Interpretation ID: nht79-4.39

DATE: 08/03/79

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Ontario Bus Industries Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your July 16, 1979, letter asking two questions about the test procedures of Standard No. 217, Bus Window Retention, as they apply to buses you manufacture.

First, you ask whether side service doors can be counted in determining the proper amount of bus emergency exits as required by the standard. As long as side service doors comply with all requirements applicable to emergency doors, they can be considered emergency exits for purposes of compliance with the standard.

Your second question asks whether glazing in a door is tested for window retention, and if so, whether it is tested while the door is installed in a bus. The answer to both parts of this question is yes. All bus glazing, that is of the minimum size specified in the standard, must comply with the window retention requirement. The intent of the window retention requirement is to prevent openings in buses that might result in the ejection of occupants from the vehicle during an accident. In order for this requirement to have meaning, the glazing must be tested as it is installed in the vehicle to ensure the integrity of both the glazing and its surrounding structure. This means that glazing in vehicle doors is tested while the door is in the normal closed condition. If the door opens during the test, the vehicle would not be in compliance with the requirements.

SINCERELY,

Ontario Bus Industries Inc.

JULY 16, 1979

Office of Chief Counsel, NHTSA

Dear Sir,

This company was the designer and manufacturer of the Orion Mid size Transit bus.

More recently the deliveries to the U.S. market have been taken over by Transportation Manufacturing Corporation of Roswell, New Mexico, who manufacture and market the buses in the U.S.A. under the "Citycruiser" trade name.

A query has arisen concerning the application of MVSS 217 to this model bus on a point that was raised before the introduction of the model and for which a verbal answer was given when the prototype was presented in Washington on October 5th 1977.

The point at issue was to what extent and under what Criteria the service doors can be considered as "unobstructed openings for emergency exit" as required in S 5.2 (provision of emergency exits) and more particularly the "side exits" as required in S 5.2.1 (Buses with GVWR of more than 10,000 pounds).

It was verbally confirmed at the time that service doors could be regarded as side exits for emergency exit, provided they met the requirements of S 5.3 (Emergency exit release), S 5.4 (Emergency exit extension) and S 5.5 (Emergency exit identification). Official confirmation of the above is hereby requested.

Finally, a clear ruling was not given on the application of S 5.1 Window retention when applied to the glazing in service doors. It is reasonably clear that the glass in the door frame should meet the requirements. It is less obvious that the door in its frame, when used as a service door, must meet this requirement, ie. the glass be tested in the door, the door being in the bus.

If not, does this requirement become mandatory, when the service door is designated as a side exit?

The doors are presently being constructed so as to meet this requirement, but a ruling on this point is hereby requested.

CC: E. CUMMINGS -- TRANSPORTATION MFG. CO.