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"OBJECTIONS" TO ELECTRICAL (OVERHEAD SYSTEM) TRAMWAYS., Issue 7976, 3 August 1889, Supplement
"OBJECTIONS" TO ELECTRICAL (OVERHEAD SYSTEM) TRAMWAYS.
TO THE EDITOR. Sir,—At the present moment the possible danger, nuisance, aud general vandalism of electrical tramways is an unknown quantity to some of the City councillors and to many of the citizens, and it may therefore be of use if they read the following extracts from a paper lately read before the Society of Arts, in Boston, on 4 Electric Street Railways,’ by Captain Eugene Griffin, Parenthetically I may say that Captain Griffin (U.S. Army) is assistant to the Engineer Commissioner of the district of Columbia, and was deputed to inquire into the practical working of, and general opinirn concerning the use of, electricity as a motive power for street railways. Ills report was published by the United States Senate as ‘Miss. Doc., No. SI, First Session Fiftieth Congress.’—l am, etc., Wai.ikp. Prince, Dunedin, July 31.
In the course of his paper Captain Griffin said; ‘‘The objections usually urged against the overhead wires are:-Ist. They are dangerous, as they carry death-dealing cut rents. tii.il. They are eyesores. 3rd. The poles obstruct the stre-t. 4th. They are iu the way iu cite cf fins. Now, ilie railway wire should not he confounded with other electric wires. Arc and incandescent wires, telegraph and telephone wires, have simply to cany the current from the point where it is generated to the point where it is to be used, and so far as this puiposn is concerned they may be aboveground or umbrgrouud. The railway wire, on the other hand, must have current taken from it every differ. utial of an inch from one end to the other. The wire must be hare, that the trolly wheel may be iu constant contact. To put ibis wire underground, and to keep it properly insulated, ia a very different problem from burying the other whes. The re.ilwny wire camr;t ho considered in the same category with oth“T electric wires. Now, as to danger. For railway work we use a constant potential generator, and the cars and motors arc placed between the two conductors on the multiple arc tys'ern. [See analogous explanation lower down, W.P.] Ono conductor—the overhead wireruns out from ono pole of the generator; the other conductor—the rail-runs out from tho other pole of the generator. An electrical connection between these two conductors completes tho circuit, and the current flows through tho connecting material whatever it may be. If it be the motors on a car, then the cais move; if it be a mm, he n ceives a shock.
Each connecting material, be it car, man, wre, or whatsoever, receives a current of elect icity which is absolutely and always determined by Ohm’s law that the current is equal to the electro-motive force or pressure divided by the resistance. The electro motive force is always 500 volts. With several cars iu oprra tion, the arnpdres of current (pints if you like) in the overhead system near the generator may run as high as 180: but each car takes its own proportion according to its own resistance. The average resistance of a man is 4,000 ohms. If he place himself in the circuit, he wilt receive a current which is measured in aropdres by dividing 500 by 4,000 ; or, in other words, a 500 volt current can only drive Jth of an ampdre through tho average human body. It would not make a particle of difference to the man whether the overhead wire be touched was carrying a current ef ono ampdre or 180 amperes, or 180,000 amperes; he would receive Jth of an ampere. Were this not true, then the whole theory of multiple arc distribution would bs false, and electric railways, as at present operated, would bo impossibilities. It would make no difference as to danger whether or e or a million cars were in operation on the line.
To make this matter plain to those unfamiliar with electrical terms, we may suppose the overhead wire to be a large pipe or main through which a pump (the generator) is forcing water ; the rails, electrically connected, as another large pipe, through which the water is to bo forced back to the station. Suppose the diameter of these mains is 12in. If they are closed at tho outer ends we may fill tho overhead main, but after that no water cun flow until we connect the two pipes. Now, we will put in a lin pipe connecting the upper main with tho lower main, say I,oooft away from the pump or generator. A certain amount of water will flow through tho connecting pipe, which amount depends on its eize (lin) and upon the pressure of tho water in the upper main. From the generator to the lin connecting pipe the same amount of water flows in the upper main as flows down through the connection—no more and no less. Beyond the connecting pipe no water is flowing in the upper main. Now, wo will put in a second connecting pipe l,ooofii beyond the first. For the first l,OoCfc we have twice as much water flowing as before. Half of it goes down tho first pipe. It is the same with every additional connecting pipe we put in until we roach the capacity of the upper main, or the capacity cf the generator to force water through it. By increasing the pressure we know that wc could force more water through tho lin connecting pipe, but, so long as the pressure remains tho same, the quantity flowing through the lin pipe will be tho same, whether the upper main be 12in, 12ft, or I,oooft in diameter.
The analogy to electric railway work is close. Electricity takes tho place of the water, and the connecting pipes are electric cars, or It may be some unfortunate man placed w here he ought not to be. He is on'y an inch pipe, however, and the pressure (-"00 volts) can only drive so much electricity through him. The current for railway woik has been fixed at 500 volts, as this is well within the safe limits. A shock from 500 volts is jinpleasant but not dangerous. No man, woman, or child has ever been killed or even seriously injured by a 500-volt current. The United States Senate had this question before them last summer. After a thorough investigation the Distiiot Committee unanimously reported that aSO '-volt current is not dangerous. , ■ , Tho danger limit with the electric current a probably about 1,000 to 1,200 volts,
The poles cannot obstruct the street, as they are inside the curb. They are just as much an obstruction to the sidewalk as lamp posts or awning posts are; no more and no less. If the sidewalks are narrow, and permission can be obtained from the property owners, hooks or eyebolts may be placed on the buildings, the cross wires fastened to these, and the poles done away with entirely. Every overhead wire is objectionable to the Fire Commissioners, The railway wire is less objectionable, because there is but one wire, and this wire is in the middle of the street, away from the buildings. . , . The overhead wire may be divided into sections of 1,000, 3,000, 4,000, 6,000 ft in length. At tbo ends of each section a cut-out or switch may he placed on the pole like a fire-alarm box, so that in case of fire the current may be cut out of the section or sections in the viciuity of tho fire. The firemen would then have no difficulty in handling the wires, which in any event are easily cut by pliers with insulated handles. As ladders are usually raised parallel to tho face of the building rather than across the street, and as the cross wires are 125 ft apart, it would be a very rare thing that the railway wires would be found to interfere at all with tho operations of the fire department. As Professor Thomson pertinently remarked to the insurance representative : it will not be long before you will be taking power from these wires to put out your fires. Jt will not be long before we have electro-motor fire-engines.
Charles Van Depoele and Leo Dift were the pioneers in modern electric railway work in this country. The first roads were built in 1884-85. The new motive power was, however, viewed with suspicion, and progress was slow until the Richmond road was built in 1887-88. This road did much to popularise electro-motors, The rapidity with which the horse is now going is shown by the growth of the Thomson-Houston Electric Company, one of the several companies working in this field. In the spring of 1488 this company purchased the patents of the Van Depoele Electric Company of Chicago. At that time there were some fourteen roads operated upon the Van Depoele system, The first Thomson-Houston car was started at Crescent Beach, Mass., July 4, 1883. On the Ist of April, 1889, in loss than nine months, there were eighteen roads with 104 motor cars in operation, and thirty-three reads with 210 motor cars under contract. The Americans sm essentially a fast people. We live fast, ami. unfortunately, we die fast. But as long as we do dv- we go Anytime-saving device is gladly wblcomi d, and at once becomes popular. Tho limit with horse cars is about eight miles per hour. With electricity the only limit is what we may fix as a safe spe-d, If horse cars are delayed, there is little or no chance of making up lost time. With electricity we have rapid transit, and we can obtain it in a very simple and not too expensive way. Electric cars do not smoke, or give off noxious gases, or make disagreeable noises. It is not necessary to run them in tha air or under the ground, though they run well in either position. They are safe, clean, fast, and reliable. They do not keep the street in an unclean and unhealthy condition. They do not take up as much of the street as do horse cars, for they have no horses. They a r e brilliantly lighted at night. All these qualities appeal to the public, and the verdict is everywhere favorable to electricity. The United States Benatc aid House of Representatives, in reporting on a proposed < xtonsion of the Washington road, said: “It is undoubtedly tho best electric railway in the United States, and beyond comparison to any horse railway.” Electricity has undoubtedly come to stav.
We believe that the public have little idea as to the unrest that pervades street railway circles in regard to motive power, and the desire there is among street railway men for sometning batter than animal locomotion. It may be well, therefore, to call attention to the facts recently developed by inquiries instituted by ths ‘Street Railway Journal.’ Qn the basis of several hundred replies, that enterprising paper reports that 18 per cent, do not contemplate any change from horses : 15$ per cent, did not answer, and lienee may be placed in the same category ot conservatives; 16 per cent, ere “on the fence ” awaiting developments and preferring some kind of mechanical traction ;16$ per cent, fa vor mechanical methods other than electricity ; 34 per cent, are using or will adopt the electric motor. In this class, one-third prefer the overhead system, and one.-rdr.th like the storage battery, Thus it will bo seen that practically 66$ per cent, of the roads of the country aie already saying good-bye to horses ; and that of these more than one-half are supporters of electricity. We think that electrical engineers have no reason to complain of this showing made by an impartial authority. To us it is a justification (f our steadfast advocacy of the electric motor during the last five years for street railways, We are perfectly satisfied with the figures, but we are of opinion that .a ernvaas of the new roads, as distinguished from those now in operation, would bring out an overwhelming preponderance of sentiment it favor of electricity. Probably far more than half the new roads have satisfied themselves that electricity is what they want.—‘New York Electrical World.’
"OBJECTIONS" TO ELECTRICAL (OVERHEAD SYSTEM) TRAMWAYS., Issue 7976, 3 August 1889, Supplement
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