File:The Street railway journal (1906) (14755825081).jpg

Identifier:streetrailwayj271906newy (find matches)
Title: The Street railway journal
Year: 1884 (1880s)
Authors:
Subjects: Street-railroads Electric railroads Transportation
Publisher: New York : McGraw Pub. Co.
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Smithsonian Libraries

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Text Appearing Before Image:
DIAGRAMMATIC LAYOUT OF SIGNAL SYSTEM ON THE GREAT NORTHERN & CITY RAILWAY ning tunnels, where restricted clearance and frequent trainservice allow of no time for inspection along the track duringtraffic hours, the system was so arranged that all the control-ling and moving apparatus are installed in the signal towers,where the essential parts are accessible at all times and canbe seen in operation and easily maintained. The signallingis automatic at through stations, and semi-automatic at sta-tions equipped with switches and crossings and at terminals.The running rails on the Great Northern and City Rail-way are not utilized as a return for the train current, andtherefore were available and have been used for the track-circuit signal control. Both running rails are bonded, onerail being bonded continuously, and the other bonded and
Text Appearing After Image:
TAIL BRUSH PASSING OVER TREADLE divided up into sections to correspond with the sectionscontrolled by each signal. Simple direct-working relaysare placed across the track rails at one end of eachsection, and the current is fed in at the opposite endof each section, at a pressure varying from 3 volts to 7volts. This current is supplied from a 100-volt generator,and the pressure is reduced by lamp resistances between the100-volt main and the track rails. To guard against anyirregular operation of the track relays by stray currents, a nal to the section or sections in the rear. That is, the func-tion of the track relay is to drop its armature, putting thesignal to danger by opening the local signalling circuit whenany pair of wheels enters the section it controls. Once thesignal has gone to danger, it remains locked there by a stopwhich falls into place by gravity, and can only be removedwhen the train has passed the corresponding treadle in ad-vance. It will be observed that should a tr

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