(a) This section applies to any curved track where operations are conducted at a qualified cant deficiency, Eu, greater than 5 inches, and to all Class 9 track, either curved or tangent.

(b) For the conditions defined in paragraph (a) of this section, the combination of alinement and surface deviations for the same chord length on the outside rail in a curve and on any of the two rails of a tangent section, as measured by a TGMS, shall comply with the following formula:

Where— Am = measured alinement deviation from uniformity (outward is positive, inward is negative). AL = allowable alinement limit as per § 213.327(c) (always positive) for the class of track. Sm = measured profile deviation from uniformity (down is positive, up is negative). SL = allowable profile limit as per § 213.331(a) and § 213.331(b) (always positive) for the class of track. [78 FR 16107, Mar. 13, 2013]