. The street railway review . enoid which, so long as the current ispassing through it, loosens the brake but throws it on theinstant the current stops. The motors also have a powerfulbraking effect. In going down grade the motors can be controlled intwo different ways. They may be connected in the samemanner as going up grade with the resistance inserted inthe rotors or the rotor windings may be short train has the same speed going down hill as going up;they have to keep in step or in synchronism with the alter-nators. The motors act as generators going down hill andreturn curre
. The street railway review . enoid which, so long as the current ispassing through it, loosens the brake but throws it on theinstant the current stops. The motors also have a powerfulbraking effect. In going down grade the motors can be controlled intwo different ways. They may be connected in the samemanner as going up grade with the resistance inserted inthe rotors or the rotor windings may be short train has the same speed going down hill as going up;they have to keep in step or in synchronism with the alter-nators. The motors act as generators going down hill andreturn current to the circuit. It was necessary to make pro-vision for this at the power station, for if all the trains onthe line were descending the locomotive motors would gen-erate so much current that the alternators at the stationwould run as motors from the line currents. A load resist-ance is automatically inserted in the circuit when the alter-nators exceed a certain speed. The fact that the motors will return energy to the line. FIG. 3.—TRUCK. was demonstrated by experiments last November on a com-pleted portion of the line a mile in length. During the testsa fully loaded train w-as run down hill with the motors con-nected as generators and the train maintained the samespeed as in going up grade without any application of thebrakes. The excess current was absorbed at the power sta-tion by a water rheostat. The test also showed that a loco-motive hauled a fully loaded train over every grade evenly and smoothly, and when the rotor resistance was out ofcircuit the speed was independent of the grade or load. The cars, station, buildings, etc., are all lighted by elec-tricity, there being small transformers at the stations to
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Keywords: ., book, bookcentury1800, bookdecade1890, booksubjectstreetrailroads
