. The Street railway journal . therefore, be = 4 10,594 pounds—not counting the force necessary to con-trol the inertia of the car and load. It is manifest that the strains produced in a carwheel by this force at / must be very severe, since theyare transverse. It is also evident that these strains aregreater in proportion to. the suddenness with which forceat / is brought into play. Aside from tending to twist the truck into properposition by causing the outside wheel to slide, the guardrail at the point / obstructs the forward motion of the in-side wheel and thus causes it to slip upon the r
. The Street railway journal . therefore, be = 4 10,594 pounds—not counting the force necessary to con-trol the inertia of the car and load. It is manifest that the strains produced in a carwheel by this force at / must be very severe, since theyare transverse. It is also evident that these strains aregreater in proportion to. the suddenness with which forceat / is brought into play. Aside from tending to twist the truck into properposition by causing the outside wheel to slide, the guardrail at the point / obstructs the forward motion of the in-side wheel and thus causes it to slip upon the rail by rea-son of its rotation. This causes the outside of the truckto swing around. It is evident that the strain upon the wheel would bediminished by raising the line a b (Fig. i) to some suchposition as a b\ the effect being to diminish the force at /.There are, of course, limitations to this plan and the ex-tent to which it can be carried is very small. Neverthe-less it is good practice to carry it to the farthest FIG. 2.—PROPER AND IMPROPER PLACING OF GUARD RAIL. It is evident that the forces which produce the differ-ence in motion between the inside and outside wheelsshould be brought to bear as gradually as possible and begiven the maximum time in wliich to do their work. Thismakes it of great importance that the guard rails shouldbe set properl}^ particularly at the entrance of the curvewhere the speed of the car is usually greatest. Let Fig. 2 represent the inside rail at the entrance ofa curve in Avhich c d \s the guard rail, h k the track rail,and f g the developed line of contact of the flange of thewheel with the guard rail. With the guard rail set asshown in a, it is evident that the wheel will get an un-necessary shock as it strikes the guard rail at and thatthis shock is more serious because, as has been stated, thecar is usually running at a greater speed at the entrancethan at any other point of the curve. By drawing theguard rail close to the line
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
