The street railway review (1891) (14756987921)

Identifier: streetrailwayrev07amer (find matches)
Title: The street railway review
Year: 1891 (1890s)
Authors: American Street Railway Association Street Railway Accountants' Association of America American Railway, Mechanical, and Electrical Association
Subjects: Street-railroads
Publisher: Chicago : Street Railway Review Pub. Co
Contributing Library: Carnegie Library of Pittsburgh
Digitizing Sponsor: Lyrasis Members and Sloan Foundation



Text Appearing Before Image:
wo old ilouble reduc-tion motors. Under each corner of the car is a shoe, mak-ing two contacts with the rail for testing the drop of poten-tial across the rail joints, as shown in the engraving of the nections of the testing circuits. It will be noticed that inaddition to the voltmeter wires leading from each pair ofshoes there is another set connected to a few battery cellsand an electric bell circuit. This is for purposes of testing,to be sure that the shoes make contact, for if they donot make contact there can be no voltmeter deflection,and if one of the shoes should be raised or the circuitbroken, considerable testing might be done with theoperator under the impression that everything was all rightbecause he got no deflections, when really the truth wouldbe that the circuit was open. By using a few cells ofdry battery and an electric bell it can be found in an instantwhether the circuit is all right. The voltmeters used havethe zero point in the middle of the scale and deflect to
Text Appearing After Image:
TEST AND IJKII-I- CAR OF THE LINDELL RAILWAV, ST. LOUIS. tar herewith. From the two contacts on each shoe, wireslead up to the low reading voltmeter terminals, and also toa test circuit explained later. Two voltmeters are used, onefor each side of the track. The object in having contactshoes on each end of the car is to make it always possilileto take the readings on joints between the car and the powerstation. The car is usually sent out during the night, whennothing but owl cars are running. Consequently the cur-rent taken by the test car plays an important part in thedrop of potential at any one joint. Therefore, when the caris approaching the power station, or a negative feeder run-ning to it, the shoes on the front end of the car are used, andwhen the car is going away from such a feeder those on therear end are used. The voltmeters employed read to twelve-thousandths of a volt. Whenever aileflection of five-hun-dredths of a volt is obtained the joint is nuirked as bad andis rebo