298 FOREST PRODUCTS 



plates should be of sufficient size to offer a much larger bearing surface 

 than the base of the rail on the tie. The bottom of many of the plates 

 is ribbed or provided with prongs or sharp points which embed them- 

 selves into the tie. The general sentiment, however, is in favor of a flat 

 plate. In either case, the upper face should be provided with a shoulder 

 on which the outer part of the screw spike head may be supported. 

 Otherwise the lateral thrust may bend the. spike out of position. 



Two screw spikes are provided on each side of the rail and holes are 

 made in the plate designed to accommodate rails and spikes of given 

 dimensions. Tie plates should, in all cases, be as wide as the tie and 

 from 6 to 9 in. long. When hewed ties are used in the treated condition 

 they should be bored and adzed prior to treatment to provide an even 

 bearing surface for the tie plate. Many of our treated ties are now 

 being laid with screw spikes and plates to prevent mechanical wear and 

 thereby increase their length of service. 



BIBLIOGRAPHY 



Annual Proceedings, Miscellaneous Articles; American Wood Preservers' Associa- 

 tion, Baltimore. Society of American Foresters, Washington. American 

 Railway Engineering Association, Chicago. American Society of Civil Engi- 

 neers, New York. 



Bureau of Census and U. S. Forest Service, Washington. Statistics of Cross Tie 

 Production for Various Years to and Including 1915. 



Gibson, H. H. Future Tie Materials in the United States; Hardwood Record, 

 Chicago. Vol. 37, 1914. 



Miscellaneous Articles in Railway Age Gazette, New York; Forestry Quarterly, 

 Toronto. (Now merged with the Proc. Soc. Am. Foresters, Washington.) 

 Engineering News, New York; Engineering Record, New York; Railway 

 Review, New York. 



Rehm, N. F. Ties and Tie Plates. Track Standards, Chicago, 1910. 



Raymond, W. C. Cross-ties. In Elements of Railway Engineering, 1908. 



Sherfesee, W. F. The Seasoning and Preservative Treatment of Hemlock and 

 Tamarack Cross Ties. U. S. Forest Service, Circ. 132, 1908. 



VoN ScHRENK, HERMAN. Cross-tie Forms and Rail Fastenings. Bureau of Forestr.v, 

 Bull. 50, 1904. 



Weiss, H. F. and Winslow, C. P. Service Tests of Ties. U. S. Forest Service, 

 Circ. 209, 1912. 



Winslow, C. P. The Grouping of Ties for Treatment; Railway Age Gazette, New 

 York, Vol. 62, p. ISO, 1917, 



