ON AMKRICAN PEHMANENT WAY. 



593 



Oil Amerlcaii Perhianenl Day. 

 7^/ Joseph .M. Wilsdx, A.M., M.Inst.C.E. 



[A communicatioii oi'ileroil by tlio Cenoral Conimittco to be printed In cxtensu 



among the Hcport.-.] 



[I'LATES VI. VIII.] 



Tm. word 'American ' covers a very wide field, iiK:ludiu<>; not only Canada 

 and the United States, but the whole continent : a vast extent of country, 

 with all its varying conditions of climate, of constructive material, and of 

 I'iiilway requirements. 



When, therefore, American Permanent Way comes to be considered, 

 tlie subject must necessarily involve a cojisiderable variety of construc- 

 tions, depending upon location and other conditions. Thus the form of 

 eonstruction required for a railroad in the Xorthern United States or in 

 Canada, built to resist the severe winters of these latitudes, might be 

 uunecessaril}' expensive for the mild climate of the south ; also roads with 

 heavy traffic require a more solid and substantial construction than those 

 having only a light service ; then, again, the materials of construction 

 available in places geogra])hically far apart are often very different, and 

 the engineer must adapt himself to circumstances, using what materials 

 he can best obtain at a reasonable cost. 



Permanent Way, or railway superstrncture, as it is sometimes called, 

 is that portion of railway which directly receives the weight of the 

 moving trains, and transmits it to the road-bed below. It comprises the 

 rails, the cross-ties or sleepers to which these are attached, and the dis- 

 tributing material in which the ties or sleepers are bedded. The object 

 of the permanent way, no matter how constructed, is in all cases the same 

 — to provide a way for the running equipment of the road to move upon, 

 nud to so transmit and distribute the weight from this to the substructure, 

 that the latter, which is usually a soft material, as earth, may be able to 

 sustain the load without settlement. 



American Permanent Way only differs from that of other countries in 

 the adaptation of the materials available for the construction of the work, 

 taking into consideration their relative abundance and value, and dis- 

 playing, perhajis, some of the aptness for which Americans have a 

 repntation. 



It is necessary for a first-class ]ierfect track to have good surface, 

 good drainage, true line, accurjite gauge, and tight joints. 



Rails have been made of wood, iron, and steel. "Wood is so soft a sub- 

 stance, and so perishable, that it can only be employed for very light 

 and temporary service, such as is sometimes required in lumber regions. 

 It has been so employed, and may be considered as essentially ' American.' 

 Iron and steel are the materials used throughout the world for railway 

 service proper, and the cost of steel in late years has so nearly aftproached 

 that of iron, that with its vastly superior qualities it is rapidly driving 

 iron out of use; in fact, the use of iron may already be said to be of the 

 past. The shape and weight of the rail is governed by several conditions. 

 Its section must be so formed at the top as to properly carry the wheels of 



1884. Q Q 



