Current Literature. 73 



Sennce Tests of Ties: Progress Report. By H. F. Weiss and 

 C. P. Winslow. Circular 209, U. S. Forest Service. Washing- 

 ton, D. C. 1912. Pp. 25. 



"Since 1902 the Forest Service has constructed eight test 

 tracks in co-operation with seven different railroad organizations. 

 Because a long time must elapse before data can be obtained on 

 durability, few of these tracks have thus far yielded conclusive 

 results. The information already received indicates that test 

 tracks, if property constructed and inspected, prove a valuable 

 index in showing economies in track maintenance. 



"So far as can be told by present results, all treatments, with 

 one exception, have increased the durability of the ties over that 

 Oi similar untreated material. Just how much the natural life 

 of the ties can be prolonged is not yet determined, but that it 

 may in many cases be doubled or even trebled seems certain. 

 For example, untreated loblolly pine and hemlock ties laid in 

 Texas lasted only 1.5 years, while of those burnettized over 70 

 per cent, were still serviceable after seven years. 



"Ties with low decay resistance, such as loblolly pine, hemlock, 

 tamarack, and beech, if laid untreated, should not be tieplated, as 

 they will decay before they will wear out. 



"The increased resistance to decay secured from preservative 

 treatment makes it highly desirable to protect treated ties from 

 deterioration by mechanical cause. This is particularly true of 

 ties with low-crushing strength. 



"Experience thus far is not conclusive as to the best form of 

 plate to use. Wooden plates, when simply laid under the rail, 

 have not proved satisfactory, as they either become loose, split, 

 or, in some cases, become embedded in the tie. Flanged metal 

 plates have a decided tendency to split the tie, thus forming 

 cracks which enable moisture to reach the interior and hasten 

 decay. Metal plates with flat or slightly corrugated bottom have 

 thus far given the best results. 



"Service tests on screw and cut spikes have, to the present time, 

 yielded no definite conclusions. It has been shown, however, that 

 when screw spikes are used it is desirable to have some form of 

 boss on the plates to re-enforce the heads of spikes against 

 lateral thrust." 



S. J. R. 



