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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. 84. §181. TRESTLES. 215. FiQ. 85. elevation. (Fig. 85.) This weakens the cap and requires thatall ties shall be notched to abevelled surface to fit the string-ers, which also weakens the centrifugal force will tend totwist the stringers and rack thetrestle. (c) Placing wedges underneaththe ties at each stringer. Thesewedges are fastened with twobolts. Two or more wedges willbe required for each tie. The a
. 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. 84. §181. TRESTLES. 215. FiQ. 85. elevation. (Fig. 85.) This weakens the cap and requires thatall ties shall be notched to abevelled surface to fit the string-ers, which also weakens the centrifugal force will tend totwist the stringers and rack thetrestle. (c) Placing wedges underneaththe ties at each stringer. Thesewedges are fastened with twobolts. Two or more wedges willbe required for each tie. The ad-ditional number of pieces requiredfor a long curve will be immense, and the work of inspection andkeeping the nuts tight will greatly increase the cost of main-tenance. (d) Placing a wedge under the outer rail at each tie. Thisrequires but one extra piece per tie. There is no need of awedge under the inner tie in order to make he rail normal tothe tread. The resulting inward inclination is substantially thatproduced by some forms of rail-chairs or tie-plates. The spikes(a little longer than usual) are driven through the wedge intothe tie. Sometimes lag-screws are used instead of experience
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Keywords: ., bookauthorwebbwalt, bookcentury1900, bookdecade1920, bookyear1922