. Railway master mechanic . top-heavy and unbalanced. Alarge portion of its weight is above the axis of the having set up a crosshead on end thus: (See sket<h.)I found the amount of this overhang or unbalanced yiov-of to inches from 11km-imi- Wl i the el-nsshead, ve found the fracture tohe force producing the formula: e velocity of the crank pin with ii2 iu. wheelsmiles per hour is 34 ft. per second, and the crank1 ft. We have then W = 100 lbs., v = :J3 ft., r ■Substituting these values in the formula we have: 100 X 34 X 34 33-2 X 1 _ .i,.,90 lh^. At the speed nam
. Railway master mechanic . top-heavy and unbalanced. Alarge portion of its weight is above the axis of the having set up a crosshead on end thus: (See sket<h.)I found the amount of this overhang or unbalanced yiov-of to inches from 11km-imi- Wl i the el-nsshead, ve found the fracture tohe force producing the formula: e velocity of the crank pin with ii2 iu. wheelsmiles per hour is 34 ft. per second, and the crank1 ft. We have then W = 100 lbs., v = :J3 ft., r ■Substituting these values in the formula we have: 100 X 34 X 34 33-2 X 1 _ .i,.,90 lh^. At the speed named the pisff persecond, whi, ii m,m. iii. Ibeloadof 3,590 lbs., acting on an arm of m i .i,,, , aiul removed 10 limes per second. Tie i. ter where it offers the mmmmm le^i-: „ , , ■■. For a load thus sud- denlyapplied .1. i, . : ,. lernating tensile and com- pressive sti-es,. , ■ i 1 safety should be at least 10. by the formula 10 PI 10 d where P = 3,.WU lbs., (=10 uehes, d =3;!,, inches, / — the working stress. J> = = 17,200 lbs. pr. sq. in. which shows a factor of safety of less than five, or onlyone-half of what it should be; and a stress of more th:uihalf the elastic resistance of the steel. As explained, the formula is based on the strength of thewhole section, and the maximum fiber stress must be muchgreater than that here obtained. If these rods had beenmade of iron they would have bi-oken sooner, for with ironor steel subject to such stresses, it is only a question of time .«the nnitcrial having the least strength lonest. Piston rods, being now generallyle freciueut f:iilui-e of them in Laird cross-ly created a strong prejudice against steels. But the cause of the faUure should be|iro,,e,-ly belongs, namely, to this excessive break the ; -e bend could beSinn and Resolved. That we consider the above action to benot only in accordance with the demand of popularopinion and the laws passed by the several state legis-latures, but largely to the best interests
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Keywords: ., bookcentury1800, bookdecade1870, bookidr, booksubjectrailroadcars
