(a) For a single deviation in track surface, each track owner shall maintain the surface of its track within the limits prescribed in the following table: ------------------------------------------------------------------------
Class of track
Track surface (inches) -----------------------------------
6 7 8 9------------------------------------------------------------------------The deviation from uniform \1\ 1 1 \3/4\ \1/2\
profile on either rail at the mid-
ordinate of a 31-foot chord may not
be more than.......................The deviation from uniform profile 1 1 1 \3/4\
on either rail at the mid-ordinate
of a 62-foot chord may not be more
than...............................Except as provided in paragraph (b) 1\3/4\ 1\1/2\ 1\1/4\ 1
of this section, the deviation from
uniform profile on either rail at
the mid-ordinate of a 124-foot
chord may not be more than.........The deviation from zero crosslevel 1 1 1 1
at any point on tangent track may
not be more than \2\...............Reverse elevation on curves may not \1/2\ \1/2\ \1/2\ \1/2\
be more than.......................The difference in crosslevel between 1\1/2\ 1\1/2\ 1\1/4\ 1
any two points less than 62 feet
apart may not be more than \3\.....
On curved track, the difference in 1\1/4\ 1\1/8\ 1 \3/4\
crosslevel between any two points
less than 10 feet apart (short
warp) may not be more than.........------------------------------------------------------------------------\1\ Uniformity for profile is established by placing the midpoint of the
specified chord at the point of maximum measurement.\2\ If physical conditions do not permit a spiral long enough to
accommodate the minimum length of runoff, part of the runoff may be on
tangent track.\3\ However, to control harmonics on jointed track with staggered
joints, the crosslevel differences shall not exceed 1 inch in all of
six consecutive pairs of joints, as created by seven low joints. Track
with joints staggered less than 10 feet apart shall not be considered
as having staggered joints. Joints within the seven low joints outside
of the regular joint spacing shall not be considered as joints for
purposes of this footnote.
(b) For operations at a qualified cant deficiency, Eu, of more than 5 inches, a single deviation in track surface shall be within the limits prescribed in the following table: ------------------------------------------------------------------------
Class of track
Track surface (inches) -----------------------------------
6 7 8 9------------------------------------------------------------------------The difference in crosslevel between 1\1/4\ 1 1\1\ \3/4\
any two points less than 10 feet
apart (short warp) may not be more
than...............................The deviation from uniform profile 1\1/2\ 1\1/4\ 1\1/4\ 1
on either rail at the mid-ordinate
of a 124-foot chord may not be more
than...............................------------------------------------------------------------------------\1\ For curves with a qualified cant deficiency, Eu, of more than 7
inches, the difference in crosslevel between any two points less than
10 feet apart (short warp) may not be more than three-quarters of an
inch.
(c) For three or more non-overlapping deviations in track surface occurring within a distance equal to five times the specified chord length, each of which exceeds the limits in the following table, each track owner shall maintain the surface of the track within the limits prescribed for each deviation: ------------------------------------------------------------------------
Class of track
Track surface (inches) -----------------------------------
6 7 8 9------------------------------------------------------------------------The deviation from uniform profile \3/4\ \3/4\ \1/2\ \3/8\
on either rail at the mid-ordinate
of a 31-foot chord may not be more
than...............................The deviation from uniform profile \3/4\ \3/4\ \3/4\ \1/2\
on either rail at the mid-ordinate
of a 62-foot chord may not be more
than...............................The deviation from uniform profile 1\1/4\ 1 \7/8\ \5/8\
on either rail at the mid-ordinate
of a 124-foot chord may not be more
than...............................------------------------------------------------------------------------ [78 FR 16106, Mar. 13, 2013]