600 



iiEi'oiiT — 1884. 



In Canada, i? -narac and cedar arc also used for tics. Tamarac can 

 only be obtained in certain districts. It is a timber somewhat rescmblinff 

 larch, is higher priced than hemlock, but lasts longer. Cedar and locnst 

 are both good woods in lasting properties, bat are softer than desirable, 

 particularly the former. 



Uniformity in the size of cross-tics is imporlant, especially in cold 

 latitudes, as in the spring of the year large tics hold the frost much longer 

 than the smaller ones, and irregularity in line and surface of road occur 

 under service. 



The spikes which are used to secure the rails to the cross-tics should 

 not be less than 5 inches in length, better 5.', inches, should be scpiaro in 

 section /*. of an inch each side, and should have a flat head projecting to 

 one side to catch the flange of the rail. The lower end of the spike should 

 be flat- or chisel-pointed in a direction to cut across the grain of the tic, 

 and not to split it. The spikes should bo sound, smooth, wcU-shapcd, 

 and of double-refined iron, bending cold at least ninety degrees without sign 

 of fracture. The length of spike necessitates the depth of cross-tics being 

 at least G to 7 inches, and they should also be of this size to pcrfornT 

 their other requirements. They should have not less than 8 inches 

 across their flatted surface, and ought to bo at least 8 or, better, 8', feet 

 long for a 4 feet Hh inches or 4 feet t> inches gauge. 



Some years ago the regular distance for laying cross-tics was 2 feet 

 6 inches centre to centre, and this may still be the custom on some of the 

 lighter roads, but those with heavier surface are now laying them much 

 closer. They are usually placed 18 inches to centres under joints, and 

 2 feet to centres at other places, making for a 30-feet rail 2,()40 ties to 

 the mile of single track. Circumstances may, however, justify the 

 engineer increasing the distance. The question is governed by the 

 width of tie, the allowable carrying length of rail, and the space recpiired 

 between the ties to provide for proper tamping of ballast around them. 



A true track requires, of course, that the tics should be laid to a 

 uniform top surface. If the tie is twisted it should be made true on top 

 by adzing, to give an even bearing to the rail for the whole width, but 

 under no circumstances should a tie be notched. This onlj- allows water 

 to enter the pores and decay the timber, besides being a disfigurement to 

 the track. The ends of the ties should be lined up ])arallel with the rail 

 on one side, always the outside for double track, the ties should be well 

 rammed into the ballast or bearing material below them, and they must 

 have a solid bearing for their whole length. The rails must be spiked on 

 the inside and outside at each tie, on straight lines as avcII as on curves, 

 and the spikes must be driven so as to keep the ties at right angles to the 

 rails. There are therefore four spikes to each tic. Those on opposite 

 sides of the .same rail should not be placed in line, as it increases the 

 tendency of the tie to split; and this rule should be carried out also at 

 splices, the two spike notches in each splice being made unsymmetrical 

 >vith the centre of splice so as to insure this result. Special ties are rccpiircd 

 under switches and crossing.s, according to the standard diagrams of the 

 special road for which they are intended. 



The ordinary life of a tie is from five to ten years, depending upon 

 location, drainage, service, <tc. White oak ties only last on the main 

 line of the Pennsylvania Railroad from five to six years on an average, 

 but they might have nearly double that life on a road with less and 

 lighter traffic. Hemlock and spruce, in favourable locations, will last 



