[Code of Federal Regulations] [Title 49, Volume 4] [Revised as of October 1, 2005] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR213.137] [Page 113] TITLE 49--TRANSPORTATION CHAPTER II--FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 213_TRACK SAFETY STANDARDS--Table of Contents Subpart D_Track Structure Sec. 213.137 Frogs. (a) 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.