49 CFR §238.707

1. (a)Colliding equipment.
   1. (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:
      1. (i)All vehicles in the initially-moving trainset and initially-standing train consists are positioned at their nominal running heights;
      2. (ii)The lead vehicle of the initially-moving trainset shall be perturbed laterally and vertically upwards by 3 inches at the colliding interface; and
      3. (iii)The lead vehicle of the initially-moving trainset shall be perturbed laterally and vertically downwards by 3 inches at the colliding interface.
   2. (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:
      1. (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
      2. (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
2. (b)Connected equipment override.
   1. (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:
      1. (i)All vehicles in the initially-moving trainset and initially-standing train consists are positioned at their nominal running heights;
      2. (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,
      3. (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.
   2. (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:
      1. (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
      2. (ii)The tread of any wheel of the initially-moving trainset shall not rise above the top of rail by more than 4 inches.