55 
These tests were made upon small pieces of wood, about 1A inches in 
width. It is difficult to combine them so as to represent the proper re- 
lations of the layers of wood in a tic. These tests were also made upon 
dry wood. .Made upon actual ties, containing the same percentage of 
moisture as those in the ballast, the results would be modified ; Chestnut 
would not show so high, and Cedar would be reduced but little; Hem- 
lock would be lower, as also the Yellow Pine; and after three years' 
decay the results would be still further modified. The Hemlock would 
show marked depreciation, also the Yellow Pine; the Cedar would be 
quite uniform, while the Oak and Chestnut would show some reduction. 
Experience shows that, with the exception of White Cedar, if the 
fibers can be protected from becoming softened, they are sufficiently 
hard to sustain from twice to three times as much traffic as they do when 
untreated. 
Length (aid size of ties. — For a 4-foot 8J-inch guage the majority of 
railroads use a tie 8 feet long ; some S.| feet long, and a few 9 feet. 
Specifications call for a G-, 7-, and 8-inch face for the flatted ties; and 
some roads call for joint-ties with a 10-inch face. In depth the dimen- 
sions vary from G to 7 inches. The Chestnut ties now being bought are 
required to be 7 inches deep. A few roads use Cedar ties only G inches 
deep, but most of the recent ones are 7 inches. With Chestnut and 
Cedar ties this is perhaps advisable, but with other woods, owing to the 
manner of decay, it is doubtful whether anything is gained. 
Most of the Yellow Pine ties which reach the North are rectangular 
and uniform in size. The Kew York Central and Hudson Eiver Kail- 
road Company use a tie J by G£ inches and 8 feet long ; sixteen of these 
are put under a 30-foot rail, making the space between each one narrow 
for tamping such deep ties, and requiring more time and care to do the 
work. But of course the track remains very firm after it is put up. 
RECAPITULATION. 
Destruction of ties. — Railroad ties in service are injured, destroyed, 
and rendered unserviceable by three principal causes : 
(1) Mechanical disintegration of the layers, and the abrasion of the 
fibers under the rails. 
(2) Injury to the wood by spiking and respiking. 
(3) General decay of the wood, induced by fungi. 
In regard to the first cause, extensive examinations show that there 
is more or less up-and-down movement of the rails under all passing 
trains. This is true to some extent of tracks laid with even the heaviest 
and stiffest rails that are used at the present time, but the undulation 
of such tracks is greatly reduced. 
