. Electrical world. ine room also contains steam-driven exciters, sub-station plantand a main switchboard. Three-core paper-insulated metallic-sheathed cables convey thehigh-tension current to the sub-stations, and are laid on what isknown as the solid system, at a suitable depth along the com-panys right of way. The sub-station equipments, similar in character, consist of trans- 2l8 ELECTRICAL WORLD and ENGINEER. Vol. XLIII, No. 5. formers, which step-down the three-phase alternating current of7,500 volts to low-tension alternating current, from which it isconverted in rotary converters to di
. Electrical world. ine room also contains steam-driven exciters, sub-station plantand a main switchboard. Three-core paper-insulated metallic-sheathed cables convey thehigh-tension current to the sub-stations, and are laid on what isknown as the solid system, at a suitable depth along the com-panys right of way. The sub-station equipments, similar in character, consist of trans- 2l8 ELECTRICAL WORLD and ENGINEER. Vol. XLIII, No. 5. formers, which step-down the three-phase alternating current of7,500 volts to low-tension alternating current, from which it isconverted in rotary converters to direct current at 600 volts. Therotary converters are nominally of 600-kw capacity, four being pro-vided in each sub-station, and three static transformers, cooled bymeans of air blast, are provided in connection with each connections from these sub-stations to the third rail are madeby insulated copper cables, run underground in troughing. The third rail is carried outside the track rails, and is supported. FIG. I.—M.\P OF ROUTE. at intervals of 10 feet on insulators. The center of the rail is 3feet liyi inches from the center line of the track, and the top ofthe rail 3 inches above the surface of the track rails, these being pany,limensions agreed upon betweenall the British railway companies. The third rail, which is of spe-cial composition to secure con-ductivity, weighs 70 pounds per _yard, and is protected by a timberg^ard rail at points where theremight be danger of accidental con-tact. To insure a good return cir-cuit a fourth rail, supported onwooden blocks, has been placed inthe 4-foot way, and bonded to eachrunning rail; this method of re-turn, it was thought, would inter-fere least with the running would permit the easy removal of any running rail at anytime. The cars differ from those usedon the steam lines of the com-pany, and were built especially for the service iSO-hp motors on each truck, and with multiple-unit control. Thefront end has a
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectelectri, bookyear1883
