(a) General. Tier III trainsets shall comply with the requirements in paragraphs (b) and (c) of this section to demonstrate the integrity of the end structure for other than the cab ends.

(b) Collision post requirements.

(1) Each unit of a Tier III trainset shall have at each non-cab end of the unit either:

(i) Two full-height collision posts, located at approximately the one-third points laterally. Each collision post shall have an ultimate longitudinal shear strength of not less than 300,000 pounds at a point even with the top of the underframe member to which it is attached. If reinforcement is used to provide the shear value, the reinforcement shall have full value for a distance of 18 inches up from the underframe connection and then taper to a point approximately 30 inches above the underframe connection; or

(ii) An equivalent end structure that can withstand the sum of forces that each collision post in paragraph (b)(1)(i) of this section is required to withstand. For analysis purposes, the required forces may be assumed to be evenly distributed at the locations where the equivalent structure attaches to the underframe.

(2) Collision posts are not required for the non-cab ends of any unit with push-back couplers and interlocking anti-climbing mechanisms in a Tier III trainset, or the non-cab ends of a semi-permanently coupled consist of trainset units, if the inter-car connection is capable of preventing disengagement and telescoping to the same extent as equipment satisfying the anti-climbing and collision post requirements in subpart C of this part. For demonstrating that the inter-car connection is capable of preventing such disengagement (and telescoping), the criteria in §238.707(b) apply.

(c) Corner post requirements.

(1) Each passenger car in a Tier III trainset shall have at each non-cab end of the car, placed ahead of the occupied volume, two side structures capable of resisting a:

(i) 150,000-pound horizontal force applied at floor height without failure;

(ii) 20,000-pound horizontal force applied at roof height without failure; and

(iii) 30,000-pound horizontal force applied at a point 18 inches above the top of the floor without permanent deformation.

(2) For purposes of this paragraph (c), the orientation of the applied horizontal forces shall range from longitudinal inward to transverse inward.

(3) For each evaluation load, the load shall be applied to an area of the structure sufficient to not locally cripple or punch through the material.

(4) The load area shall be chosen to be appropriate for the particular car design and shall not exceed 10 inches by 10 inches.