. The Street railway journal . on the North Shore andNew York Subway systems is used in this system, the onlychanges being of minor importance. The electromotive forceat the relay is a little more than i volt. In blocks 3000 there is a pressure of about 6 volts at the transformer, thedifference being due to the high impedance of the rail with thealternating current. The relay is placed at the entrance end of a block and thetransformer at the exit end. With no train in a block, theenergy absorbed l)y each block is approximately 50 a train enters the block at the relay end, th
. The Street railway journal . on the North Shore andNew York Subway systems is used in this system, the onlychanges being of minor importance. The electromotive forceat the relay is a little more than i volt. In blocks 3000 there is a pressure of about 6 volts at the transformer, thedifference being due to the high impedance of the rail with thealternating current. The relay is placed at the entrance end of a block and thetransformer at the exit end. With no train in a block, theenergy absorbed l)y each block is approximately 50 a train enters the block at the relay end, the energy isseldom more than 75 watts, and about 300 watts when thetrain is exactly opposite the transformer. As the train is ex-actly opposite the transformer but a few seconds at a time, theaverage actual energy consumed is quite small. LIGHT SIGNALS In the East Boston Tunnel light signals only are used, asshown in Fig. 3. The signals have two colored lenses, red fordanger and green for safety. The signals are lighted by two. FIG. 4.—LIGHT SIG- FIG. 3.—LIGHT SIGNALS USED IN NALS FOR ELEC- EAST BOSTON TUNNEL, CON- TRIFIED SUB- SISTING OF 4-CP, oO-VOLT LAMPS WAY DIVISION IN MULTIPLE OF LONG ISLAND RAILROAD 4-cp 50-volt lamps connected in multiple. The lamps are placedclose together, and in line with the lens, the focus of the lensbeing midway between the two lamps. Very little differencein the action of the lenses is noticed by this lamps with a coiled filament are used; on ac-count of their low pressure and low efficiency these lampshave long life. Being connected in multiple, both would haveto be out at once before the signal would be out of commis-sion ; even then there would be no danger, as no light in asignal is considered a danger signal. The current for the lightsis furnished from a separate winding on the transformer. Electrically-lighted signals are fast displacing the oil-lightedones. They were adopted on the New York Subway after veryca
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
