49 CFR § 213.143 - Frog guard rails and guard faces; gage.
(a) The guard check and guard face gages in frogs shall be within the following limits—
Table 1 to § 213.143(a)
| Class of track | Guard check gage | Guard face 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— | 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
|
4′5
|
| Class 2 track | 4′6
|
4′5
|
| Class 3 and 4 track | 4′6
|
4′5
|
| Class 5 track | 3 4′6
|
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 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.
3 See paragraph (b) of this section.
(b) For any heavy-point frog (HPF) on Class 5 track, the guard check gage may be less than 4′6 1/2″ but not be less than 4′6 3/8″, provided that:
(1) Each HPF and guard rails on both rails through the turnout are equipped with at least three serviceable through-gage plates with elastic rail fasteners and guard rail braces that permit adjustment of the guard check gage without removing spikes or other fasteners from the crossties; and
(2) Each HPF bears an identifying mark applied by either the track owner, railroad, or the frog manufacturer that identifies the frog as an HPF.