. The Street railway journal . shown at c—/ and /—n in , and represent braking from the same speed. The curvesshow the importance of quick ?.pplication in case of u 1 LEVEL TRACK 0K 11 -- m u 1 11/ ^^ ,^ Qj 1 1 ^ •^ n TO 11 K y . J— -^ ^ tiU / y ^— ^ sC oO (a // _y. U ^U cr%r, h„ f tj I 4 y^- % <m^^.. dO r ■^ / - \y I ft ■Aec 7-- .£ 20 s y M 100 r~ ■A :f 0 20 iO CO See, l Mm. 3 4 b Sti L-ft 1 3 TIME FIG. 1,—ORDINARY SPEED-DISTANCE CURVES emergency braking. During the first half of the time re-quired to stop, the car travels three-fourths of the totaldistance, while in the las
. The Street railway journal . shown at c—/ and /—n in , and represent braking from the same speed. The curvesshow the importance of quick ?.pplication in case of u 1 LEVEL TRACK 0K 11 -- m u 1 11/ ^^ ,^ Qj 1 1 ^ •^ n TO 11 K y . J— -^ ^ tiU / y ^— ^ sC oO (a // _y. U ^U cr%r, h„ f tj I 4 y^- % <m^^.. dO r ■^ / - \y I ft ■Aec 7-- .£ 20 s y M 100 r~ ■A :f 0 20 iO CO See, l Mm. 3 4 b Sti L-ft 1 3 TIME FIG. 1,—ORDINARY SPEED-DISTANCE CURVES emergency braking. During the first half of the time re-quired to stop, the car travels three-fourths of the totaldistance, while in the last half of the time the car travelsonly one-fourth of the total distance; hence any fault inthe brake apparatus is more serious at the beginning thanat the end of the braking period. Fig. 3 shows the speed-distance curves corresponding tothese several rates of deceleration. The curves are of con-siderable interest because they show at a glance the dis-tance required to stop a car running at various speeds,. FIG. 2.—SPEED-TIME AND DISTANCE CURVES FORBRAKING FROM 33 MILES AN HOUR Feet 900 FIG. 3.—SPEED-DISTANCE CURVES CORRESPONDING TOSEVERAL RATES OF DECELERATION till his hand begins to turn off the power; the time to turnthe controller to the off position, pull the sand leverand move the air brake handle; the time the air piston istaking up the slack in the brake rigging and setting theshoes against the wheels, and in which the brake-shoestake hold or grip the wheel surfaces; and the remain-ing time, during which the brakes are exerting their fullforce in stopping the car. Evidently the first three inter- * Abstract of a paper presented at tlie Indianapolis meeting of the In-diana Engineering Society. with different rates of braking. Thus, the shortest possi-ble distance in which a car could be stopped from a speedof 30 m. p. h. is 125 ft. With the ordinary hand brake,which does not have an average retardation much above im. p. h. p. s., the distance requ
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
