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Rh 3. Design specifications to insure that the collision posts resist more adequately the impact loads which are likely to be applied by crash forces generally along the axis of the car. The design should not permit such impact loads to produce torque or lateral bending when applied at the logical points by an end to end collision. Collision posts and other structures should be designed to resist torque and bending efficiently.

There is also a lesson to be learned from an earlier collision of two highliner cars at 95th Street during the acceptance testing period, which was described in evidence. In that accident, two cars of current design crashed at speeds of 15 to 18 m.p.h., resulting in costly damage to both cars. There was small-scale, but generalized, permanent distortion of stressed skin caused by wrinkling and buckling of the underframe. The structure served effectively from an injury-prevention point of view, in that no override occurred, and there was no intrusion into the passenger area. However, the implications of the damage, which required complete structural replacement for both cars, are disquieting from the viewpoint of long—term operational costs. The Board believes that it is technically unnecessary to sustain such broad-scale damage in order to protect passengers. The Safety Board therefore recommends:

4. That UMTA require specific statements of intended capability of cars to resist low—speed collision damage in specifications for newly designed cars which are candidates for Federal capital grants. Such specifications should be coordinated with injury resistance specifications which may arise from current funded research.

These recommendations will be released to the public on the issue date shown above. No public dissemination of the contents of this document should be made prior to that date.

Reed Chairman, McAdams, Thayer, Burgess, and Haley, Members, concurred in the above recommendations.

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