Track alinement.

(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, E u , 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]