49 CFR 213.143 : Transportation (§ 1.1 To Parts 1581-1699) — (§ 200.1 To Parts 273-299) — Other Regulations Relating To Transportation (Continued) (§ 200.1 To Parts 273-299) — Federal Railroad Administration, Department Of Transportation (§ 200.1 To Parts 273-299) — Track Safety Standards (§ 213.1 To Appendix D To Part 213) — Track Structure (§ 213.101 To § 213.143) — Frog guard rails and guard faces; gage.

4 Aug 2016

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 1 track	4′6 1/8″	4′ 5 1/4″
Class 2 track	4′6 1/4″	4′ 5 1/8″
Class 3 and 4 track	4′ 6 3/8″	4′5 1/8″
Class 5 track	4′6 1/2″	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.

49 CFR 213.143