230 



TRACKWORK 



CROSS-OVERS 



A cross-over is a stretch of track that connects two parallel 

 tracks, and enables a train to pass from one track to the other. 

 Thus, in Fig. 9, if UV and U'V are two parallel tracks, the 

 track RZR' is a cross-over. This cross-over consists of two 

 equal turnouts Rm and R'm', whose frog angles at K and K f 

 are equal, and a reversed curve mZm' connecting the ends of 

 these turnouts, Z being the point of reversal. 



Cross-Over Between Two Parallel Straight Tracks. To 

 lay out the cross-over, it is necessary to know the radius r, 

 the central angle M, and the distances BE = B'E'. The 

 radius r may be taken from the table for stub switches. Then, 



and 



When the tracks are less than 30 ft. apart, the value of 



