49 CFR § 213.137 - Frogs.

---
identifier: "/us/cfr/t49/s213.137"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 213.137 - Frogs."
title_number: 49
title_name: "Transportation"
section_number: "213.137"
section_name: "Frogs."
chapter_name: "FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
part_number: "213"
part_name: "TRACK SAFETY STANDARDS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 20102-20114 and 20142; 28 U.S.C. 2461 note; and 49 CFR 1.89."
regulatory_source: "63 FR 34029, June 22, 1998, unless otherwise noted."
cfr_part: "213"
---


# 213.137 Frogs.

(a) Except as provided in paragraph (e) of this section, the flangeway depth measured from a plane across the wheel-bearing area of a frog on Class 1 track shall not be less than 1
3/8 inches, or less than 1
1/2 inches on Classes 2 through 5 track.

(b) If a frog point is chipped, broken, or worn more than five-eighths inch down and 6 inches back, operating speed over the frog shall not be more than 10 m.p.h.

(c) If the tread portion of a frog casting is worn down more than three-eighths inch below the original contour, operating speed over that frog shall not be more than 10 m.p.h.

(d) Where frogs are designed as flange-bearing, flangeway depth may be less than that shown for Class 1 if operated at Class 1 speeds.

(e) The flange depth requirements in paragraph (a) do not apply to a frog designed as a flange-bearing frog (FBF) used in a crossing diamond in Classes 2 through 5 track, provided that the crossing angle is greater than 20 degrees unless movable guard rails are used.

[63 FR 34029, June 22, 1998, as amended at 85 FR 63388, Oct. 7, 2020]