. The Street railway journal . ns on cable roads are broughtabout by weak trucks on flat curves, as it is here that thegreatest damage of :;I1 ii done, forming the first factor in 644 STREET RAILWAY JOURNAL. [Vol. XXIX. No. 15. making corrugations. The unequal wheels oscillating in thegrooves form regular corrugations of definite wave-length,though the wheels are not so harsh in their movements aswith geared axles, wherein the two forces are acting againsteach other. As the width of the check rail varies, so willthe pitch of the corrugations. It also follows that as thelongitudinal play of the
. The Street railway journal . ns on cable roads are broughtabout by weak trucks on flat curves, as it is here that thegreatest damage of :;I1 ii done, forming the first factor in 644 STREET RAILWAY JOURNAL. [Vol. XXIX. No. 15. making corrugations. The unequal wheels oscillating in thegrooves form regular corrugations of definite wave-length,though the wheels are not so harsh in their movements aswith geared axles, wherein the two forces are acting againsteach other. As the width of the check rail varies, so willthe pitch of the corrugations. It also follows that as thelongitudinal play of the axle increases, the corrugations willbe formed at lower speeds. Hence the gradual extensionof corrugations over the whole system, deeper at places ac-cording to the rail level and road camber. Truck Design.—This matter of rail corrugation is now re-ceiving the close attention of British manufacturers, the ex-perience with early American designs and practice provingdisastrous, as, in the hurry to secure cheap methods of pro-. FIG. 8.—METHOD OF BRACING IRUCK duction in order to compete with one another in foreignmarkets, the standard stamp of durability required in thiscountry was not maintained. It follows, therefore, that alarge percentage of the trucks under our street cars are notcapable of meeting modern requirements, because of theinability of the frames to withstand side strains, so fre-quently found in city and suburban districts, wdiere the flatcurves (taken at a high speed) are usually frequent and ofshort radii. Such trucks may be cheap at the beginning,but constantly require repair, while at the same time theyneed more current to draw them, and are most expensive inthe end, as many managers have learned to their present-day bogie truck frames of riveted and built-upconstruction, as used by most electric railway companies,carry the load in the center, and are themselves supportedupon equalizing springs instead of on journal springs. Thisgives a short sp
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
