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. Railroad construction, theory and practice; a text-book for the use of students in colleges and technical schools, and a hand-book for the use of engineers in field and office . Fig. 76,—3keleton Elevation op Trestle. upper stories of uniform height p,nd let the odd amount go to thelowest story, as shown in Figs, 75 and 76. 172. Span. The shorter the sp^n the greater the number oftrestle bents; the longer the span the greater the required strength9f the stringers supporting the floor. Economy deniands theadoption of s^ span that shall inake the sum of these require-. FiG. 77.—Knee-braces for
. Railroad construction, theory and practice; a text-book for the use of students in colleges and technical schools, and a hand-book for the use of engineers in field and office . Fig. 76,—3keleton Elevation op Trestle. upper stories of uniform height p,nd let the odd amount go to thelowest story, as shown in Figs, 75 and 76. 172. Span. The shorter the sp^n the greater the number oftrestle bents; the longer the span the greater the required strength9f the stringers supporting the floor. Economy deniands theadoption of s^ span that shall inake the sum of these require-. FiG. 77.—Knee-braces for Long-span Stbjingi^rs. ments a minimum. The higher the trestle the greater the cqstof each bent, and the greater the span that would be all trestles have bents of variable height, but the advan-tage of employing uniform standard sizes is so grea+ that many §173. TRESTLES. 209
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Keywords: ., bookauthorwebbwalt, bookcentury1900, bookdecade1920, bookyear1922