(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: ----------------------------------------------------------------------------------------------------------------
Tangent track Curved track
-----------------------------------------------------------
The deviation of The deviation of The deviation of
the mid-offset the mid-ordinate the mid-ordinate
Class of track from a 62-foot from a 31-foot from a 62-foot
line \1\ may not chord \2\ may not chord \2\ may not
be more than-- be more than-- be more than--
(inches) (inches) (inches)----------------------------------------------------------------------------------------------------------------Class 1 track....................................... 5 \3\ N/A 5Class 2 track....................................... 3 \3\ N/A 3Class 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: ------------------------------------------------------------------------
Curved track
---------------------------------------
The deviation of The deviation of
the mid-ordinate the mid-ordinate
Class of track from a 31-foot from a 62-foot
chord \1\ may not chord \1\ may not
be more than-- be more than--
(inches) (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]