(a) Except as provided in paragraph (b) of this section, alinement may not deviate from uniformity more than the amount prescribed in the following table:
| Class of track |
Tangent track |
Curved track |
| The deviation of the mid-offset from a 62-foot line 1 may not be more than - (inches) |
The deviation of the mid-ordinate from a 31-foot chord 2 may not be more than - (inches) |
The deviation of the mid-ordinate from a 62-foot chord 2 may not be more than - (inches) |
| Class 1 track |
5 |
3 N/A |
5 |
| Class 2 track |
3 |
3 N/A |
3 |
| Class 3 track |
1 3/4 |
1 1/4 |
1 3/4 |
| Class 4 track |
1 1/2 |
1 |
1 1/2 |
| Class 5 track |
3/4 |
1/2 |
5/8 |
1 The ends of the line shall be at points on the gage side of the line rail, five-eighths of an inch below the top of the railhead. Either rail may be used as the line rail; however, the same rail shall be used for the full length of that tangential segment of the track.
2 The ends of the chord shall be at points on the gage side of the outer rail, five-eighths of an inch below the top of the railhead.
3 N/A - Not Applicable
(b) For operations at a qualified cant deficiency, Eu, of more than 5 inches, the alinement of the outside rail of the curve may not deviate from uniformity more than the amount prescribed in the following table:
| Class of track |
Curved track |
| The deviation of the mid-ordinate from a 31-foot chord 1 may not be more than - (inches) |
The deviation of the mid-ordinate from a 62-foot chord 1 may not be more than - (inches) |
| Class 1 track 2 |
3 N/A |
1 1/4 |
| Class 2 track 2 |
3 N/A |
1 1/4 |
| Class 3 track |
3/4 |
1 1/4 |
| Class 4 track |
3/4 |
7/8 |
| Class 5 track |
1/2 |
5/8 |
1 The ends of the chord shall be at points on the gage side of the outer rail, five-eighths of an inch below the top of the railhead.
2 Restraining rails or other systems may be required for derailment prevention.
3 N/A - Not Applicable
[78 FR 16100, Mar. 13, 2013]