CFR > Title 49 - Transportation > SUBTITLE B—Other Regulations Relating to Transportation > CHAPTER II—FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (Parts 200–269) > PART 213—TRACK SAFETY STANDARDS > SUBPART G—Train Operations at Track Classes 6 and Higher (§213.301 to §213.369) > 213.355—Frog guard rails and guard faces; gage.

213.355—Frog guard rails and guard faces; gage.

The guard check and guard face gages in frogs shall be within the limits prescribed in the following table—
Class of track Guard check gage—The distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face, measured across the track at right angles to the gage line, 2 may not be less than— Guard face gage—The distance between guard lines, 1 measured across the track at right angles to the gage line, 2 may not be more than—
Class 6 track 4′61/2″ 4′5″
Class 7 track 4′61/2″ 4′5″
Class 8 track 4′61/2″ 4′5″
Class 9 track 4′61/2″ 4′ 5″
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 5/8 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.