. The Street railway journal . essure, in order that the cost of cables and the losses intransmission might be reduced. Twelve thousand volts was thehighest pressure heretofore carried for heavy power distribution 77o STREET RAILWAY JOURNAL. [Vol. XVI. No. 32. in underground cables, and many were the prophecies of cable, 2 ins. in diameter, was used for each 2000 hp trans-mitted. Each cable contains three wires, each .4 in. in diameter,separated and insulated from each other and from a lead sheath bycommon manilla paper impregnated with resin oil, linseed oil andother insulating co
. The Street railway journal . essure, in order that the cost of cables and the losses intransmission might be reduced. Twelve thousand volts was thehighest pressure heretofore carried for heavy power distribution 77o STREET RAILWAY JOURNAL. [Vol. XVI. No. 32. in underground cables, and many were the prophecies of cable, 2 ins. in diameter, was used for each 2000 hp trans-mitted. Each cable contains three wires, each .4 in. in diameter,separated and insulated from each other and from a lead sheath bycommon manilla paper impregnated with resin oil, linseed oil andother insulating compounds. The cable is drawn in cement conduit An attendant is required to supervise the transforming andconverting apparatus at the sub-station and to care for the low ten-sion railway distributing switchboards. Copper feeders distributethe power from these switchboards to the different trolley 1,200,000 lbs. of copper are required for these local dis-tributions. The current at the car is under the control of the. Street FIG. 7.—REAR 46-IN. TURBINE FLUME AND CASE ducts 3 ins. in diameter. These ducts are protected by concreteand are laid about 3 ft. below the roadbed. Manholes are lo-cated every 500 ft. for the purpose of drawing the cables in theduct, making cable splices and for inspection and repairs. Draw-ings of cables and splices are reproduced in Fig. 8. SUMMARY Reviewing the complete cycle, let us start over again with thewater which formerly tumbled down the rapids below St. AnthonyFalls. It has been dammed, a pond formed and a fall of 18 ftproduced. The falling water, in passing through the turbines,develops 10,000 hp, which is converted into electric power bythe generator attached to the turbine. Direct current of lowpressure is provided by two of the 1000-hp generators, whilealternating current of moderately high pressure is generated bythe remaining eight generators. All the electric power is firstcarried to a switchboard in the gallery.
Size: 2562px × 976px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, bookidstreetrailwa, bookyear1884
