THE ELECTRIC RAILWAY. Persons to whom the care of machinery is intrusted should know something about that machinery, how to operate it to get the best results, how to repair it if it gets out of order, and especially how to run it so that repairs will seldom be needed. Electrical machinery is new to many workmen. Its operation is somewhat of a mystery. Those who have the care and management of such machinery should know enough of the construction and operation to handle them intelligently, whether it is in the shop, central or power station or on the electric railway. This is notably true in the development of the electric railway, where new experiences and new problems are coming up continually. These problems are being solved in many cases by the engineers in the "inner circle" of the large companies, and the knowledge is confined to the favored few. Many of the same difficulties and problems come also to the men directly in charge of the motors; men who do not understand much theory, and who are not informed of what is well known to the favored few.. In view of this withholding of necessary knowledge, the reader, especially if connected with the electric railway ser THE ELECTRIC RAILWAY. vice, is seriously advised to acquire a knowledge of the general principles of electricity, of the dynamo and motor and to then apply them to the special line here explained. Briefly, the system of electric car propulsion consists in the production of the electric current by mechanical means, its transmission through conductors to the electric motors on the cars, where it is again transformed into mechanical energy, which gives the motion to the car. The current which drives the motors may be derived from two sources: I, from an accumulator carried with the car; 2, by a current from a dynamo placed by the side of the conducting lines, hence outside the car. The accumulator will be mentioned and described hereafter. The line system may be divided into three divisions : NOTE.-A novel plan of making use of both these systems is a combination of electric trolley and storage battery in operation upon a suburban railway in Hanover, where, after a long trial, it has been adopted. Electric accumulators are placed beneath the seats of the cars. The road is equipped with trolley wires and motors on one section only. While the car is traveling over the trolley section the accumulators are charged, receiving a current through the same feed wire as the trolley. When the end of the trolley is reached, which is at the city limits, within which the overhead wires are prohibited, the car continues on its way over a track that was formerly used as a horse car line, relying absolutely for power upon the electric energy stored in the accumulators during the trip over the trolley road. THE ELECTRIC RAILWAY. The surface system (3) which is not much used consists in an arrangement where the iron or steel tracks are used for conductors. The underground system (2) is still somewhat in an experimental stage. It calls for the use of underground "conduits " very similar to those in use in connection with the cable-car system of propulsion—but, Conduits themselves are exceedingly expensive to construct, and cannot be operated unless there is a system of sewerage in connection with them, and in case of damage are exceedingly difficult to repair. Hence the system known as the "Trolley" line has come into such general favor that nearly one thousand million dollars have already been invested in the system in the United States alone. The Trolley Wheel is represented in Fig. 239; there are various forms of it, but usually they are made of brass, about five inches in diameter, mounted on the end of a pole about 12 feet long, bent over as shown in Figs. 195 and 197. The end of this pole sets in a frame attached to the car roof, and springs acting on the lower end press the wheel against the trolley wire. The pole may be of wood or steel. The action of the wheel is such that it does not increase the sag of the wire but tends to push it up a little in its passage. |