Electric "L" Cars - Tesla's Discovery of the Rotating Magnetic Field Has Solved the Problem of Motive Power

Tesla’s Discovery of the Rotating Magnetic Field Has Solved the Problem of Motive Power.

TEST FOR THE MANHATTAN.

Officials Will Watch an Early Application of the System at the Westinghouse Works.

GREAT PROMISES ARE MADE.

Speed, Safety and Economy Result, It Is Claimed, from Tesla’s Latest Find.

That electricity will be the motive power on the New York elevated railways is quite well assured, and promises to be certain within a few days. The trial trip of a new motor is to be made at Pittsburg by the Westinghouse Electric Company so soon as arrangements are made with the elevated railway people to witness it.

“The trial trip will likely be made within ten days, though it may be longer,” said Mr. George Westinghouse, two days ago, when I saw him in his office. “We are now almost ready, and will notify the elevated people according to the understanding between us. The experiments and severest tests have produced the most satisfactory results. In fact, the new motor is away beyond our expectations. It is Tesla’s greatest discovery, and solves the problem of rapid transit motive power. It cannot help being the power to be used.”

ROTATING MAGNETIC FIELD.

Nikola Tesla was found in his laboratory, in East Houston street, surrounded by the mysterious appliances of his science, and quite ready to give information of interest to the public.

“This polyphase alternating current as used in the new motor to be soon put on its trial trip in Pittsburg is sure to furnish the motive power for our elevated roads,” he said. “It cannot be avoided, simply because it will do the work surely, safely and economically. Then it is so easily managed, and without the constant danger of requiring an expert electrician to care for it.

“Now, the whole secret lies in my discovery of what is known as the rotating magnetic field. What it is I cannot explain, neither is it explainable. I can only give the facts which have been discovered through experiment. The discovery of these scientific facts has done entirely away with the commutator, which has heretofore been used on all electric motors. This commutator, with its close adjustment, delicate and intricate parts, has been the cause of all of the trouble. It is that complicated piece of machinery which shows the scores of pieces of brass arranged fan like, only making an entire circle. A slight injury to this commutator, which may arise from the presence of even a drop of water, may destroy the whole machine. The danger is now all done away with by discarding the commutator entirely.

“This result is accomplished by utilizing the rotating magnetic field, which simply means that if a circular metal disk is placed on an axle and brought near the electric coil it will revolve. The disk touches nothing but its own bearings, yet it revolves and thus produces power. This power is what is used in the new motor.”

PREPARING FOR THE TRIAL.

In the yards of the Westinghouse Electric Company, at East Pittsburg, a new combination electric locomotive engine and passenger car is now being equipped with these new motors, and in a few days will be ready for the trial trip. When all is in readiness the motor car will be coupled to five passenger coaches, and the special test for the benefit of the Manhattan Elevated Railway officials will be given. An actual demonstration of results now known will follow, and the gas and smoke producing engine will disappear from the streets of New York.

The new locomotive, which was in place last week, is forty-six feet long on the outside and thirty-eight feet inside. There are seats on both sides running lengthwise and exactly like “L” coaches. The motorman will stand at one end of the car. There will be a controller or lever at either end, and it will not be necessary to turn the locomotive. A pilot will be at either end to brush obstructions from the track.

There will be no fireman on the new locomotive, which will be equipped with air as well as hand brakes. It has a cast iron bottom to give it adhesion and weight. On the heavy axles are four motors of 100 horse power each, and the hauling capacity will be equal to that of 400 horses. The motors have been tested and were found equal to the task of hauling six or seven “L” passenger coaches in addition to the locomotive at a maximum speed of twenty-eight miles per hour. The average that would be maintained on the Manhattan system, it is claimed, would be from sixteen to eighteen miles per hour.

The new locomotive is entirely different from the first electric locomotive equipped at the Westinghouse works, and by which it was intended to make the “L” test. This machine is now used exclusively in shifting freight cars in and about the Westinghouse yards. Then a second one, which was an improvement on the first, was equipped. It in turn gave way to the Suburban electric locomotive, which contains all the improvements known to date. This is what has delayed the test.

This will be the first time the Tesla system will be used for railway work, and it is expected to revolutionize the present trolley and steam railroads. The cars are standard gauge and the test will take place on the tracks of the Turtle Creek branch of the Pennsylvania Railway. The line has been wired, the double trolley system being used, and the tracks reballasted, so that the highest speed can be attained. The test track, which is about three miles long, has been divided with posts set in the ground every quarter of a mile. These posts are numbered from one up, and represent the “L” stations. At these posts the train will be stopped and started as if running on the elevated tracks in New York. With stop watches the time of stopping and starting will be taken. In a preliminary test with the direct current a speed of ten miles per hour within a distance of sixty feet was acquired.

The train will be exactly the same weight as an “L” train, and everything will be arranged so that the test will be as if it occurred in New York.

SOME OF THE ADVANTAGES.

One advantage claimed for the new system, and one that will be appreciated in New York, is that the current used to run and light the trains could also be utilized to light the stations and operate a passenger elevator service.

The great advantage of the alternating system is that it saves lives in case a person takes hold of a live wire. Using the direct current 500 volts are necessary for ordinary street car work. This must be transmitted over expensive copper wire. By the invention of Tesla the current can be transmitted long distances over ordinary iron telegraph or telephone wires. The voltage can be so reduced that a person might take hold of a live wire with safety. He would be shocked, but would not be killed. With the general introduction of the new system it is claimed that electrocutions from the trolley will be rare.

In the direct current motor the commutator, which gathers the electricity from the armature and carries it to the brush, and the brush itself, are expensive and necessary features. They are continually breaking, wearing out and needing repairs, and add largely to the maintenance and operative cost of the system.

With the Tesla polyphase motor, these difficulties are obviated. The heavy copper feed wires, which are always dangerous by reason of having to carry at least 500 volts, will be replaced by lighter wires having a voltage of about 210. No commutators or brushes are needed, the armature playing in a field. The power plant can be located many miles away from the road if found necessary. If the new system is adopted in New York, one power plant in Westchester could furnish sufficient power to operate all the “L” lines and surface roads in the city. This would do away with the expense of having to erect power houses where land is valuable, and where the smoke would prove a nuisance.

When the great revolution in street railway motive power will be completed it is difficult to say, for both sides have moved slowly and been conservative. The street railway people have been slow to decide on changes that would involve expense and perhaps prove experimental, and the men who are furnishing the capital for the great plants that are making the tests have been equally conservative. But within a few weeks there has been a great change, and both sides appear to think that they stand on safe ground, that the problem has been solved and that the great change is about to be entered upon. The questions of speed, safety, durability, convenience and economy appear to have been settled, and now only a formal acceptance of the inevitable is necessary. It means much for a great railway company to revolutionize its motive power, but the Manhattan Elevated people have admitted for some time that a change would come, and they have only delayed to be certain that the new system embodied all of the requisites. Now all sides appear satisfied that the trial being arranged for at Pittsburg will be satisfactory, pronounce the fate of steam in cities and establish electricity as the great motive power.