost equal to the round type now on the line, but of a design somewhat different in details, were furnished by a third porcelain works. These were all supposed to have been tested, and to have successfully withstood a pressure of 40,000 volts at the factory before shipment. When, however, these were tested at Niagara Falls by Mr. Lincoln, the electrical superintendent of. the Cataract Construction Company, it was found that a large majority of them broke down under a 40,000, volt test, illustrating that a dry test, such as had previously been made, is useless for practical purposes. The method of test used at Niagara Falls was as follows: The insulators were set inverted in a shallow iron pan in lots of about twenty, the bottom of the pan being covered with an inch or two of water containing a little salt. A little of the same brine was poured into the pin-hole of each insulator, and into this was thrust a small piece of metal, such as an ordinary iron spike or the small, round, zinc rod from an ordinary sal-ammoniac battery, this being connected to one side of the testing circuit, the other side being connected to the pan containing the insulators. After the metal rod had been placed in the brine in the pin-hole of an insulator, the primary circuit of the testing transformer, specially built for the purpose, was closed, and, if the insulator was weak, this was quickly manifested by a series of sparks through the punctured porcelain. Experiments made with pure water and with brine showed that there was no difference in the results, but that any weakness was manifested a little more quickly with brine; besides which, the salt imparted the characteristic bright sodium color to sparks otherwise almost colorless and difficult to detect use.

As it was important that the line should be ready to deliver current by a specified date, the test was reduced on these insulators to 20,000 volts, and all that withstood this pressure were passed for temporary use. These insulators were later replaced by some of those now on the line, all of which successfully passed a 40,000-volt test made as above described. The temporary insulators illustrated the old saying that every rule has its exception, for when, after removal from the line, they were tested under 40,000-volt pressure, a solitary insulator, from a total of 1,150, was able to pass muster.

Of the insulators shipped by the fourth factory, and of the two types now on the line, about twenty five to forty per cent were usually found to be defective, breaking down under 40,000 volts ; this percentage decreasing in the last shipments received. It is, however, worthy of special note that since the last of the temporary insulators were removed from the line, there has not been one minute's suspension of current supply due to defective insulators. During this time, some three or four months, three insulators have been replaced, none of these being of the oval type. Two of these three had been broken while being put in place, and the third was broken by a stone or other missile. In all three cases, only the outer petti coat was broken, and the insulator continued to do satisfactory service until such time as it could be replaced without affecting the operation of the line. Apparently, therefore, it has been demonstrated that it is possible to secure insulators that are reliable. That there have been no greater troubles in the past from defective insulators, is probably due to the fact that most of the large transmission plants in operation under high voltage, up to within a few months, have been in the far West, where a climate prevails very different from that natural to this immediate region.

In the above and other experiments with insulators, some interesting facts have been developed, and are worthy of note. The insulating strength of porcelain depends almost entirely on the thoroughness of its vitrification, and very little on its thickness; a thin china teacup having successfully withstood a pressure of 60,000 volts, while a coarse piece of porcelain two inches thick was readily pierced by 25,000 volts. It is, therefore, practically unnecessary to test electrically any insulator which, when broken, will not pass a good absorption test, using red ink or other fluid.

It is quite, if not entirely, impossible to puncture a glass insulator, even an ordinary pony telegraph insulator withstanding any pressure that can be applied, the last being determined by the pressure that will send an arc around the insulator. The objection to using glass insulators in the past has been due to the difficulty in getting a well annealed and mechanically strong insulator of such massive design as is needed for this work, and to the hydroscopic property of glass, which is not shared by porcelain. The first can unquestionably be overcome by care in manufacture. The importance of the second has probably been exaggerated in most calculations made in the past, due to an inadequate appreciation of the static effects of 10,000 volts in warding off snow-flakes and drops of rain, and, to a less extent, of the rapidity with which water falling on such insulators is evaporated by the heat of the current leaking over the surface. It is, consequently, reasonable to expect that the use of glass insulators for high-voltage lines will greatly increase with improved manufacture. Meantime, any lines erected should have the best obtainable porcelain, and every insulator should be subjected to test.

Before closing, it is natural to ask, "Is the line as built a genuine success? Can it be depended on, and is it effective?" In answering, let me give briefly some of the facts. The line now in operation is over twenty-six miles long, of which the last 4,000 feet is under ground, the current being carried in lead-covered cables with rubber insulation , these having been drawn into terra-cotta duct conduit built especially as part of this line. These cables successfully withstood a test of 40,000 volts, are guaranteed for five years. under working pressure up to 25,000 volts, and were punctured during test only by a pressure estimated by Mr. Lincoln as about 80,000 volts. They have given no trouble since current was first turned on the line, November 15th last, except at two imperfectly made joints. Except for the short time needed to repair one of these joints, there has not been a single shut down chargeable to the transmission line itself since. the last temporary insulators were removed, some three or four months ago. A number of interruptions to service have occurred during that time, due to derricks used on the work now being done on the Erie Canal hitting wires, undermining of poles and conduit by this work, and to allow new lightning arresters to be put in circuit at transformer houses. Except for these extraneous and unusual causes, the service has been perfect, with the slight exception noted above. One short interruption early last winter was due to the dead limb of a tree blowing across the wires, illustrating the fact that all trees should be cut down for some considerable distance on both sides of any high-voltage line. The line shows an insulation resistance of some 250,000 to 300,000 ohms on wet, and about 1,000,000 ohms on dry, days, this being between any one of the three wires and the ground, the insulation, therefore, varying from 6,000,000 to 25,000,000 ohms per mile of wire.

The actual working efficiency, as shown by the wattmeters in the low-tension alternating circuits at Niagara, and the direct- current 500-volt circuit at Buffalo, was 79.6 per cent, this being for a consider able period and a fluctuating load. This efficiency included loss in step-up transformers, line, step-down and rotary transformers. It is probable that any decrease in this, due to greater line loss with larger load, would, to a considerable extent, at least, be offset by increased efficiency of transformers. In view of these figures, we hope you will feel warranted in indorsing the opinion that Niagara power is now being satisfactorily delivered in Buffalo. One of the questions often asked is why this entire line was not placed under ground.

One of the principal reasons was that the line of twelve wires, having a capacity of 20,000 horse-power, would cost, irrespective of right of way, fully one million and a quarter of dollars, if under ground, and only about one-third of that amount over head, making a difference in interest charge.

Of such total costs, about twenty per cent would cover cost of conduit, complete, including manholes, the remaining eighty per cent being lead-covered cables.

Of the overhead construction cost, slightly over eighty per cent is bare copper wire; less than ten per cent covers poles set in place and about three per cent covers insulators.

It is probable, therefore, that the depreciation of the lead-covered cables will greatly exceed that on pole line, the first cost being some thirty times as great and the depreciation of the bare copper being negligible. Aside from this, experience to date has not demonstrated that the underground line would be more reliable, which alone could justify the increased depreciation and interest charge.

As a final deduction, it seems reasonably certain that it is now possible to build either overhead or underground transmission lines-even in regions subject to much cold, damp weather-capable of carrying current at 10,000 volts, or higher, pressure, which can be operated with efficiency and every assurance of uninterrupted service.

DISCUSSION

THE PRESIDENT: Gentlemen, this paper is now open for discussion.

MR. SEELY: I should like to ask Mr. White whether it is necessary to shut off the current when they replace their insulators?

MR. WHITE: Some insulators have been changed without shutting down, and it is quite practicable to do that where the wire has not been tied in. Where it has been tied in, unless on a very dry day, I would rather somebody else should attempt to replace the insulators with the current on. But I know of other 10,000-volt lines where it is done, and by having a large stool, mounted on four porcelain insulators, on which a ladder can be placed , it will be entirely possible for a man to get up to the line and replace the insulator. The only trouble about it is that with 10,000 volts the capacity of a man is sufficient to absorb considerable spark, and if the man were nervous he might get shock enough to knock him off the ladder, so it is not a pleasant task ; but it is entirely possible of accomplishment. We did replace a number of insulators where the wire had not been tied, by lifting the wire on the top of another insulator which was mounted on a long stick, and then replacing the insulator and letting the wire come back into place. In actual construction, the wire, as you probably know, was not placed at the corners of a triangle, but the line was divided into six sections, and at five points the three wires were given a twist, so that for two of the six sections each of the three wires occupied relatively the position of one, two and three, and this counteracts to a considerable extent the induction that would otherwise be exerted.

MR. BEAN : I understood, Mr. White, that it was necessary to cut the trees for a certain distance on each side of the line.

MR. WHITE: Yes; I should say that, under all circumstances where it is possible, unless the right of way cost too much or is too expensive, it ought to be done, so that no falling trees can reach the line. Of course, that would make it , absolutely safe. But from that limit, what is feasible would be determined largely by the cost of getting the right to cut down trees, and would be advisable, certainly thirty or forty feet on each side, and more if possible.

MR. SEELY: I presume time alone will demonstrate the efficiency of the 30,000 or 40,000- volt tests applied to the insulators ?

MR. WHITE: Yes ; of course there are no data as to that. But the mere fact that not a single insulator has broken down during this time, is pretty good evidence. With the other insulators which were put up temporarily, the depreciation on the line was quite rapid, as mentioned in the paper. We used to have cross arms burn off quite frequently, and that came from the fact that, although these insulators had stood the 20,000-volt test, and there were only 10,000 on the line, yet enough rain would strike them to gradually moisten the porcelain, and, of course, as they absorbed this moisture, the insulating properties would drop down to so small a value that they allowed the current to go through until it burned off the cross arms with the arc that would form. That, of course, would break the contact, and the arc would stop of its own free will. In regard to these two insulators, I might say that the probable cause why this one (indicating) has stood more than the other, is that it is a little stronger mechanically, and the three breaks were all due to some mechanical trouble, and it is probable that the difference is due only to that mechanical strength. The advantage that those have carrying the rain over and letting it drop down to the side of the cross arm is perhaps of some value, although not as yet demonstrated to be of any great importance. The only place where we have had any illustration of an advantage that it might be, was where a tie wire, after being twisted around the insulator, was carried down toward the cross arm, and the arm was burned by the current starting, following a drop of rain from the end of the tie wire to the arm, and thus burning the arm, and for that reason it might be better to have the rain carried off to the end, and then it will drop clear of the arm to the ground. But probably that is not of any great importance.

MR. DOHERTY : I should like to ask Mr. White how many lightning arresters they distribute.

MR. WHITE: The lightning arrester problem is still in process of being solved, and it is largely in the experimental stage. There are very few of them on the line. We protected the line from lightning as much as we could by running two barbed fence wires on top of the poles, one carried on the outer cross arm by an iron pin eighteen inches long and one inch in diameter, which went through the cross arm, and had a little fork at the top supporting the barbed fence wire ; a second, similar wire was carried on the peak of the pole, the poles all being roofed, and a third is intended to be put up on the other side of the cross arm when additional wires are put up. Every fifth pole, these barbed fence wires are grounded with a number six copper wire running to the bottom of the pole and being coiled there, so that we can expect discharges to be carried off by these numerous points without accumulating sufficiently to give a lightning stroke. But the lightning arresters themselves are placed only at the transformer houses up to date; and these have given some trouble, so that, probably, none will be placed on the line until something has been put in the transformer houses that is perfectly satisfactory.

MR. SEELY : I should assume, Mr. White, that it would be preferable to place the wires under ground entirely. It would cost, probably, according to your figures, about $800,000 more.

MR. WHITE : That would be forty dollars per horse power.

MR. SEELY : At the rate of forty dollars per horse power; yes. Then you have a permanent installation under ground ; you are not troubled with the defects discovered with the overhead wires.

MR. WHITE : That view, of course, may be correct. But, as I stated in this paper, it has not been demonstrated up to date, from the fact that the only trouble due to the line thus far was from a joint in the cable. There has been no trouble due to the insulators, and there are 4,000 feet under ground as against over twenty-four miles of insulators ; so we have about thirty-five chances to one, so far as distance is concerned, of trouble with the overhead as com pared with the underground.

LIEUTENANT S. DANA GREENE: It seems to me, Mr. President, that the question of lighting on a line is really the most serious one to be considered ; that is, in considering the comparative advantages of the overhead and the underground lines. It is a fact that no tests that any manufacturing company of which I know can produce at their works, are at all indicative of the results to be obtained on the line here ; and it has been found actually necessary for them, in testing lightning arresters and fuses, to bring the experimental apparatus to Niagara Falls and actually test it by short-circuiting the machines here. In other words, the effect of a short circuit with 5,000- horse power generators on a 10,000- volt line is very different from anything obtained in ordinary use and practice. While it is probable that the lightning protection that has now been devised in the line will be sufficient to answer the purpose for the present, there will yet be always more or less risk from lightning until the wire is put underground. It seems to me that that is the evident conclusion one must arrive at; that is the weak point in the whole system at this time, and must be until these are finally put under ground.

MR. INSULL: Did I understand Mr. White to say. that it would cost $600,000 more for a line to carry 20,000 horse power under ground ?

MR. WHITE: It would cost about a million and a quarter, I estimate, for a line carrying 20,000 horse power ; that is, four series, three wires each, making twelve wires total, for a distance of twenty-seven miles ; it would cost fully a million and a quarter with the lead-covered cable, of which four-fifths would be for lead-covered cable and one-fifth for conduit. That would mean sixty dollars per horse power, in other words, and it would cost about one-third of that amount over head, or twenty dollars per horse power.

MR. INSULL : Then the interest on it would form an important part of the cost ?

MR. WHITE : If placed under ground at sixty dollars, the interest charge would be three dollars, allowing five per cent, and an additional amount at least equal to that would be allowed for depreciation , and probably a good deal more than that. It is hard to tell what the depreciation would be on lead- covered line under those circumstances, but five per cent would certainly be moderate ; probably ten would be more nearly correct. In that case, the depreciation would be six dollars per horse power and interest three, allowing ten per cent depreciation, to be safe.

MR. INSULL : That would be a very important proportion. If you were going to sell power at twenty dollars, it would be thirty-three per cent of the gross receipts. On this question of lightning arresters, I should like to ask Mr. Greene whether it is not true that, in units up to 1,000 horse power, lightning arresters can be furnished that will carry a lightning dis charge, and will, at the same time, interrupt short circuit of the dynamos without serious trouble. Of course, as he says, with 5,000 horse power it is a very serious matter to stop an arc after it has once formed, but up to 1,000 horse power it can be done more easily, and is probably possible.

LIEUTENANT GREEN : I think it may be possible, but I do not think any company will guarantee a device to be an absolute protection against lightning, and, as the amount of power delivered in Buffalo increases, it seems to me that the success of the sale of power in Buffalo is going to depend very largely upon the absolute reliability of the service. It is possible, for instance, that the poles themselves might be struck and destroyed by lightning-might cause very serious danger to the line. Of course, the network which Mr. White described as having been placed on the top of the poles is a good protection. I do not think it can be said that it is an absolute protection against lightning under all conditions of stroke.

MR. INSULL : When I first saw this overhead line , what seemed to impress me particularly was the awful responsibility of running such high potential above ground . But the figures just given by Mr. White would seem to indicate that if the line were put under ground it would render transmission from here to Buffalo almost prohibitive. With triple compound condensing engines, the cost, including real estate, installing, say, 20,000 horse power, would certainly be within $2,000,000-$100 per horse power. Now, if to convey the same amount of power it is going to cost sixty dollars per horse power for the underground system, if they ultimately have to go to underground work, it would seem to show that the cost of the installation here at the source of power, and the cost of the conveying power of the plant, would be so great as to render long-distance distribution, even to so short a distance as Buffalo is from Niagara, almost prohibitive. I do not imagine, from looking at the plant here, that it can be installed for much less than $100 a horse power. It would seem to me, therefore, that a long- distance power transmission plant, including the underground conductors, would cost at least sixty per cent more than the steam plant to produce the best possible results from steam in the city of Buffalo.

MR. BEGGS : I think, Mr. President, that the paper read by Mr. White, and the discussion that has followed, should be very satisfactory to investors in local electric lighting plants, who, for a few years, have heard that their business was likely to be taken away from them by these long-distance transmission plants of very high potential. I have myself seriously questioned the great advantage that was to be derived at points very remote from these great sources of power, for the reasons that have now come out in this paper of Mr. White's, to which I have listened with a great deal of interest, and which I think we shall follow those of us who are charged with the management of electric lighting properties, and, likewise, electric rail way properties, as some of us are, and who are investors in them--- with a great deal of interest to see the development. I heartily agree with the idea suggested by Mr. Insull, and I very seriously question whether even this great plant at Niagara Falls can compete with the modern steam plant fifty miles from Niagara Falls. I do not believe it possible; and yet it is hard for us even to imagine what the future developments of this long distance transmission have in store. I have been called in by some friends within the last thirty days to look over a proposition submitted to them as capitalists and investors in this class of property, where it is proposed--and this is a serious proposition, and one that is under consideration at the present time, and the process of raising capital to install it now under way--to transmit, not the 10,000 volts which Mr. White has been discussing here, but to transmit 60,000 volts a distance of sixty miles, and to transmit 40,000 horse power-the initial installation being 4,000 horse power on a number four wire ; and that is held out as a proposition, to carry this current and supplant the entire steam plant in a city of some 60,000 inhabitants. The only satisfaction of the electric lighting plant and the electric railway plant in the city where it is proposed to deliver this power, is that it is proposed to do it at about two-thirds of what it is now costing them to produce it. I think if they can realize that result, why, they had better take that end of it, without attempting to install the transmission plant themselves. I have had others of the same kind. There is a proposition in Pennsylvania to- day by some of my friends interested in electric lighting plants in which I am myself largely interested--a proposition to put at Conewago Falls, on the Susquehanna River, a large power-transmission plant, to carry power into the city of Baltimore ultimately, but to Port Deposit and the city of Harrisburg and certain other cities in Pennsylvania. They, I believe, have made some proposition that they would supply power at the city of Harrisburg at twenty dollars a horse power. I advised my friends to corral it all; simply to make a contract to take the entire amount that could be delivered and utilized there at that figure. But the point I want to make is that I do not think that those of us interested in central stations that may be menaced, as some of us have been, by these long-distance transmission plants, I do not believe that we are in any serious danger. It is not a question of developing power, it is a question of transmitting; and the point that I raised some weeks ago, in a long day's discussion of this long-distance transmission in the far West, and the plant that has been dwelt upon here, is the difficulty of insulation of clearing a path for your line. You can readily realize what it means to do what Mr. White has suggested here, and which is absolutely necessary. You must have a clear right of way that will enable you to cut down all the trees that can possibly fall across your line. One might never fall there, but you cannot take the risk of its falling; therefore, you must clear away sufficiently to prevent the possibility of limbs falling in a storm , or a tree crossing your line. And I think that is the serious difficulty that these long-distance transmission plants are going to encounter in the use of overhead lines, while the underground conditions are prohibitive from two causes, as has been well brought out in this discussion first, the initial cost of your line makes it prohibitive, and then the great depreciation, many of the elements of which are not known in these high potentials at all. Those of us who have been dealing with underground lines for eight or ten years, know that the item of depreciation on an underground line, even under moderate conditions, is very great indeed. So it would seem to be almost impracticable, from a commercial standpoint, to put lines under ground, and very difficult to maintain them over head.

MR. WHITE: On this question just spoken of by Mr. Beggs, it is almost certain that the localities are very few, and the circumstances must be very exceptional, that will support a transmission line fifty miles long. In the first place, it would be necessary to have an ideal water power-unusually good water power; and in the second place, a very high cost of fuel, or the power could be generated more cheaply by steam. But there are localities where plants of that kind would pay, and could earn, not only fair, but in some instances an extremely high, interest on the cost, even for such long distances. The only part of this country, perhaps, where that would apply would be out in the Rocky Mountains, where in some regions wood is scarce and coal costs, perhaps, eleven dollars a ton. In such localities, the cost of maintaining the interest on a line even fifty miles long can well be afforded. But under ordinary circumstances, as Mr. Beggs states, power could probably be generated far more economically with a triple compound-condensing steam plant than it could be developed and carried fifty miles over head, and certainly decidedly more cheaply than it could be carried fifty miles under ground. In this line, taking Mr. Insull's suggestion as to the interest charge, it would certainly not be wise to entail a charge of perhaps ten dollars per horse power for depreciation and interest under ground as against two dollars per horse power for depreciation and interest over head, unless the former were absolutely necessary and it were found by experience that lightning occasioned such trouble that it could not be handled satisfactorily. I do not believe such is the case. As to the insulation, it is possible to have that satisfactorily arranged. I know a plant in Michigan, from which I had a report two or three weeks ago, that has been running all winter, and in a climate where there is a great deal of rain and snow, and they have had quite a severe winter, at least in the way of a good many storms. That plant has been shut down but once in four months, and that was on Sunday noon, when notice had been given to the customers that there would be a shutdown at noon the next day. The shutdown was for ten minutes, and it was to tighten the key on the water wheel shaft. The plant has no duplicates ; has only one generator, and no duplicate machinery of any kind; and the only shutdown in four months was this one of ten minutes on Sunday noon to tighten the key in that shaft. So it is possible to run a plant satisfactorily and not have any trouble with it.

MR. STEINMETZ : 1 think it is dangerous to generalize too freely in such matters, and to state that it is or is not economical to transmit power fifty miles. It all depends on what the power is used for, as to whether the transmission is economical or not. The problem changes very greatly according to whether the transmission is used in a factory for twenty-four hours a day-a steady load-or whether it is used where the whole load is only an hour-a-day run, and the remainder is idle, and you have to pay the same price ; that is, you have to pay for the maximum load continuously, and use it for only a very short time. And then there is the other question coming in as to whether your railway network of the city depends upon continuous power, never shutting down under any circumstances, or whether you run into a continuous lighting system; whether you have a big storage battery, and when you send out a man to repair the line the storage battery carries you over the break. All these conditions change the problem very greatly, and you must investigate the individual case to see whether the steam-engine plant is the more economical, or the long- distance transmission, but you cannot lay down any general rules.

MR. SCOTT : The question of lightning arresters is one of vital interest in long-distance lines. A little experience is worth a good deal of theory in this matter. In the plant at Telluride, Colorado, which has been in operation for some half dozen years, a great deal of difficulty was experienced with lightning during the first year. The lightning destroyed, with great avidity, all the arresters that were sent there during the first season. The subject was gone into very carefully, and a new form of arrester was provided, and since that time there has been almost complete freedom from difficulty arising from lightning. While it is probable that there can never be absolute security from danger from lightning, just as there can never be absolute security from breaking of shafts or falling down of poles, yet lightning protection can be accomplished with the same co-efficient of safety that pertains to other apparatus. The original plant at Telluride was for 3,000 volts, and this has been increased to 10,000. The distribution extends over the mountains, and at some seasons the lightning is quite severe. The plant supplies stations distant from two and one-half to eighteen miles, in large number and widely distributed. There has been trouble from lightning. Some transformers were burned out, and careful investigation showed that the ground wire of the lightning arrester had become affected by some. workmen or some change taking place. The experience at that plant has been such as to justify the statement that 10,000- volt transmission, through a country that is particularly susceptible to lightning disturbances, can be adequately protected.

MR. WHITE : I was very glad of the remarks of Mr. Steinmetz, calling attention to the well known. fact that any problem of this kind is an engineering problem , and deserves solution and attention on its merits, irrespective of the general conditions and theories which may apply to other plants and do not apply to that, and I can best illustrate that, perhaps, by the result of some tests that we had made at Leadville, Colorado. We sent a man out there to make some investigation as to an electric power plant in that region. He found that in some instances power was costing the miners as high as $2,000 per horse power for the actual indicated horse power used. This was a hoist, of course. In that region, and over in Cripple Creek, some investigations were made. A great many miners have hoists, and have their boilers heated and power on for twenty-four hours in the day, and perhaps they use it but once in thirty minutes, or once an hour, to hoist a load. But they require an engine and they require fuel for the whole twenty-four hours, and fuel there costs eleven or twelve dollars a ton delivered at the mines, and water costs seventy-five cents a barrel, and with the use of a ten or fifteen-horse-power engine, but a few minutes each hour, you can readily perceive that the figures would run up to a very high degree. Even with plants using a considerable amount of power, the cost is usually from $200 to $300 per horse power indicated. So there are cases where power can be transmitted fifty miles or more and allow a good profit.

MR. WALBANK : I should like to ask Mr. White if he has ever put up any steel or iron poles—has had any experience with them?

MR. WHITE : I presume Mr. Walbank means for long-transmission work ?

MR. WALBANK : Yes, sir.

MR. WHITE : No ; we have not. Our experience with iron poles has been on ordinary lighting or street car work.

MR. WALBANK : In this Buffalo transmission, the poles are all of white cedar, I understood you ?

MR. WHITE : Yes, sir.

MR. WALBANK : And cost about forty dollars per horse power?

MR. WHITE: Twenty dollars.

MR. WALBANK : Twenty-two miles ?

MR. WHITE : Twenty- five.

MR. WALBANK : We have just constructed a steel pole line from Lachine Rapids into Montreal, and we constructed all of our line of steel poles ; that is, we took a channel iron and cut it diagonally through, and then riveted the reverse ends so as to make it about eight inches at the top and twenty inches at the bottom ; put two of these columns up and then latticed them together ; and your wooden cross arms are almost identically the same as we have, but without any braces underneath ; and we have, altogether, thirty-six wires on. Our poles are placed 108 feet centres, and they stand, probably, thirty feet high, including seven feet in the ground. They are bedded seven feet in concrete.

MR. WHITE : That ought to give very good construction.

MR. WALBANK : The way we tested the poles, we placed 200 pounds of pig iron on the top, with a fulcrum to take the place of the ground. Our pole line, complete, with wire, insulators, cross arms, and everything, will cost us, for a distance of 30,000 feet for the complete line about $92,000. We figured that for underground work it was going to cost over $300,000 to do the same thing with lead cable. We have not tested it practically yet, because it is now just about completed.

THE PRESIDENT : I shall have to close this discussion now. It is very interesting, and I wish we had more time at our disposal. We have another very interesting paper, and I shall call upon the author presently. I am sure we are all very much indebted to Mr. White for the instructive paper that he prepared. I know personally that he put himself to a great deal of trouble in the preparation of this paper for the benefit of our members, and feel that he must feel more or less repaid by the appreciation that has been shown and the knowledge that it has elicited on a number of important points.

MR. FERGUSON : Mr. President, I move that a vote of thanks of the association be tendered to Mr. White for his very interesting and able paper.

MR. SEELY : I second the motion.

THE PRESIDENT : It is moved that a vote of thanks be tendered Mr. White for his instructive paper. Is it your pleasure that that motion carry ? Carried.

THE PRESIDENT : Mr. White, the thanks of the association.

THE PRESIDENT : I now have to call upon Mr. Arthur Wright, president of the Brighton, England, Electricity Supply Company, and president of the British Municipal Electric Light Association, to read his paper upon "Profitable Extensions of Electricity Supply Stations." It has been my good fortune to read this paper and I think it one of the most instructive that I have yet heard, and it will probably lead to a good deal of discussion. It treats of the subject from a commercial standpoint, and from a standpoint which all of us that are interested in the operation of companies can appreciate. I have much pleasure in calling upon Mr. Wright and in introducing him to the members of the association.