. Official proceedings . forces used in the testing hereafterdescribed were 68,500 pounds direct vertical— pounds 134 transxcrsL and !);) iidiinds iwisliiiL;. I Idwcvct. in the tables-hereafter described, the results (hie to the transverse load havebeen increased 50 ])er cent, and represent the stress (hie to atransverse load of (;,oo:) ixmnds. Tliere mii,dit be some f| in tliis proce(hire. if it liad not ah-eady l)een found in acttialtest that for all jjractical i)urposes the stress at an\- point inthe traine was directl) i)r(j])ortione(l to the loads as lon,i>- as theelas
. Official proceedings . forces used in the testing hereafterdescribed were 68,500 pounds direct vertical— pounds 134 transxcrsL and !);) iidiinds iwisliiiL;. I Idwcvct. in the tables-hereafter described, the results (hie to the transverse load havebeen increased 50 ])er cent, and represent the stress (hie to atransverse load of (;,oo:) ixmnds. Tliere mii,dit be some f| in tliis proce(hire. if it liad not ah-eady l)een found in acttialtest that for all jjractical i)urposes the stress at an\- point inthe traine was directl) i)r(j])ortione(l to the loads as lon,i>- as theelastic limit of the metal was not reached. Method of Testing to Determine Stresses. For the i)ur]X)se of determinini^ the stress throu,^-hout theIrame under the three different loads, namely, direct verticaLtransverse and twistinL;-. the llerry Strain Gage was used. Thesegages are so constructed that the elongation in a two inch gagelength can be determined to .0002 of an inch. A photographof this gage is shown in Tig. It will be seen that the dial of the instrument is dividedinto 100 parts. The movement of the hand over each of thesedivisions, which is approximately one-sixteenth of an inch, isequivalent for the cast steel used in these tests to a stress of 135 2/00 pounds per s(|uarc inch. This 2700 vahie was arrivedat by determining- the modulus of elasticity of the steel whichfrom several tests was found to be approximately 27,000,000. I will sav that this instrument is a delicate machine andit requires some patience and skill to operate. .V common(\r\ laborer could not obtain accurate results. In preparation for a test the frame was mounted as shownin Fig. 6 and 7, on two heavy supporting castings on the bed])late of the testing machine. The machine used was a 300,000])ound Richie Testing ^Machine, located at the Granite City Plantof the American Steel Foundries. The distance between thesupport was equal to the wheel base of the truck. Double knifeedge bearings over the
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Keywords: ., bookauthorrailwayc, bookcentury1900, bookdecade1900, bookyear1901
