TRACK. 31 



All narrow banks must be widened to the standard width 

 from centers, as established by the engineer. 



Transition curves will be used at the end of all curves of 

 3 and upwards. The rate of change per degree of curvature 

 should preferably not exceed 1 for each chord of 50 ft. in 

 length, except on mountain grades, where the chord may be 

 reduced to the minimum length of 25 ft., when necessary. 



Short sags should be avoided, and in all cases vertical 

 curves should be provided at grade intersections, for which 

 the engineer will establish line and grade wherever required. 



The roadbed at sub-grade should be crowned to facilitate 

 drainage by raising the center 4 to 6 ins. higher than the sides, 

 making due allowance for ballast in establishing final grade 

 elevation. 



Ditches in cuts should be taken out in accordance with the 

 standard cross-section as follows: In earth, 3 ft, wide at sub- 

 grade, 1 ft. deep, with side slopes 1 to 1. In rock 1 ft. wide at 

 sub-grade, 1 ft. deep, vertical sides. 



Material used for ballasting, widening banks or raising sags 

 should be procured at points where the removal of same will 

 benefit the roadbed by widening cuts, reducing grades or 

 ditching. Engineers will give this subject their special atten- 

 tion. 



TIES. 



The number of ties per rail will necessarily vary with the 

 width of the ties furnished, and will usually be from 15 to 17 

 ties per rail length. The minimum width between ties must 

 not be less than 10 ins. On construction, ties will be laid 2 ft. 

 c. to c., or 2,640 ties to the mile. 



The best ties will be selected for use at joints, with faces 

 not less than 8 ins. nor more than 10 ins. wide, and must be 

 so placed that the outside bolt will come about the center of 

 ties; the maximum spacing between ties at joints must not 

 exceed 10 ins. 



"Rail cut" ties must be adzed to uniform bearing, old spike 

 holes plugged, and joint ties properly spaced for suspended 

 Joints, after the new rails are laid, and before the ballast is 

 distributed. 



