. The Street railway journal . FIG. 6.—TAP SWITCH-BOX. FIG. 5.—DRAWING IN CABLES WITH EL1XTRIC WINCH Cables may be pulled into the ducts by hand or powerwinches. Fig. 5 shows one method of pulling in cables bymeans of an electric motor. High speeds of from 50 ft. to 75ft. per minute may be used with safety provided the pull issteady. D. C. CABLES As the size of the distributing feeders must be calculated forthe maximum load which is likely (o be encountered, the loadfactor of each trolley section is an important item. Long sec- tions have better load factors than short ones, consequentlyare mo
. The Street railway journal . FIG. 6.—TAP SWITCH-BOX. FIG. 5.—DRAWING IN CABLES WITH EL1XTRIC WINCH Cables may be pulled into the ducts by hand or powerwinches. Fig. 5 shows one method of pulling in cables bymeans of an electric motor. High speeds of from 50 ft. to 75ft. per minute may be used with safety provided the pull issteady. D. C. CABLES As the size of the distributing feeders must be calculated forthe maximum load which is likely (o be encountered, the loadfactor of each trolley section is an important item. Long sec- tions have better load factors than short ones, consequentlyare more economical in the amount of copper required to feeda given length of trolley wire. Three methods are commonly used in calculating feeders,viz.: (1) Make all trolley sections of equal length and calculatethe feeder to give a predetermined drop under full load. (2) Make all feeders of equal size and vary the length ofsections according to their distance from the sub-sta-tion to give a predetermineddrop. (3) A combination ofboth methods may be fol-
Size: 2170px × 1151px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
