Interpretation ID: nht76-2.13

DATE: 04/30/76

FROM: AUTHOR UNAVAILABLE; S. P. Wood; NHTSA

TO: Transportation Design & Technology, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your November 14, 1975, request to know how the tensile strength at a joint is determined under S6.2 of Standard No. 221, School Bus Body Joint Strength, in the case of more than two body components joined by the same fastener.

An extensive discussion of joint strength requirements and test procedures was recently sent to Blue Bird Body Company. Your question is addressed in that discussion and a copy is enclosed for your information.

YOURS TRULY,

Transportation Design & Technology, Inc.

14 November 1975

Mr. Frank A Berndt Acting Chief Counsel U.S. Department of Transportation National Highway Traffic Safety Administration

I have been asked to contact your office for a clarification of the joint integrity ruling. Where two pieces of sheet metal overlap to form a joint and are also attached to a body post of a much higher yield material, does the joint calculations apply to the surface metals only or should the higher yield material of the inner post be taken into account?

There appears to be some doubt in the minds of several people I have spoken with and therefore, I would appreciate your comments at your earliest convenience.

L. W. Smith President