. Railway mechanical engineer . ng to P5 and the line la is drawn parallel to tlie bottomchord. Then the stress in the diagonal can be scaled offfrom the line xa and the stress in the bottom chord from theline la. In a similar manner xb and ab are drawn, then beand cm, xd and cd, de and ne, xf and ef and fg and og, inthe order mentioned. The sizes of the truss members are then determined as ejoor-i / 5/ c « / neooM nsooM / / 36600(-> / <i ^ / 43000r-l t I m „ \ . follows: The maximum stress in the bottom chord is 43,000lb. For this member a 9-in., 13J^-lb. channel is used, whichhas a cro
. Railway mechanical engineer . ng to P5 and the line la is drawn parallel to tlie bottomchord. Then the stress in the diagonal can be scaled offfrom the line xa and the stress in the bottom chord from theline la. In a similar manner xb and ab are drawn, then beand cm, xd and cd, de and ne, xf and ef and fg and og, inthe order mentioned. The sizes of the truss members are then determined as ejoor-i / 5/ c « / neooM nsooM / / 36600(-> / <i ^ / 43000r-l t I m „ \ . follows: The maximum stress in the bottom chord is 43,000lb. For this member a 9-in., 13J^-lb. channel is used, whichhas a cross-sectional area of sq. in. Deducting thecross-sectional area of two j-^-in. holes in the flange and twoin the web, leaves a net section of sq. in., which givesa unit stress of 14,650 lb, per sq. in. The diagonal, ax, with f d X / / / A \ e / a maximum stress of 8,600 lb., would require an area ofonly sq. in., or say Y?, in. by in. section. Add-\w the width of one /16-in. hole would increase the size. f CroaiBearar Dlagr-im Showing Size of Members and Riveting In Side Truss that diredion. The last load, p., brings the force line backto the .starting point, x. To find the other forces acting at any points in the trussthrough the diagonals or tqi or lK)ttom , the triangleof forces is drawn. For example, liavinj? Ix proportional tothe force p., xa is drawn from x j)arallcl to the diagonal ex- to in., but to get satisfactory arrangement of rivets, a;(i-in. by 3-in. bar is used. The diagonals, dc, dc and fg, are in compression and actas columns. The stresses are checked by tin- A. k. Iv , but inasmuch as tlie diagonals are stiffened bybolting to the side sheathing, possible buckling is disrc- 644 RAILWAY MECHANICAL ENGINEER Vol. 96, No. 11 garded, and wherever the unit stress is less than 14,000 sq. in. the section is considered safe. The stresses inthese members and the properties of the sections are asfollows: BC. maximum str
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroadengineering
