The guard check and guard face gages in frogs shall be within the limits prescribed in the following table-- ----------------------------------------------------------------------------------------------------------------
Guard check gage Guard face gage
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The distance between the gage
line of a frog to the guard
line \1\ of its guard rail or The distance between guard
Class of track guarding face, measured lines,\1\ measured across the
across the track at right track at right angles to the
angles to the gage line,\2\ gage line,\2\ may not be more
may not be less than-- than--
----------------------------------------------------------------------------------------------------------------Class 6, 7, 8 and 9 track......................... 46\1/2\" 45"----------------------------------------------------------------------------------------------------------------\1\ A line along that side of the flangeway which is nearer to the center of the track and at the same elevation
as the gage line.\2\ A line five-eighths of an inch below the top of the center line of the head of the running rail, or
corresponding location of the tread portion of the track structure. [78 FR 16112, Mar. 13, 2013]