. The street railway review . he poles are ofsteel in three sections and are 30 ft. long. The bracket arm is un-usually long from an American point of view, the center of thetrolley line being 12 ft. from the pole. This distance, of course,varies with the width of the street. The bracket is to thepole at a point 2 ft. from the top and the pole is set 6 ft. in theground, which brings the wires 22 ft. above grade. The feeders arelaid underground in the city and where connection is made withthe trolley wires they are carried up the interior of the poles; thedetail drawings in Fig. 4 show
. The street railway review . he poles are ofsteel in three sections and are 30 ft. long. The bracket arm is un-usually long from an American point of view, the center of thetrolley line being 12 ft. from the pole. This distance, of course,varies with the width of the street. The bracket is to thepole at a point 2 ft. from the top and the pole is set 6 ft. in theground, which brings the wires 22 ft. above grade. The feeders arelaid underground in the city and where connection is made withthe trolley wires they are carried up the interior of the poles; thedetail drawings in Fig. 4 show the construction where the feedersenter and leave the poles. The insulators are supported by two wires fixed in harps, the to allow the trolley car to rise between them. In case of a loosesuspension, to prevent the trolley wire from coming in contact withthe bracket and being short-circuited, a guard is placed above eachsuspension. Guard wires are placed above the line where thereare telephone or telegraph wires crossing FIG. 4-POLE AND FEEDER DETAILS. The trolley lines are divided into half-mile sections, which is re-quired by the Board of Trade regulations. A switch is placed onthe pole at each of these section insulators which is normally closedand carries the current around the insulator to the next section. Mau. is, lyoo/ STREET RAILWAY REVIEW. 139 riuTc are fmir dislribuliiig boxes placeil at iiiipiirlaiit fccdiiiKlioiiits along the line, cacli being supplied by one of the four feed-ers; three of the feeders arc of .24 srj. in. cross section and 900 ft.,, ft. and 5,700 ft. long respectively; the fourth one is of .5 srj. and 3,600 ft. long. In the distributing boxes there arc fectivc radius at each point bears a constant ratio to the sine ofthe angle the trolley arm makes with the axis of the tension of the springs being transmitted to the trolley armby a wire cable which runs over the cam, it Is evident that the up-ward thrust at the tro
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Keywords: ., book, bookcentury1800, bookdecade1890, booksubjectstreetrailroads
