File:Cross tie forms and rail fastenings with special reference to treated timbers (1904) (14574292508).jpg

Identifier: crosstieformsrai50vons (find matches)
Title: Cross tie forms and rail fastenings with special reference to treated timbers
Year: 1904 (1900s)
Authors: Von Schrenk, Hermann, 1873-1953
Subjects: Railroads Ties Wood Preservation
Publisher: Washington, D.C. : U.S. Dept. of Agriculture, Bureau of Forestry
Contributing Library: U.S. Department of Agriculture, National Agricultural Library
Digitizing Sponsor: U.S. Department of Agriculture, National Agricultural Library

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pidly increased to such an extent that the spike no longerholds. Water collects in the enlarged hole, and decay sets in. (SeePI. IV, tig. 2.) Third. Whenever a spike becomes so loose that it no longer holds,it is pulled out and driven in at another point. This constant respik-ing rapidly ruins tin4 tie. It is worth while to discuss these objections in detail. First, as tothe effect of rail motion under a moving train load. This motion isundulatory in eharacter. Without going into details describing thevarious elements of this motion, it will be sufficient for the presentpurpose to note that one of its results is gradually to lift the spike outof the wood. The upward pull has to be repeated many times beforeany impression is made on the spike, but eventually the resistance ofthe wood fibers holding the spike in position is overcome, so that aftersix months the head of the spike will stand one-fourth inch or moreabove the rail flange. a W. M. Camp: Notes on Track, p. 978, Chicago, 1903.
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RAIL FASTENINGS. 33 Another effect of the wave motion of the rail upon the tie is to sawout the wood fibers immediately under the rail. The sawing is at firstslight, hut increases rapidly as the spike is pulled and after a fewfibers have been broken. This is well illustrated by PI. I, figs. 1and 2. It will be seen that this sawing is at first in the nature of acompression, breaking the fibers in some instances, as shown particu-larly near the top of fig. 1, and in other cases completely sawingthrough the fibers, as shown in the lower left-hand corner of fig. 1.After long-continued action of the rail it may wear away enough ofthe tie to be embedded in it for a half inch or more. (See PI. I, fig. 2.)The extent of wear will depend a great deal upon the wood and thecharacter of the rail. A recent case cited in a paper by Dr. P. H.Dudley may be referred to. Doctor Dudleya shows figures of— A number of yellow pine cross-ties which had been in use on the New YorkCentral and Hudson River Ra

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