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(6) GAGES AND FLANGEWAYS FOR CURVED CROSSINGS
V. ANGERER, Chairman;
H. A. LLOYD, W. P. WILTSEE,
J. DEN. MACOMB, J. V. NEUBERT,
W. S. McFETRIDGE, J. B. BAKER
G. J. SLIBECK, R. A. BALDWIN,
J. B. STRONG,
Sub-Committee. Tables No. 1 and No. 2 are submitted in Appendix A, Item III, for adoption and publication in the Manual.
Table No. 1 is submitted as a suggested solution for "Concrete Rules for Recommended Practice" in the widening of gages and flangeways in curved track and curved crossings.
Table No. 1 is based on the theoretical study submitted in last year's report. The columns on the left give the approximate rigid wheel base of locomotives in combination with the number of pairs of flanged drivers stated that will operate on the gage of the track shown on the right under “Degrees of Curvature.” Two columns are given for the wheel bases ; one for plain, unguarded curves, and the other for guarded curves and curved crossings.
On a plain, unguarded curve the gage is determined by the largest wheel base locomotive operated over it, full allowances being made for play at journal boxes and tight setting of end drivers, when there are more than three pairs of flanged drivers.
On a guarded curve the width of the inside fangeway is determined by the largest locomotive and in which the gain from play at journal boxes is reduced by one-half the amount of the tight setting of end drivers. The outside rail must then be set a sufficient distance from the inside guard line so that the flanges of the outside wheels of smaller locomotives and four-wheel trucks will clear the outside rail and frog points when the inside wheels bear against the inside guard, thus determining the gage necessary to make the guard effective. The outside guard rail has to be set the same distance from the inside gage line as a maximum to give clearance for the center drivers of locomotive when these center drivers are forced towards the inside gage line by the contact of the end drivers on the inside guard. This distance made 4 ft. 634 in. gives a theoretical clearance of 32-in. with normal wheel setting. The diagram sketch illustrates the above conditions in the operation of locomotives and four-wheel trucks over the same guarded curve. The gage for guarded curves given in the table having thus been determined from the flangeway, the width of Alangeway can be found by deducting the 4 ft. 634 in. from the gage.
In the calculations by the formulæ given in last year's report the diameter of the wheels has been assumed to be the maximum permitted by the wheel base. The allowances for lateral play at journal boxes and tight setting of outside drivers as per Note 4 are in accordance with average practice of locomotive builders, but there is no strict uniformity. More play would permit a corresponding reduction in the width of flangeway and gage.
Particular attention is called to Note 5 on the table, which contains recommendations as to what width of gage may be used when no definite data as to the kind of locomotives to be operated over a given curve or curved crossing are available.
The gages designated under series “A” conform to the rule for "Gage on Curves” given in the 1915 Manual, page 117; the present tabulation shows the limits of the wheel bases of locomotives to which this rule will apply. Gages designated under series “B” are narrower gages, which would answer average conditions in yards and sidings, where main line locomotives do not operate.
Wide flangeways in crossings are apt to produce excessive wear through the pounding of the wheels in going across the fangeway. By Note 6 it is recommended that crossings should, wherever possible, be limited to 4 ft. 9 in. gage, 274-in. flangeway and the corresponding curvature permitting this limit for the equipment operated over the crossing.
Table No. 1 is sufficiently correct for general practical purposes. The figures for the gage are within 18 in. and the figures for the wheel base within 6 in. in order to avoid the use of smaller fractions.
For finding the more nearly exact gage necessary for a given locomotive on a given curve in cases where it may be desirable, the graphic table No. 2 is also submitted. The diagrams on Table No. 2 may be read to a small fraction of an inch. For other wheel bases than those shown, additional lines may be interpolated. A comparison of the readings of the diagrams with the figures on Table No. 1 will show the fractional differences.
The figures have been verified by some observations and some comparisons with actual practice and conditions. They have also been examined, including the recommendations contained in Notes 5 and 6, and are endorsed by the crossing builders, members of the Manganese Track Society.