. The Street railway journal . having a dipat the center point to provide clearance for the passage ofthe sliding collector. Deflectors are for use with sliding collectors and are de-signed to depress the collector when a car is turning froma siding to the main line, or crossing from one track to an-other. They will not interfere with the operation of wheelcollectors. For ordinary conditions the messenger cable should be of7/16-in. extra galvanized Siemens-Martin steel. For pull-offs J4-jn. cable is satisfactory, and for general guying pur-poses extra galvanized Siemens-Martin strand is gen-er
. The Street railway journal . having a dipat the center point to provide clearance for the passage ofthe sliding collector. Deflectors are for use with sliding collectors and are de-signed to depress the collector when a car is turning froma siding to the main line, or crossing from one track to an-other. They will not interfere with the operation of wheelcollectors. For ordinary conditions the messenger cable should be of7/16-in. extra galvanized Siemens-Martin steel. For pull-offs J4-jn. cable is satisfactory, and for general guying pur-poses extra galvanized Siemens-Martin strand is gen-erally recommended. Special conditions may call for highstrength cable but as this cable requires mechanical fasten-ings on account of its stiffness, it should be used only whereabsolutely necessary. For curve work, either steady brace or pull-off construc-tion may be adopted. The steady braces are recommendedfor all curves not sharper than 4 degs., or 1433 ft. will generally be found that curves sharper than 10 degs.,. ARRANGEMENT OF FEEDER TAP IN BRACKET CONSTRUCTION or 574 ft. radius, can be more cheaply installed by the useof pull-offs on account of the greater pole spacing allow-able with this class of construction. The pole spacings are planned to keep the trolley wirewithin from 4 to 6 ins. of the track center, as it is believedthat a greater variation than this will give excessive strainsfor wooden poles. Where a sliding collector is to be used, the tangent lineshould be staggered by steady braces in bracket construc-tion, or pull-offs, in span construction, to avoid wearinggrooves in the collector contact surface. For this purposethe trolley wire should be displaced approximately 8 ins. oneach side of the center line of the track every 1000 ft., i. e.,there should be one complete wave from the extreme posi-tion on one side across the track and back to the extremeposition on the same side in each 2000 ft. of line. As there are in this construction two wires to b
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
