Electric Power Consumption for Yard Switching

In the application of various types of locomotives to switching service, it is at times quite desirable to have data concerning the energy requirements involved. A convenient figure for expressing such requirements in relation to work done is watt hours per ton-mile. The determination of such a figure involves certain difficulties peculiar to switching service, in that trailing loads and distances moved are continually varying. The electrified Oak Point Yard of the New York, New Haven & Hartford Railroad in New York City offered an excellent opportunity for determining figures of watt hours per ton-mile for different kinds of switching. Accordingly two electric locomotives were equipped with the necessary instruments, and a total of 391/6 hr. of operation was observed and recorded. The paper describes in some detail the entire procedure of the tests and lists in tabulated form the data obtained. Basic figures necessary for calculating watt hours per ton-mile, it was found, could be expanded to give a much broader scope to the results, so that many interesting data became available. Incidentally, the data will permit of even further expansion where certain special figures or factors are desired. Although electric locomotives of different types were used, the results set forth in the paper should be considered without regard to either type. It is hoped that data concerning switching operations on other railroads may become available.