{"data":{"id":"us/49-cfr-238.707","jurisdiction":"us","citation":"49 CFR 238.707","heading":"Override protection.","body":"(a) Colliding equipment. (1) Using the dynamic collision scenario described in § 238.705(a), anti-climbing performance shall be evaluated for each of the following sets of initial conditions:\n(i) All vehicles in the initially-moving trainset and initially-standing train consists are positioned at their nominal running heights;\n(ii) The lead vehicle of the initially-moving trainset shall be perturbed laterally and vertically upwards by 3 inches at the colliding interface; and\n(iii) The lead vehicle of the initially-moving trainset shall be perturbed laterally and vertically downwards by 3 inches at the colliding interface.\n(2) For each set of initial conditions specified in paragraph (a)(1) of this section, compliance with the following conditions shall be demonstrated after a dynamic impact:\n(i) The relative difference in elevation between the underframes of the colliding equipment in the initially-moving trainset and initially-standing train consists shall not change by more than 4 inches; and\n(ii) The tread of any wheel of the first vehicle of the initially-moving trainset shall not rise above the top of the rail by more than 4 inches\n(b) Connected equipment override. (1) Using the dynamic collision scenario described in § 238.705(a), anti-climbing performance shall be evaluated for each of the following sets of initial conditions:\n(i) All vehicles in the initially-moving trainset and initially-standing train consists are positioned at their nominal running heights;\n(ii) One vehicle is perturbed laterally and vertically upwards by 2 inches, relative to the adjacent vehicle, at the first vehicle-to-vehicle interface in the initially-moving trainset; and,\n(iii) One vehicle is perturbed laterally and vertically downwards by 2 inches, relative to the adjacent vehicle, at the first vehicle-to-vehicle interface in the initially-moving trainset.\n(2) For each set of initial conditions specified in paragraph (b)(1) of this section, compliance with the following conditions shall be demonstrated after a dynamic impact:\n(i) The relative difference in elevation between the underframes of the connected equipment in the initially-moving trainset shall not change by more than 4 inches; and\n(ii) The tread of any wheel of the initially-moving trainset shall not rise above the top of rail by more than 4 inches.","path":["Title 49—Transportation","Subtitle B—Other Regulations Relating to Transportation","CHAPTER II—FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","PART 238—PASSENGER EQUIPMENT SAFETY STANDARDS","Subpart H—Specific Requirements for Tier III Passenger Equipment"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-49.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:34Z","sha256":"2e861042ec59995d884cea4286e50998398ca73015ec318febe17376ea5cc4d1","source_id":"us-cfr","stale":true,"prev":"us/49-cfr-238.705","next":"us/49-cfr-238.709"},"notice":"GroundRules: Original legal text. Not legal advice."}