CROSS TIES 269 



These will be at once apparent when reviewed in the light of the 

 above discussion. Such species as the red oaks, hard maple, yellow birch, 

 beech, red and black gum and elm meet these conditions to best advan- 

 tage and all of them are now rapidly coming into common use for treat- 

 ment. Maple and beech, untreated, last only about four years in the 

 track, but when subjected to a treatment of lo lb. of creosote per cubic 

 foot, they should last from sixteen to twenty years or more, whereas such 

 highly durable woods as redwood, cedar and cypress give a service in the 

 track of only about ten to twelve years. 



Since sapwood is generally more easily impregnated with chemical 

 preservatives than heartwood, it is considered a desirable quahfication to 

 have an even distribution of sapwood entirely surrounding the heartwood 

 when the ties are intended for treatment. 



SAWED VERSUS HEWED TIES 



There is a wide range of opinion among those experienced in the use 

 of both sawed and hewed ties as to the relative advantages and disad- 

 vantages of each form. As noted before, about 80 per cent of all ties are 

 hewed, and this form is almost universal in the East as contrasted with 

 the Pacific Coast, where about 80 per cent of all ties produced are sawed. 



Inasmuch as ties are generally produced from small holdings such as 

 farmers' woodlots, scattered bodies not reached by a logging operation, 

 and from tops and cull trees left after logging, there seems to be no dis- 

 position to change the method of making them. In fact, the proportion 

 of hewed to sawed ties has remained about the same for the past decade or 

 more. The introduction of wood preservation on an extended scale, 

 however, has tended to increase the demand for a uniform sized tie and 

 one which offers an even bearing surface for both tie plates and rails. 



The principal points in favor of the hewed tie may be summarized as 

 follows : 



1. They shed water more readily than sawed ties and hence are 

 likely to be more durable. This is obviously of little impor- 

 tance when the ties are to be treated. 



2. Hewed ties are cut with a straight grain, hence they may have 

 superior strength to sawed ties. 



3. The railroad receives a larger volume of wood when buying 

 hewed ties because sawed ties are always cut to fixed specifica- 

 tions, whereas in hewing the object is to keep above these fixed 

 dimensions so that the volume of wood is likely to be much 

 larger. 



