474 



FORESTRY AND IRRIGATION 



Octobei 



just been published, gives the latest re- 

 sults of these investigations. 



The manner in which ties have hith- 

 erto been made has been determined 

 largely by the ease and rapidity with 

 which they could be cut. They have 

 been obtained from trees of all diameters, 

 from 9 inches upward, the most service- 

 able portions of live straight trees being 

 selected . The sapwood top sections and 

 trees killed by fire, insects, disease, etc. , 

 or blown down, could not be utilized, 

 owing to the fact that ties from sapwood 

 or dead timber decay rapidly. 



Although large ties make a better 

 roadbed than the same amount of tim- 

 ber in a greater number of small ties, 

 the first consideration is to have as great 

 a bearing surface as possible on the bal- 

 last. A trapezoidal or modified half- 

 round tie, with a base of 10 to 12 inches 

 and a top-bearing surface of 6 inches, 

 distributes the weight of moving train- 

 loads upon the roadbed as effectually 

 as a rectangular tie 10 to 12 inches 

 broad. The half-round tie is good for 

 the lumberman, because in numerous 

 instances two ties of this form can be 

 made from a log which would furnish 

 but one rectangular tie ; in other cases 

 material f or several boards is saved where 

 a rectangular tie would have taken the 

 entire log. This form is beneficial to 

 the forest, since it encourages the cut- 

 ting of large trees and the saving of 

 small ones until they reach more valua- 

 ble size, and permits the utilization of 

 much timber from the tops, hitherto 

 left in the woods. The half-round tie is 

 advantageous from a mechanical stand- 

 point also, because it gives greater bear- 

 ing surface per mile and a correspond- 

 ingly more stable track than rectangular 

 ties. This tie form is therefore advo- 

 cated by the Bureau of Forestry as eco- 

 nomical of timber, conservative of the 

 lumber supply, and at the same time 

 equally efficient with the forms in com- 

 mon use. 



Ties are commonly graded as first, 

 second, and third class, and culls, or 

 ties which either in size or in quality 

 fall below the specifications, but which 

 the railroads generally accept up to a 

 certain percentage of the total number of 

 ties, though at a greatly reduced price. 



There is, however, no accepted standard 

 as to what constitutes a first, second, or 

 third-class tie, and the specifications of 

 the various railroads show wide differ- 

 ences in the dimensions required. It is 

 proposed by Doctor von Schrenk that a 

 standard classification be adopted, con- 

 sisting of six or more classes, to be known 

 as A, B, C, etc., each class to be of a 

 definite size, and no provision to be made 

 for culls. This will tend to economy, 

 since the smaller-sized ties will fall into 

 the smaller classes and will be sold at 

 their market value to the roads which 

 want them, instead of, as largely now, 

 to roads which do not want them, but, 

 having received a certain proportion of 

 them mingled with those of the specified 

 size, do not feel warranted in rejecting 

 them altogether. This proposal has 

 been adopted by the American Engineer- 

 ing and Maintenance of Way Associa- 

 tion. 



A far greater economy, however, than 

 can be hoped for from the adoption of a 

 new tie form or a new tie classification 

 is that promised by the studies which 

 the Bureau of Forestry has directed 

 toward opening new sources of supply 

 of ties. This it aims to do by making 

 possible the utilization of cheaper and 

 more abundant kinds of timbers in place 

 of the high-grade woods now employed. 

 The commonest as well as the best tie 

 material of the past and present in this 

 country is white oak, which resists both 

 wear and decay excellently, and is con- 

 sequently cheaper in the long run than 

 less expensive woods like beech, red oak, 

 or loblolly and lodgepole pine ; but 

 white oak, besides being one of our finest 

 timber trees, is becoming high-priced, 

 and further, as railroad men know well, 

 is becoming scarce even faster than the 

 advancing price would indicate. Not 

 only is it very wasteful to make ties of 

 white oak, which can be manufactured 

 into much more valuable products, if a 

 lower-grade wood will do, but soon, 

 under the present demand, white oak 

 ties will no longer be obtainable in the 

 required quantity at any price. 



The first step in the search for sub- 

 stitutes was to discover how to prevent 

 rapid decay of softer woods when laid 

 in the track. Preservative treatment 



