Interpretation ID: 77-4.48

TYPE: INTERPRETATION-NHTSA

DATE: 12/06/77

FROM: AUTHOR UNAVAILABLE; F. Berndt for J. J. Levin, Jr.; NHTSA

TO: Ellcon National, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your September 2, 1977, letter concerning the applicability of Standard No. 217, Bus Window Retention and Release, to a thermopane driver's window in a bus.

In response to your first question, the window to which you refer is required to comply with the requirements of the standard. The fact that it is a driver's window does not exempt it from the coverage of the standard.

Your second question asks how to test thermopane glazing. According to our enforcement staff, testing of thermopane windows can be conducted using the same criteria used for other window glazing. By following the procedures established in S5.1 of the standard, you should be able to accurately test thermopane glazing.

SINCERELY,

September 2, 1977

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

A question has arisen as to the qualification of an interpretation in a test to be performed on a driver window in a bus we are to supply to our customer.

Subject window is a dual slider containing thermopane glazing and we would appreciate clarification with regard to FMVSS 217. Is it necessary for a test performance in compliance to FMVSS 217?

If test is necessary, how should interpretation of force be measured with regard to thermopane which consists of two 3/16" thick pieces of glass with a 1/4" thick space sealed unit?

Your clarification in this matter would be appreciated. Thank you for assisting us in this matter.

ELLCON-NATIONAL, INC.

Stanley Brajer Project Engineer