. The Street railway journal . tions of economywith respect to in do not necessarily holdfor all parts of a gi\en system, and second, the question ofeconomy in is quite subordinate to that ofsuccessful operation. As regards tlie former consideration, the average energydelivered to an electric railway system is a very differentthing from either the maximum energy or the averageenergy during the hours of heavy load. The load factor,i. e., the ratio between average and maximum output on arailway system is generally rather unsatisfactory, as has al-ready been indi
. The Street railway journal . tions of economywith respect to in do not necessarily holdfor all parts of a gi\en system, and second, the question ofeconomy in is quite subordinate to that ofsuccessful operation. As regards tlie former consideration, the average energydelivered to an electric railway system is a very differentthing from either the maximum energy or the averageenergy during the hours of heavy load. The load factor,i. e., the ratio between average and maximum output on arailway system is generally rather unsatisfactory, as has al-ready been indicated. It ranges in general from .3 to .6,varying greatly with the size of the system, the characterof the service and the habits of the people who ride. Incities many interesting facts appear from the load curveof an electric railway—the movements of workingmen,the crowd of shoppers going downtown in the forenoon,the migration in the early afternoon, the homegoing atsix and the theatre crowd an hour and a half later. All 31. 12 1 2 3 4 5 C 7 8 J 10 H 12 1 2 3 i 5 C 7 S !l 10 11 13Time I Time Street Rj. Joiirn:>l FIG. 41. these factors of load operate with var3dng force, not only indifferent places, but in different parts of the .same changes from da} to day are considerable, but on thewhole the same line preserves its character remarkablywell. The result of a varying load factor is a in the permissible loss of energy. For if wehave a load factor of .3, the average loss of energy, what-ever economy of transmission may indicate cannot be sogreat as to cause at maximum load a drop in voltage suffi-cient to interfere with the proper operation of the cars. Ifwe write for the maximum drop, V, v for thedrop corresponding to the loss of energy for greatest econ-omy of transmission, for the load factor, L, and for the dropassumed, V\ we have the following in equality which setsa limit of drop which must not be exceeded I \ < L V Ver
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
