TRACKWORK 



255 



The rails should be carefully curved before being laid, and 

 great pains should be taken to secure a perfect line. 



To Lay Out a Point Switch. The frog point K, Fig. 12, 

 having been located exactly as for a stub switch, the lead KB 

 is next laid off from K to the toe of switch B, and the positions 

 of B and D are marked on the main-track rails. From D, 

 the length DN of the switch rail, which is usually 15 ft., is then 

 measured forwards to N, and the position of N is marked on 

 the web or flange of the rail. The heel M is usually 5f in. 

 from the point N. The point 7 is located on a line perpen- 

 dicular to MD and at a distance $g from M. The point J is 

 similarly located from the point H. 

 As a check on the work, the length 

 of the chord JI should have the 

 value given in the table for point 

 switches. 



Switch ties of the requisite num- 

 ber and length should be prepared 

 and placed in the track in proper 

 order. As in the case of stub 

 switches, all long switch ties should 

 be in place before the rail is cut 

 for placing the frog; also, the ends 

 M and L of the rails, with which 

 the switch points connect, should 

 be exactly even; otherwise the tie- 

 rods will be skewed, and the switch 

 will not work or fit well. The tie- 

 rods should next be fastened in position, care being taken to 

 place them in their proper order, the head-rod being num- 

 bered 1. Each rod is marked with a center punch, the 

 number of punch marks corresponding to the number of the rod. 



The switch rails are now coupled with the rails LK and MK r 

 and the sliding plates are then placed in position and securely 

 spiked to the ties. The head-rod is then connected with the 

 switch stand, and the switch is closed, giving a clear main 

 track. The stand is then adjusted for this position of the 

 switch, and bolted fast to the head-block. Next, rail BR is 

 crowded against the switch point so as to insure a close fit, and 

 18 



FIG. 12 



