. Electric railway journal . endency for the wire to increaseprogressively in sag with the recurrence of high tem-peratures. The temperature limits experienced in theMelbourne district are between 27 deg. F. and 175 sun temperature. At tensioning points, other than at track terminalpoints, two terminating structures 180 ft. apart areemployed. The wires in either direction overlap this180-ft. span. The overlapping wires are arranged 15in. apart horizontally, and for a distance of about 15ft. on either side of the center of the overlapping span,the pantograph makes contact with both conta
. Electric railway journal . endency for the wire to increaseprogressively in sag with the recurrence of high tem-peratures. The temperature limits experienced in theMelbourne district are between 27 deg. F. and 175 sun temperature. At tensioning points, other than at track terminalpoints, two terminating structures 180 ft. apart areemployed. The wires in either direction overlap this180-ft. span. The overlapping wires are arranged 15in. apart horizontally, and for a distance of about 15ft. on either side of the center of the overlapping span,the pantograph makes contact with both contact the center of this span each contact wire risesgradually to its automatic tensioning attachment, andthe supporting catenaries are terminated on the ten-sioning structures at points vertically above the con-tact wireswhich they support. I Supporting Structures The supports for the simple catenary system consistof pairs of tensioning anchor structures situated ap-proximately 3000 ft. apart with light intermediate. STANDARD INTERMEDIATE TWO-TRACK STRUCTURE: ADAPTED TO CARRY SIGNALS structures spaced at 300-ft. intervals on tangent trackand at lesser intervals on curved track to suit theradius of curve. On curve work with single and two-track construction, light pull-off masts are located be-tween the intermediate supporting structures. One of the views on page 137 shows a pair of anchorstructures at a tensioning point. These structures con-sist of 34-in. X 34-in. laced angle masts bolted togravity-type foundations with a bridge of two channel booms having a light angle brac-ing between booms. The contact vidre tensioningpulleys are attached to the bottom boom. The catenariesare rigidly anchored to the top bridge boom. Theseanchor structures are designed to be capable of carry-ing signal semaphores. The other view on page 137 shows the supportingstructure on curve construction. It consists of two masts with a 6-in. channel supporting bri
Size: 1794px × 1392px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyorkmcgrawhillp
